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Heat exchanger tube plate anti-corrosion how to protect the effect better
2022 / 10 / 05
The material of heat exchanger is generally based on carbon steel, stainless steel and copper, and the connection between plate and tube is generally in the form of welding, expansion and expansion welding combination. The anti-corrosion protection of the tube plate and tube using expansion welding combined way, due to the shape of the weld exists in varying degrees of defects, such as depressions, porosity, slag, etc., the distribution of weld stress is also uneven, weld welding led to changes in its own material, when encountering corrosive media, the weld position is very easy to corrosion, rust caused by leakage in the weld position. Secondly, the chlorine ions in the water and electrochemical corrosion problems are also prone to cause corrosion in the weld position resulting in leakage, affecting the service life of the heat exchanger and causing losses to the production enterprises. For a long time this problem has not been properly solved and has become an industry problem. The development of heat exchanger tube plate corrosion technology For corrosive media caused by the heat exchanger tube plate and weld position corrosion problems, the traditional way is to play pressure mark leakage point after the way to patch welding. However, after welding, the release of welding stress and welding position material changes, are prone to cause secondary corrosion leakage of the tube plate. In addition, by upgrading the material grade of the equipment itself, to improve the corrosion resistance of the body and extend the service life, but will add a lot of costs to the enterprise. Polymer composite material protection process. The use of polymer materials to implement surface organic coating anti-corrosion is currently one of the proven anti-corrosion measures. Polymer composites are high-tech disciplines developed on the basis of polymer chemistry, o
Common defects in pressure vessels and how to deal with them
2022 / 09 / 27
Pressure vessels in chemical plants are often encountered with defects such as corrosion, cracks and deformation. Operators must carry out regular technical inspections to eliminate hidden problems as early as possible and prevent defects from continuing to develop and expand, which can have an impact on production. Corrosion is one of the most common defects in pressure vessels during use, especially in chemical vessels. It is caused by chemical or electrochemical changes in the metal and the medium it is in contact with. Corrosion types The corrosion of the container can be uniform corrosion, pitting corrosion, intergranular corrosion, stress corrosion and fatigue corrosion. No matter which kind of corrosion, when serious, will lead to the failure or destruction of the container. Corrosion can occur on both the internal and external surfaces of the pressure vessel. The outer wall of the container is generally the corrosion of the atmosphere, the corrosion of the atmosphere and the region and the season, etc. have a close relationship, in dry areas or season, the corrosion of the atmosphere than the humid areas or rainy season is much lighter. Corrosion of the outer wall of the pressure vessel is often produced in a wet state and easy to accumulate moisture or moisture parts. In the container and the contact surface of the support, the container and the ground contact part is easy to produce corrosion. The corrosion of the inner wall of the container is mainly due to the working medium or it contains the role of impurities and generated. Generally speaking, the working medium has obvious corrosive effect of the container, design are taken to prevent corrosion measures, such as the choice of corrosion-resistant materials, surface treatment or surface coating, lining the inner wall, etc.. Therefore, the corrosion of the inner wall of these containers is often caused by the destruction
12 types of heat exchanger working principles - Bookmarked!
2022 / 09 / 21
1.Casing type heat exchanger Principle: Each section of the casing is called "a course", the course of the inner tube (heat transfer tube) to borrow U-shaped elbow tube, while the outer tube with a short tube connected in turn into a row, fixed in the bracket. Heat is transferred from one fluid to another through the walls of the inner tube. Typically, the hot fluid (fluid A) is introduced from the top, while the cold fluid (fluid B) is introduced from the bottom. The ends of the outer tube of the casing are connected to the inner tube by welding or flanging. The inner tube is mostly flanged to the U-shaped elbow tube to facilitate the cleaning and addition or removal of heat transfer tubes. The effective length of each heat transfer tube is taken from 4 to 7 metres. This heat exchanger heat transfer area of up to 18 square metres, so suitable for small capacity heat transfer. Advantages: simple structure, can withstand high pressure. The heat transfer area can be increased or reduced according to needs, easy to apply. Disadvantages: more pipe ends, easy to leak. Large footprint, unit heat transfer surface consumption of metal 2.Floating head type heat exchanger Principle: floating head type heat exchanger floating head end structure by the cylinder, the outer head cover side flange, floating head tube plate, hook ring, floating head cover, outer head cover and silk hole, steel ring and other components Advantages: When there is a temperature difference between the heat exchanger tube and the shell, the shell or the heat exchanger tube expands without constraining each other and does not produce temperature stress. Tube bundle can be withdrawn from the shell, easy to clean the tube and between the tubes Disadvantages: more complex structure, large amount of material used, high cost. Floating head cover and floating tube plate between if the seal is not tight, the occurrence of internal leakage, resu
