What Are the Different Types of Centrifuge?
A centrifuge is a machine that uses centrifugal force to separate components of liquid and solid particles or a mixture of liquid and liquid. Centrifuges are mainly used to separate solid particles from liquids in suspensions, or to separate two liquids of different densities in emulsions that are incompatible with each other (such as separating cream from milk); it can also be used to remove Liquids in wet solids, such as washing clothes to dry clothes with a washing machine; special ultra-speed tube separators can also separate gas mixtures of different densities; using solid particles of different densities or particle sizes with different sedimentation speeds in the liquid, and some sedimentation Centrifuges can also classify solid particles by density or particle size.
- Chinese name
- Centrifuge
- Foreign name
- centrifugal machine
- Classification
- Filter centrifuges and sedimentation centrifuges
- Scope of application
- Chemical, petroleum, food, pharmaceutical
- A centrifuge is a machine that uses centrifugal force to separate components of liquid and solid particles or a mixture of liquid and liquid. Centrifuges are mainly used to separate solid particles from liquids in suspensions, or to separate two liquids of different densities in emulsions that are incompatible with each other (such as separating cream from milk); it can also be used to remove Liquids in wet solids, such as washing clothes to dry clothes with a washing machine; special ultra-speed tube separators can also separate gas mixtures of different densities; using solid particles of different densities or particle sizes with different sedimentation speeds in the liquid, and some sedimentation Centrifuges can also classify solid particles by density or particle size.
Centrifuge classification
- A centrifuge is a machine that uses centrifugal force to accelerate the separation of different materials that need to be separated. Centrifuges are widely used in chemical, petroleum, food, pharmaceutical, mineral processing, coal, water treatment and shipbuilding sectors.
- The main principle of the filter centrifuge is to accelerate the liquid phase in the solid-liquid mixed liquid out of the drum through the centrifugal force generated by the high-speed centrifugal drum (with the appropriate filter material), and leave the solid phase in the drum. , To achieve the effect of separating solid and liquid, or commonly known as dehydration.
- The main principle of the sedimentation centrifuge is to accelerate the sedimentation speed of different specific gravity components (solid phase or liquid phase) in the mixed liquid by the strong centrifugal force generated by the high-speed rotation of the rotor, and separate the different sedimentation coefficients and buoyancy densities in the sample.
- Centrifuges are widely used in mineral processing, coal, water treatment and shipbuilding sectors.
- The selection of the centrifuge must be based on the size and concentration of solid particles in the suspension (or emulsion), the density difference between the solid and the liquid (or two liquids), the viscosity of the liquid, and the characteristics of the filter residue (or sediment). Refer to "Selection and Safe Use of Centrifuge [Selection Guide]".
Centrifuge price
- There is not much difference between domestic centrifuges and imported centrifuges, and the core technology of centrifuges has been mastered in China. The price difference between centrifuges of the same grade is not very large, and the main differences are in performance and configuration.
- The difference between the mainframes is that in terms of performance, centrifuges with refrigeration are much more expensive than ordinary ones, and some centrifuges also have heating functions. The more the control program, the higher the price of the centrifuge. The big difference is the configuration, and sometimes the price of the accessory is higher than the price of the host. When purchasing, please pay attention to the rotor (number and type) selected in addition to the main machine, plus the necessary centrifuge tubes, tube sleeves, special centrifuge bottles or blood bags. price.
Centrifuge industry status
- In 2012, due to the impact of the overall economic environment, the large-scale projects specializing in centrifuges did not show a booming trend. The overall market size was about 3.996 billion yuan, a year-on-year decline of about 2.5%. In terms of cooling capacity, the proportion of large-capacity centrifuge products in total sales has increased (Figures 4, 5, and 6).
- Today, with the further rise of domestic brands, the diversified pattern of centrifuges is becoming more and more obvious.
- In 2012, Johnson Controls York, Carrier, Trane, and McQuay had a market share of approximately 81.4%.
- This year, the centrifuge product market also has the following characteristics: First, investor confidence has been frustrated, and large projects have significantly decreased. Affected by the large environment, not only did the number of civilian projects drop sharply in 2012, but even government projects that have always been strong are not as good as in previous years. In the past, large orders in the fields of rail transit and aviation have rarely won bids this year. Second, the price war has intensified. In the past, the pricing power of centrifuge products was basically controlled by the hands of several major US-owned brands, and the price has remained at a relatively high level for many years.
- In order to change this pattern, some brands have lowered their shipping prices regardless of cost, and this sacrificed not only profit for the prosperity of the centrifuge market, but also more contribution to let the industry know more about the mystery of centrifuge products. Third, pay more attention to market segments. This year's brands have strengthened their penetration in the chemical, petroleum, food, pharmaceutical, coal, water treatment, and shipbuilding sectors, and competition in market segments has intensified significantly. In addition, the brand has successively introduced more economical and energy-efficient miniaturized centrifuge products. As the refrigeration capacity of miniaturized centrifuge products overlaps with screw machines, it has a certain impact on the screw machine product market, and its market recognition is gradually increasing.
- In terms of product promotion, this year's centrifuge brand adopted relatively high-profile and diversified publicity methods. At the beginning of 2012, Midea was the first to launch a falling film two-stage centrifugal chiller as the main model in 2012, and has obtained rich returns; Gree held a two-month 2012 national tour conference of new products from early March, including its Star product high-efficiency DC frequency conversion centrifuge; In 2012, Haier launched its self-developed air-cooled magnetic levitation product, with a unit's comprehensive energy efficiency ratio of up to 7, which is more than 50% energy saving than traditional units. Not only that, Haier also held a large-scale magnetic energy levitation centrifuge energy-saving application exchange meeting, allowing users, experts, and dealers to meet face-to-face; In addition, Johnson Controls York, Dun An, Carrier, McQuay, Trane, Dunham Bush, LG, Guangzhou Hitachi, Century Dongyuan and other brands have also stepped up promotion efforts through various forms. It is worth mentioning that Yantai Liaoyuan, which just entered the centrifuge camp in 2012, performed well. In addition, in the coming 2013, the entry of Guoxiang and other brands makes the competition in the centrifuge market more exciting! From a regional perspective, East China, South China, and North China are still the main markets for centrifuge products. After the decline of the South China and East China markets in 2011, the East China and South China markets continued to show a downward trend in 2012. The North China market continued to stabilize and rebound, and the Central China market maintained steady growth. After several years of high growth, the Southwest market showed a downward trend this year. . It is worth mentioning that due to the relatively low base, centrifuge products in the western and northeast regions have basically increased to a certain extent every year.
