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  1. Original Title: [Dry Goods Super Long Article] The Past and Present Life of MWD in Directional Drilling 1 Basic concepts 1. What is MWD instrument? MWD is the abbreviation of Measurement While Drilling. MWD instrument is an important member of the whole measuring instrument family. 2. What does the measuring instrument measure? The data obtained by the measuring instrument are the well deviation, azimuth and tool face of the instrument near the current downhole bit. What do these parameters mean? For example, these data can now be measured by ordinary mobile phones: A. Well deviation (horizontal and vertical angle) is equivalent to measuring the horizontal and vertical state of the mobile phone, and the horizontal or vertical screen will be given on the mobile phone. B. The direction (north, south, east and west) is equivalent to the compass of the mobile phone. C. The tool surface of the instrument (how to turn the head up, down, left and right) is equivalent to some "720-degree panoramic websites" of the mobile phone, and the scene picture can be updated with the rotation of the mobile phone. Expand the full text Measuring instrument integrates well deviation, azimuth, tool face and other measurements, but at the beginning of the invention of this kind of instrument more than 100 years ago, it mainly focused on well deviation data, so many people in China's petroleum circle still call it "inclinometer". 3. Why measure? Drilling is like walking, there must be a turn to reach the end, walking with eyes open to observe which intersection turns. Drilling also needs to control the drill bit to drill to the target point, and the measuring instrument is the so-called eye. Tell me where it is and where the target is. As an example in the figure below, a directional well needs to meander several kilometers underground to reach the target point of the oil layer under the guidance of the survey instrument. 4. What is measurement while drilling? The meaning of while drilling is relative to the traditional stop drilling. It is different from the wireline logging instrument or other instruments to obtain data at the cost of "stopping drilling" and then running in the measuring instrument. The method of stopping drilling at intervals is equivalent to walking a few steps with your eyes closed, stopping and opening your eyes to see where it is. If there is drilling technology, we can get real-time downhole data and know the specific location when drilling. It's like walking with your eyes open. 5. Why measure while drilling? A. First of all, it will take time and money to stop drilling. Once the drilling is stopped for measurement, it will take at least 4-6 hours, and more than 8-10 hours. If it is operated at sea, this period of operation may cost hundreds of thousands to millions of dollars per day. B. Pure blind drilling without the guidance of measurement data may lead to deviation from the target point, resulting in borehole collision and other risks. C. When measuring, the drill pipe is still, which causes the collapse of the well wall and the sticking of the drill pipe. Therefore, MWD overcomes the disadvantages of "stop drilling" measurement. The downhole data can be obtained in real time when drilling, and the specific location can be known. In addition to the high price, the measurement while drilling is better than the "stop drilling" measurement method in other aspects. 6. How to realize "real-time data" while drilling? The downhole instrument has no cable to connect with the surface instrument. That requires a coded transmitter for downhole instruments, a receiver at the surface, and a set of decoding programs. There are generally two ways to realize the coding transmitter of downhole tools. A. Drilling fluid pulse. It is equivalent to putting the hand in the water flow under the faucet, twisting the knob of the faucet, and the impact pressure on the hand will change. The downhole instrument limits the flow of drilling fluid through an electronic mechanical switch and transmits data in a certain frequency sequence, and the ground sensor will sense the pressure change and demodulate the signal. And B, wireless electromagnetic pulse, wherein that downhole instrument transmit a radio signal pulse. There is a wireless receiver on the ground to receive the wireless signal. MWD, a modern measurement while drilling instrument, is evolved step by step from the predecessors of "stop drilling measurement". Let's straighten out MWD and its predecessors. 2 The History of the Family of Measuring Instruments At the very beginning, the measuring instrument may only be used to measure where the well is finally drilled. If there is no instrument that can control the trajectory, it can only be known but not controlled, and its role is limited. Therefore, the development of measuring instruments is closely related to the development of trajectory oriented control instruments. The more advanced the directional instrument is, the stronger the controllability is, and the higher the requirements for data quality including measurement frequency and accuracy are, which objectively promotes the development of measurement instruments, so that the oilfield can obtain greater productivity in a certain space and time, and improve the efficiency of the oilfield industry. 1. Chemical acid bottle method or physical firing pin method measuring instrument The acid bottle method was invented abroad at the beginning of the 20th century and was basically eliminated internationally in the 1940s. It was widely used in China in the 1950s and 1960s. In China, after the drilling is stopped, an instrument string containing a small bottle of hydrofluoric acid liquid is lowered from the drill pipe by a wire rope. When the instrument touches the valve seat at the bottom of the drill pipe, it triggers a physical mechanism or timer. If there is a deviation, the liquid level of hydrofluoric acid will corrode on the vial, forming marks of different heights in different directions. After pulling the instrument string out of the wellhead, observing the corrosion marks on the liquid level, the downhole deviation and azimuth instrument surface can be obtained. This method has been eliminated with the development of science and technology because of its high failure rate and low accuracy due to chemical and physical reasons. At present, it is almost invisible in textbooks. There is also a physical firing pin type, which leaves a physical impact mark on the compass compass after the timer is triggered. This has also been replaced with the development of science and technology. 2. Photographic measuring instrument This method was invented abroad in the early 20th century and widely used in the early 1920s and 1930s. It began to be studied in the 1970s and 1980s in China, and began to be imported and applied in the 1980s and 1990s. When there is a "memory" of camera film that can be recorded, there is no need to use the permanent marking method of acid bottle corrosion scale. In this way, a small instrument with compass compass and heavy hammer is connected to a timing camera. A steel wire is lowered into the drill pipe that stops drilling. The battery opens the shutter grating of the camera to expose and image. Then the instrument is taken out to the ground and the film observation results are developed. The general instrument cannot rotate the film, and only one photo can be taken for each construction. Most of the commercial chemical formulas and photographic models are also "Single Shot", because each construction can only measure the data once, and take it out to the ground to see the results. This is different from the concept of "Multi Shot", which can measure multiple data in one construction. Photographic inclinometers have been widely used in land drilling teams in recent years, and in the South China Sea, they were basically eliminated around 2014. 3. Electronic Multi Shot As the name implies, down the hole bit , the multi-point inclinometer can measure multiple points in one construction when the drilling is stopped for measurement. With the development of wireline logging, the instrument has been gradually improved. It has been invented since the beginning of the 20th century and has been continuously improved and developed. When the whole industry entered the electronic age, the electronic multi-point inclinometer gradually matured. A. First of all, the cable replaces the wire rope. Because the cable can supply power, obtain data and control the instrument, the battery in the instrument is saved. In this way, the computer on the ground can send measurement commands to the downhole instrument through the cable at any time, and the on-site QC data can be measured, and the points with low quality can be re-measured immediately. Secondly, electronic components such as electronic gyroscopes, electronic gravimeters and electronic compasses have replaced physical weights and compasses; electronic memory has replaced camera film. And C, a depth sensor attached to the cable roller can measure the length of the cable and provide accurate depth calculation for the measuring point. This configuration is still widely used in the modern oilfield industry. The wireline logging department and the directional well department are generally responsible for these operations, providing wireline winches and measuring instruments. 