The concepts of absolute, gauge and vacuum
2022 / 09 / 13
Pressure is one of the most commonly used words in today's society, but this pressure is not the same pressure. For industrial processes, chemical operators and instrumentation maintenance personnel need to understand the concept of different pressures. The concepts of absolute pressure, gauge pressure and vacuum Absolute pressure, or true pressure, is the pressure calculated with absolute zero pressure as a starting point. or vacuum as the starting point for the calculation of the pressure, absolute pressure, or absolute pressure for short. The gauge pressure, or gauge pressure for short, is the pressure calculated using the local atmospheric pressure at the time as a starting point. When the pressure of the system being measured is equal to the local atmospheric pressure at the time, the pointer of the pressure gauge points to zero. That is, the gauge pressure is zero. Vacuum, when the absolute pressure of the measured system is less than the local atmospheric pressure, the difference between the local atmospheric pressure and the absolute pressure of the system is called the vacuum degree. The pressure measuring instrument used at this time is called a vacuum gauge. The relationship between absolute pressure, gauge pressure and vacuum is shown in the diagram The relationship between absolute pressure, gauge pressure and vacuum A- Pressure at the pressure measurement point is less than the prevailing atmospheric pressure B- B- pressure at the pressure measurement point is greater than the prevailing atmospheric pressure Pressure gauge Difference between gauge pressure, absolute pressure and differential pressure absolute pressure is the absolute pressure (the engineeri
The most complete Q&A on heat exchanger technology, it's really all in the collection!
2022 / 09 / 02
1. How is heat exchanger equipment classified? A: According to the "Petrochemical Corporation Equipment Classification Catalogue" can be divided into. (1) shell and tube heat exchanger (2) Casing-type heat exchanger (3) water immersion heat exchanger (4) spray type heat exchanger (5) rotary (snake tube) type heat exchanger (6) Plate heat exchanger (7) Plate and fin heat exchanger (8) Tube and fin heat exchanger (9) Waste heat boiler (10) Other 2. How does heat transfer take place in a heat exchanger? A: In the most common inter-wall heat exchangers, there are two main types of heat transfer: conduction and convection. The thermal fluid is first convected to the heat transfer to one side of the tube wall, and then the heat transfer from one side of the tube wall to the other side by conduction, and finally the other side of the tube wall to convect to the heat transfer to the cold fluid, thus completing the heat transfer process of the heat exchanger. 3. What is the effect of media flow rate on heat transfer? A: The greater the flow rate of the medium in the heat exchanger, the greater the heat transfer coefficient. Therefore, improve the medium in the heat exchanger flow rate can greatly improve the heat transfer effect, but the negative impact of increasing the flow rate is to increase the pressure drop through the heat exchanger, increasing the energy consumption of the pump, so to have a certain appropriate range. 4. What is the effect of the heat exchanger tube surface structure on the heat transfer effect? A: The use of specially designed heat exchanger tube surface structure, such as finned tubes, nailhead tubes, threaded tubes, etc., on the one hand, to increase the heat transfer area, on the other hand, the role of special surface disturbance greatly increases the degree of fluid turbulence outside the tube, both aspects can improve the over
Have you encountered any of the most common problems in distillation column operation?
2022 / 08 / 23
Distillation technology is widely used in the production of various chemicals, and distillation columns in chemical plants is also one of the more common devices. In practice, we will encounter such and such problems, today we will give you a summary of the distillation operation of a summary of several common problems, see you have encountered? In the future encounter problems, can refer to the method given by the editor Yo ~ ~ ~ 01 Distillation operation how to adjust the pressure of the tower? What are the factors affecting the change in tower pressure? The operation of any distillation tower, should be controlled within the specified indicators, to adjust other parameters accordingly. Tower pressure fluctuations are too large, it will destroy the whole tower of material balance and gas-liquid balance, so that the product does not reach the required quality. Therefore, many distillation towers have their specific measures to ensure that the tower pressure is stable within the appropriate range. For the pressurised tower tower pressure, there are two main methods of adjustment. 1. tower condenser for the top of the condenser, tower pressure is generally dependent on the amount of gas phase extraction to regulate. In other conditions remain unchanged, the gas phase extraction volume increases, the tower pressure decreases; the gas phase extraction volume decreases, the tower pressure increases. 2. tower top condenser for the full condenser, tower pressure is mostly by the size of the cold dose to adjust, that is, equivalent to adjust the temperature of the reflux liquid. Under the premise of other conditions remain unchanged, increase the cold dose, the temperature of the reflux liquid is reduced, the tower pressure is reduced; if the cold dose is reduced, the temperature of the reflux liquid rises, the tower pressure rises. For the pressure control of the reduced pressure distill
Which three pressure tests are required for floating head heat exchangers?
