Liquid viscosity

Filling production line

There are currently dozens of filling schemes used in the liquid filling line to apply a variety of filling liquids. The core filling unit has a ring-open design and a closed-loop design. The stability of closed-loop design in the filling can be relatively more reliable, but the production line design is relatively more complex and costly. Open loop design, can greatly simplify the complexity of the production line, but requires the core filling unit has a good consistency and stability, and in the production process according to the characteristics of the filling unit to do product sampling work, according to the timely sampling results adjust to ensure product consistency.

All the filling program can be made closed-loop control, filling results can be detected using induction probe, laser detection, weight detection. The advantage of making the closed loop is that the accuracy of the filling unit is reduced, and it is possible to ensure that the filling results are correct as long as the detection device is working properly, and this test is generally applicable only to occasions where precision required is not very high , such as cosmetics, food and other products of the filling, the filling accuracy of these products only need to ensure that achieve the national norms. If the closed-loop accuracy required is high, the detection device can only use the pressure sensor to measure, in the higher precision requirements, the pressure sensor data processing takes longer, the air flow, equipment, vibration, The impact of the container will have an impact on the pressure sensor, so the filling speed will be very slow, unable to meet the bulk mass production.

There are several ways can be used to make open-loop filling unit of the program, this article mainly explain the peristaltic pump open-loop filling system. From the filling accuracy, the piston pump open-loop filling accuracy and stability is the best, peristaltic pump is the type of pump products only after the piston pump; from the filling machinery pipeline design, as the peristaltic pump has a good self-sealing, its filling system piping design is the simplest; from the filling level of the equipment, the peristaltic pump is the highest health level, which the other kind of pump can not match. The peristaltic pump only needs to be replaced the tubing, and all other parts are maintenance-free. This is the most economical and cost-effective solution for the users. From the filling equipment of the flexible design, because the flow of peristaltic pump can be changed by replaced a tube, so the use of peristaltic pump filling equipment can adapt to a variety of different filling volume without changing the mechanical structure of filling equipment.

At present, the new liquid filling machinery has been more and more use of peristaltic pump filling program, of course, there are some problems to be overcome of the peristaltic pump in the liquid filling process, with the emergence of a variety of new peristaltic pump, peristaltic pump filling process problems are gradually being resolved or will be resolved, in the future, the design of filling machinery will be carried out around the peristaltic pump, which is the development trend of the filling industry.

This article is write by Baoding ZHUNZE Precision Pump Manufacturing Co., Ltd. original, without authorization can not be reproduced!

Pharmaceutical Industry

The pharmaceutical industry is a relatively special industry, generally speaking, when we talk about the filling machinery, the pharmaceutical industry filling line will be separated, this is because the pharmaceutical industry directly related to personal safety problems, so the requirements of the pharmaceutical machinery will be relatively higher.

For the production of drugs, the first is to ensure that the health level of the production environment to reach the medical level. Mainly on the two aspects, on the one hand is the production workshop to achieve the required medical level, including the air dust and fungi limit the number; the other is the production of drugs from the maintenance and production process to achieve the medical level of the provisions.

Involving the production of drugs machinery, the most important thing is to control the direct contact with the drug material, the current is mainly 304,316 or with medical grade plastic and rubber materials. Drug production process transfer and packaging will use the pump products, the use of these pump products is the most prone to pollution.

At present, many of the pumps used in the transfer of finished products are 304 stainless steel impeller pump products. Although this kind of pump products may be allowed from the material, but the impeller pump body will have a lot of health inside the corner, it is extremely difficult to clean, need to pump all open, disinfection and then assembled, this process May also introduce other pollution, cleaning time is longer.

In the drug packaging, the most used pump products are piston pumps and similar structure of the pump products. This kind of product filling also exists a lot of health dead ends, need to remove the whole pump to clean regularly. The need to remove the cleaning site is even more if concerned about the replacement of the type of drug filling, almost the entire production line should be cleaned again. Wasting great manpower and material resources.

In all pump products, the highest level of hygiene is peristaltic pump, so the peristaltic pump is particularly suitable for use in the pharmaceutical process. Peristaltic pump work process, the liquid only in a dedicated tube transmission, will not touch any other metal and non-metallic parts, as long as the tube to ensure the medical level, the production of drugs will meet the requirements. The flow of peristaltic pump is wide, to meet the small flow to large flow of all needs, it does not require maintenance, health disinfection is very simple.

In the application of drug packaging, we need to ensure the filling time and filling accuracy. About the filling time, the peristaltic pump is fully able to meet the requirements. About the filling accuracy, the filling speed of the peristaltic pump has gone through three stages of development: the first stage is time control, filling accuracy is low; the second stage is the pulse control, the precision is much higher than the time control, But limited by the peristaltic pump pulsation phenomenon, filling volume or in a certain range of cyclical fluctuations, does not apply to the the occasion of high precision requirements; the third stage is Baoding ZHUNZE precision pump Manufacturing Co., Ltd. developed pulse + Angle control technology, this control method made the precision of peristaltic pump have a qualitative overflight. Achieve the same accuracy with the piston pump. But limited by changes in the flexibility of the tube. In reality, after a period of time, we need to micro adjust the flow, the current peristaltic pump micro adjustment is somewhat inconvenient, which limits the peristaltic pump In the use of high-speed automated pharmaceutical filling machine. ZHUNZE is being developed in the fourth stage of the new type of peristaltic pump in order to solve this problem, the peristaltic pump can do 1 μl of fine adjustment. matching machine that can automatically adjust the signal feedback, and it will be the perfect alternative to the existing plunger pump.