4. Input MWD Input MWD is an epoch-making product, which realizes real-time measurement data transmission. One of the leading technologists of the instrument should be Anon of Schlumberger, who published a large number of papers on the development and improvement of MWD from 1981 to 1984. Before tripping in, put a section of throw-in MWD instrument on the valve seat in the drill collar, and then enter the well for normal drilling. During the drilling process, the instrument transmits real-time measurement data to the surface. Because there is no cable to transmit data, modulation transmitters are designed into instruments to transmit data to the surface through pressure changes, while pressure sensors are installed on the surface to demodulate the signals transmitted underground and turn them into data that can be read by human beings. Of course, when there was no cable power, the battery was redesigned into the instrument. This kind of input instrument is relatively easy to maintain and low cost for modern industry. It is widely used in land oilfields. Some products of foreign enterprises have mature products in the 1990s. Domestic research and development began in the late 1990s. 5. Integrated MWD The throw-in MWD combined with the drill collar becomes an integrated MWD. This device is an upgrade to the drop-in MWD. The driving force is the demand for LWD and RSS matching with MWD. What are these needs? A. Addition of power generation turbine modules or upgrade of larger batteries. MWD, as the pioneer of downhole equipment and the necessary equipment for basic data acquisition, shall be provided to other equipment LWD and RSS power. B. Generation of communication interfaces of other downhole instruments, and upgrade of hardware and software required to communicate with other downhole equipment. C. Integration of more sensors. All these require the MWD to have a larger volume, and the large volume is contradictory to the small internal space of the drill collar, so the modules of the MWD are fixed in special drill collars in different shapes to save space. This is the integrated MWD. As shown in the figure, Schlumberger has been working on various MWDs of input and integration since the early 1980s. And it's still evolving. Integrated MWD is now the mainstream measuring instrument for foreign enterprises. Its disadvantages are high integration, complex maintenance and relatively high cost. The leading products in the world include TeleScope of Schlumberger, OnTrack of Baker Hughes, and then many foreign companies such as Halliburton, Weatherford and International Scientific Drilling SDI in the second line. The leading domestic enterprises are also involved. Only the instruments produced by COSL around 2015 are still in the stage of experimental improvement; PetroChina had a similar scientific research problem around 2012, but recently it seems that no sound can be heard. 6. Future integrated/decentralized products? As sensors become smaller and more diverse, future products may integrate MWD, various LWDs, and rotary steering to a high degree. If you want to know more about the inside of the wellbore. It is necessary to decentralize the attachment of instruments at various positions of several kilometers of drill pipe. However, the development of this technology needs to be promoted by the progress of intelligent drill pipes of international foreign enterprises. Intelligent drill pipes are still being developed and tested, so it is difficult to predict the commercialization time of future measuring instrument products. Among the above inclinometers, the acid bottle type and mechanical type have been eliminated and will not be included in the future discussion. Other generations of products are used in the oilfield. The accuracy of required data is one aspect of instrument selection. The deviation accuracy of each generation of instrument is about 0.1 degree, and the azimuth accuracy is about 1 degree. Can meet that requirement of general well conditions. The cost consideration is mainly the rental price and reliability of the instrument. The price of different instruments may vary by tens of times. If the instrument fails, the potential cost of pulling out and replacing the instrument can be estimated, but the indirect loss of wellbore instability is incalculable. The more complex the well is, the greater the potential loss caused by instrument failure is, so the reliability of instrument is a very important factor. 3 Overview of China's Skew Instrument Market The key technologies of the mainstream measurement instruments in the world are in the hands of Schlumberger, Baker Hughes, Halliburton and Weatherford. Many small and medium-sized enterprises located in Europe and the United States also have leading or equal positions in some technologies. Domestic manufacturers of inclinometers are mainly oil service companies or R & D and design institutes of directional well companies affiliated to domestic state-owned petroleum enterprises, while private enterprises are mainly companies with geological and mineral exploration design, space shuttle navigation or military background. As far as the use of inclinometers in China is concerned, single-point inclinometers are basically outdated products, and there may be a little market on land. Multi-point inclinometer technology has been relatively mature in China, and it is the main instrument used in onshore oilfields, which has been basically localized, and rarely used offshore. Input-type MWD is active on land and a small number of offshore platforms in China. The instruments mainly used in China mainly come from two companies: one is the Solar series instruments of Sperry Sun of Halliburton, which were sold to COSL more than 10 years ago. Simple maintenance can be carried out in COSL, and the overhaul still needs to be returned to Halliburton's overseas base; Second, Schlumberger made a joint venture with Jindi Weiye, a domestic private enterprise, six years ago, and transferred part of SlimPluse to Jindi Weiye in a certain form, and then seized the low-end market on land. These foreign manufacturers have taken the lead in technology and quality. Although many domestic input instruments also have part of the market in the land drilling team, the overall reliability is not high. Domestic products have basically not entered the offshore drilling market. Integrated MWD is mainly used in a small number of onshore drilling fleets and most offshore platforms, mainly instruments such as Schlumberger's TeleScope and Baker Hughes' OnTrack, which enter the Chinese market through subcontracting by COSL or directly signing contracts with CNOOC. Halliburton and Weatherford also have a small number of markets. At present, Welleader, a product of COSL, has also been tested around 2015, but has not yet been put into the market on a large scale. The main problems of domestic instruments are the precision of mechanical part, the temperature and oil resistance of rubber seal ring, the shock resistance of electronic part and the adaptability of temperature deviation. In order to enter the international market of MWD and other fields, it is difficult for domestic small and medium-sized enterprises to complete alone,dhd drill bit, which requires the state to set up projects and concentrate technology and funds to tackle key problems. Perhaps in this case, in the next 10 years, domestic products can achieve curve overtaking and occupy the international leading level. Welcome to the official account: Petroleum Link Return to Sohu to see more Responsible Editor:. wt-dthtools.com
  2. Original Title: Knowledge of Cutting Tools: Drill Technology 1. Craft /Processing 1.1 Craft According to the diameter and total length of the designed drill bit, the alloy bar cutting machine or wire cutting equipment can be selected for fixed-length processing. For the bar cut to a fixed length, the two ends of the bar are flattened, which can be realized on a hand tool grinder. Chamfer or punch the ground end face of the alloy bar to prepare for grinding the outer diameter and shank of the drill bit, depending on whether the external grinding fixture is a male or female center. Expand the full text The excircle diameter of the drill bit, the outer diameter of the clearance part and the shank part are processed on a high-precision cylindrical grinder to ensure the design requirements of the outer diameter cylindricity, circular runout, surface finish and the like. In order to improve the machining efficiency on the CNC grinding machine, the drill point can be chamfered before the alloy bar is placed on the CNC grinding machine, for example, the drill point angle of 140 ° can be roughly ground to 142 ° during chamfering. After the chamfered alloy bar material is cleaned, the chamfered alloy bar material is transferred to a numerical control grinding machine process, and each part of the drill bit is processed on a five-axis numerical control grinding machine. If it is necessary to improve the finish of the chip groove and excircle of the drill, it can also be ground and polished with wool wheel and abrasive before or after the fifth step. Of course,Borehole Drill Bits, in this case, the drill needs to be processed in more steps. For the drill bit that has been processed to be qualified, it shall be marked by laser, and the content may be the company's brand LOGO and drill bit specifications and sizes. Package the marked drill bit, and then deliver it to a professional tool coating company for coating. Note 1. Uch as a drill chip groove. ,dth rock bit, or spiral shape or straight groove shape. This step also includes the negative chamfering of the peripheral cutting edge. Then, the cutting edge of the drill tip is processed, including the tooth clearance part of the drill tip and the relief angle part of the drill point. Then, the back part of the peripheral cutting edge is processed to grind out a certain amount of drop, so as to ensure that the contact surface between the outer diameter part and the hole wall of the workpiece is controlled in a certain proportion. 2. Machining of negative chamfering for the cutting edge of drill point ? It can be divided into CNC grinding machine processing or manual processing, which is different due to the different processes of each factory. 1.2 Processing problems When machining the excircle part of the drill bit on the cylindrical grinder, pay attention to whether the fixture fails and fully cool the alloy bar during machining, and maintain the good habit of measuring the outer diameter of the drill tip. Drill machining is carried out on the CNC grinding machine, and the programming is divided into two steps of rough and fine machining as far as possible, so as to avoid the existence of potential thermal cracks caused by too much grinding, DHD Drill bit ,dth drill bits, which will affect the service life of the tool. Use the material tray with reasonable design to carry out the handling of cutting tools, so as to avoid the damage to the cutting edge caused by the collision between cutting tools. The blackened diamond grinding wheel should be sharpened with oilstone in time. Note: The processing technology is different according to the processed material/equipment/working condition. The above process arrangement only represents the author's personal opinion and is only used for technical exchange. 