2022 / 08 / 17
Floating-head heat exchanger, kettle-type reboiler (floating-head tube bundle) pressure test sequence: a) Test pressure ring and floating head special pressure test tool for the head test pressure, the kettle type reboiler should be equipped with a special shell for head test pressure; b) Pipe test pressure; c) Shell test pressure. When the shell test pressure is equal to or higher than the test pressure of the tube process, the shell process should be first test pressure, after the test pressure of the tube process, and finally the shell process for test pressure. ① shell process test pressure: remove the tube box, outer head cover and floating head cover, install the test pressure ring at both ends, pressurize the shell process, check the connection parts of the shell and heat exchanger tube and tube plate. ②Tube-process test pressure: remove the test pressure ring, install the tube box and floating head cover, pressurize the tube process, check the seal at the flange of the tube box and the flange of the floating head cover and related parts. ③ Shell process test pressure: install the outer head cover, pressurize the shell process, check the pipe box flange seal and the outer head cover flange seal and related parts. When the test pressure of the pipe process is higher than the test pressure of the shell process, the test pressure of the pipe bundle will be carried out first, then the test pressure of the pipe process, and finally the test pressure of the shell process. ①Pipe bundle test pressure: pull out the pipe bundle, install the test pressure ring, pipe box and floating head cover, pressurize the pipe bundle, check the heat exchanger tube and pipe plate joint parts and floating head cover flange seal and other relevant parts.
Chemical reactor equipment cleaning methods
2022 / 08 / 11
Reactor equipment scaling for stirred reactors, has the following major effects. 1. Low production efficiency Due to the low performance of heat exchange, resulting in an increase in reaction time. It is important to note that even a thin layer of dirt can significantly reduce the heat transfer performance. 2. Reduction in product quality Problems such as dirt falling off the inner wall of the kettle, mixing of residues from the previous kettle, longer reaction times due to dirt adhesion and consequent formation of foreign reactants, discolouration of the product and uneven quality of the product in each kettle. Not only for small quantities of multi-species reactors, but also for continuous reactors, once such problems occur, the losses are enormous. 3. Increase in corrosion This affects the service life of the reactor itself. The "corrosion" referred to here is the formation of a local battery effect in the gap between the dirt and the wall surface of the kettle due to the concentration of liquid, which results in the formation of pore corrosion and stress corrosion on the dirt attachment surface, thus reducing the durability of the reactor. 4. Other. If the thermometer inserted into the reactor is fouled, this causes a delay in temperature measurement (Time Lag), which affects the overall reaction control system. Dirt on the mechanical shaft seal in the kettle may lead to leakage of liquid from the kettle or even to the risk of gas ejection from the kettle. Dirt in the bearings and rotating parts of the kettle can cause excessive vibration in the mixer and damage to the mechanical shaft seal, which can affect the overall safety of the production unit. Cleaning methods for reactors There are mainly three methods: mechanical cleaning, chemical cleaning and manual cleaning
Safety measures for confined space operations in chemical equipment
2022 / 08 / 09
Chemical production process is relatively complex, chemical equipment towers, kettles, tanks, tanks, boilers, pressure vessels and pipelines most of the special equipment, and these chemical equipment operating in contact with the media, most of them are toxic, harmful, flammable, explosive, strong alkali strong acidic substances, in the chemical process operation process and in the high temperature, high pressure environment. Therefore, there are many unsafe factors in the process of overhauling restricted spaces in chemical equipment. To ensure the safety of workers in chemical equipment, it is necessary to strictly implement the relevant safety regulations and seriously implement safety measures for restricted space operations. The person in charge of site safety at the base unit and construction unit should provide the necessary safety education to site guardians and operators. This should include at least the relevant safety rules and regulations; the possible dangers and hazards and the safety measures to be taken; the use of personal protective equipment and precautions; knowledge of accident prevention and self-rescue; and the experience and lessons learned from relevant accidents. Safety emergency plans or safety measures should be formulated, including escape routes and rescue methods in case of emergencies, contact signals agreed between the guardian and the operator, life-saving facilities and fire-fighting equipment to be equipped on site, etc. Site personnel should be familiar with the contents of the emergency plan and be equipped with a certain number of emergency rescue appliances (including air breathing apparatus, air-supplied protective masks, lifelines, etc.) and fire-fighting equipment in accordance with the regulations at the site outside the confined space. There should be no obstructions inside or outside the entrances and exits to ensure that they are unobstructed, allowing easy access and rescue evacuation.