Centrifuge related products
- Three-foot centrifuge (speed 600-1200r / min)
- Various centrifuges (25 photos)
- Plate type centrifuge (speed 600-1200r / min)
- Desktop centrifuge (mostly used in laboratory \ speed 0-22000r / min) horizontal centrifuge (speed 870-6000r / min)
- Disc separator (speed 4000-10000r / min)
- Tube type high speed separator (rotation speed 30,000r / min)
Centrifuge principle
- When the suspension containing fine particles stands still, the suspended particles gradually sink due to the effect of the gravity field. The heavier the particles, the faster they sink, whereas the particles with a density lower than the liquid will float up. The speed at which particles move under the gravity field is related to the size, shape, and density of the particles, and also to the strength of the gravity field and the viscosity of the liquid. Particles the size of red blood cells, several micrometers in diameter, can be observed to settle under normal gravity.
- In addition, when the substance settles in the medium, it is accompanied by a diffusion phenomenon. Diffusion is unconditional absolute. Diffusion is inversely proportional to the mass of the substance, and the smaller the particles, the more severe the diffusion. The settlement is relative and conditional. It can only be moved by external force. The sedimentation is directly proportional to the weight of the object. The larger the particles, the faster the sedimentation. For particles smaller than a few microns, such as viruses or proteins, they are in a colloidal or semi-colloidal state in solution, and it is impossible to observe the sedimentation process using only gravity. Because the smaller the particles, the slower the sedimentation, and the more serious the diffusion phenomenon. Therefore, a strong centrifugal force needs to be generated by the centrifuge to force these particles to overcome the diffusion and settling movement.
- Centrifugation is to use the strong centrifugal force generated by the high-speed rotation of the centrifuge rotor to accelerate the sedimentation rate of particles in the liquid and separate the different sedimentation coefficients and buoyant density substances in the sample.
- Conversion between centrifugal force (g) and speed (rpm)
- The conversion formula between centrifugal force G and RPM is as follows:
- G = 1.11 × 10 ^ (-5) × R × (rpm) ^ 2
- Among them, G is the centrifugal force, which is generally expressed in multiples of g (gravitational acceleration).
- 10 ^ (-5) is the negative fifth power of 10, (rpm) ^ 2 the square of the speed, R is the radius, and the unit is centimeter.
- For example, a centrifugal radius of 10 cm and a rotation speed of 8000 RPM, the centrifugal force is:
- G = 1.11 * 10 5 * 10 * 8000 2 = 7104
- That is, the centrifugal force is 7104g.
- When the centrifugal force is 8000g, the speed should be: 8489, which is about 8500rpm.
Centrifuge classification criteria
- According to the separation factor Fr value
- The centrifuge can be divided into the following types:
- 1.Normal speed centrifuge
- Fr3500 (generally 600 ~ 1200), this kind of centrifuge has low speed and large diameter.
- 2.High-speed centrifuge
- Fr = 3500 ~ 50000, this kind of centrifuge has a high rotation speed. Generally, the diameter of the drum is small and the length is long.
- 3.Ultra high speed centrifuge
- Fr> 50000, because the rotation speed is very high (more than 50000r / min), the drum is made into a slender tube type.
- The separation factor Fr refers to the ratio of the centrifugal force that the material receives in the centrifugal force field to the gravity that the material receives in the gravity field.
- Divided by operation method
- The centrifuge can be divided into the following types:
- 1.Gap centrifuge
- Its feeding, separation, washing and slag discharge operations are all gap operations, and manual, gravity or mechanical methods are used to remove slag, such as three-legged and top-suspended centrifuges.
- 2.Continuous centrifuge
- The feeding, separation, washing, and slag discharge processes include gap automatic and continuous automatic.
- Divided by slag discharge method
- The centrifuge can be divided into the following types:
- 1.Scraper unloading centrifuge
- The process is indirect and the operation is automatic.
- 2.Piston pusher centrifuge
- The process is semi-continuous and the operation is automatic.
- 3.Screw unloading centrifuge
- The process is continuous and the operation is automatic.
- 4.Centrifugal unloading centrifuge
- The process is continuous and the operation is automatic.
- 5.Vibration discharge centrifuge
- The process is continuous and the operation is automatic.
- 6.Turn the unloading centrifuge
- The process is continuous and the operation is automatic.
- According to process use
- Centrifuges can be divided into: filter centrifuges, sedimentation centrifuges.
- Divided by the way of installation
- It can also be divided into vertical, horizontal, inclined, overhang, and three-legged.
- Divided into the following four according to national standards and market share
- 1.Tripod centrifuge
- 2.Horizontal spiral centrifuge
- 3. Disc type separator
- 4.Tube type separator
- Divided by
- 1.Sedimentation centrifuge
- 2.filter centrifuge
Centrifuge history development
- Industrial centrifuges were born in Europe. For example, in the middle of the 19th century, three-legged centrifuges for textile dewatering and top-hanging centrifuges for separating crystalline sugar from sugar factories. These earliest centrifuges were intermittently operated and manually discharged.
- Due to the improvement of the slag unloading mechanism, continuous operation centrifuges appeared in the 1930s, and intermittent operation centrifuges were also developed due to the realization of automatic control.
- Industrial centrifuges can be divided into filter centrifuges, sedimentation centrifuges and separators according to their structure and separation requirements.
- A centrifuge has a cylinder, called a rotating drum, that rotates at high speeds about its axis, usually driven by an electric motor. After the suspension (or emulsion) is added to the drum, it is quickly driven to rotate at the same speed as the drum, and the components are separated and discharged separately under the action of centrifugal force. Generally, the higher the drum speed, the better the separation effect.
- The centrifugal separator has two principles: centrifugal filtration and centrifugal sedimentation. Centrifugal filtration is the centrifugal pressure generated by the suspension under the centrifugal force field, which acts on the filter medium, making the liquid pass through the filter medium to become filtrate, and the solid particles are trapped on the surface of the filter medium to achieve liquid-solid separation; centrifugal sedimentation is used Suspension (or emulsion) components with different densities quickly settle down in the centrifugal force field to achieve liquid-solid (or liquid-liquid) separation.