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Laboratory and scientific research

In the experimental and scientific research process, we usually need to transfer kinds of liquid, such as inorganic salts solution, acid and alkali solution, organic corrosion solution. Limited by the size of the experimental table, the type of pump needs to be as small as possible. Trapezoidal pumps are the most reliable and convenient option in the absence of special high pressure requirements or pulsating requirements.

Peristaltic pump has a strong self-priming ability, it is easy to absorb the liquid directly from the beaker, tube or other containers. The other type of pump required to be filled with liquid before using. It is dangerous to use other type of pump if the liquid corrosive strong.

Peristaltic pump has a good self-sealing. The transfer of liquid will immediately stop as long as the peristaltic pump stop working. The liquid will not drop or droplet because of the change of liquid level, the pipeline design is very simple, no solenoid valve or check valve and other accessories.

The peristaltic pump has good flow stability, the change of pressure will not affect the flow, which is the performance that other pumps do not have. In the test, the peristaltic pump has a wider applicability.

Peristaltic pump liquid transmission has a good linearity. We need to keep abreast of the liquid transmission flow rate in the experimental process, and sometimes the installation of flowmeter is very difficult, at this time we need to use the peristaltic pump linear characteristics, this stable linear characteristics Is not available in other pump type.

Peristaltic pump can transmit strong acid and alkali, strong corrosive liquid, because the liquid flows only through the tube when transferring , the pump can transfer as long as the pump tube is corrosion-resistant material , this is the other pump can not reach. At present, the peristaltic pump tubing is versatile and can transmit almost all of the liquid currently known.

The peristaltic pump can transmit high temperature liquid, and the peristaltic pump tubing can withstand temperatures above 100 ° C, where the fluoro rubber tube can withstand temperatures above 200 ° C, which is not available for other pumps.

Peristaltic pump tube can be replaced by a new tube to transmit a variety of different liquids, will not cause cross-contamination, will not adversely affect the experimental results, other pump type need to be disassembled before cleaning, completely clean up is almost impossible.

The peristaltic pump can transmit air and can run for long periods, which is not available for other pumps.

Peristaltic pump machine has a variety of functions, we can adjust the flow rate, regular quantitative filling, can also be customized according to the user’s requirements, peristaltic pump is the most abundant among this multi-functional integration applications.

At present, peristaltic pump is an indispensable liquid transmission tool for experimental research.

This article is write by Baoding ZHUNZE Precision Pump Manufacturing Co., Ltd. original, without authorization can not be reproduced!

Equipment and equipment supporting

With the emergence of a variety of new instruments and equipment, experiments and production become more and more simple. There was an experiment or a production of product need to purchase a variety of instruments to complete, now can be more integrated products to complete independently.

For this highly integrated product, are generally divided into several functional modules to design, and fluid transmission module is one of the important components. There are many types of products that can be used as fluid transfer modules, gear pumps, plunger pumps, diaphragm pumps, impeller pumps, screw pumps, peristaltic pumps, and so on.

From the type of liquid that can be transmitted, the peristaltic pump is the most powerful. Peristaltic pump can transmit inorganic salts, strong acid and alkali, all kinds of organic matter and even strong corrosive organic matter; In addition, peristaltic pump can transmit a certain viscosity of the liquid.

From the maintenance point of view, peristaltic pump only need to replace the tube, don’t need to disassemble, do not need daily maintenance. ZHUNZE peristaltic pump head roller adopts the self-developed sealing structure, which can effectively prevent the pollution of the roller bearing caused by the rupture of the tubing and so on, and improve the reliability of the product under the limit condition.

From the inherent characteristics of view, peristaltic pump has a strong self-priming ability, can make the instrument and equipment design more convenient; in addition to peristaltic pump also has a good self-sealing, the overall design of the product can save a lot of valves, To improve the reliability of equipment.

From the use level, the peristaltic pump has a good linearity if the speed change is not big, can control the flow of the liquid by changing speed exactly, which is convenient on the overall control of the device design.

In addition, the change of the outlet pressure of the peristaltic pump has little effect on its flow rate, which is not available in other pumps. The hygienic level of the peristaltic pump is the highest and can effectively prevent cross-contamination between different liquids. Peristaltic pump can transfer air for a long time, in some cases, this is particularly conducive to the design of a device design features.

At present, there have been more and more instruments and equipment began to use peristaltic pump design, and this is also a trends of lot of equipment design.

This article is write by Baoding ZHUNZE Precision Pump Manufacturing Co., Ltd. original, without authorization can not be reproduced!

The main factors that affect the price and quality of peristaltic pump

Different manufacturers of products, achieving the same function, but the price is higher or lower, it is possible to buy a good product with a low price, and may be a low-quality product with a high price, how to distinguish, how to judge is the homework that consumer needs to do.

Any product price can be composed by the normal price and the product brand premium. The normal price of the product is determined by the profitability of the product's industry, and the degree of profit chasing of the producer of the product. Brand premium is easy to understand, the more well-known brand, the higher the additional price of its products.

This article mainly explains the commonly used materials, control methods and production technology of peristaltic pump products. Mean to explain the impact of the price of the two important parts of the peristaltic pump-drive and pump head and how to judge whether the price of peristaltic pump is reasonable.

Part 1: About the pump head

Pump head mainly composed by the shell and roller assembly.

1. About the shell. Some of the cheap pump head shell uses the ABS, PC etc., these materials are very cheap, and the mold is easy to process, so the cost is very low. But the stiffness and corrosion resistance of the pump head are relatively poor. High-quality peristaltic pump will generally use PPS material with good rigidity, toughness, corrosion resistance, of course, the price of raw material is 5 times more expensive than the average material, the requirements of the mold is very strict, the cost of production is very high, ZHUNZE peristaltic pump head shell is using imported PPS raw materials.