Exploring the safe handling of chemical equipment during maintenance
2022 / 08 / 05
Achieve chemical safety overhaul not only to ensure the safety of overhaul operations, to prevent major accidents, to protect the safety and health of workers: but also to promote overhaul operations on time, according to quality, according to the amount of completion, to ensure the quality of equipment overhaul operations, so that the equipment into operation after stable operation, high operating rate, to eliminate accidents and pollution of the environment, to create good conditions for safe production. To this end, it is important to do a good job in the safety and technical processing of parking before and after overhaul. 1, before the overhaul parking safety technology processing Parking program once determined, should be strictly in accordance with the parking program to determine the parking time, steps, process changes, as well as to confirm the parking operation sequence table, organized, orderly. The smoothness of the plant stopping phase will, on the one hand, affect the safety of production and, on the other hand, the safety of plant maintenance operations and the quality of safety maintenance. The main safety techniques for stopping the plant are as follows: 1.1 Stop the plant in strict accordance with the scheduled stopping programme. Stop the plant in strict accordance with the stopping programme by maintaining close contact with the upstream and downstream processes and relevant sections (e.g. boiler room, distribution room, etc.). 1.2 Pressure relief should be slow and moderate Pressure relief should be carried out slowly and the equipment should not be dismantled until the pressure has been relieved. 1.3 The material in the equipment must be emptied and disposed of. Before discharging residual materials, the discharge port must be inspected and no flammable, explosive, toxic or corrosive materials should be discharged arbitrarily into the sewer or onto the ground, but the residual materials in the equipment or piping should be discharged to a desi
The main manufacturing process of pressure vessels
2022 / 08 / 01
The manufacturing process of pressure vessel includes preparation of raw materials, scribing, undercutting, bending, forming, edge processing, assembly, welding, inspection, etc. Preparation of raw materials Before scribing the steel, the steel should first be pretreated. The pre-treatment of steel refers to the purification, straightening and application of protective primer to materials such as steel plates, pipes and sections. Decontamination is the removal of rust, oxidation, oil and welding slag from the surface of steel plates, pipes and sections before scribing, cutting and welding and after cutting, beveling, forming and welding. Straightening is the process of correcting the deformation of steel produced during transport, lifting or storage. Applying protective paint is mainly to improve the corrosion resistance of steel, prevent oxidation and prolong the life of parts and equipment by applying a protective coating to the surface. Our company is engaged in the development of various types of automation control systems and automation projects in various industries, the development and production of chemical equipment (with D1,D2 pressure vessel production license), the technical team has accumulated a wealth of technology and experience in automation control, is a focus on the development of automation control systems, automation projects and technical services of technology-based enterprises. Automation configuration tight automatic emergency cut-off interlock device, and should be equipped with light and sound alarm system. Scribing Scribing is the first process of the pressure vessel manufacturing process, it directly determines the dimensional accuracy and geometric shape accuracy of the parts after forming, and has a great impact on the subsequent grouping and welding process. Scribing is in the raw material or by the initial processing of the billet scribed out of the material line, processing lin
What sub-sectors are included in the fine chemical industry
2022 / 07 / 29
In recent years, various countries around the world, especially developed industrial countries are the development of fine chemical products as one of the key development strategies for upgrading and adjusting the structure of the traditional chemical industry, its chemical industry are to "diversification" and "refinement" of the direction of development. With the further development of social economy, the demand for electronic, automobile, mechanical industry, new materials for construction, new energy and new environmental protection materials will rise further, and electronic and information chemicals, surface engineering chemicals, pharmaceutical chemicals, etc. will be further developed, and the global market scale of fine chemicals will keep growing faster than the traditional chemical industry. 01 Fine chemicals Fine chemicals are chemicals with high technical density, high added value and high purity that can enhance or give a (class) of products with specific functions or possess specific functions in small quantities. In 1986, the former Ministry of Chemical Industry divided fine chemicals into 11 categories: (1) pesticides; (2) dyes; (3) coatings (including paints and inks); (4) pigments; (5) reagents and high-purity substances; (6) chemicals for information (including photographic materials, magnetic materials and other chemicals that can accept electromagnetic waves); (7) food and feed additives; (8) adhesives; (9) catalysts and (10) chemicals (APIs) and chemicals for daily use (produced by chemical systems); (11) functional polymer materials in polymers (including functional films, polarizing materials, etc.). With the development of the national economy, the development and application fields of fine chemicals will continue to develop and new categories will be added. Fine chemicals have the following characteristics. (1) A wide range of products and applications Internationall