- There is also a class of separators for experimental analysis, which can perform liquid clarification and solid particle enrichment, or liquid-liquid separation. These separators have different structural types that operate under normal pressure, vacuum, and freezing conditions.
- An important index for measuring the separation performance of a centrifugal separator is the separation factor. It indicates the ratio of the centrifugal force and gravity of the material to be separated in the drum. The larger the separation factor, the faster the separation, and the better the separation effect. The separation factor of industrial centrifugal separators is generally 100 to 20,000, the separation factor of super-speed tube separators can be as high as 62,000, and the separation factors of ultra-speed separators for analysis can be as high as 610,000. Another factor that determines the processing capacity of a centrifugal separator is the working area of the rotating drum, which has a large working area and a large processing capacity.
- The filtering centrifuge and the sedimentation centrifuge mainly rely on increasing the diameter of the rotating drum to enlarge the working surface on the circumference of the rotating drum; in addition to the peripheral wall of the rotating drum, the separator has additional working surfaces, such as the disc and chamber of a disc separator. The inner cylinder of the separator significantly increases the settlement work surface.
- In addition, the more detailed the solid particles in the suspension, the more difficult it is to separate, and the fine particles taken away from the filtrate or the separation solution will increase. In this case, the centrifuge needs a higher separation factor to effectively separate; When the viscosity of the liquid is large, the separation speed is slowed down; the density difference of each component of the suspension or emulsion is large, which is beneficial to the centrifugal sedimentation, and the centrifugal filtration of the suspension does not require the density difference of each component.
- The selection of the centrifugal separator must be based on the size and concentration of solid particles in the suspension (or emulsion), the density difference between the solid and liquid (or two liquids), the viscosity of the liquid, the characteristics of the filter residue (or sediment), and the requirements for separation A comprehensive analysis was carried out to meet the requirements for the moisture content of the filter residue (sediment) and the clarity of the filtrate (separation liquid), and which type of centrifuge was initially selected. Then according to the throughput and the automation requirements for the operation, the type and specifications of the centrifuge are determined, and finally verified by actual tests.
- In general, for suspensions containing particles larger than 0.01 mm, a filter centrifuge can be used. For suspensions with small particles or compressible deformation, a sedimentation centrifuge should be used. For suspensions with low solid content, small particles and When liquid clarity is required, a separator should be used.
- The future development trend of centrifugal separators will be to strengthen the separation performance, develop large-scale centrifugal separators, improve the slag unloading mechanism, add special and combined drum centrifuges, strengthen the study of separation theory and study the optimization control technology of centrifugal separation processes.
- Strengthening the separation performance includes increasing the rotating speed of the drum; adding new driving force during the centrifugal separation process; accelerating the speed of pushing the slag; increasing the length of the drum to prolong the time for centrifugal sedimentation and separation. The development of large-scale centrifugal separators is mainly to increase the diameter of the drum and use double-sided drums to increase the processing capacity to reduce equipment investment, energy consumption and maintenance costs for processing unit volume materials. In terms of theoretical research, it mainly studies the fluid flow condition and filter residue formation mechanism in the drum, and studies the calculation method of minimum resolution and processing capacity.
Centrifuge daily maintenance
- Drum
- Before running the centrifuge, you should cut off the power and release the brake of the centrifuge. You can try to rotate the drum by hand to see if there is any bite brake.
- Check for looseness and abnormality in other parts.
- Turn on the power and start in a clockwise direction (usually it takes about 40-60 seconds from the standstill to normal operation).
- Normally, each device must run empty for about 3 hours after arriving at the factory, and it can work without any abnormal conditions.
- The material should be placed as evenly as possible.
- It must be operated by a person, and the capacity must not exceed the rated capacity.
- It is strictly forbidden to run the machine at overspeed, so as not to affect the service life of the machine.
- After the machine is started, if there is any abnormal situation, it must be stopped and inspected. If necessary, it must be disassembled, washed and repaired.
- The centrifuge is running at high speed, so do not touch the drum with your body to prevent accidents.
- The mesh size of the filter cloth should be determined according to the size of the solid phase particles of the separated material, otherwise the separation effect will be affected. In addition, the filter cloth should be installed when the filter cloth is installed.
- The sealing ring is embedded in the drum sealing groove to prevent material from running in.
- To ensure the normal operation of the centrifuge, please refuel and maintain the rotating parts every 6 months. At the same time, check the running lubrication condition of the bearing, whether there is wear and tear; whether the components in the brake device are worn, and they should be replaced seriously; whether there is oil leakage in the bearing cover.
- After the machine is used, it should be cleaned properly to keep the machine tidy.
- Do not separate non-corrosion-resistant centrifuges from highly corrosive materials; otherwise, operate strictly in accordance with equipment requirements and regulations. Non-explosion-proof centrifuges must not be used in flammable and explosive situations.
- "Surge"
- The "surge" phenomenon often occurs in the centrifuges of refrigerated centrifugal units.
- The principle of a refrigeration centrifugal compressor is to compress a large molecular weight refrigerant into a small space by high-speed movement to compress it, and then condense it by lowering the temperature.
- The centrifugal chiller's energy adjustment method is to adjust the compression ratio by adjusting the angle of the high-speed rotating guide.
- When the cooling capacity is reduced, the work done by the guide is reduced, and the pressure of the compressed gas is similar to the pressure of the gas sucked into the compressor, resulting in mechanical forced vibration due to the backflow of gas. (Also called "surge") Surge can cause damage to mechanical parts.
- Development of centrifuges Centrifuges are instruments that separate samples and are widely used in fields such as biomedicine, petrochemicals, agriculture, food hygiene, etc. It uses the difference in precipitation speed of different substances in the centrifugal force field to achieve the analysis and separation of samples. Since the advent of the centrifuge, it has undergone changes of low speed, adjustment and overspeed, and its progress is mainly reflected in two aspects of centrifugal equipment and centrifugal technology, which complement each other. From the perspective of rotation speed, desktop centrifuges basically belong to the category of low-speed and high-speed centrifuges, so they have the technical characteristics of low-speed and high-speed centrifuges, and their structure is mainly composed of motor drive systems, refrigeration systems, mechanical systems, rotors, and system control. Compared with the floor centrifuge, the composition is only a little smaller in size and capacity. The development of universal desktop centrifuges has blurred the boundaries of low-speed, high-speed, micro- and large-capacity centrifuges, and many rotors provide researchers with a wide range of applications, becoming the first choice for scientific research laboratories, such as the ST2l from Sorvall, USA , Germany Heraeus new model Biofuge Stratos and so on.