2. About the roller assembly. It is an important moving part of the peristaltic pump, generally composed by the spindle, needle roller, roller, wheel, bearings, washers and other parts. The following mainly explain the process of each component and its cost.

a, The spindle, needle roller and roller can be made of many kinds of materials such as plastic, carbon steel, stainless steel, the cost is increasing in turn, and the performance gradually increased, too.

b. The wheel is divided into three types according to the different operation modes. The different operation modes are of different cost.

The first is the metal shaft with plastic roller. This kind of roller can only run at low speed, with poor bearing capacity, short life, low precision and there will be friction noise;

The second is the metal roller with oil bearing, this roller has strong carrying capacity, but only low-speed running, shorter life, low accuracy, there may be wheel Percussion;

The third is metal roller with ball bearing, the bearing capacity by this way is moderate, it can run with high speed, high precision, low noise, long life.

The cost of the three ways increases in turn.

c, About the roulette, it can be made of plastic, aluminum and stainless steel. Miniature peristaltic pump head wheel generally will use plastic material, mainly to reduce its cost, a stainless steel wheel cost might be more than the cost of a whole peristaltic pump head. Medium flow of peristaltic pump head, such as YZ series of products, generally will use aluminum alloy material, because of the 3mm thickness wheel, if use stainless steel, it can only be processed in the processing center, So that the cost will be high, but this can improve the rigidity of the pump head, but the pump head will adapt to a more corrosive environment, and can improve the reliability of peristaltic pump. And our YZ series of peristaltic pump head is using stainless steel wheel, the product quality second to none.

d, The bearings are generally divided into stainless steel high-speed high-temperature bearings and ordinary bearing steel bearings, the cost of the former is higher, ZHUNZE pump head bearings are all using high-speed stainless steel bearings.

e, the lowest cost on the wheel is the washer, and almost all of the peristaltic pump manufacturers are using the rubber material O-ring. This washer because of its good elasticity, the products can also be assembled with low accuracy of wheel and the spindle. However, this material, if encountered in the corrosive liquid or air, or encountered high temperature liquid or using a long time, will gradually aging, and then break. All the washer of ZHUNZE products are made of Teflon. This material is ten times more costly than rubber, but can withstand almost all chemical corrosion and high temperature environments.

Part II: About the drive

The drive is mainly composed of a chassis and an internal drive circuit and a motor etc. The chassis is generally made of plastic by injection molding, iron and stainless steel. The appearance of the injection box is relatively beautiful, and the weight is light, the initial cost of the mold is high, the cost of a single product is much lower. The cost of Iron chassis spray will be much higher, the weight is relatively heavy, but it can be used in the factory with harsh environment, the adaptability is much higher than the plastic chassis. The cost of stainless steel chassis is the highest, But the adaptability is the strongest.

Drive circuit and motor are generally supporting. At present, the types of motors used in the peristaltic pump are AC motor, DC motor, brushless DC motor, stepper motor and servo motor, the cost is increased in order and the accuracy is increased. However, some manufacturers use the product is a servo motor, in fact, is a false servo system, the precision is much lower than the stepper motor. The stability at low speed, stepper motor is the highest. Compared with stepper motor, the vibration of the servo motor is small, with overload capacity. Compared with servo motor, the reliability of the stepper motor is much higher because its torque is large at low speed, and do not need to gear box. In addition, the stepper motor can achieve very high positioning accuracy under open-loop conditions, which is unmatched by any other motor.

In terms of reliability, the DC motor is the least reliable because it needs brush and gearbox mechanisms; followed by AC motors, brushless DC motors, and servo motors because the speed of the peristaltic pump head is limited by the tube elasticity, are generally working within the speed of 600RPM, so that in order to achieve low speed creep pump the required torque, we need to install the gear box, this small gear box general quality is not very good, the cost will be higher than the total cost of the whole peristaltic pump if using the high-quality gearbox. Therefore, the reliability of this drive mode is limited by the part of the gearbox; the stepper motor does not contain the brush mechanism, and nor does it require a gear box, its reliability is the most reliable of all power combinations. If the accuracy of the peristaltic pump is required, the optimal choice is stepper motor or servo motor system.

This article is original created by Baoding ZHUNZE Precision pump Manufacturing Co., Ltd. Reproduced without authorization is prohibited!

The reason of the peristaltic pump pulsation phenomenon

The pulsation is an inherent phenomenon of peristaltic pump, and it is impossible to eliminate in terms of the current structure However, there are some use of the occasion where the pulsation is not allowed, or need to be appropriately reduced to meet the requirements. If the use of the occasion cannot have any pulsation, the peristaltic pump is not appropriate, so we need to choose a more stable pump type, such as impeller pump or fine gear pump.

The so-called pulse refers to a stream of liquid squirts comes instantaneously with the fluid transmission of the peristaltic pump. There are two parameters to describe the pulsating phenomenon, the frequency of pulsation and the amplitude of pulsation. (See below).