Hydrogen peroxide storage tank material selection applications and considerations
2022 / 07 / 25
Hydrogen peroxide has a strong oxidizing and corrosive, although itself is not combustible, but the oxygen generated by decomposition can strongly fuel combustion, and flammable materials, organic materials in contact with the explosion will be caused by impact, friction and vibration when there is a risk of combustion and explosion. So how to choose the material of hydrogen peroxide storage tank? Storage of hydrogen peroxide need to pay attention to what matters? The following I will take you to understand the knowledge of hydrogen peroxide storage tanks. Hydrogen peroxide storage tank Chemical name for hydrogen peroxide, is another hydrogen oxide in addition to water. Slightly more viscous than water, it is chemically unstable and is generally stored in the form of a 30% or 60% aqueous solution. Hydrogen peroxide is highly oxidising and weakly acidic. In GB1616-2003 "Industrial Hydrogen Peroxide" it is stipulated that dark plastic polyethylene storage tanks are used for storage below 50% mass fraction and for 70% mass fraction, passivated stainless steel storage tank material is used. Storage and transportation matters of hydrogen peroxide storage tank. 1. Packaging and storage and transportation of hydrogen peroxide should be made of plastic storage tank material or stainless steel storage tank material, and its upper cover should be equipped with dustproof exhaust port to safely release the possible gas and avoid the explosion. 2. Hydrogen peroxide is a strong oxidising agent and corrosive, so care should be taken to paint the storage container with the "oxidising agent mark" and "corrosive goods mark" specified in GB190, as well as the "upward" mark specified in GB191. sign". 3. Hydrogen peroxide storage tanks should be stored in a cool, ventilated warehouse; in the storage and transportation process, avoid direct sunlight or heat. 4. Do not mix with alkalis, metals and met
On the requirements of welding skills for stainless steel pressure vessels
2022 / 07 / 22
The importance of welding work Pressure vessels are explosive hazards and when an explosion occurs it can be catastrophic. It has been proven that most of the pressure vessel leaks and explosions originate from the fracture of the welded joints. Therefore, welding quality is the key to ensure the safety and reliability of pressure vessels. Welding requirements The welding requirements for stainless steel pressure vessels are as follows. 1. The beveled surface of the welded joint must be constructed by mechanical means. 2. Welding materials must be de-hydrogenated and strictly cleaned. 3. The operator who undertakes the assembly of the welded joint must wear clean gloves and must not touch the bevel and the area near its sides. 4. Welding should be carried out immediately after the cleaning of the welded joint is completed. 5. The purity of argon and helium for welding should not be less than 99.99% and the dew point should not be higher than minus 50°C. 6. Before welding titanium, the bevel and the 25mm range on both sides should be subjected to strict mechanical cleaning and degreasing treatment. Measures should be taken to prevent bevel contamination during the welding process. 7. Effective measures should be taken to avoid the mutual dissolution of steel and titanium during welding. When required by the drawing, iron contamination tests should be done. 8. In the welding process, after each weld, the surface colour of the weld layer must be checked, the surface colour of the weld and heat affected zone is silvery white or golden yellow. The surface colour is not qualified, all should be removed, and then re-welded. Surface colour inspection should refer to the provisions of the relevant standards. 9. Inert gas double-sided protection arc welding or plasma welding must be used. The connection between th
The use of methanol recovery tower know-how and process
2022 / 07 / 21
Different recycling tower use know-how, people generally believe that methanol recovery tower is mainly in the chemical industry, in fact, not so, in many industries in the recovery tower have played a great material recycling, because the material itself is mainly stainless steel 304 models to produce, and the structure can be customized according to the requirements of the industry, and the built-in aspects of the recovery tower will also have a certain shelf life All in all, the recycling tower is too widely used. Also because of the simple operation of the structure, as long as it is according to the manual drawings to operate without problems, as long as in the normal operation of the situation, there will be no interruptions stop. In addition, in the methanol recovery tower operation to have reasonable guidance, do not use without the actual operation of the situation, so that not only the equipment itself has an impact on the other connected equipment also has a great stimulus, in the resources recovered will also produce the corresponding chemical reaction, not the same methanol recovery tower is a great difference in material, the internal structure of the change is more conducive to the play of the equipment itself The methanol recovery tower is made of different materials and has a large gap in terms of internal structure. Methanol recovery tower waste gas out of the production line temperature is high, in 70 to 80 degrees, may contain a small amount of solid impurities, so first filter to remove impurities, and then into an absorption section, in this absorption section using a solvent concentration of fifteen to twenty percent of the mixed aqueous solution in an absorption section to absorb waste gas, absorption of the absorbent solution according to the material constant calculation, part sent to distillation recovery, the rest continue to cycle. Due to the high concentration