Centrifuge aerospace applications
- In order to make the astronauts adapt to the huge acceleration of the rocket, the pressure is often simulated by a centrifuge. The pressure on the rocket is 8 times its own weight. If the astronauts are not trained, they may be crushed to death by huge pressure. Therefore, this training is a required course for astronauts.
Centrifuge practical application
- While the pharmaceutical production industry actively implements the GMP, the pharmaceutical equipment industry serving the pharmaceutical industry production has accordingly proposed guiding standards such as "General Rules for Pharmaceutical Equipment Complying with Quality Management Specifications for Pharmaceutical Production" to support the implementation of the specifications. The "compliance" proposed by the pharmaceutical equipment and the "implementation" of the pharmaceutical industry here means that the manufacturer and the user must not "perform" well if they do not "conform." Segmented links. Before discussing the issue of separation machinery products conforming to GMP, first understand the implementation of GMP in the pharmaceutical industry, and then discuss the issue of separation machinery compliance with GMP from the perspective of pharmaceutical equipment product compliance with GMP.
- Overview of GMP implementation in the pharmaceutical industry
- GMP originated from the United States FDA in 1962 in order to ensure the management of pharmaceutical production quality. The World Health Organization (WHO) introduced GMP to the world in 1969. China announced two GMP revisions in 1988. GMP really received widespread attention and was strengthened after the 1998 revision. GMP is very authoritative and restrictive in the pharmaceutical industry. Its enforcement is unprecedentedly unprecedented. Countries and enterprises have invested considerable energy, financial resources, material resources and manpower. Domestic enterprises that have not obtained the GMP certification for pharmaceuticals are Suspension; GMP-certified drug manufacturing enterprises, their facilities, equipment, process technology, etc. have been significantly updated, the production environment and production conditions have been completely changed, drug production safety and drug quality have been significantly improved, and drug production has been significantly improved. Enterprises can say that they have undergone reborn changes. From the perspective of the implementation of GMP, China's implementation of GMP is based on the "internationalization" model recommended by the World Health Organization WHO to guide countries to implement. CGMP implemented in developed countries such as the United States and Europe is also called dynamic drug production. There is still a large gap in quality management standards. The key is the difference between static process management and dynamic process management. As far as the implementation level of China's GMP is concerned, it can only indicate that China's pharmaceutical production management is in line with international standards. China's "GMP certification" in international trade still lacks the recognition of developed countries, so cGMP has become China's pharmaceutical production management. Turn to full process quality control and more effective implementation goals. The "Xinfu" incident that occurred in China in 2006 is a typical example of a pharmaceutical company not strictly implementing the sterilization procedures. Therefore, the GMP is urgently needed to deepen in the "fundamental" direction, and the country is also intensifying its rectification. The special supervision operation recovered 86 GMP certificates. Some enterprises were driven by interests. Borrowing equipment or instruments were used to deal with the evidence, and they were subsequently deactivated, which jeopardized the safety of public medication. The domestic Chinese medicine, veterinary medicine, and food industries are also adopting GMP management methods. It is reported that the State Food and Drug Administration has organized consideration for the formulation of cGMP. Therefore, during the "Eleventh Five-Year Plan" period, the pharmaceutical industry will face another step up in quality management.
- GMP compliance is the basic principle for the development of pharmaceutical equipment
- The production and production quality of pharmaceuticals are closely related to the factors of pharmaceutical equipment. The significance of GMP is to minimize human errors that affect the quality of pharmaceutical production, prevent all drug contamination, cross-contamination, and reduce the quality of pharmaceuticals, and ensure the safety and security of pharmaceuticals. The quality of the production is foolproof, so the development of pharmaceutical equipment must also comply with this principle.
- Pharmaceutical equipment, as a means of drug production, is also one of the contamination factors that cannot be ignored. The US FDA has launched an investigation into the alarming drug difficulty caused by contaminated infusions (that is, the septicemia case that occurred frequently in the 1960s). The conclusion was unexpected, not that the company did not perform sterility inspection or violated the drug. The regulations are based on the limitations of the sterility inspection itself, the defects in the design of the equipment or system, and the deviations in the production process, resulting in: (1) the pressure gauge and temperature display on the equipment are inconsistent with the actual site requirements and have not been achieved Sterilization requirements; (2) Defective equipment seals lead to recontamination of drugs. In addition, the problems also involve the materials of the manufacturing equipment, the medium used, the structure of the equipment (anti-static, explosion-proof, sealing, lubrication, cleaning structure), operation methods and equipment emissions (dust, heat dissipation, exhaust gas, waste water), etc. As the design, manufacturing, and use of pharmaceutical processing equipment may have potential dangers of contamination and cross-contamination, the FDA attributed the cause to "out-of-process", so the management of the pharmaceutical production process and the verification of production equipment were proposed. It is stipulated that GMP is born, which makes pharmaceutical equipment different from general-purpose machinery and is in a monitored state. This is GMP's clear view of pharmaceutical production equipment. In view of GMP's special requirements for pharmaceutical equipment, as well as various pharmaceutical properties (heat sensitivity, adhesion, hygroscopicity, volatility, reaction, etc.), dosage forms (films, plasters, suppositories, aerosols, infusions, etc.) involved in pharmaceutical equipment Agents, tablets, capsules, pellets, etc.), pharmaceutical processes or processes (reaction, crystallization, fermentation, distillation, extraction, separation, concentration, vacuum and microwave drying, sieving, humid and dry heat sterilization, crushing, cutting , Selection, washing and drying, moisturizing, medicinal pure water and pure steam, etc.), making pharmaceutical equipment a cross-disciplinary, multi-field technology, diversified product special industry. There are specialized organizations or institutions for GMP verification in pharmaceutical companies. Equipment verification has become a routine task for pharmaceutical companies before equipment purchase or commissioning, and is becoming a more convincing way of market recognition for quality. It has virtually become a means for users to select and evaluate pharmaceutical machinery products. Validation drives product competition between equipment manufacturing enterprises more intense, making manufacturers have to pay attention to the performance and level of their own products, equipment verification allows enterprises to feel the integration of product production and the market and the connotation of social responsibility standards proposed by ISO.