The frequency of pulsation refers to the number of pulses per unit time; the unit time can be 1 second or 1 minute or other time. Peristaltic pump work in a long period, within a minute of the total amount of transmission is consistent, that is, the amount of the last minute and the next minute transmission is equal. However, if the time is shortened to a few seconds or less, the amount of liquid will be different, because the instantaneous velocity of the peristaltic pump is periodically changing. In some cases, such as when the handheld machine dispensing glue usually need to very uniform on the bag. In order to achieve a more uniform smear process, the general method is to use the peristaltic pump to transfer glue to cotton or sponge, and then through the contact with cotton bags or sponge to take the glue evenly. If you want to smear more uniform, cotton or sponges glue saturation should ensure the relative stability. If the peristaltic pump pulsation frequency is low, the interval between the two streams will be longer because the handheld machine is always high-speed operation, this interval will take away a lot of glue, making glue in the cotton or sponge saturation significantly reduced, which led to uneven coating. So in order to apply evenly, you must quickly fill the cotton or sponge glue, so that saturation is maintained at a relatively stable value, you can solve this problem by increasing the frequency of peristaltic pump pulsation to. There are two ways to improve the ripple frequency. The first is to improve the speed of the peristaltic pump. In the case of fixed pump head, improve the speed is the most direct way to increase the ripple frequency. However, if the flow rate has strict requirements, it is not possible to improve the speed simply, because the liquid flow rate will be a corresponding increase of the motor speed is increased, it should replace the thinner hose, and then increase the speed. This will ensure that the flow rate is required, and frequency improved. The second is to increase the number of pump head roller, at the same speed, the pulse frequency will be increased significantly. Nevertheless, when the number of rollers increased with the same arc and roller structure, the pump head flow rate will be reduced. So we should increase the pump speed to achieve the same flow rate, that the frequency of peristaltic pump pulse will be further increased.

The amplitude of pulsation is another important parameter of pulsation. Different pump head and hose have different amplitude of pulsation. The amplitude of the pulsation is determined by the size of the hose and the diameter of the roller. The pipe is placed horizontally and then the roller is pressed down in the direction perpendicular to the tube. After being completely pressed, the volume of the tube that is reduced by squeezing deformation is the magnitude of the pulsation. IN fact, when the peristaltic pump fluid transmission, not only the middle of the two pulsations does not transfer the liquid, but also a short distance backflow. Then between the whole process of transmission, the fluid is the transmission - back flow - transmission, so the cycle action. In a long period, peristaltic pump transmission speed is stable, instantaneous speed is changing at any time, in some cases, such a transmission is not allowed. In order to reduce or even eliminate this pulsation, there is a product, which called pulsation damper. The general principle is that the big mouth into the liquid, small mouth out of the liquid, so that when the each liquid come quickly, the liquid is too late to quickly out of the small mouth. The pressure of the excess liquid will be absorbed by the air in the damper, with the air pressure in the cavity gradually increases, the flow rate at the small mouth will be correspondingly increase, and ultimately reach a relatively stable state. Why can it reduce the pulsation?  Because in principle, in the case of all the same state of the pipeline, as long as the air pressure in the cavity can ensured absolute stability, the flow rate at the exit will be stable. If the volume of cavity is much larger than the amplitude of the pulsation, the impact of the air pressure on the damper cavity will be small when a single pulse arrived. so that the relative pressure of the cavity will be relatively stable under a very small fluctuation The flow rate at the  small mouth will only have a small fluctuation. Because the pulsation damper cannot be unrestricted, the fluctuation of the fluid will certainly exist, but the phenomenon of backflow has been eliminated. The use of pulsating dampers is conditional. Firstly, the transmitted fluid must be accessible to the air. Secondly, the volume of the damper is compatible with the flow rate, that is, the size of the cavity to ensure that the pulse with the appropriate ratio, this is based on the requirements of the stability of the flow rate to decide. The same pulsation damper cannot accommodate all flow rates, but only for a very narrow flow rate range has a better buffer effect. So if the liquid transmission involves a wide flow rate range and must significantly reduce the flow rate of the pulse, then the pulsation dampers alone cannot be achieved. You can imagine that if the flow rate is too low, the pulsation damper cavity cannot produce a steady pressure. It cannot be very good to reduce the pulsation. If the flow rate is too fast, pulsation can be significantly reduced. However, because of the mouth want to increase the flow rate, cavity pressure will need to multiply, but the peristaltic pump itself is a low-pressure pump type, its general working pressure does not exceed 0.15Mpa, and long-term under critical pressure, the life of the hose will be significantly reduced. So, in use should be overall considered. Moreover, after using the pulsating damper, when the pump is down, because there is pressure in the cavity, exports will continue to flow out of the liquid, until the chamber pressure is reduced to the same extent as the outside pressure.

Using a similar principle, it is also possible to consider the use of the elasticity of the hose to absorb pulsations. The first requirement of the hose used by the peristaltic pump is that the elasticity should be high enough, so as to ensure the stability of the flow rate. Then the hose can be extended at the exit of the pump, generally more than one meter will have a very significant effect. At the exit of the hose, transfer the appropriate inner diameter of the fine joint or needle according to the requirements of different flow rate. Also when the peristaltic pump working, every time the pulse arrives, due to fine joints or needles too late to discharge all the liquid quickly, there will be pressure in the hose at the exit, when the velocity of the fine joint or needle is the same as the speed of the peristaltic pump, the pressure inside the hose will be stable, and every time the pulse arrives, the excess pressure will be absorbed by the overall expansion of the hose, to achieve the role of reducing the pulse. It can achieve the same effect as using a pulsating damper, and can also transmit air-sensitive liquids. So the pulsation damper has been rarely used. The same small diameter of the joints or needles can only be adapted to a very narrow flow rate range, after the pump stops, the exit will continue to flow out of the liquid, until the pressure inside and outside the tube balance.

The third way to reduce the pulse is slightly different, the used principle is that liquid level difference and pipe state unchanged, the flow rate of liquid at the outlet is constant. In fact, the most fundamental principle is the same , they are all trying to build a steady pressure, to achieve the purpose of reducing the pulse. Use a peristaltic pump to control the level of a sink to change within a small height difference, then the flow rate at the exit will certainly maintain a very stable state. But this kind of use is only suitable for very few cases, it is not much used. The most common way is the second option, use the flexibility of the hose itself to work. 

