Pneumatic diaphragm pump works

1, compressed air as power. 2, is a volumetric displacement pump caused by the reciprocating deformation of the diaphragm. The working principle of the diaphragm pump is similar to that of the piston pump. Due to the working principle of the diaphragm pump, the diaphragm pump has the following features: (1) The pump can not overheat: Air-powered, in the exhaust is an expansion of endothermic process, pneumatic pump temperature is reduced, no harmful gas emissions. (2) will not produce spark: pneumatic diaphragm pump without electricity as power, grounding and then prevent the static spark Pneumatic diaphragm pump (3) can contain particles of liquid: because the volume of work and imports for the ball valve, it is not easy to be blocked . (4) Extremely low shear force on the material: How to suck in the work and how to spit it out, so the material agitation is minimal, which is suitable for the transportation of unstable substances (5) The flow rate can be adjusted, and the section can be installed at the exit of the material Flow valve to regulate flow. (6) Self-priming function. (7) Can be air operated without danger. (8) can dive work. (9) The fluids that can be delivered are extremely wide, ranging from low viscosity to high viscosity, from corrosive to viscous. (10) There is no complicated control system, no cables, fuses and so on. (11) small size, light weight, easy to move. (12) Maintenance is easy without lubrication, and will not pollute the work environment due to drip. (13) The pump is always efficient and will not be reduced by wear. (14) 100% energy utilization, shut down the outlet, the pump automatically shut down, the device moves, wear, overload, fever (15) no dynamic seal, easy maintenance to avoid leakage. No dead spots at work. First, the composition and classification of diaphragm pump Diaphragm pump, also known as control pump, is the main type of actuator, by receiving the control signal output of the control unit, with the power to change the fluid flow. Diaphragm pump generally by the implementing agencies and valves. If you press the actuator used by its power, the diaphragm pump can be divided into pneumatic, electric, hydraulic three, namely compressed air as the power source of the pneumatic diaphragm pump to electric power source electric diaphragm pump to liquid medium (Such as oil, etc.) pressure-driven electro-hydraulic diaphragm pumps, in addition, according to their functions and characteristics of points, as well as solenoid valves, electronic, intelligent, field bus diaphragm pumps. Diaphragm pumps are many types of products, the structure is also diverse, but also constantly updated and changing. Generally speaking, the valve is universal, it can be matched with the pneumatic actuator, but also with the electric actuator or other actuator. Pneumatic diaphragm pump principle Second, the choice of diaphragm pump type 1, diaphragm pump valve body type selection The choice of diaphragm is the most important part of the diaphragm pump. Diaphragm valve body types, commonly used through a single seat, through two-seater, angle, diaphragm, small flow, tee, eccentric rotation, butterfly, sleeve, spherical and other 10 species. Before selecting a valve, carefully analyze the medium, process conditions, and parameters of the control process, collect enough data to understand the system's requirements for the diaphragm pump, and determine the type of valve to be used based on the data collected. In the specific choice, the following aspects can be considered: (1) spool shape and structure based on the selected flow characteristics and unbalanced forces and other factors to consider. (2) Abrasion resistance When the fluid medium is a suspension containing high concentration of abrasive particles, the valve core and seat joint surfaces will be severely rubbed each time they are closed. Therefore, the flow of the valve should be smooth, the valve's internal material to be hard. (3) Corrosion resistance Due to the corrosive medium, try to choose a simple structure of the valve in the case of regulatory function. (4) Medium temperature, pressure When the medium temperature, high pressure and changes, should use the valve core and valve seat material by temperature, pressure changes in small valves. (5) to prevent flash and cavitation flash and cavitation only produce liquid medium. In the actual production process, steam and air not only affects the calculation of flow coefficient, vibration and noise will be formed, so that the shortened life of the valve, thus preventing the valve of the steam and air valves should be selected. 2, the choice of diaphragm pump actuator (1) the output force considerations Actuator no matter what type of output force is used to overcome the effective load (mainly refers to unbalanced and unbalanced torque plus friction , Sealing force, gravity and other related forces). Therefore, in order for the diaphragm pump to work properly, the associated actuator must be capable of producing enough output force to overcome various resistances and ensure a high degree of sealing and valve opening. For double-acting pneumatic, hydraulic, electric actuator, there is usually no return spring. The size of the force has nothing to do with its direction of operation, so the key to choosing an actuator lies in knowing the maximum output force and the torque of the motor. For single-acting pneumatic actuators, the output force is related to the opening of the valve. The force appearing on the diaphragm pump will also affect the kinematics and therefore a force balance across the opening of the diaphragm pump is required. (2) Determination of the type of implementing agency After determining the output of implementing agencies, select the appropriate implementing agencies according to the requirements of the environment for process use. For on-site explosion-proof requirements, pneumatic actuators should be used, and the junction box for the explosion-proof, you can not choose the electric actuator. If there is no explosion-proof requirements, the pneumatic and electric actuators can be used, but from the energy-saving aspects, should try to use electric actuators. For the hydraulic actuator, its use is not as good as the pneumatic, electric actuators a wide range, but with high precision, fast