Some reasons for corrosion of plate heat exchanger
2022 / 07 / 19
Under the scale corrosion is a special local corrosion phenomenon. The mechanism of corrosion under the scale for when the various types of impurities in the water in the defective parts of the heat exchanger scaling, will form a special environment under the scale lack of oxygen, scale outside the oxygen-rich. In this environment the formation of low-potential ferrite as the anode, high-potential iron carbide as the cathode of the corrosion battery, which leads to the occurrence of corrosion under the scale heat exchanger. Depending on the type of deposit, there are four forms of inorganic salt scale, fouling, biological slime and material deposition. Plate heat exchanger common corrosion patterns are under the scale corrosion, chloride ion corrosion, erosion corrosion, stress corrosion and other types. 1. Under the scale corrosion Under the scale corrosion is a special local corrosion phenomenon. The mechanism of corrosion under the scale for when the various types of impurities in the water in the heat exchanger defective parts of the scaling, will form a scale under the lack of oxygen, scale outside the special environment rich in oxygen. In this environment the formation of low-potential ferrite as the anode, high-potential iron carbide as the cathode of the corrosion battery, which leads to the occurrence of corrosion under the scale heat exchanger. Depending on the type of deposit, there are four forms of inorganic salt scale, fouling, biological slime and material deposits. Sub-scale corrosion not only affects the flow efficiency of the heat exchange medium as well as the heat transfer efficiency, but also leads to the corrosion failure of the equipment, which has a huge impact on the work of the heat exchanger. 2. chloride ion corrosion (1) circulation medium temperature: in the media containing chloride ion conditions, Cl- corrosion cracking sensitivity increases with
2022 / 07 / 18
Plate heat exchanger plate as the most important heat transfer link of the plate exchange system, the quality of the metal material directly affects the service life of the equipment. So in the parameters selection design, plate exchange manufacturers will be strictly in accordance with the parameters provided by the user to repeat the design, the flow through the medium will also confirm its physical properties to ensure the selection of the corresponding material to avoid leakage! For different media and what kind of plate should be selected? Today in the three heart to take you to understand the following. Water Common tap water, pure water in general we choose stainless steel 304 material; then if it is well water, river water, closed loop water and other media, we have to consider using 316L, because the composition of these media are more complex, 304 corrosion resistance is not as good as 316L. Then if it is seawater, then we must give priority to pure titanium GR1 material, seawater chloride ion concentration is relatively high, titanium material can meet the requirements. If you consider the cost performance, super stainless steel 254SMO can also be used in 316L above the chloride ion environment. Acid Dilute sulphuric acid concentration of less than 10%, the temperature is less than 50 ℃, you can use stainless steel 316L material, if greater than then need to use super stainless steel 904L, 254SMO or Hastelloy C276 and other materials. The same principle applies to phosphoric and hydrochloric acids. Steam Steam conditions are more common, generally the South choose to use stainless steel 316L material, because the temperature of steam is generally above 120 ℃. The North will choose 304 material in consideration of the cost of the customer, but over time, the plate heat exchanger plate has the possibility of deformation Oil General equipment lubricating oil, hydraulic oil are
Precautions before installation of tubular heat exchanger
2022 / 07 / 15
The column tube heat exchanger is a heat exchanger with simple structure, high heat transfer efficiency and strong adaptability (can be used at high temperature, low temperature, high pressure or low pressure). The main structure of the invention is a bundle of multiple parallel arranged tubes in a cylindrical shell with flanges at both ends and end caps connected to the shell by bolts, and the shell and end caps with small flanges for the import and export of two media respectively to facilitate the connection of the corresponding pipes. There is a lot of knowledge about heat exchangers, today we will talk about the preparation work before the installation of tubular heat exchangers. 1.Construction site preparation According to the construction site plan layout, other aspects of the site for the actual survey, measurement to determine the transport route, parking location, unloading location and the surrounding environment whether to affect the transport and installation of equipment, and coordination with relevant parties to meet the requirements of lifting conditions. Roads are kept level and firm so that vehicles can pass smoothly and the heat exchanger can be transported safely to the site and the installation width should meet the installation requirements. 2. Acceptance of heat exchanger equipment Carefully check equipment drawings, including model, quality, geometry, orifice orientation, technical features, etc. Check the factory certificate of conformity, instructions, quality assurance and other technical documents, check whether the equipment is damaged or missing (including gaskets, bolts, washers, accessories, etc.). Make inspection and acceptance records. 3. Foundation acceptance Before installation, the foundation of the heat exchanger should be carefully checked and accepted. Foundation construction units should be submitted to the quality certif