2. Bit Material 2.1 High speed steel High speed steel (HSS) is a kind of tool steel with high hardness, high wear resistance and high heat resistance, also known as high speed tool steel or sharp steel, commonly known as white steel. High speed steel cutting tool is a tool that is tougher and easier to cut than ordinary tools. High speed steel has better toughness, strength and heat resistance than carbon tool steel, and its cutting speed is much higher than carbon tool steel (iron-carbon alloy), so it is named high speed steel; while hard alloy steel has better performance than high speed steel, and its cutting speed can be increased by 2-3 times. Characteristic The red hardness of high-speed steel can reach 650 degrees. High speed steel has good strength and toughness, sharp cutting edge and stable quality after sharpening. It is generally used to make small and complex cutting tools. 2.2 Cemented carbide The main components of cemented carbide drill material are tungsten carbide and cobalt, which account for 99% of all components, and 1% are other metals, so it is called tungsten steel (cemented carbide). Tungsten steel is a sintered composite material containing at least one metal carbide. 。 Tungsten carbide, cobalt carbide, niobium carbide, titanium carbide and tantalum carbide are common components of tungsten steel. The grain size of the carbide component (or phase) is typically between 0.2 and 10 microns, and the carbide grains are held together using a metallic binder. The bonding metal is generally an iron group metal, and cobalt and nickel are commonly used. Hence tungsten-cobalt, tungsten-nickel, and tungsten-titanium-cobalt alloys. Tungsten steel drill bit material sintering molding is to press the powder into blank, then heat it to a certain temperature (sintering temperature) in the sintering furnace, and keep it for a certain time (holding time), and then cool it down, so as to obtain the tungsten steel material with the required performance. Characteristic And that red hardness of the hard alloy can reach 800-1000 degree. The cutting speed of cemented carbide is 4-7 times higher than that of high-speed steel. High cutting efficiency. Its disadvantages are low bending strength, poor impact toughness, high brittleness, and low ability to withstand impact and vibration. 3. Application problem /Measures 3.1 Worn drill tip Reason 1. The workpiece will move downward under the force of the drill bit. ? The drill bit springs back after drilling through. 2. The rigidity of the machine tool is insufficient . 3. Bit material is not strong enough . 4. Bit runout is too large . 5. Insufficient clamping rigidity Drill bit slip. Measures: 1. Reduce the cutting speed . 2. Increase the feed rate 3. Adjust the cooling direction (Internal cooling) 4. Add a chamfer 5. Check and adjust the coaxiality of the drill bit . 6. Check whether the relief angle is reasonable. . 3.2 Ligament rupture Reason 1. The workpiece will move downward under the force of the drill bit. ? The drill bit springs back after drilling through. 2. The rigidity of the machine tool is insufficient . 3. Bit material is not strong enough . 4. Bit runout is too large . 5. Insufficient clamping rigidity Drill bit slip. Measures: 1. Use a bit with a larger back cone. . 2. Check the runout range of the main shaft drill bit (<0.02mm) 3. Punch the top hole with the preset centering drill . 4. Use a more rigid bit ? Hydraulic Chuck with necking sleeve or shrink kit. 3.3 Accumulate and cut tumor Reason 1. Caused by the chemical reaction between the cutting material and the workpiece material (Mild steel with higher carbon content) Measures: 1. Improve the lubricant ? Increase oil or additive content. 2. Increase the cutting speed ? Reduce the feed rate and contact time. 3. If drilling aluminum ? Drill bits with polished and uncoated surfaces may be used. 3.4 Broken knife Reason 1. The spiral groove of the drill bit is blocked by cutting. ? The cutting is not discharged in time. 2. When the hole is almost drilled ? No reduction in feed rate or change from motorized to manual feed. 3. When drilling soft metals such as brass ? The clearance angle of the drill bit is too large, and the rake angle is not ground, so that the drill bit is automatically precessed. 4. Excessive sharpening of drill edge ? The phenomenon of chipping occurs, and the knife fails to retract quickly. Measures: 1. Shorten the cycle of changing tools . 2. Perfect installation and fixation For example, increase the support area, increase the clamping force. 3. Check the main shaft bearing and sliding groove . 4. Use high precision tool holder ,rock drilling tools, such as a hydraulic tool holder. 5. Use a more ductile material . Copyright notice: Because some of the articles are from the Internet, and some of the articles are pushed without timely contact with the original author. If the above copyright issues are involved, please contact us to delete or deal with the original author. Return to Sohu to see more Responsible Editor:. wt-dthtools.com
  3. Original title: Running 10: Zhou Shen challenges the Olympic champion, contracts the whole period to watch, and the hot search topic breaks tens of millions of seconds! The tenth program of "Running Bar 10" was still filmed in Changji, Xinjiang. At the beginning of the program, the whole staff appeared in Changji Stadium. The powerful singers in the music world, Zhou Shen and Bai Lu appeared in the same frame, wearing a sportswear, a white coat with red sports pants, showing a special style of painting with a sense of CP. They also put out the shape of "white crane shining wings". He looks very handsome in everything. All kinds of flying kicks make all the guests laugh, which is worthy of being the laughing point of the whole program. Where there is Zhou Shen, there will be laughter, which can bring us unexpected surprises every time. This time, unlike previous programs, the running man family will face the challenge of "kicking the hall". That is to say, the flying guests in this program are all here to "smash the field" and fight with the six champions. The first flying guest is weightlifter Lv Xiaojun. The program also took Zhou Shen, white deer, baby as an example. After watching his personal short film, Zhou Shen's face was full of envy. When shaking hands with Lv Xiaojun, the program also gave Zhou Shen the word "seconds". In fact, it's not that Zhou Shen is afraid to meet with athletes, but out of respect. You know, Zhou Shen is the only image spokesman for the Beijing Winter Olympics. Expand the full text In front of the sportsmen, there was no star shelf at all, and his face was full of smiles. Comedian Sha Yi deliberately accosted Lv Xiaojun and pretended to be very familiar with him. Once again, he was a real "iron fool". The second was Xu Mengtao, who had just participated in the skiing ceiling of "Riding the Wind and Breaking the Waves 3" not long ago. Sigong regretted to withdraw from the competition,mining dth bit, which became a difficult feeling in the hearts of many audiences. Her departure caused Cyndi Wang's team to dance again overnight. Unfortunately, she sprained her foot. For Mango TV, without the pistachio Xu Mengtao, it was really a big loss. I never thought that she would be in the same frame with Zhou Shen in Running Man 10. One is the famous pistachio, the other is the little prince. They are bound to put on a good show. The third is the champion of the women's volleyball team, Zhang Changning, who is 1.95 meters tall. Zhou Shen is very cute. He shakes hands with her while jumping. In front of Zhang Changning, Zhou Shen is more like a middle school student. Zhang Changning also deliberately lets Zhou Shen clap hands with himself, but it is not difficult for Zhou Shen to jump and easily touch his opponent's right hand. It can be seen that Zhang Changning is also a die-hard fan of Zhou Shen. Otherwise,mining drill bit, he would not only interact with Zhou Shen. The fourth one is Gao Tingyu, a flying man on ice, and the fifth one is Liu Huihong, a good friend of Jay Chou. He reproduces the famous fitness scene and is known as the Godfather of fitness. From a certain point of view, this program should be called "Athletes Special Show". As soon as he came out, he made a big move. The muscles on his body successfully attracted Zhou Shen's attention. Finally, the finale was the good friend of the champions, Xie Na's apprentice and Zhou Shen's good friend Wei Daxun. His style was extremely different. He looked more like the silly son of the landlord's family. Before opening the game, Liu Huihong led the whole team to warm up and danced the popular "calisthenics" again. The background music is also Jay Chou's masterpiece "Compendium of Materia Medica". Zhou Shen has learned it well, and every movement is in place, which is in sharp contrast to other guests. The plot of Zhou Shen and Liu Huihong dancing "aerobics" is enough to be recorded as a famous scene in the Chinese music world. The first game is called'Summit Duel '. The two teams decide their own order of playing. The members with the same serial number will have a one-to-one battle. They will tear up their nametags and decide the size of their nametags by drawing lots. The more they tear up, the more chances they have to win. After listening to the rules of the game, Zhou Shen shouted,' Is there only one game recorded today? ' No one expected that the program group would play so much at the beginning. Sha Yi was the second to appear on the stage. His opponent was Zhang Changning. He was led by the nose from beginning to end. He had no initiative at all. He