This article is write by Baoding ZHUNZE Precision Pump Manufacturing Co., Ltd. original, without authorization can not be reproduced!

What kind of liquid can peristaltic pump transfer

During the process of peristaltic pump transferring, the liquid flows only through the tube and does not come into contact with other parts of the pump, so that the peristaltic pump can transfer as long as the tube can transmit.

Peristaltic pump tube commonly used material is silicon rubber, this silicone material is improved, it is not the same with the market ordinary silicone tube material, because the requirements of the tube used on the peristaltic pump are relatively high, the tubing needs to have high resilience, abrasion resistance, fatigue resistance, and a certain degree of corrosion resistance, ordinary silicone tube is not possible. Under normal circumstances, peristaltic pump silicone tube can withstand non-corrosive, weak acid and alkaline liquid transmission, food, beverages, cosmetics, biological products, pharmaceutical and other liquids. ZHUNZE pump tube is medical grade platinum vulcanization process of silicone tube.

Import tube common materials are as the following:

Pharmed tube, in some special occasions, the replacement of the tube is more cumbersome, hoping the tube has a high service life, this time import pharmed tube will be used, the composition is polypropylene and USP mineral oil mixture, Life of this tube is the longest one in the all peristaltic pump tube and can achieve up to ten times the life of the silicone tubing, which is the ideal choice for working with pressure. Pharmed tubing can be used to transfer medium acid-base liquid transport, tissue cell culture, fermentation, synthesis, separation, purification and process detection control (available for sensitive cell culture), production filtration and fermentation, aseptic filling, BPC tubing Road systems, food and beverage, cosmetics, biological products, pharmaceutical and other industries, the flexibility is particularly suitable for solenoid valve applications.

Chemical tube, this tube is double wall tube, the inner wall is made of Teflon material, the outer layer is made of thermoplastic elastomer, smooth surface, without plasticizer, can be resistant to strong acid and strong corrosive organic solvents, can transport 98% concentrated sulfuric acid, acetone, toluene.

Viton tube, the composition is fluorine rubber, can be resistant to strong acid (such as 98% concentration of concentrated sulfuric acid), most of the strong corrosion of organic solvents (such as chloroform, etc.).

Tygon tube, the composition is thermoplastic rubber, PVC and plasticizer mixture, can be used in medium acid-base liquid transmission, physical and chemical analysis equipment, can withstand almost all of the laboratory commonly used inorganic chemicals, can be used as condensation Equipment, incubator, trachea, drainage pipes, peristaltic pumps and other experimental hose.

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The main factors that affect the accuracy of peristaltic pump

Peristaltic pump is a kind of tubing pump, relying on the flexibility of the tube to work, can be used to continuous transmission and filling, the liquid only flows through the tube, so the health level is the highest of all kinds of pump. Peristaltic pump has a good self-sealing, can be simplified in the pipeline design, so in recent years, more and more filling machinery began to use peristaltic pump as a filling unit. However, some of the structural characteristics of the peristaltic pump will cause accuracy error during transmission, the following to explain in detail the reasons and solutions.

Peristaltic pump transmission of liquid is a share of a transmission, if the amount between each share is equal, then whether it is filling or continuous transmission can get very accurate results. The volume of the liquid is the volume of the tube between the two rollers of the peristaltic pump. The formation of this cavity has two factors: first, need two rollers to be cut off, and secondly, the tube itself needs to have Elasticity, the flexibility of the tube during operation will change, so the volume of the cavity will change, resulting in the problem of transmission accuracy.

A new tube with a cross-section is circular. When it is squeezed on the peristaltic pump for a few minutes, the cross-sectional area of the tube will become elliptical (see figure below), the time is very short and the oval shape will gradually become more elliptical shape, the process is relatively long, the amount of change is relatively slow, so the new tube flow rate attenuation at the beginning is relatively fast, and will gradually slow down until the hose ruptures.

 So the peristaltic pump precision problems are all around the elasticity of the tube, resulting in changes of the elasticity of the tube including three reasons, first, the elastic characteristics of the tube itself, Second, the pump head size accuracy ; Third, the amount of change of the transmission of liquid.

First explain the reasons for the first, the flexibility of the tube itself is determined by two aspects, one is the material problem, the other is the size of the tube, the tube material is no longer explain for details here, please see "Types and Selection of Peristaltic Pump tubings". The problem with the size of the tube is well understood. In the case of the same wall thickness, the greater the inner diameter of the tube, the worse the elasticity, on the contrary will be better; in the case of the same diameter of the tube, the thicker the wall thickness , The better the flexibility, and vice versa is worse. So when the high precision is required, it is improtant to use the appropriate size of the tube to minimize the resulting error.

Second, explain the reasons for the second aspect of the pump head accuracy, in the case of the same tube, if the gap between the wheel and the arc is too small, or the gap is not uniform, will cause the tube was over-squeezed, Resulting in the tube plastic deformation and dramatic changes in the flexibility of the tube, which ultimately affect the transmission accuracy. Uneven pressure pipe, will lead to a significant reduction in tubing life, therefore increasing the cost of peristaltic pump.

Thirdly, regarding the amount of change in the transfer liquid. The amount of change in the same type of liquid can be summed up by two factors. First, the amount of change in the temperature of the transfer liquid, because the tube is a flexible plastic body, different temperatures, will make its elastic changes, Said the higher the temperature, the worse the flexibility of the tube; second, the transmission of liquid night changes (that is, peristaltic pump suction range changes), because the peristaltic pump absorbs the liquid depending the elasticity of the tube, so the effect of suction the peristaltic pump has a large effect on the flow rate of the peristaltic pump (the head lift of the peristaltic pump has little effect on the flow rate) because the resistance generated by the suction line will directly counteract the resilience of the tube and affect the size of the rebound cavity.