speed and smooth characteristics, therefore, in some cases, in order to achieve better regulation effect, you must use hydraulic actuator Institutions, such as power plant transparent speed control, refinery catalytic reactor temperature control and so on. Third, the role of the diaphragm pump diaphragm pump action mode is selected only when the pneumatic actuator only, the role of the positive and negative effect through the implementing agencies and the positive and negative valve action combination. There are four types of combination that is positive (air-off type), positive and negative (air-type), anyway (air-type), anti-anti (anti-off type) Open and Qi off two. For the diaphragm pump mode of action, mainly from three aspects: a) process safety; b) the characteristics of the media; c) to ensure product quality, economic loss is minimal. Fourth, the choice of flow characteristics of diaphragm pumps Diaphragm pump flow characteristics refers to the relative flow of the medium through the valve displacement and the relationship between the displacement (the relative valve opening), the ideal flow characteristics are straight, equal percentage (logarithm), parabola And quickly open 4 kinds. The only commonly used ideal flow characteristics, such as straight line, such as the percentage (logarithm), quickly open three. Parabolic flow characteristics between the straight line and equal percentage, the general percentage of the characteristics can be used instead of the other, while the fast opening characteristics are mainly used for two-bit adjustment and program control, so the selection of diaphragm pump is actually a straight line and equal percentage flow characteristics s Choice. The choice of diaphragm pump flow characteristics can be calculated theoretically, but the methods and equations used are complicated. At present, the use of more experience guidelines, specifically from the following aspects: ① from the regulatory system to adjust the quality of analysis and selection; ② from process piping considerations; ③ from the load changes. Select the flow characteristics of the diaphragm pump, you can determine the valve spool according to its flow characteristics of the shape and structure, but for such as diaphragm valves, butterfly valves, due to their structural characteristics, it is impossible to change the shape of the valve spool to achieve The required flow characteristics can be achieved by changing the feedback cam profile of the valve positioner fitted. Diaphragm pump structure Five Diaphragm Pump Diaphragm Diaphragm selection and determination of the main basis for the flow of the valve that Cv. In a variety of engineering design and selection of instruments, should be on the diaphragm Cv calculations, diaphragm pumps and provide design specifications. Cv calculated from the diaphragm to the diameter of the valve to determine the general subject to the following steps: 1, to determine the flow calculation. Existing production capacity, equipment load and medium conditions, decided to calculate the flow rate of Qmax and Qmin. 2, before and after the valve to determine the pressure. According to the selected valve flow characteristics and system characteristics selected S (resistance coefficient), and then determine the calculation of pressure. 3, calculate Cv. According to the adjusted medium to choose the appropriate formula and chart Cmax and Cmin. 4, the choice of Cv. According to Cmax, in the selected product standard series select> Cmax and its closest level C. 5, diaphragm pump opening checking. The general requirements of the maximum flow when the calculation of the opening ≯ 90%, the minimum calculation of flow when the opening ≮ 10%. 6, the actual adjustable diaphragm pump checking. Generally require the actual adjustable ratio ≮10. 7, Seat diameter and nominal diameter of the determination. After verification, according to C to determine. VI Conclusion diaphragm pump selection is a very meticulous work, not only have a solid professional theoretical knowledge, but also have rich practical experience. Good choice not only conducive to adjusting the control loop PID parameter setting, so that the parameters are to be tuned to better control effect, but also greatly increase the service life of the diaphragm pump. The choice of diaphragm pump should be adapted to local conditions and not static. To summarize and innovate constantly in the process of practice, especially with the application of mechatronics, computer and digital information technology, the structural function of diaphragm pump becomes better and more comprehensive, For the choice of diaphragm pump provides a great convenience. QBY pneumatic diaphragm pump, DBY electric diaphragm pump. Product Overview: QBY series of pneumatic diaphragm pumps using compressed air, steam, industrial exhaust gas as the power source for a variety of corrosive liquids, with particles of liquid, high viscosity, volatile, flammable, highly toxic liquids, can be pumping Light absorption, with self-priming pumps, submersible pumps, shielded pumps, mud pumps and impurity pumps and other transportation machinery, many of the advantages of widely used in petroleum, chemical, electronics, ceramics, textile and other industries. The series of pumps placed in a variety of special occasions, used to pump a variety of conventional pump can not be aspirated medium, have achieved satisfactory results. Pumping medium range: 1, diaphragm pump peanut butter, pickles, mashed potatoes, small sausage, jam apple pulp, chocolate and so on. 2, diaphragm pump paint, gum, paint. 3, adhesives and glue, all types available diaphragm pump. 4, all kinds of tiles, porcelain, brick and pottery glaze. 5, the well drilled, with the diaphragm pump deposits and grouting. 6, diaphragm pump a variety of emulsifiers and fillers. 7, diaphragm pump all kinds of sewage. 8, pump for tankers, barge clearance to absorb the warehouse water. 9, hop and baking powder slurry, syrup, molasses. 10, diaphragm pump mine, tunnel, tunnel, mineral processing, slag in the water. 11, diaphragm pump grouting and mortar, all kinds of rubber pulp. 12, a variety of abrasive, etchant, oil and mud, grease and general cleaning containers. 13, a variety of highly toxic, flammable, volatile liquid. 14, all kinds of acid, alkali, strong corrosive liquid.