lost without any suspense. Invisibly, he also created a lot of famous scenes in the circle. Zhou Shen played in the third round against weightlifter Lu Xiaojun. At this time, Zhou Shen's strength was far less than that of the other side, but he had a special Olympic spirit. If you want to challenge, choose the character of the king level. Only when the strong fight against the strong, dth button bits ,fastest dth hammer, can you rub out different chemical reactions. After the start, Zhou Shen is particularly methodical. He used the legendary'Lion Roaring Skill 'to give the other side a blow first. He pulled the momentum full, and his hands and feet were extremely flexible. But Lv Xiaojun did not play cards according to the routine. He grabbed Zhou Shen's hand and refused to let go. When the other side was not paying attention, his firepower was all open. Netizens also called it "deep stubbornness". In order to help the team win the honor, Zhou Shen used all his strength and was thrown one after another, which made people feel very distressed. Although he lost to the other side, it was still glorious to lose. As long as he worked hard, after all, the other side was an athlete. In the end, the brother team lost to the champion team with a score of one to five. The second round of the game is called'Fast Meteor '. The two teams take turns to send people to challenge. Members choose the distance to challenge, press the button, and the ball begins to fall. Members need to receive the ball before it falls to the ground. The challenge is successful. The test is the speed of the guests. Each person has two chances to challenge. It has to be said that the program group is so good at playing that they try their best to torment the guests. Zhou Shen, as usual, had a special group soul. He was the first to represent his brother team. He chose to challenge the distance of 8 meters. After starting, he was as fast as lightning and successfully caught the volleyball. Because he was too serious, he was also hit in the throat. It can be called "one ball seals the throat". But Zhou Shen did not complain at all. He always sent out the positive energy of his idol and refreshed the previous cognition of netizens. In the second round, the difficulty increased and the challenge was 9.1 meters. As expected, a kneeling slip, like a rocket, caught the ball steadily and won the applause of the whole team. He proved himself with his strength. Interestingly, when it was Zhang Changning's turn to challenge, Zhou Shen compared her arm length with her leg length, showing the most adorable height difference, which made many audiences laugh. In addition to Sha Yi, the brother team played very well and successfully pulled back a game. In the third round of the game, the members of the two teams were leggings, six people and seven groups. They needed to complete the forward roll, paper cup pass, cross the high ground waist pole, jump rope, a total of five checkpoints. Finally, the team with the shortest time won, testing the tacit understanding of the members. After listening to the rules, Zhou Shen reappeared the classic expression package. In the process, Zhou Shen contracted all the jokes. I believe that many audiences, like me, pay attention to Zhou Shen all the way. Any link is completed perfectly. When the paper cup is passed, the singer's strong vital capacity is brought into full play. The paper cup is passed without hands. The lower waist passes easily. Finally, under the leadership of Zhou Shen, he completed the challenge in 4 minutes and 39 seconds. When it was the champion team's turn, the brother team kept making trouble and lost successively when they went down to cross the pole. In this regard, Zhou Shen's online singing of "Lonely Brave Man" "Love You don't Kneel" once again filled the comedy effect of this program. All the audience in the bullet screen shouted "I haven't heard enough". The final competition was a comprehensive endurance race of marbles. To put it bluntly, let the marbles compete. The marble Zhou Shen got was'Dalmatian ', and the white deer got'Little Jelly', and Sha Yi got'Desert '. Li Chen was the first in the first round. Zhou Shen's'Dalmatian' played in the second round. He felt that Zhou Shen was more excited than he was to participate in the competition. He shouted'Come on Dalmatians' all the way, but unfortunately none of them rushed into the finish line. Finally, the champion team'Win-win 'won the victory of this issue. The audience was very satisfied with the result. After all, This period want to convey is professional ability and sportsmanship. After the broadcast, ZhouShen as always was pushed on the micro Bo hot search, Hot words'Running man vs world champion'Reading volume until today, Reached 32.49 million. In addition, The topic'ZhouShen speed skating catch '' ZhouShen vital capacity is how strong'Hot search seconds break ten million, Zhou Shen This shows how strong the influence of idol Zhou Shen is. I don't know if everyone has any different views on Zhou Shen's performance? Welcome to collect, forward, leave a message, one key three! Return to Sohu to see more Responsible Editor: (function() { function getBrandHtml() { var brands = [],overburden drilling systems, html = ''; for(var i = 0; i < brands.length; i++) { var brand = brands; if(brands.length i+1) { html+= ''+brand.name+''; } else { html+= ''+brand.name+'、'; } } return html; }; if(document.getElementById('linkBtn')){ document.getElementById('linkBtn').onclick = function() { $('#brands').removeClass('brand');$ ( '# tipInfo').text ( 'Real name responded'); $ ('#linkBtn').remove();$ ('.real-response .content').css('line-height', '20px');$ ('.real-response .time').css('line-height', '20px'); }; document.getElementById('brands').innerHTML = getBrandHtml(); }; })(); wt-dthtools.com
  4. Original title: See how Wassara, a mining company, uses metal 3D printing to solve deep drilling problems? The mining industry needs new drilling solutions to cope with increasing cost versus benefit pressures. Compared with the current drilling scheme, the new scheme is not only more environmentally friendly, but also more economically advantageous. Many existing underground mines are close to the limit of mining depth, so it is difficult to ensure the controllability of various costs by current drilling methods. The new deposits are deeper and less productive. The combination of various factors requires mining enterprises to realize the rational planning and large-scale exploitation of mineral resources, so the adoption of more efficient and accurate drilling methods has become an inevitable choice. Background Wassara, a mining equipment company from Sweden, has a number of innovative products that minimize the negative impact on the environment while mining ore. Wassara's core technology is a down-the-hole (DTH) hammer driven by a high-pressure water jet. Wassara's hydraulic down-the-hole hammer is the most environmentally friendly method of percussive drilling available. Dth hammers are driven by high-pressure water jets and do not use grease for lubrication,dth hammer bit, so they do not pollute the air or groundwater. In addition, high-pressure water is effective in suppressing dust. The incompressibility of water is a key factor in the efficient operation of the Wassara Dth hammer. Wassara's technology results in significant energy cost savings compared to relatively conventional pneumatic Dth hammer technology because less energy is required to drive a hydraulic Dth hammer. High pressure water was selected by Wassara as the transmission medium due to its ability to drive the hammer to produce high frequency, high energy impact motion. In addition,mining dth bit, when the flow leaves the hammer, it is fast enough to bring the drilled core and debris back to the surface and clean the hole. This technology has many excellent advantages, such as high drilling efficiency, good borehole quality, and strong wall protection ability for drilling rock formation. With the addition of liquid drive Dth hammer technology, mining enterprises have more choices when choosing the most suitable mining method for ore body characteristics, which is regarded as a big step towards scientific mining. Expand the full text Challenge Each down-the-hole hammer is made up of a number of complex components. The core component of the down-the-hole hammer is a sliding shell which provides two-way high-pressure water diversion for the piston assembly, dth drilling hammer ,Mining Drilling Equipment, and the inside of the shell requires a plurality of high-pressure water flow holes; due to the complexity of the design, a plurality of processed parts must be jointed together to manufacture a complete shell. The complex design also makes the component relatively expensive to manufacture. In addition, the total cost of ownership of the down-the-hole hammer is further increased by the frequent occurrence of non-conforming products during the joining process, as well as equipment failures due to component wear or pitting during use, which increases maintenance costs. Solutions Wassara approached Renishaw to find out whether additive manufacturing (AM) technology could be a suitable alternative manufacturing solution in order to reduce costs and improve the reliability of sliding enclosure components. One of the significant advantages of metal additive manufacturing is the ability to combine discrete parts into a complex 3D geometry and simplify the processing steps, for example, when processing cross-holes requiring blind plugs or welding at one end. When there is no significant difference in design between the components manufactured by additive method and the components manufactured by traditional method, they can be tested in the same application environment, and the results can be used as an ideal basis for verifying the usability of metal additive components. A detailed comparison of the performance of the two types of components under standard test conditions, with any significant differences in the results directly attributable to changes in manufacturing technology. The geometry of the Wassara