2022 / 07 / 14
Two pharmaceutical intermediates wastewater treatment cases Pharmaceutical intermediates are chemical raw materials or chemical products required for drug production, and the pharmaceutical intermediates required for different drugs are different. So, will the industrial wastewater discharged from different pharmaceutical intermediates be similar? It is even that the same method can be used to treat our pharmaceutical intermediate wastewater. Pharmaceutical intermediate wastewater is a very typical and difficult to treat industrial wastewater, of which high concentration, poor biochemical properties and high salt content are important labels attached to its head, and it is impossible to get rid of this label. And the two pharmaceutical intermediate wastewater is the same have this write characteristics, but their products are not the same, the discharge of COD concentration and pollutants will be different. ① A pharmaceutical intermediate wastewater has a volume of 120m3/d, which comes from process wastewater, waste gas treatment wastewater, equipment flushing wastewater, etc.. The COD concentration of one of the process wastewater is more than 30,000mg/L, which needs to be done to include the discharge standard of the park - COD<500mg/L. ② The other pharmaceutical intermediate wastewater has a volume of 300m3/d, the source is similar, but its process wastewater COD concentration will be higher, exceeding 60,000mg/L, and the discharge standard is the same. In fact, they both achieve a stable COD concentration below 500mg/L, using the same method, pre-treatment (iron carbon micro-electrolysis and Fenton oxidation) + biochemical treatment + deep treatment. Treatment method of pharmaceutical intermediate wastewater The pretreatment process is required to remove the hard-to-degrade pollutants from the pharmaceutical intermediate wastewater and reduce the concentration of COD, which actually reaches the tolerable ra
Stainless steel reactor installation precautions
2022 / 07 / 13
Stainless steel reactor installation details precautions, stainless steel reactor application areas throughout all walks of life, so its use is not the same, but as a production equipment, some of its precautions or can not be ignored, I hope to reasonably install stainless steel reactor, so that it maximizes the service for user friends. High pressure stainless steel reactor should be placed indoors. When equipped with multiple high-pressure kettles, they should be placed separately. Each operation room should have an exit directly to the outdoors or channel, and should ensure that the equipment location is well ventilated. The stainless steel reactor is an integrated reaction vessel. The stainless steel reactor should be placed indoors and each operating room should have direct access to the outdoors or to a passageway, ensuring that the equipment is well ventilated. The following are 8 points to note about the installation of stainless steel reactors. Stainless steel reactor installation points 1. When installing the kettle cover, prevent the kettle body and kettle cover from bumping against each other. Put the cover carefully on the kettle body according to the fixed immobile position, and when twisting the main nut, it is indispensable to twist it gradually by diagonal and symmetrical times. Stainless steel reactor installation points 2, positive and negative nut connection, only allowed to rotate the positive and negative nut, two circular arc syncline can not be relative rotation, reactor all nut pattern connection parts have installation, to be coated with lubricant. Stainless steel reactor installation points 3, needle type valve system line seal, only need to gently turn the valve needle, pressure can not be divided cover, you can achieve a better seal actual effect. Stainless steel reactor installation points 4, the reactor with the hand to move the kettle on
Storage tank welding tips are all here
2022 / 07 / 11
Storage tank welding project is more common, especially large storage tank welding requirements are more stringent, here is a brief introduction to the operation process and welding skills of tank welding project with large vertical storage tank as an example. Vertical cylindrical storage tank is a vertical tank composed of a circular tank wall with the central axis perpendicular to the ground, a flat disc-shaped tank bottom and different forms of tank roof, a vertical tank, accessories (such as ladders, platforms, etc.) and accessories (such as liquid level measurement, fire fighting facilities, etc.). General nominal volume greater than 100m? storage tanks called large storage tanks, the standard used: GB50128-2005. Second, the storage tank foundation Tank foundation is the place where the tank is placed, requiring strong, solid; it not only affects the aesthetics, and will lead to uneven stresses on the tank. Tank foundation is a civil construction category, must be in accordance with the foundation construction drawings and technical standards requirements. Tank installation must be checked before the foundation of the tank, qualified before installation. Three, prefabricated assembly For large vertical storage tank manufacturing, general division, segmentation and combination of prefabrication, and then assembly, to improve production efficiency is very helpful, the first should be the construction of storage tanks selected materials and accessories for review, prefabricated assembly includes: bottom plate, wall plate, floating roof and internal floating roof, fixed roof top plate, wind ring, strengthening ring, wrapped edge angle steel and other components, parts. Fourth, the welding of storage tanks 1, welding process assessment For the first use of steel, according to the steel number, plate thickness, welding method
What is difficult about laser cutting thick plates?