- In order to guide the development of GMP in the pharmaceutical equipment industry, the industry has successively formulated guiding standards such as "General Principles for Pharmaceutical Equipment Compliant with Quality Management Specifications for Pharmaceutical Production" and "Guidelines for Validation of Pharmaceutical Machinery (Equipment)". With the occurrence of GMP, URS (user standard), CIP (cleaning in place), SIP (sterilization in place), TTW (through-wall isolation technology), dust-free docking transmission system, and structures that do not see sunlight have been produced. New design methods and new industry terminology. GMP's requirements for pharmaceutical equipment can be summarized in the following aspects:
- (1) Purification, cleaning, and sterilization: Purification includes two meanings to the equipment, that is, the equipment itself does not cause pollution to the production environment and does not pose a threat to the safety of the drug; cleaning and sterilization, equipment in place Sterilization technology (referring to the function of cleaning or sterilizing the system or mechanism without any movement and changing conditions in the original installation position) is an effective method to control cross-contamination, but requires technical support in terms of equipment structure and control.
- (2) Material, appearance and safety design: The materials of the manufacturing equipment shall not affect the properties, purity and quality of the medicines, shall be non-toxic, corrosion-resistant, and shall not cause chemical reactions with the contacted substances, shall not cause adsorption, and shall not produce particles ; Concise appearance is a prerequisite to achieve the purpose of complete cleaning or cleaning; safety protection also includes two meanings, one is that from the perspective of drug safety, the equipment must not change the nature and quality of the drug; the second is the safety of equipment operation and operation and Protective performance.
- (3) Structural design: There are many situations where mechanical power components in the equipment come into contact with materials, and often it is difficult to handle the structural design (such as powder mixing, moving shaft sealing, and other bad structures that are in contact with drugs are very easy to form) Pollution). In addition, it also involves simple and smooth design, the choice of lubricating structure and lubricants, local 100-level laminar air purification, and the influence and threat of its own factors on the environment and drugs in the use of equipment. All structural design must pay attention to .
- (4) On-line detection, control and verification: On-line detection and control is to meet the requirements of safe and continuous production, and requires the application of advanced technologies such as digital display, analysis, recording, program control, and alarm. Verification is a documented activity that systematically confirms the quality of pharmaceutical equipment. It includes four stages: design verification, installation verification, operation verification, and performance verification. The user must go through the above verification of the equipment. Manufacturers must pay attention to product design to comply with GMP during the R & D phase.
- (5) Relevant public works: The equipment does not exist independently. The media (water, gas, steam, etc.) used by the pharmaceutical equipment and the divergence factors of the equipment also have a non-negligible impact on the safety of pharmaceutical production, and also involve the same with pharmaceutical equipment. Supporting facilities and equipment interfaces (process port, verification port, sampling port, maintenance port, etc.).
- In the face of GMP, we hope that the design of pharmaceutical equipment can meet the requirements of "zero defects" in the safe production of pharmaceuticals. Some requirements are nearly harsh on the design of mechanical structures. Such as: (1) there should be no dead corners of the retained materials in the container structure; (2) the seal of the moving shaft must not leak to the material side; (3) how to achieve CIP and SIP; (4) reduce process exposure; (5) ) Avoid cross-contamination in process, transfer or equipment operation; (6) Closed production system that realizes continuous and aseptic "no sunlight"; (7) Prevent human error. From the strict requirements of GMP for pharmaceutical equipment, it has given a lot of room for research and improvement in the structure and function of pharmaceutical equipment, and formed a competitive development based on technological innovation and modern technology applications during the "11th Five-Year Plan" period for pharmaceutical equipment. period.
- Discussion on how separation machinery meets GMP
- Separation machinery is the main process equipment of the drug substance production process in the field of pharmaceutical production. The most widely used separation machinery in pharmaceutical production is the centrifuge. Its equipment includes: three-leg type, spiral type, tube type, disc type, side filtration type, Centrifuges such as hanging bags. Due to the particularity of the use environment, the nature of the liquid and the process conditions, as a medicinal centrifuge, more consideration must be given to the design, such as materials, structure, material input and output methods, safety, labor intensity, control, cleaning Or disinfection and sterilization should adapt to and meet the requirements of pharmaceutical production processes. In the implementation of GMP, manufacturing companies have developed bag-type centrifuges to reduce artificial pollution and reduce labor intensity in order to adapt to the production of pharmaceuticals; they have developed polyphenylene sulfide-coated centrifuges to solve the various corrosive and adhesive properties of drugs. ; In order to be suitable for fine and viscous materials, we also developed side filtration and side filter centrifuges without filter cake resistance filtration.
- Medical centrifuges require cleaning and sterilization when changing batches and varieties during production, but general purpose centrifuges are not the main. There are almost no centrifuges with real CIP and SIP functions. The design lacks cleaning and sterilizing devices and process interfaces, verification ports, etc. It is also a major problem that the inside of the drum cannot be completely cleaned. Many centrifuges consider manually cleaning the inside of the machine. Of course, the cleaning effect of manual cleaning is not denied, but as a medicinal equipment, it should be considered from the perspective of preventing various pollution sources and avoiding re-contamination. CIP and SIP have proven to be the most effective. Program. In the production of pharmaceuticals, the centrifuge is usually cleaned every shift or batch. Sterilization is generally determined as a sterilization cycle. Each sterilization must be cleaned, blown, steamed and continued for several hours. According to the idea of GMP, our cleaning and sterilizing functions of medicinal centrifuges and their actual cleaning and sterilizing effects cannot be regarded as one thing. Their functional effects must be verified through verification. The bacteria need to establish a verification system composed of biological indicators and thermocouples.