sliding enclosure has been redesigned to incorporate the benefits of additive manufacturing in terms of design freedom. The next challenge to overcome with a metal additive manufacturing solution is the use of the appropriate metal alloy for the particular application. In this case, the component originally used standard alloy steel 527 M20, an alloy structural steel that would not normally be used for metal additive manufacturing due to its medium carbon content. The alloy steel more suitable for additive manufacturing is 316L stainless steel. However, although this alloy steel has better corrosion resistance, it is not expected to guarantee sufficient corrosion and erosion resistance during service. Another alternative proposed by Renishaw was to produce test parts using maraging alloy steels. Maraging steels are age-hardening tool steels with a wide range of applications; they can be heat treated to obtain material properties tailored to the requirements of specific applications by adjusting the process temperature. This is the first test and application of this type of steel in the field of mining, so the sliding shell was heat treated after machining to ensure maximum hardness. Result To test the performance of the additive sliding shell, Wassara assembled it into a complete down-the-hole hammer for test use under standard mining conditions, i.e., drilling a typical long passage hole in a selected rock face. Routine visual inspection and maintenance of the down-the-hole hammer followed, and the additively manufactured sliding housing showed no signs of pitting and minimal wear compared to the conventional housing. The down-the-hole hammer was then reassembled and more drilling operations continued. Upon completion of the above work, Wassara performed a second inspection of the additively manufactured sliding enclosure and found that there were indeed some signs of wear, but other than that, there was no pitting on the surface of the component (the second most common cause of equipment failure). A third drill test was then carried out by Wassara,Tapered Rock Bit, this time for a duration well beyond the normal Dth hammer cycle, in order to establish as far as possible whether there was any evidence of pitting, but there was still no pitting. This leads to the preliminary conclusion that additive components made of maraging steel have superior potential pitting resistance compared to conventional sliding enclosures made of standard alloy steel. Return to Sohu to see more Article Source: Renishaw Responsible Editor:. wt-dthtools.com
  5. Original title: The Second Evaporation and Crystallization New Technology Industry Development Conference in 2022 The Second Evaporation Crystallization New Technology Industry Development Conference in 2022 All relevant units: 2021 is the centenary of the founding of the Communist Party of China, the first year of China's "14th Five-Year Plan", and the first year of our March towards the goal of the second century. With the concept of "green mountains are golden mountains and silver mountains" deeply rooted in the hearts of the people, the construction of ecological civilization in China is developing in a high-quality direction, and China attaches unprecedented importance to environmental protection. According to the forecast, the annual market space of chemical wastewater in China is 200 billion yuan, which is nearly three times that of urban sewage. For chemical wastewater, our country has also promulgated strict wastewater salt limit discharge standards. How to treat high salt wastewater efficiently has become an urgent problem to be solved in our country. As we all know, the treatment process of organic high-salinity wastewater is complex, and the target of resource utilization and zero discharge is heavy and demanding. Under the general trend of vigorously promoting energy conservation and environmental protection, the national industrial policy encourages the evaporation and crystallization equipment industry to develop in the direction of high-tech products. Evaporation and crystallization are important technical units in the treatment of high-salinity wastewater, and they are the key technologies to realize the recycling and reduction of waste. In order to promote the application of new evaporation and crystallization technologies and equipment, save energy consumption, improve the quality of target products and solve the problems encountered in the application, the Joint Authority of Industrial Environmental Protection Network will hold the "2022 Conference on the Development of New Evaporation and Crystallization Technologies Industry" in Hangzhou from March 11 to 12, 2022. At that time, authoritative experts from relevant scientific research institutes, cbd crystallization equipment ,jacketed glass reactor, senior executives of well-known enterprises and engineers and technicians will be invited to participate in the discussion and exchange. All relevant units are invited to actively send personnel to participate, and the relevant matters are hereby notified as follows: I. Contents of the Meeting (I) New Evaporation Crystallization Technology 1. Industrial application of low temperature evaporation technology; 2. Case introduction of MVR evaporation and multi-effect evaporation combination process; 3. Selection and maintenance of pumps, compressors and centrifuges in the evaporation and crystallization system; 4. Scale prevention measures and treatment scheme of evaporation system; 5. Application of evaporation system in waste acid disposal and recycling; 6. Selection of materials for evaporation and crystallization equipment; 7. Form, type selection and material selection details of the evaporator; 8. Application of evaporation and crystallization technology in "zero discharge" of chemical wastewater; 9. Key points of organic matter removal, particulate matter removal and grease removal in evaporative influent water; (II) Water washing fly ash saline resource reduction 1. Domestic status and direction of fly ash treatment 2. Co-processing of fly ash in cement kiln; 3. Key issues of design optimization of potassium and sodium salt separation process and separate crystallization; 4. Discussion on the new technical route of extracting sylvite; Expand the full text 5. Optimization design of equipment combination of fly ash washing and dewatering system; (III) Resource reduction of waste salt 1. Centralized disposal route of regional and park waste salt 2. The long-term operation of the dual crystallization technology route 3. Harmless disposal technology of crystallization mother liquor 4. Concentrated brine water salt crystallization recycling technology 5. Seawater desalination and evaporation device for industrial waste heat 6. High-salinity wastewater concentration treatment technology 7. Selection and maintenance of pumps, compressors and centrifuges in the evaporation and crystallization system; 8. Resource treatment technology of mixed salt and strong brine 9. Analysis of the long-term operation of the dual crystallization technology 10. Application of MVR evaporation and crystallization technology in zero discharge of high-salinity wastewater; 10. Relevant engineering cases of salt-containing wastewater and waste solid crystallization salt separation (IV) Application of evaporator in wastewater treatment of lithium battery industry 1. Characteristics of wastewater from lithium battery industry and new treatment technologies; 2. Application and case sharing of MVR evaporation crystallization technology in lithium battery industry; 3. Selection and application of steam compressor in MVR process; 4. Selection and application scope of evaporator in wastewater treatment of lithium battery industry; 5. Evaporation crystallization homogeneous multi-component separation technology; 6. Research and application of low temperature heat pump evaporation technology in lithium battery industry; 7. Common problems and solutions in the application of evaporation crystallization process equipment in lithium battery industry; 8. Feasibility analysis of MVR evaporator to realize zero discharge of wastewater treatment in lithium battery industry; 9. Application and successful case sharing of multi-effect evaporator in lithium battery wastewater treatment. II. Participants Experts from evaporation and crystallization equipment manufacturing enterprises, scientific research institutions, environmental protection engineering companies, colleges and universities, engineering and technical personnel, representatives of wastewater treatment units, chemical enterprises and power enterprises, etc. III. Time and Place of the Meeting Meeting time: March 11-12, 2022 (all-day registration on March 10) Venue: Hangzhou (registration place after registration) IV. Speech Collection This seminar will collect new technologies, case sharing and conference speeches related to the theme for the whole country. 5. Participation fee: Conference fee (including preparation fee, venue fee, expert fee, lunch, conference journal, etc.) is free for members of Industrial Environmental Protection Network and 3500 yuan per person for other units. Remarks: Please consult the conference affairs group for conference co-sponsorship,rotary vacuum evaporator, corporate speeches, conference journal covers, inserts and other related information. VI. Contact information: Return to Sohu to see more Responsible Editor:. toptiontech.com