2022 / 07 / 08
What is difficult about laser cutting thick plates? 01 Laser cutting machines are no longer a problem for cutting steel plates up to 10mm thick. But if you want to cut thicker plates, often require the help of high power lasers with an output power of more than 5kW, and the quality of the cut is also significantly reduced. Due to the high cost of high power laser equipment, the output laser pattern is also not conducive to laser cutting, so the traditional laser cutting method in cutting thick plate, does not have the advantage. The following technical difficulties exist in the cutting of thick metal plates. The quasi-steady combustion process is difficult to maintain The actual cutting process of the metal laser cutting machine is limited in the thickness of the plate that can be cut through, which is closely related to the fact that the cutting front iron cannot be burned steadily. For the combustion process to be sustainable, the temperature at the top of the cut must reach the ignition point. The energy released by the iron-oxygen combustion reaction alone does not actually ensure that the combustion process can be sustained. On the one hand, this is due to the fact that the slit is continuously cooled by the oxygen stream emitted from the nozzle, which reduces the temperature at the cutting front. On the other hand, the ferrous oxide layer formed by combustion covers the surface of the workpiece and hinders the diffusion of oxygen, and the combustion process will be extinguished when the concentration of oxygen is reduced to a certain level. When laser cutting with a conventional convergent beam, the laser beam acts on a small area of the surface and, due to the high laser power density, not only does the workpiece surface temperature reach the combustion point in the area of laser radiation, but a wider area reaches the combustion point temperature due to heat transfer. An
Pressure vessel installation process
2022 / 07 / 06
Personnel All personnel involved in the construction work (heavy lifters, welders, electricians) must be licensed and all construction personnel involved in the installation of pressure vessels should be familiar with this procedure and the relevant drawings and specifications. Prerequisites 1. Technical data The construction drawings are complete and the technical personnel in charge of the construction have made a drawing handover to the construction personnel; the construction personnel are familiar with the content of the construction drawings. Construction personnel have been familiar with the content of the construction procedures. Construction record forms are available. The local special equipment safety supervision and management department is informed in writing before construction, and can be constructed after being informed. 2. Working environment requirements The civil foundations have met the requirements and have been accepted as acceptable, foundation handover procedures have been carried out, underground works near the foundations have been completed and the site has been levelled and hardened. Temporary roads for construction and transportation have been renovated to ensure smooth transportation. Lighting and electrical equipment and materials for construction are complete to meet the construction requirements. Lifting equipment for installation has arrived. 3. Construction preparation Familiarisation with drawings and relevant information, mastering technical parameters of equipment and technical requirements for installation, and understanding environmental conditions for equipment installation. Determining technical measures and construction methods according to construction procedures. Safety technical briefing for construction personnel participating in pressure vessel installation to ensure that pressure vessel installation
How to effectively prevent the emergence of gas holes in argon arc welding?
2022 / 07 / 05
Argon arc welding process often appear porous, today we introduce several reasons and solutions for the appearance of porosity. The reason for the occurrence of pores (1) the base material is not clean; bevel edge cleaning is not clean. (2) The composition and properties of the welding material used and the base material have a large variability. (3) Welding shielding gas problems. (a) Insufficient pressure of argon gas in the cylinder. (b) welding gas flow rate adjustment is too large. c) There is a leak in the gas feed tube. d) argon gas purity is not enough, resulting in harmful gases mixed into the melt pool. e) The welding arc is too long, causing the effective distance of the protective gas shield to be insufficient. f) The tungsten electrode is stretched out too long, resulting in the effective distance of the protective gas cover being insufficient. g) The tungsten electrode rolling head or rolling head casing is burnt by the arc, resulting in a disturbed protective airflow. h) The air outlet of the torch is blocked by a foreign object and the airflow is not smooth, resulting in a reduced flow of protective gas. (i) Improper wind protection measures, such as: the welding site has a wind through the hall, destroying the protective airflow cover. (4) Welding operation problems. a) The angle of the welding torch is too large. (b) operation, with the control button of the argon arc welding torch, not in the welding before the first gas, the arc caused by the gas flow out of the moment too large. (5) Problems with the welding process. a) Welding speed is too fast. b) Incorrect arc extinguishing method. c) Improper welding current. Preventive measures
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