- The functional requirements for the use of medicinal centrifuges are the issues that manufacturers are most concerned about. As far as the use of the pharmaceutical industry is concerned, due to the wide variety of substances and large differences in properties, from the perspective of drug preparation, the finely pulverized materials are effective for drugs. The analysis results are favorable, and the corresponding extraction rate will be better, but the viscosity of the drug residue will be relatively larger, which will increase the difficulty of solid-liquid separation, and become a problem that plagues separation efficiency and unloading, making some centrifuges unsuitable. Relatively speaking, scraper-type unloading is a more effective method, but scraper-type centrifuges need to be optimized in terms of automatic feed control, effective removal of residue layers, and CIP functions. In order to prevent pollution, the design of the through wall structure that separates the transmission part of the centrifuge from the working part and installs different clean room areas can be considered. There are already fully-enclosed centrifugal dryers in foreign countries that concentrate the centrifugation, washing, drying process and charging process in one In the equipment, 100% of the pulse gas is discharged to eliminate the hidden dangers of drug exposure. It can be mainly used for products such as sterility and high activity. It overcomes the problem that the centrifuge cannot be completely dried and realizes a closed and efficient production process. In addition, in efforts to reduce labor intensity and reduce turnover, bag-lifting, bag-turning, and side-filtration centrifuges are high-efficiency models that can guarantee the integrity of the grain. Inspired by the idea of continuous production, a multi-process or multi-step design can be considered. A separation machine with solid-phase precipitation and liquid-phase filtration functions will help improve the filtration and separation effect, and also avoid the need to upgrade the centrifuge. The separation factor is limited by the strength and speed of the material. In addition, fermentation is an important process for pharmaceuticals. The whole fermentation broth extraction has entered the industrialization in foreign countries. China is still blank. It is the key to realize the full fermentation broth extraction high-efficiency demulsifier and three-phase separator.
- After going through the GMP implementation process, the company began to try to solve the problems of centrifuge operation relying on user experience as the mainstay, material transfer, cleaning and manual issues, and also focused on the development of automatic control functions on the interface with related systems.
- Conclusion
- This article starts with an overview of the implementation of GMP in the pharmaceutical industry, elaborates that GMP compliance is the basic principle for the development of pharmaceutical equipment, and discusses pharmaceutical centrifuges in this way. For the development of medicinal centrifuges, the author believes that efforts should be made from these aspects: (1) understanding the pharmaceutical process requirements is a prerequisite for the development of medicinal centrifuges; (2) should focus on automatic program control, human-machine isolation operation, easy cleaning, Research and improvement of disinfection and sterilization structure, on-line analysis and separation of different traits; (3) There is still a lot of "articles" to do in the direction of full function, low pollution, high control, and improvement of aseptic operation. .
Centrifuge Code of Practice
Centrifuge Code
- 1. When the centrifuge is in the pre-cooling state, the centrifuge lid must be closed. The rotor removed after centrifugation should be inverted on the experimental table, and the remaining water in the cavity should be dried. At this time, the centrifuge lid is open.
- 2. The rotor cover can be placed on the platform of the centrifuge or on the experimental table during pre-cooling. Never float the rotor cover tightly, because once it is started by mistake, the rotor cover will Will fly out and cause an accident!
- 3. After tightening the rotor cover, be sure to touch the gap between the rotor and the cover with your fingers after tightening. If there is a gap, unscrew it and re-tighten until the gap is confirmed before starting the centrifuge.
- 4. During the centrifugation process, the operator must not leave the centrifuge room. Once an abnormal situation occurs, the operator cannot turn off the power (POWER) and press STOP. Fill in the centrifuge record before pre-cooling.
- 5. Do not use inferior centrifuges to make tubes, and do not use aging, deformation, cracks
- Textured centrifuge tubes.
- 6. The last use of the centrifuge during holidays and evenings must be carried out after routine security checks.
- 7. When a machine failure occurs during the use of the instrument, the manufacturer should be contacted in time when the component is damaged.
Use of centrifuge
- Commonly used in laboratories are electric centrifuges. Electric centrifuges rotate at high speeds. Pay attention to safety, especially to prevent the centrifuge from moving while working due to imbalance or aging of test tube pads during the operation of the centrifuge. After falling, or because the lid is not covered, and the centrifuge tube is broken due to vibration, the glass fragments spin and fly out, causing an accident. Therefore, when using a centrifuge, you must pay attention to the following operations.
- (1) Cotton or test tube pad should be placed on the bottom of the centrifuge tube.
- (2) If there is noise or vibration of the electric centrifuge, the power should be cut off immediately to eliminate the fault immediately.
- (3) The centrifuge tube must be placed symmetrically in the sleeve to prevent the body from vibrating. If there is only one sample tube, the other one must be replaced with water of equal quality.
- (4) When starting the centrifuge, cover the centrifuge top cover before slowly starting.
- (5) After the separation is completed, first close the centrifuge. After the centrifuge stops rotating, open the centrifuge lid and take out the sample. You cannot use external force to force it to stop moving.
- (6) The centrifugation time is generally 1 to 2 minutes. During this period, the experimenter must not leave to do other things.
- In enterprises or research institutions of institutions, low-speed experimental centrifuges with a rotation speed of about 3000 rpm have been more commonly used, such as 315 filter + sedimentation integrated experimental centrifuge, 100 experimental centrifuge, 200 experimental centrifuge and so on. These centrifuges are reasonably designed, have a low center of gravity, and are safe and stable. They have gained greater application in the analysis of early samples in the chemical, food, and medical fields.
Centrifuge operation method
- 1. When using various centrifuges, it is necessary to precisely balance the centrifuge tube and its contents on the balance in advance. The difference in weight during balance must not exceed the range specified in the instructions of each centrifuge. The different rotors of each centrifuge have For the allowable difference, the singular tube must not be loaded in the rotor. When the rotor is only partially loaded, the pipes must be placed symmetrically to each other in order to distribute the load evenly around the rotor.
- 2. When centrifuging at a temperature below room temperature. The rotor should be pre-cooled in the refrigerator or centrifuge rotor before use.
- 3. Don't leave at will during centrifugation. Observe whether the instrument on the centrifuge works normally at any time. If there is any abnormal sound, immediately stop the machine for inspection and remove the fault in time.
- 4. Each rotor has its maximum allowable speed and accumulation limit. When using the rotor, please refer to the instruction manual, and do not use it at excessive speed. Each rotor must have a use file to record the accumulated usage time. If it exceeds the maximum use limit of the rotor, it must be used at a reduced speed.