  6. Original Title: Good Helper for Railway Coal Transportation in Northern China in Winter-Anti-freezing Dust Suppressant Antifreezing dust suppressant is an antifreezing dust suppressant specially developed for railway coal transportation in northern China in winter. The dust suppressant well combines the dust suppression function and the anti-freezing function together, so that the dust suppressant not only has excellent moisture retention, bonding, film forming and crusting capabilities, but also has an effective anti-freezing function, thereby well solving the problems encountered in coal transportation by trains in northern areas in cold winter. The outstanding features of the antifreeze dust suppressant include: 1, that antifreeze dust suppressant organically combines dust suppression and antifreeze, so that the product has various effects of antifreezing,wiped film distillation, moisturizing, bon, forming a film, forming a shell and the like. And 2,jacketed glass reactor, the antifreezing dust suppressant is an instant type, is easy to dissolve in water, does not agglomerate or pill in water, reduces the stirring time, saves electric energy, reduces the labor intensity of workers, winterization filtration ,hemp extraction centrifuge, and is more convenient to use. 3. The dust suppression component of the antifreezing dust suppressant is modified plant fiber, which can form a high-viscosity network structure when sprayed on the surface of coal, and has good dust suppression effect. 4. The antifreezing dust suppressant can greatly reduce the freezing point and prevent the bulk water-containing materials and wagons from freezing. In severe cold seasons or severe cold areas, the bulk materials containing water transported by wagons, such as mined coal, will be frozen together with the wagons and cannot be unloaded. Before unloading, they must be thawed in the thawing room, which not only wastes a lot of time, but also consumes a lot of resources, reduces the efficiency of vehicles, increases transportation costs, and delays production. And 5, that dust suppressant is a powdery product, is more convenient and SAF to store and transport than a liquid dust suppressant, and is not affected by cold weather. Usage: 1. Preparation of the antifreezing dust suppressant solution: according to the local winter temperature, add the antifreezing dust suppressant into the water according to the proportion recommended by the sales engineer, and stir it while adding materials until it is completely dissolved, that is, prepare the dust suppresser solution. 2. Spraying amount of dust suppressant liquid: coal shall be sprayed on the surface of coal at the amount of 1.6 to 2 liters per square meter during railway transportation. If the coal has a high moisture content, the spray rate may be increased to 2.5 to 3.5 liters per square meter for frost protection. Return to Sohu , see more Responsible Editor: (function() { function getBrandHtml() { var brands = [],50l rotovap, html = ''; for(var i = 0; i < brands.length; i++) { var brand = brands; if(brands.length i+1) { html+= ''+brand.name+''; } else { html+= ''+brand.name+'、'; } } return html; }; if(document.getElementById('linkBtn')){ document.getElementById('linkBtn').onclick = function() { $('#brands').removeClass('brand');$ ( '# tipInfo').text ( 'Real name responded'); $ ('#linkBtn').remove();$ ('.real-response .content').css('line-height', '20px');$ ('.real-response .time').css('line-height', '20px'); }; document.getElementById('brands').innerHTML = getBrandHtml(); }; })();。 toptiontech.com
  7. Original Title: Evaporator Classification Design Selection Information All You Want Is Here 1 Type of evaporator With the continuous development of industrial evaporation technology, the structure and type of evaporation equipment are constantly improved and innovated, with a wide range of different structures. At present, there are more than 60 kinds of evaporation equipment in industry, of which more than 10 types are most commonly used. This section only introduces a few commonly used types. The common evaporator is mainly composed of a heating chamber and a separation chamber. There are many types of heating chambers. At first, jacketed or coiled heating devices are used, followed by horizontal and vertical short-tube heating chambers. Then the vertical long tube liquid film evaporator and the scraper film evaporator were invented. According to the flow of solution in the evaporator, the indirect heating evaporator commonly used in industry can be roughly divided into two types: circulation type and one-way type. 1. Circulation type evaporator The characteristic of this kind of evaporator is that the solution circulates in the evaporator. According to the principle of liquid circulation, it can be divided into two types: natural circulation and forced circulation. The former is the natural circulation caused by the density difference of the solution due to the different heating degree of the solution at different positions of the heating chamber, while the latter is the forced circulation of the solution by external power. At present, the commonly used circulating evaporators are as follows: (1) Central circulation tubular evaporator Expand the full text The structure of the central circulation tube evaporator is shown in the picture. Its heating chamber is composed of a vertical heating tube bundle (boiling tube bundle). In the center of the tube bundle, there is a tube with a larger diameter, called the central circulation tube, whose cross-sectional area is generally 40 ~ 100% of the total cross-sectional area of the heating tube bundle. The central circulation tube evaporator has the advantages of compact structure, convenient manufacture and reliable operation, so it is widely used in industry and is called "standard evaporator". But in fact, due to the limitation of structure, its circulation speed is relatively low (generally below 0.5m/s); and because the solution circulates continuously in the heating tube, its concentration is always close to the concentration of the finished solution, so the boiling point of the solution is high and the effective temperature difference is reduced. In addition, the cleaning and maintenance of the equipment is not convenient enough. (2) Basket evaporator Since the boiling liquid is in contact with the evaporator shell at a lower temperature, there is less heat loss. The basket-type evaporator is suitable for evaporating the solution which is easy to scale or has crystal precipitation. Its disadvantage is that the structure is complex and the amount of equipment materials required for unit heat transfer surface is large. (3) Externally heated evaporator The characteristic of the external heating evaporator is that the heating chamber is separated from the separation chamber, which not only facilitates cleaning and replacement, but also reduces the total height of the evaporator. Because the heating tube is long (the ratio of the tube length to the tube diameter is 50-100) and the solution in the circulating tube is not heated, the circulating speed of the solution is high, which can reach 1.5m/s. (4) Levin evaporator The advantages of Levin evaporator are high circulation speed and good heat transfer effect. Because the solution does not boil in the heating tube, it can avoid the precipitation of crystals in the heating tube, so it is suitable for the treatment of solutions with crystal precipitation or easy scaling. Its disadvantage is that the equipment is huge and the required plant is high. In addition, since the static pressure of the liquid layer is large, the pressure of the heating steam is required to be high. (5) Forced circulation evaporator This kind of evaporator has the advantages of large heat transfer coefficient and good adaptability to materials with high viscosity or easy crystallization and scaling, but its power consumption is large. 2. One-pass type evaporator The characteristic of this kind of evaporator is that the solution flows along the wall of the heating tube in the form of a film and reaches the required concentration once through the heating chamber, while the residence time is only a few seconds or more than ten seconds. The main advantages of the single-pass evaporator are high heat transfer efficiency, fast evaporation speed and short residence time of the solution in the evaporator, so it is especially suitable for the evaporation of heat-sensitive materials. According to the flow direction of materials in the evaporator and the reasons for film formation, it can be divided into the following types: Rising film evaporator; Falling film evaporator; Rising-falling film evaporator; Scraper film evaporator. (1) Rising film evaporator The heating chamber of the rising film evaporator is composed of one or several vertical long tubes. The diameter of the heating tube is usually 25 ~ 50mm, and the ratio of the tube length to the tube diameter is 100 ~ 150. The climbing film evaporator is suitable for the solution with large evaporation capacity (i.e. dilute solution), heat sensitivity and easy foaming, but not suitable for the solution with high viscosity, crystal precipitation or easy scaling. (2) Falling film evaporator The falling film evaporator can evaporate the solution with higher concentration, and is also suitable for the material with higher viscosity. However, it is not suitable for the solution which is easy to crystallize or scale. In addition, because the liquid film is not easy to distribute evenly in the tube, its heat transfer coefficient is smaller than that of the climbing film evaporator. (3) Rising-falling film evaporator The rising film and falling film evaporators are installed in a casing to form a rising-falling film evaporator. After being preheated,wiped film evaporator, the raw material liquid is first raised by the rising film heating chamber, then lowered by the falling film heater, and finally separated from the secondary steam in the separation chamber to obtain the finished liquid. This kind of evaporator is mostly used in the situation where the viscosity of the solution changes greatly in the process of evaporation, the evaporation of water is not large and the height of the workshop is limited. (4) Scraper film evaporator In some cases, the solution may be evaporated to dryness to obtain a solid product directly from the bottom. The disadvantages of this kind of evaporator are complex structure, large power consumption, small heat transfer area, generally 3 ~ 4 m2, the maximum is not more than 20 m2, so its processing capacity is small. 