If we want to improve the accuracy of peristaltic pump, it is necessary to exclude optimization according to the above factors one by one. First, the choice of a higher elastic material of the tube, and try to use the size of a reasonable tube; second, using of higher quality peristaltic pump head, ZHUNZE pump head has done a comprehensive optimization for the above effects factors, basically can be ruled out because the impact of the size of the pump head; third, to ensure uniformity of transmission of liquid, and liquid surface stability.

The above is the problems of the peristaltic pump using in the case of high-precision transmission need to pay attention to, in the conventional transmission, that is, the accuracy is not very high occasions, some problems can be negligible.

This article is write by Baoding ZHUNZE Precision Pump Manufacturing Co., Ltd. original, without authorization can not be reproduced!

The main factors affecting the life of the pump tubing

       在蠕动泵的使用中，软管是唯一的耗材，不同的软管材质适用于不同的液体，同一软管在不同的使用条件下也具有不同的使用寿命，不论什么材质的软管，影响其寿命的因素都类似，这里我们以硅胶管为例进行讲解，主要有以下几种因素：

第一、转速。转速与软管的寿命成反比，转速越高，软管的寿命越短，反之则越长。业内标定的软管寿命一般是600RPM连续运转的寿命（一些细管除外），一般来说，硅胶管在此条件下，连续工作寿命达到200小时是最基本的（三滚轮泵头）。之所以寿命跟转速有直接的关系，是因为正常破损的软管均是由于两侧内部挤压将壁厚磨损被折断，而这种折断和挤压的次数有直接的关系，在泵头的滚轮数量一致的情况下，相同时间挤压的次数又和转速有直接的关系，所以软管在滚轮数较多的泵头（泵头本身的尺寸精度一致）上运转会比滚轮数较少的泵头上寿命短一些。软管的寿命可以通过转速来直接计算，比如600RPM寿命为200小时，那么300RPM寿命至少是400小时，100RPM寿命至少是1200小时。

第二、泵头的尺寸精度。理想情况下，泵头的滚轮和泵头的圆弧应该是平行的，并且间隙应当是均匀的，但是在实际生产中，由于注塑零件的变形、金属零件的加工误差以及不恰当的装配工艺都会造成间隙不均匀，不平行。为了保证蠕动泵的密封性，都会控制蠕动泵的最低压力不能为“零”，即任意位置不能漏气，这样其实是保证了滚轮与圆弧之间的最大间隙处不漏气，这种情况下，间隙小的地方就会严重过压，这个地方在运行过程中软管就极易容易破裂，严重影响泵管的使用寿命。在实验中，一个1.5KG压力的泵头和3KG压力的泵头，软管表现的寿命会相差十几倍。品质高的蠕动泵泵头应该尽可能的保证因为尺寸精度的误差对软管造成的损伤，因为这不只是会影响软管的寿命，还会影响泵头运行的稳定性和传输精度。准择蠕动泵泵头针对于泵头精度的问题均做了特殊处理，保证滚轮与圆弧的平行度及间隙的均匀性。

配图，YZ泵头的图片

第三、传输的液体的化学性质，软管和液体的相容性一般会分为ABCD四种等级，适用性依次降低。

A 没有影响

B 轻微影响

C 有影响， 不建议长期使用

D 严重影响，不建议使用

在实际使用中，有时候液体的腐蚀性很强或者很特殊，可能没有完全适用的软管材质，这样就只能使用B和C等级的软管，这个时候因为软管收到液体的腐蚀，寿命就会比一般情况下短。

第四、传输液体的温度，温度越高，软管的弹性越差，抗拉能力会降低，这种情况下软管更容易因为滚轮的挤压而磨损，从而降低软管的寿命。

第五、输送压力，如果蠕动泵传输时软管内具有压力，会导致软管膨胀，这样软管每次被滚轮压扁后，又在压力的影响下迅速膨胀（相当于更高程度的疲劳折损），会显著降低软管的寿命。

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Reasons and solutions of bubble in peristaltic Pump

在使用蠕动泵传输流体时候，某些情况下在传输管路内会有气泡的产生，其原因是多种多样的。这些气泡的存在在某些场合是不允许出现的，所以就需要根据气泡产生的原因来进行消除或者改善。

下面通过几个客户提出的案例进行具体的分析：

案例1：

现象：吸程端某个或者某几个固定点持续或者间歇性的有气泡产生，其它部位没有产生气泡的现象。

原因：这种情况下，一般是吸程端有气泡产生的部位存在接头密封不严、软管有破损、软管局部孔隙过大（从软管外部是看不出有破损的，属于软管生产问题）。

解决方法：将软管接头从新接插一下，如果还是有气泡产生，则需要更换新接头；如若是软管的问题，则需要更换新软管。

案例2：

现象：吸程端液体密布非常多的气泡（气泡是漂浮于液体中间的），而在扬程端几乎看不到气泡。

原因：这种现象一般是传输较粘稠的液体，且吸程较大或着吸程处软管较细导致气泡产生。一般液体中都会有溶解的空气，正常大气压力下是看不到的，而这种粘稠的液体在蠕动泵软管内传输时候阻力是很大的，如果吸程较大或者吸程处软管较细，这种阻力会更加严重，这就导致蠕动泵吸程处软管内部有较大的负压产生。在负压情况下，溶解在粘稠液体中的空气小气泡体积就会变大，导致能在吸程端看到非常多的密集的气泡。因为液体较粘稠，这些小气泡移动阻力大，相对位置固定，不会产生气泡聚集的现象。所以当有气泡的液体进入到扬程端后，从负压环境过渡到正压环境，气泡体积缩小，恢复到自然状态，也就看不了。