- 5. When loading the solution, it should be carried out according to the specific operating instructions of various centrifuges. Select a suitable centrifuge tube according to the nature and volume of the liquid to be centrifuged. Some centrifuge tubes have no cover, and the liquid should not be overfilled to prevent centrifugation. Throw it out, causing the rotor to become unbalanced, rusted or corroded, and the centrifuge tube of a preparative ultracentrifuge often requires that the liquid be filled to avoid deformation of the upper part of the plastic centrifuge tube during centrifugation. After each use, the rotor must be carefully checked, cleaned and dried in time. The rotor is a part of the centrifuge that must be protected. When moving, be careful not to collide to avoid injuries. When the rotor is not used for a long time, you must Apply a layer of glazed wax to protect it. Never use centrifuge tubes that are significantly deformed, damaged or aged.
Centrifuge industry standard
- GB / T 10901-2005 centrifuge performance test method
- GB 19815-2005 centrifuge safety requirements
- GB 6065-1985 TZ vertical vibration centrifuge
- GB 12258-1990 medical low speed centrifuge
- JB / T 3263-2000 horizontal vibration centrifuge
- JB / T 4064-2005 top suspension centrifuge
- JB / T 5519-1991 high speed refrigerated centrifuge
- JB / T 6118-1992 TCL sedimentation filtration centrifuge
- JB / T 53190-1999 Three-foot centrifuge product quality classification
- JB 447-1985 horizontal piston pusher centrifuge technical specifications
- JB / T 502-2004 spiral unloading sedimentation centrifuge
- JB / T 5284-1991 explosion-proof scraper discharge centrifuge
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Centrifuge original introduction
- First, the industrial centrifuge is one of the main equipment in the chemical industry
- Industrial centrifuge is one of the main equipments in the chemical industry. It mainly separates solids and liquids by centrifugal force. Generally, it consists of feeding, washing, dewatering, knives, and unloading. The material and other parts are controlled by solenoid valves and pneumatic valves. The centrifugal kettle is the main component to achieve solid-liquid separation. It is driven by a three-phase AC motor through a belt. According to the characteristics of the process, the material is mainly a solid-liquid mixture at the beginning. The load is relatively large at the start. When a certain speed is reached, the liquid flows out of the centrifugal force under the action of centrifugal force, so that some of the liquid is separated out first. With further increase, the load is correspondingly reduced. According to the process requirements, it is generally divided into several different speeds to achieve separation.
- Application of frequency converter in centrifuge
- Application of frequency converters In recent years, frequency converters have been continuously updated and developed as an industrial control device, and have been widely used in various industries. With the continuous maturity of power electronics technology, frequency conversion control theory, and microcomputer control technology, the performance of the inverter is constantly improved and its functions are continuously enhanced: such as multi-speed, programmable automatic operation, communication functions, etc. Kinds of applications. According to the production process of the centrifuge, the multi-speed function control of the inverter can be used to achieve it. In addition, the inverter generally has a built-in braking unit or an external braking unit, which can solve the difficulty of stopping the centrifuge due to the large inertia when it is stopped. The problem.
- Application of the braking unit
- The centrifuge is a large inertia load. When the inverter is used for control, it is required to add a braking unit to meet the requirements. This not only saves installation space for the user, but also saves costs. From the running characteristics of the motor, it is known that when the actual speed of the motor is higher than the synchronous speed, the motor runs in the generator state. When the centrifuge starts to stop, the output frequency of the inverter starts to decrease according to the deceleration time. Large, causing the actual speed of the motor to be higher than the synchronous speed, the motor is in the braking state of the generator, which is known by the main circuit of the inverter. At this time, the energy fed back by the motor will be fed back to the DC circuit through the freewheeling diodes D1-D6 of the inverter circuit. Filter capacitors C1 and C2, the bus voltage Ud of the inverter will increase (that is, the pumping voltage), and an excessively high pumping voltage will cause the inverter to have overvoltage protection and may even damage the inverter. A braking component must be installed. When the control circuit of the braking unit detects that the DC bus voltage reaches a certain value, it controls its switching tube IGBT to turn on, the braking resistor RB is connected to the circuit, and the braking energy fed back by the motor is consumed on the resistor. To maintain the normal bus voltage Ud.
- Debug attention issues According to the load characteristics of the centrifuge, pay attention to:
- (1) Centrifuge load requires high starting torque, which may cause difficulty in starting. At this time, the torque compensation value of the inverter can be appropriately raised. The setting parameter of SAJ-8000-G series F009 is 3, but the starting torque The compensation should not be too large, otherwise there may be alarms such as overcurrent (fault code is OC) and overload (fault code is OL). If an overcurrent alarm occurs during acceleration, the acceleration time should be appropriately extended;
- (2) The centrifuge has a large inertia. If the inverter is required to stop according to the deceleration time, a braking unit must be installed. The braking resistor can be selected from the instruction manual of the inverter. It can be selected according to the operation manual. The braking resistor can be selected during normal operation. It will generate heat due to energy consumption, and can appropriately amplify the power of the resistor and the braking action time.
- (3) Generally, the centrifuge is installed at the operation site, and multiple inverters are concentrated in the control room. If the distance between the site and the centrifuge exceeds the allowable range of the inverter, corresponding measures should be taken, such as the rational distribution of the main circuit line and control line, Install output reactor or filter to prevent the output voltage of the inverter from declining, or consider increasing the capacity of the inverter.
- The centrifuge adopts variable frequency speed control to adjust the speed according to different process requirements. It can conveniently select multi-speed operation according to different materials. At the same time, variable frequency control is used to achieve soft start of the motor to reduce the impact on the power grid. The inverter has overcurrent,
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- (2) The ground wire must be firm: The wiring of the power supply in the room must meet the requirements. China is a three-phase four-wire system. Three-phase is the three-phase in industrial power. When using three-phase power, the neutral and ground lines are separated. It is more important that whether it is three-phase industrial power or general single-phase power, the ground wire should be reliable to avoid leakage. The ground wire cannot be connected to the heating pipe or water pipe.
- (3) The ground should be flat and firm: For large centrifuges, moving the floor at the installation site should be firm to ensure that the rotor of the centrifuge can work normally without sinking in. The ground where the installation is fixed should be flat and firm.
- (4) Find a good level: find a more accurate small spirit level, open the centrifuge lid, find the level on the main shaft, find the level by adjusting the adjustment bolts next to the four casters, pay attention to one of the feet can not fall.