3. Direct contact heat transfer evaporator In actual production, in addition to the above two types of circulating and single-pass evaporators with dividing wall heat transfer, direct contact heat transfer evaporators are sometimes used. Fuel (usually coal gas or heavy oil) is mixed with air and the resulting high-temperature flue gas is directly sprayed into the evaporated solution. The high-temperature flue gas is in direct contact with the solution, making the solution boil and vaporize rapidly. The evaporated water is directly discharged from the top of the evaporator together with the flue gas. Generally, the depth of the combustion chamber of this evaporator in the solution is 200 ~ 600mm, and the temperature of the high temperature flue gas in the combustion chamber can reach more than 1000 ℃. However,thin film distillation, due to the fast heat transfer rate when the gas and liquid are in direct contact, the temperature of the gas leaving the liquid level is only 2 ~ 4 ℃ higher than that of the solution. The nozzle of the combustion chamber is easy to be damaged due to its use at high temperature, so it should be made of high temperature and corrosion resistant materials, and its structure should be considered to be easy to replace. The submerged combustion evaporator is characterized by simple structure and high heat transfer efficiency. The evaporator is especially suitable for the evaporation of materials which are easy to crystallize, scale or corrode. At present, this kind of evaporator has been widely used in the treatment of waste acid and the evaporation of ammonium sulfate solution. However, it is not suitable for the treatment of materials that cannot be contaminated by flue gas, and its secondary steam is also difficult to use. Due to the limitation of space, the working principle of various evaporators is not introduced in detail in this article. If you want to know this content, you can search for evaporation crystallization in the chemical 707 app to see more details. There are so many evaporators, so how to design and calculate the evaporation process? Let's learn together! 2 Evaporator design steps 1. The calculation of multi-effect evaporation generally adopts iterative calculation method. (1) According to the process requirements and the nature of the solution, determine the operating conditions of evaporation (such as heating steam pressure and condenser pressure), the type of evaporator (rising film evaporator, falling film evaporator, forced circulation evaporator, wiped film evaporator), process and number of effects. (2) According to the production experience data, preliminarily estimate the evaporation capacity of each effect and the composition of the finished liquid of each effect. (3) Based on experience, assume that the pressure drop of steam passing through each effect is equal, and estimate the boiling point of solution in each effect and the effective total temperature difference. And (4) calculating the evaporation capacity and the heat transfer capacity of each effect according to the enthalpy balance of the evaporator. And (5) calculating the heat transfer area of each effect according to the heat transfer rate equation. If the obtained effective heat transfer areas are not equal, the effective temperature difference shall be redistributed as described below, and steps (3) to (5) shall be repeated until the obtained effective heat transfer areas are equal (or meet the accuracy requirements given in advance). 2. Calculation method of evaporator The calculation method of multi-effect evaporation is introduced by taking the evaporation device with three-effect cocurrent feeding as an example. (1) Estimate the evaporation capacity of each effect and the composition of finished liquid In the process of evaporation, the total evaporation is the sum of the evaporation of each effect. The feed liquid in any one effect is composed of In general, the evaporation capacity of each effect can be estimated according to the average value of that sent by the General Political Department, namely For the multi-effect evaporation of cocurrent operation, due to the self-evaporation phenomenon, it can be estimated according to the following proportion. For example, In the above categories: W — total evaporation capacity, kg/H; W 1 ,W 2 ,… , wiped film evaporator ,cbd centrifugal extractor, W n — evaporation capacity of each effect, kg/H; F — Flow of raw material solution, kg/H; x 0 , x 1 ,… , X n — composition and mass fraction of raw material solution and finished solution of each effect. (2) estimate that difference between the boiling point and the effective total temperature of each effect solution In order to obtain the boiling point temperature of each effect, it is necessary to assume the pressure. Generally, the heating steam pressure and the pressure in the condenser (or the final effect pressure) are given, and the pressure of other effects can be determined according to the assumption that the steam pressure drop between effects is equal. That is Where: -difference between heating steam pressure and secondary steam pressure of each effect, Pa; P 1 — pressure of the first effect heating steam, Pa; P 'K — pressure of secondary steam in the last effect condenser, Pa. The total temperature difference of effective heat transfer in multi-effect evaporation can be calculated by the following formula: Where: -total effective temperature difference, which is the sum of effective temperature difference of each effect, ℃; T 1 — temperature of the first effect heating steam, ℃; T 'K — the saturation temperature of the secondary steam at the operating pressure of the condenser, ℃; — Total temperature difference loss, which is the sum of temperature difference loss of each effect, ℃. In the formula — loss of temperature difference due to drop in vapor pressure of the solution, ℃; — loss of temperature difference due to the static pressure of the solution in the evaporator, ° C; — Temperature difference loss caused by pressure drop due to pipeline fluid resistance, ℃. The solutions of, and are respectively introduced as follows: a. The temperature difference loss caused by the decrease of the vapor pressure of the solution can be corrected by the correction factor method and the Duhring method. The rule is obtained. In the formula — temperature difference loss caused by solution vapor pressure drop under normal pressure, ℃; The boiling point, t a, of some solutions at atmospheric pressure can be obtained from the manual; — Correction factor, dimension one. Where: T '1 — Boiling point of water at operating pressure, i.e. saturation temperature of secondary steam, ℃; R '— vaporization heat of secondary steam under operating pressure, kJ/kg. Turing's rule: The boiling point of a solution is linearly related to the boiling point of a standard liquid (usually water) at the same pressure. A set of straight lines, called Turing lines, can be obtained on a rectangular coordinate graph with the boiling point of water as the abscissa, the boiling point of the solution as the ordinate, and the composition of the solution as the parameter. According to the composition of the solution and the boiling point of water at the same pressure, the boiling point of the solution at the same pressure can be found out by using the Duhring diagram, and then the value can be obtained. An approximation of the boiling point of a liquid at various pressures can also be calculated from Turing's rule. This method is based on the fact that the ratio of the difference between the two boiling points of a liquid at two different pressures to the difference between the two boiling points of water at the same pressure is a constant, namely Obtaining the value of K, the t 'A of the boiling point at any other pressure can be obtained from the following equation: (1-11) Therefore, the value of the solution can be calculated without using the Duhring diagram. b. Loss of temperature difference due to the static pressure of the solution in the evaporator Some evaporators are in the operating room, and the solution in the evaporator needs to maintain a certain liquid level, so the pressure inside the solution in the evaporator is greater than the pressure at the liquid level, resulting in a higher boiling point inside the solution than at the liquid level. The difference between the two is the temperature difference loss caused by the static pressure of the solution. For the sake of simplicity, the boiling point inside the solution can be found by the average pressure of the liquid surface and the bottom layer. The average pressure is approximately estimated according to the static equation: (1-12) Where: P m — average pressure between the liquid level and the bottom in the evaporator, Pa; P '— pressure of secondary steam, i.e. pressure at liquid surface, Pa; ρ — average density of solution, kg/m3; L — height of liquid layer, m; G — acceleration of gravity, m/S2. (1-13) Where: TPM — the boiling point of water calculated according to the average pressure, ℃; TP — boiling point of water calculated according to the secondary vapor pressure, ℃. Temperature difference loss caused by pressure drop due to pipeline flow resistance In multi-effect evaporation, when the secondary steam of each effect before the last effect flows to the heating chamber of the second effect, the pressure decreases due to pipeline resistance, and the saturation temperature of the steam also decreases accordingly. The resulting temperature difference loss is. According to the experience, the temperature difference loss caused by the pipeline resistance between each effect is taken as 1 ℃. According to the estimated secondary steam pressure of each effect And that Los of the temperature difference, the boiling point t of each effective solution can be estimate from the following equation. (1-14) 3. Preliminary Calculation of Heating Steam Consumption and Evaporation Water Volume of Each Effect The enthalpy balance formula of the first effect is The evaporation capacity Wi of the first effect can be obtained from the formula (1-15). If the concentration heat of the solution and the heat loss of the evaporator are taken into account in the enthalpy equation, the heat utilization coefficient η should also be taken into account. For the evaporation of general solution, η can be taken as 0.98-0.7 (where X is the composition change of the solution, expressed in mass fraction). Where: Di — heating steam quantity of the ith effect, kg/H, when no additional steam is extracted, R I — vaporization heat of heating steam of the first effect, kJ/kg; R 'I — vaporization heat of secondary steam of the first effect, kJ/kg; C PO — Specific heat capacity of feed solution, kJ/ (kg · ℃); C PW — specific heat capacity of water, kJ/ (kg · ℃); T I, t i-1 — boiling point of the solution of the i-th effect and the (i-1) -th effect, ℃; ηi — heat utilization coefficient of the ith effect, dimension is one. For the consumption of heating steam (live steam), it can be obtained by listing the enthalpy balance formula of each effect and solving it with the formula (1-2). 