解决方法：这种现象基本不会对液体流速产生影响，所以可以忽略。如果必须要消除气泡，可以考虑将液体加热或者置于负压环境减小液体的空气溶解度。

案例3：

现象：吸程端软管壁有密集大量气泡产生（可以很明显看到气泡在软管壁处产生，并且变大），并且气泡可以进入扬程端，扬程端管壁无密集气泡。

原因：这种现象一般是在吸程端软管有负压的情况下产生，主要原因是软管自身孔隙过大，密封不严，在有负压的情况下，空气能通过孔隙进入到软管内部。

解决方法：更换透气性更差的软管，可以有效防止外部空气进入软管内部（注：任何柔性软管管壁都是有孔隙存在的，不同材料孔隙的大小不同）。

案例4：

现象：吸程端和扬程端的软管管壁均有密集大量气泡产生，并且逐渐变大，并且可以顺着液体传输的方向上移动。

原因：这种现象一般出现在粘度不大的流体传输过程，主要原因是软管管壁对溶解在流体中的空气有吸附作用，导致溶解在液体中的空气会在管壁聚集，随着聚集空气数量的增加，就会产生体积较大的气泡，并且在流体传输时候会脱离管壁的束缚。在室温较高时，这种现象会更加明显。

解决方法：可以考虑将液体加热或者置于负压环境减小液体的空气溶解度；或者可以考虑降低环境的温度来减小这种现象的程度。

案例5

现象：吸程端无气泡产生或者进入，扬程端无规律性出现气泡。

原因：这种现象产生有两种原因：第一，泵头内部运行端的软管出现破损，导致空气进入；第二，传输的流体中有溶解的空气，泵头内部运行端的软管在被挤压做功的时候温度会升高，进而会对传输的流体有加热的现象，导致溶解在流体中的微小空气泡体积变大，然后产生聚集现象，当聚集的气泡足够大时，就会随着流体移动，出现在扬程端，这种现象一般出现在泵头转速较低时的情况。

解决方法：如果是第一种原因，则需要更换泵头运行端的软管；如果是第二种原因，可以考虑降低蠕动泵泵头的运行压力，即增大压管间隙，这样可以有效降低软管的温升，减小液体出现气泡的可能性，或者可以考虑将液体加热或者置于负压环境减小液体的空气溶解度，也可以通过提高蠕动泵的转速来避免这种现象的产生。

基本上，蠕动泵产生气泡的现象或者原因都包含在上述讲解的5个案例中。如果您在使用过程中，有更加特殊的现象，请致电保定准择恒流泵制造有限公司，我们将为您分析和解答。

本篇文章为保定准择恒流泵制造有限公司原创，未经授权不得转载！

Exploring the advantages and achievable accuracy of using peristaltic pumps to transport magnetic bead suspensions

Magnetic bead suspension is a special liquid composed of magnetic particles and liquid. Magnetic particles are usually small particles of metals such as iron, nickel, and diamond, which can be suspended in the night body to form a magnetic liquid. Magnetic beads are floating liquids with many unique properties, and therefore have wide applications in many fields.

Magnetic bead suspension has strong magnetism. Due to the presence of magnetic particles, magnetic bead suspensions can be controlled by a magnetic field. This property makes magnetic bead suspensions widely used in the preparation of magnetic materials, manufacturing of magnetic sensors, and other fields.

It is precisely because magnetic beads are a suspension containing small particles that the filling and transportation of magnetic beads have higher requirements for pumps. Among them, pump types that are more suitable include peristaltic pumps, ceramic pumps, etc. Ceramic pumps, due to the back and forth movement of the piston and cavity, will cause certain damage to the ceramic pump when particles enter the gap between the piston and cavity, and the magnetic bead liquid will also lose beads, which is not very friendly to production experiments.

Peristaltic pumps have the characteristic of low shear force, and some active biological liquids are also preferred to be transported and filled with peristaltic pumps. Therefore, if peristaltic pumps are used for transmission and filling, the phenomenon of bead loss should be alleviated. Moreover, such small particles can be accommodated by peristaltic pumps. Even if a 13 # fine tube with an inner diameter of 0.8mm is used to fill a slightly upgraded magnetic bead suspension, there will be no problem of pipeline blockage.

However, magnetic bead suspensions containing rare metals can be relatively expensive. In the past few years, people seem to have an inherent impression of peristaltic pumps, which is low accuracy. Therefore, in some situations where peristaltic pumps are suitable, the accuracy issue of peristaltic pumps is also avoided. In order to solve this problem and change people's perception of peristaltic pumps, our company has been committed to researching how to improve the filling accuracy of peristaltic pumps for decades, You can see that most of the videos on our company's official website showcase filling accuracy, which is our main focus. Even small quantities such as micro liter level filling are no exception. Therefore, customers who want to use peristaltic pumps but are concerned that their accuracy may not be achieved can contact us. Filling accuracy of tens of micro liters can be guaranteed to be within ± 0.5 micro liters. After our company's filling experiment, the accuracy of magnetic bead liquid is actually easier to ensure than water. We welcome users to call our company for consultation.

An in-depth analysis of the reasons why roller complementarity improves filling accuracy

Due to the pulsation phenomenon of peristaltic pump, repeatability accuracy has always been a problem in the industry when filling with peristaltic pump, the current more common solution is roller complementation, two tubes at the outlet to achieve the purpose of improving accuracy, the principle of this method is that the complementary roller will also make the pulsating curve complement, so as to obtain a smooth water flow, filling accuracy has been improved.