Centrifuge loading to find balance
- During the design and manufacture of the centrifuge, the imbalance caused by the processing errors of the rotor has been remedied by the dynamic balance test. All centrifuges have their allowed unbalanced loading. In order to compete with other manufacturers on the index of the maximum unbalance limit allowed by centrifuges, centrifuge manufacturers give as large values as possible. At this larger value, the centrifuge can run, but the unbalanced force generated at this time suddenly hits the bearings and supports at a frequency of n times per minute, and the centrifuge is damaged. Therefore, for those expensive centrifuges, users should try to find a good balance after centrifugation, which is beneficial to the life of the centrifuge.
Centrifuge to clear up standing water
- Refrigeration is used when the centrifuge is running. Due to the moisture of the air, frost is formed in the centrifuge chamber, and it will be defrosted into water after shutdown. Most foreign low-speed large-capacity centrifuges have no drainage holes, and more and more water accumulates in the centrifuge chamber. At this time, the user should remove the rotor and clean up the accumulated water. When reinstalling the rotor, be sure to install it to avoid accidents.
Centrifuge is not subject to corrosion
- Centrifuge rotors are generally made of aluminum alloy. When they are corroded, the strength decreases, which is prone to accidents. Aluminum alloy is susceptible to liquid corrosion. After cleaning, it should be dried with a hair dryer or inverted for a period of time. Some blood stations import centrifuges, but there are 6 plastic cups in 6 aluminum cups. Bleeding bags should be placed in plastic trays to avoid placing them directly in aluminum cups. Note the test tube for cracks. If the test tube (especially the test tube used repeatedly) is cracked, do not use it. Otherwise, the test tube rupture during use will cause the rotor to lose balance during rotation, which may cause vicious accidents such as broken shafts.
Centrifuge broken shaft accident
- The rotor is not installed properly, or the imbalance of the loaded sample is too large, and the centrifuge starts. Although modern imported centrifuges have unbalance protection, that is, when the unbalance amount exceeds a certain limit, the power should be automatically turned off to stop the centrifuge. But in the above circumstances, it is too late and a vicious accident will occur. One of the most serious accidents is the broken shaft. Due to the sudden broken shaft during high-speed rotation, the centrifugal rotor has no support, and the random rotation in the centrifugal cavity can make the whole centrifuge rotate at an angle of 270 °. At this time, if there are people or equipment nearby, it may cause personal injury and death and damage the equipment.
Centrifuge model
- Centrifuges can be divided into two types: industrial centrifuges and experimental centrifuges
- Industrial centrifuges, industrial centrifuges can generally be divided into filter centrifuges, piston push centrifuges, dish separators, sludge dewatering machines, top-hanging centrifuges, gravity discharge centrifuges, etc.
- The centrifuge used in the experiment can be used for liquid clarification and solid particle enrichment, or liquid-liquid separation. Such separators have different structural types that operate under normal pressure, vacuum, and freezing conditions. The main models are desktop medical high-speed centrifuges, laboratory low-speed centrifuges, and large-capacity refrigerated centrifuges, which are generally used in experimental extraction in hospitals or schools. They are also called electric centrifuges. The working principle of the centrifuge is basically the same, but this kind of The speed of centrifuges is generally above 3000 rpm, which is much higher than the speed of industrial centrifuges. The manufacturers are mainly concentrated in the Changsha area of Hunan.
- GF-separation type: It is mainly used to separate various difficult-to-separate emulsions. It is especially suitable for liquid and liquid separation (the difference in specific gravity is greater than 0.1%) with a small difference in two-phase density, as well as liquid, liquid, and solid with small impurities Three-phase separation. Separation of oil products, transformer oil, edible oil dehydration and dewaxing, turbine oil, biodiesel, coal tar, lubricating oil, marine fuel oil, quenching oil; separation of various syrups; separation of whole blood-from whole blood Separation of plasma and blood cells; separation of biological products; oil-water separation, sewage treatment, etc.
- GQ-clarification tube centrifuge is mainly used to separate various suspensions that are difficult to separate, especially suitable for solid-liquid separation with low concentration, high viscosity, fine solid phase particles and small difference in solid-liquid specific gravity.
- For example, the oral liquid of traditional Chinese medicine has large sugar content, many flocs, fine solid particles, and small solid-liquid specific gravity difference.
Centrifuge Features
- This machine separates the solid phase impurities in the liquid to achieve the effect of clarification. Used to separate a variety of difficult to separate suspensions. It is especially suitable for solid-liquid separation with small concentration and large viscosity, fine solid particles, and low solid-liquid gravity. The solid phase should be removed after shutdown.
- The main disadvantage of tubular centrifuges is intermittent operation. The drum volume is small. Shut down frequently to remove sediment. Therefore, it is necessary to strengthen the separation performance of the tubular centrifuge by strengthening the study of separation theory and centrifugation process.
Centrifuge precautions
- 1. In order to ensure safety and centrifugal effect, the instrument must be placed on a solid and horizontal table surface, and no objects can be placed on the engineering plastic cover door; the sample must be placed symmetrically, and the nut must be tightened before starting up.
- 2. Before use, check the rotor for damage and corrosion. At the same time, check the centrifuge cup for cracks and aging. If you find any doubt, stop using it immediately and contact the factory. Before turning on the machine, please tighten the rotor. Tighten the nut to prevent the high-speed rotating rotor from flying out and causing an accident.
- 3. The speed setting must not exceed the maximum speed to ensure the safe operation of the machine.
- 4. If 0.00 or other numbers appear during use, the machine is not running, it should be turned off and powered off, and then restarted after 10 seconds. After the set speed is displayed, press the run key again, the machine will run as usual.
- 5. If the specific gravity of the sample to be separated exceeds 1.2 g / cm3, the maximum speed N must be corrected according to the following formula: N = NMAX * (1.2 / sample specific gravity) 1/2, NMAX = limiting speed of the rotor.
- 6. Do not open the cover door during the machine running or the rotor is not stopped to avoid accidents.
- 7. The centrifuge cup must be filled with the same amount of sample. Do not make the rotor run in an unbalanced condition.
- 8. It is best not to run the centrifuge for more than 60 minutes at a time.
- 9. The centrifuge must be reliably grounded; the machine is not in use, please unplug the power plug.