4. Distribution of Heat Transfer Area and Effective Temperature Difference of Evaporator in Each Effect The heat transfer rate equation for any effect I (1-17) Where: Q I — heat transfer rate of the ith effect, W; K I — heat transfer coefficient of the ith effect, W; Si — heat transfer area of the ith effect, m2; T I — heat transfer temperature difference of the ith effect, ℃. The purpose of effective temperature distribution is to calculate the heat transfer area Si of evaporation. Now take the triple effect as an example, namely (1-18) In the formula (1-19) (1-20) In multi-effect evaporation, in order to facilitate manufacturing and installation, evaporators with equal heat transfer area of each effect are usually used. If the heat transfer areas obtained from Equation (1-18) are not equal, the areas shall be redistributed according to the principle of each effective area. Effective temperature difference. The method is as follows: Let t 'denote the effective temperature difference when the effective surfaces are equal, then Compared with the formula (1-18), Add the three formulas in formula (1-22) to get In the formula, ∑ t is the sum of the effective temperature difference of each effect, which is called the total effective temperature difference, ℃. After the heat transfer area S is obtained from Equation (1-23), the effective temperature difference of each effect can be redistributed from Equation (1-22). Repeat the above steps until the obtained heat transfer area of each effect is equal, and the area is the required one. 3 Selection of evaporator As mentioned above, there are many types of evaporator structures. When selecting the type of evaporator or designing the evaporator, on the premise of meeting the requirements of production tasks and ensuring product quality, it is also necessary to take into account the simple structure, easy manufacture, convenient operation and maintenance, good heat transfer effect and so on. In addition, it is also necessary to have good adaptability to the process characteristics of the material to be evaporated,molecular distillation systems, including the viscosity, heat sensitivity, corrosiveness of the material and whether it crystallizes or scales. The climbing film evaporator is suitable for evaporating low-boiling point alcohols or low-boiling point volatile organic compounds; The falling-film evaporator is suitable for the concentration of water-soluble substances and the evaporation of materials which are not easy to crystallize or scab; The horizontal falling film evaporator is suitable for the evaporation of volatile organic compounds with medium boiling points such as ethanol; The natural internal circulation evaporator is suitable for the concentration and evaporation of general materials; The forced external circulation evaporator is suitable for the evaporation and crystallization of high-concentration and easy-to-crystallize materials; The combination of falling film and forced external circulation evaporator is suitable for the concentration and crystallization of low-concentration and easy-to-crystallize materials; The combination of natural circulation and forced external circulation evaporator is suitable for the crystallization of the thickener of the medium and low concentration materials which are easy to crystallize; The combination of forced external circulation and multi-effect evaporation crystallization is suitable for secondary concentrated crystallization containing high-boiling inorganic or organic substances; Selection Criteria for Common Evaporation Equipment Return to Sohu to see more Responsible Editor:. toptiontech.com
  8. Original Title: Difference between Short-path Distillation and Molecular Distillation-Shanghai DEA Short-path distillation, "short path" refers to a shorter distance, in a broad sense, the evaporator adopts the design scheme that the distance from the evaporation surface to the condensation surface is less than 300 MM, which can be called a short-path distiller. In terms of design structure, it can be divided into scraper short-path distiller, centrifugal short-path distiller and short-path distillers evolved from the condenser installation position of film evaporator improved by some manufacturers in recent years. At present, the most mature technology widely used is the scraper short-distance distiller, which is designed to consist of a vertical evaporation cylinder heated externally,nutsche filter dryer, a central condenser and a rotating film scraper between the distiller and the condenser. The distillation process is as follows: the material is added from the top of the evaporator, and is continuously and uniformly distributed on the heating surface by the feed liquid distributor on the rotor, and then the film scraper scrapes the feed liquid into a very thin layer of turbulent liquid film, which is pushed downward in a spiral shape. In this process,rotovap distillation, the light components escaping from the heating surface are condensed into liquid on the built-in condenser through a very short route and almost without collision, and flow down the condenser tubes and discharged through the discharge tube at the bottom of the evaporator; the residual liquid, namely the heavy components, is collected in the circular channel under the heating area and then flows out through the discharge tube at the side. Molecular distillation, more precisely, the principle of molecular distillation, wiped film distillation ,thin film distillation, is different from the traditional distillation which relies on the principle of boiling point difference separation, but relies on the difference of mean free path of molecular motion of different substances to achieve separation. In the distillation process, when a liquid mixture flows along a heating plate and is heated under a certain specific pressure condition, light and heavy molecules can escape from the liquid surface and enter a gas phase, and because the free paths of the light and heavy molecules are different, the molecules of different substances have different moving distances after escaping from the liquid surface, If a condensation plate can be properly set (the distance between the evaporation area and the condensation surface is generally less than 100mm), the light molecules will be condensed and discharged when they reach the condensation plate, while the heavy molecules will be discharged along the mixed liquid when they do not reach the condensation plate. In this way, the purpose of material separation is achieved. Expand the full text Attention should be paid to "specific pressure conditions" and "evaporation surface and condensation surface distance" from the description of the distillation process. That is to say, not all raw materials can realize molecular distillation; the molecular distillation process can only be realized in a scraper type short-path distiller or a centrifugal type short-path distiller; the molecular distillation is not simply distillation in the short-distance distiller, but molecular distillation, and molecular distillation must be realized by realizing molecular-level motion and realizing a separation process at a specific pressure and a specific temperature. Therefore, it is wrong to simply confuse molecular distillation with short-path distillation, and their essence is different. Features of Shanghai DEA's scraper short-path distiller: Extremely high vacuum: The special structural design of the scraper short-path distiller allows the operating pressure to reach an extremely low operating vacuum. The vacuum of the experimental scale equipment can reach 0.001 mbar, and even the industrial scale equipment can reach 0.01-0.05 mbar. The operating temperature is much lower than the boiling point of the material: because the scraped path distillation adopts the central condensation mode, the distance between the evaporation area and the condensation surface is generally less than 50mm (the distance between the experimental device is less than 10mm), so there is only a slight pressure drop between the evaporator and the condenser, that is to say, the vacuum degree at the end of the vacuum system is almost close to the vacuum of the evaporator. The design of DEA fully meets the requirements of molecular distillation process. The heating time is short: by adopting the film forming design of the vertically rotating scraper, the residence time of the material on the heating wall is only more than ten seconds. Due to the strict distance requirement between the heating wall of short-path distillation and the condenser, the light molecules escaping from the liquid surface reach the condensing surface almost instantaneously, and the heating time of the light molecules in the vapor phase can be ignored in this process. The potential for thermal decomposition is minimized. Superior efficiency of mass transfer and heat transfer: DEA short-path distillation uses a mechanical film wiping system,decarboxylation after extraction, which is different from the uneven film formation defects of other falling film evaporators. In the short-path evaporator, the material film thickness is uniform and the flow characteristics are excellent. Because the area of the liquid level and the heating surface is almost equal, the efficiency of mass transfer and heat transfer is superior. Return to Sohu to see more Responsible Editor:. toptiontech.com