What is a diaphragm pump? And how should it be selected?

What is a diaphragm pump? And how should it be selected?

Diaphragm pump, also known as control pump, is the main type of actuator. The flow of the fluid can be changed through dynamic operation by receiving the control signal from the modulation unit. Diaphragm pump is generally composed of actuator and valve. With compressed air as power source, it can pump all kinds of corrosive liquid, granular liquid, high viscosity, volatile, flammable, highly toxic liquid.

Pneumatic diaphragm pump has four materials: plastic, aluminum alloy, cast iron, stainless steel. Electric diaphragm pump has four materials: plastic, aluminum alloy, cast iron, stainless steel. Diaphragm pump according to the different liquid medium, the use of nitrile rubber, neoprene rubber, fluorine rubber, polyvinylidene fluoride, polytetrahydroethylene. To meet the demand. Placed in a variety of special occasions, often used for pumping media cannot pump. Diaphragm pump according to the power of the actuator can be divided into pneumatic, electric and hydraulic power. They are pneumatic diaphragm pumps driven by compressed air, electric diaphragm pumps driven by electricity, electro-hydraulic diaphragm pumps driven by pressure from liquid media such as oil, as well as solenoid valves, electronic, intelligent and fieldbus diaphragms, depending on their functions and characteristics. Membrane pump. Diaphragm pump product variety, structure is also different, but also constantly updated and change. Generally speaking, valves are universal. They can be matched not only with pneumatic actuators, but also with electric actuators or other actuators.

Category: Electro-Pneumatic Diaphragm Pump -3 "Plastic Electro-pneumatic Diaphragm Pump -A80 The Verderair Almatec series adds the largest size to the pump A80. The pump is a high-capacity design consisting of three parts: two diaphragm chambers and a centrobody for easy operation and maintenance. The import and export size is DN80, the maximum flow rate is 48 cubic meters/hour, and the maximum particle size is allowed to be 15mm.

Diaphragm pump Pneumatic diaphragm pump peristaltic pump hose pump Magnetic pump Verderair Almatec has a wide range of applications from chemical to food industries. Almatec small pumps are typically used for circulation and sampling, while larger pumps are primarily used in the chemical and OEM markets. Pneumatic valve is an important part of pneumatic diaphragm pump. The patented A80 valve is completely metal-free, with high reliability and low noise. This unique design provides a continuous balanced load for the diaphragm without differential pressure, thus extending the life of the diaphragm.

First, diaphragm pump selection

The valve body selection of diaphragm pump is the most important link in the selection of diaphragm pump. There are many kinds of diaphragm pump valves, commonly used are straight through single seat, straight through two, Angle type, diaphragm type, small flow, tee, eccentric rotation, butterfly, sleeve type, spherical 10 kinds. Before selecting a valve, carefully analyze the media, process conditions and parameters that control the process, gather sufficient data to understand the requirements of the diaphragm pump system, and determine the type of valve to use based on the collected data. When making specific choices, consider the following:　

(1) The shape and structure of the spool are mainly based on the selected flow characteristics and unbalanced forces.　

(2) Wear resistance When the fluid medium is suspension containing high concentration of wear particles, serious friction will occur each time the joint surface of valve core and valve seat is closed. Therefore, the flow of the valve should be smooth, and the internal material of the valve should be hard.

(3) Due to the corrosiveness of the medium, under the condition of meeting the adjustment function, try to choose the valve with simple structure.

(4) When the temperature and pressure of the medium is high and the change is large, the valve core and seat material should be selected as the temperature and pressure change little valve.

(5) Prevent flash evaporation and gas erosion only in the liquid medium. In the actual production process, flash evaporation and cavitation not only affect the calculation of flow coefficient, but also cause vibration and noise, and shorten the service life of the valve. Therefore, the valve should be selected to prevent flash and cavitation.

Two, diaphragm pump selection

(1) The output force of the actuator, no matter what its type, is effective to overcome the load (mainly refers to the unbalanced force and unbalanced moment plus friction, sealing force, gravity and other related forces). Therefore, in order to make the diaphragm pump work normally, the supporting actuator should be able to produce enough output force, overcome all kinds of resistance, to ensure high sealing and valve opening. For double acting pneumatic, hydraulic and electric actuators, there is usually no return spring. The magnitude of the force is independent of the direction of action. Therefore, the key to choose the actuator is to find out the maximum output force and torque of the motor. For single acting pneumatic actuator, the output force is related to the valve opening, and the force on the diaphragm pump will also affect its motion characteristics. Therefore, it is necessary to establish a force balance throughout the opening range of the diaphragm pump.

(2) After the output force of the actuator is determined by the type of the actuator, the corresponding actuator is selected according to the requirements of the technological environment. On-site explosion-proof requirements for pneumatic actuator, junction box explosion-proof, electric actuator can not be selected. If there is no explosion-proof requirement, pneumatic and electric actuator can be selected, but considering energy saving, electric actuator should be selected as far as possible. In the hydraulic actuator, its application is not as wide as the pneumatic and electric actuator, but the adjustment accuracy is high.