But this is just our wishful thinking, in fact, this is not the case, my company has done experiments, the same inner diameter of the tube, there is no difference of data range between single roller filling volume and roller complementary filling volume, this is because the data range of filling volume is decided by the size of the roller diameter, tube diameter, and the arc structure, but the number of rollers has nothing to do with it, the same structure of the pump head and tube, whether the roller number is 4 or 8, will not affect the final filling volume range, it will only affect the unit size, that is, the size of a liquid between the roller and the roller, the number of rollers affects the frequency of pulsation, will not change the amplitude of pulsation, the amplitude of pulsation is reflected in the form of the range of filling volume.

But some people will ask, then why in practical applications, this complementary form of rollers really improves our filling accuracy? Yes, customers who have used roller complementary solutions will indeed feel this way, because when we get a URS, what we consider is based on meeting customer requirements, such as customer requirements to fill 5mL of liquid in 0.6 seconds, accuracy requirements ±1%, that is, equivalent to peristaltic pumps need to have a flow rate of 500mL/min, with the flow we began to choose the tube, found that this flow needs to choose 25# tube to meet the speed requirements, but the accuracy of the 25# single tube cannot meet the customer's requirements, So we switched to a roller complementary solution, the roller complementary equivalent to the double pump head in series, so when the two tubes are transmitted at the same time, the flow is doubled, so we can use a small model of tube on it, so we switched to the 16# tube, complementary scheme, at this time we will find that the accuracy is indeed improved, the customer's requirements will be solved, but our careful analysis will find that the improvement of the accuracy of this scheme is not brought by the complementary rollers, It's because we switched the tube from 25# to 16#, which has a smaller inside diameter.

It is well known that on the same pump head, the smaller the inner diameter of the tube, the higher the accuracy, and vice versa, the worse the accuracy. In this case, we changed the tube from 25# to 16#, the accuracy itself will be improved, careful customers will find that if we only switch to complementary solutions, but do not change the tube model, the accuracy is still difficult to improve, on the contrary, even if we do not use complementary pump heads, as long as the tube is changed to 16#, the accuracy will be improved.

Therefore, the improvement of the accuracy of the roller complementary scheme is that the inner diameter of the tube has become smaller, not the effect of the complementary roller, but in any case, through this dual-channel complementary method, it is indeed possible to use a smaller tube, and also solves the problem of accuracy within a certain range, but this scheme can not fundamentally solve the problem of pulsation and accuracy, and the pipeline is more complex, not all applications can accept dual-channel parallel.

Therefore, the pulsation phenomenon of peristaltic pump to be fundamentally solved, requires strong technical reserves and a large number of experiments and research, at present, the company has a set of new technologies that can greatly reduce the pulsation of peristaltic pumps, and is currently in full research and development, so stay tuned!

Baoding Zhunze Precision pump Manufacturing Co., Ltd. original

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Liquid density

Liquid viscosity

Routine maintenance of peristaltic pumps

       蠕动泵的构成分为驱动器、泵头、软管三大组成部分，在使用过程中，软管为消耗品，需要定期更换，驱动器和泵头均为免维护部件，日常只需要做好干燥清洁工作，不需要特殊的保养。

    在驱动器的使用中，常见的损坏有以下几种情况，使用中需要提起注意：

    第一、电压过高，导致驱动器烧掉；

    第二、意外的高空跌落，导致内部零部件损坏；

    第三、驱动器进水或进入腐蚀性的液体，导致电路短路或被腐蚀；

注意以上三点，一个合格的驱动器不应轻易损坏并且可以长期连续工作。

在泵头的使用中，常见的损坏有以下几种情况，使用中需要提起注意：

    第一、转速过高，超过泵头的设计转速要求

    第二、意外的高空跌落，导致泵头变形或者损坏；

    第三、软管泄露导致液体进入泵头的滚轮及主轴轴承，损坏轴承；

准择蠕动泵根据驱动器常见的问题均做了特殊的防护处理，针对工厂电压不稳定的情况，内部电路进行了宽电压设计，并且全部采用进口电子元器件；针对于高空跌落，内部一些重要元器件均做了防震处理；针对于驱动器进水或进入腐蚀性的液体，电路板均做了加厚三防处理，最大程度上保证驱动器的可靠运行。

准择蠕动泵根据泵头常见的问题也做了特殊的防护处理，所有的轴承均采用不锈钢高速轴承，解决了一些需要超高转速运转的特殊场合的应用，并且可以长期稳定的运行；且不锈钢轴承的耐腐蚀能力要比普通轴承钢材质的轴承强很多；准择蠕动泵泵头外壳采用进口PPS原材料，泵头的刚性、韧性都非常出色；稳定性、抗跌落性都有了很大的提高；针对于软管中液体的泄露问题，准择蠕动泵的滚轮做了特殊的防尘防水处理，可以有效保护滚轮轴承不受污染（滚轮轴承的损坏是蠕动泵泵头的最常见故障），同时准择蠕动泵泵头也因此具备了在恶劣工况下工作的能力。

软管作为蠕动泵使用中的唯一耗材，它的消耗决定了蠕动泵的耗材成本，一般来说，泵管寿命是蠕动泵泵头在600RPM的转速下标定的（一些特殊的小细管除外），常规硅胶管在此转速下的连续工作寿命可以达到200小时（进口长寿命的软管寿命会比常规硅胶管长十几倍），如果转速降低至300RPM，泵头的寿命至少可以达到400小时以上，也就是说泵管的寿命和转速是成反比的。在能满足传输要求的情况下，让蠕动泵泵头以较低的转速工作，能够显著的提高软管的寿命，从而降低蠕动泵的使用成本。

本篇文章为保定准择恒流泵制造有限公司原创，未经授权不得转载！