Selection of different types of industrial pumps

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This post was last edited by Reichert-Li Zongsheng on 2022-12-14 09:30. Two main types of industrial pumps – dynamic pumps and positive displacement pumps. There are mainly two types of industrial pumps: dynamic pumps and positive displacement pumps. A power pump uses centrifugal force to generate velocity in the liquid being pumped; this velocity is converted into pressure, which can be adjusted to push the fluid through the pump. A power pump contains one or more impellers; the rotation of these impellers creates a vacuum that drives the fluid within the pump casing. These are the most common types of industrial pumps, as they have the fewest moving parts and can operate continuously. Positive displacement pumps use the reciprocating motion of plungers, pistons, or diaphragms to force liquid through the pump. Unlike the steady delivery of liquids, pumps of this type typically produce a pulsed output, as liquid is captured and discharged in fixed volumes. These pumps are more complex in design than power pumps, but they can handle greater variations in flow rate and pressure. They can also handle high-viscosity liquids under high pressure. Power pumps 1. Centrifugal pumps Centrifugal pumps are the most commonly used type of industrial pump in most industries. These pumps use the rotational energy from a rotor with one or more impellers to move liquids. The liquid enters the rotating impeller along the axis of the pump and is discharged toward the pump’s outlet due to centrifugal force. Pumps of this type can handle liquids containing suspended solids. There are also centrifugal pumps of different types and sizes to meet various industrial needs. 2. Submersible pumps are primarily used for transporting sewage and rainwater, but they are also employed in other industries. These pumps are designed to operate under extreme conditions, making them an ideal choice for transporting waste, chemicals, graywater, groundwater, and food. 3. Fire pumps: Fire pumps are designed to transport liquids under various pressures (which can be classified by outlet pressure level as low-pressure fire pumps, medium-pressure fire pumps, medium-low pressure fire pumps, high-pressure fire pumps, and high-low pressure fire pumps); therefore, they are primarily used in the fire protection industry. These pumps can be installed in industrial environments or on the streets, connected directly to the municipal water supply system. Positive displacement pumps 4. Cam pumps Cam pumps consist of pairs of rotating \"cams\" that are similar to gears, even though they do not come into contact with each other. When the cams rotate together, they create a suction force that draws liquid into the pump. When liquid enters the pump housing, it is trapped because the cam rotates in only one direction. The liquid continues to be pushed toward the pump’s output area. Since the cams do not touch each other, nor do they touch the pump housing, pumps of this type can handle liquids with high density as well as liquids containing solid particles, such as molasses, cooking oils, chocolate paste, paint, ink, asphalt, paraffin, lubricants, clay, and so on. 5. Screw pump A screw pump is a type of pump that operates using several rotating screws inside a casing. When a screw pump is in operation, the screws rotate while meshing with each other; the liquid is then driven by the helical grooves on one or several of these screws and discharged in an axial direction. The main advantages of screw pumps are their compact structure, virtually pulse-free flow and pressure, smooth operation, long service life, high efficiency, as well as a wide range of applicable liquids and viscosities ； The disadvantage is that it requires high manufacturing precision, and its operating characteristics are sensitive to changes in viscosity. The gap between the screws is very small; therefore, this type of pump is more suitable for applications such as simple water transfer or the pumping of highly viscous liquids (such as those with a viscosity of 650–1000 mm2/s). 6. Diaphragm pump: Also known as a control pump, it is the main type of actuator that operates by receiving control signals from the modulation unit. Diaphragm pumps use power to regulate fluid flow. Diaphragm pumps generally consist of an actuator and a valve. Diaphragm pumps can be classified into three types based on the power source used by their actuators: pneumatic diaphragm pumps, electric diaphragm pumps, and hydraulic diaphragm pumps. In the absence of electricity, pneumatic diaphragm pumps or hydraulic diaphragm pumps are ideal choices. Diaphragm pumps are used to transport chemicals with a high flash point, such as volatile solvents and corrosive chemicals. A pneumatic diaphragm pump is a widely used type of diaphragm pump; it has two chambers equipped with diaphragms, and air is transferred between these two chambers through valves. This change in air creates a pressure that moves the fluid from one side of the pump to the other. 7. Gear pump A gear pump is a type of rotary positive-displacement pump, and it belongs to the category of rotor pumps. Inside the pump casing, there is a pair of meshing gears: one is the driving gear and the other is the driven gear, with the driving gear causing the latter to rotate through meshing. A small gap is left between the gear and the pump housing. As the gears inside the pump rotate, they force the liquid to pass through the pump by creating suction and voids within the system. The fluid entering the pump receives energy from the grooves in the gears, which in turn drives the fluid to the output area. Since the gear rotates in a specific direction, this prevents the liquid from flowing back. Gear pumps are typically used to transport viscous liquids that contain no solid substances, such as oils, greases, polymers, synthetic resins, rubber pastes, adhesives, emulsions, fats, cod liver oil, paints, shampoos, cosmetics, and so on. 8. Plunger pump: A plunger pump is a specific type of positive-displacement pump; it is a reciprocating pump that consists of a hydraulic section and a drive section. It generates suction or discharge pressure through a plunger (piston). The drive end moves the plunger backward, creating a gap and vacuum that draws the fluid into the pump housing. As the plunger moves forward, it pressurizes the chamber, and the fluid drawn into the pump is discharged. A valve is also installed in the pump to prevent fluid from flowing back from the inlet. These types of pumps are used for the simple transfer of liquid materials and to assist in the operation of more complex pumps. Plunger pumps are suitable for transporting various media with low flow rates but high pressures. When the flow rate is less than 100 m3/h and the discharge pressure is greater than 10 MPa, it exhibits high efficiency and good operational performance. For all positive-displacement pumps, when the pump is operating and the outlet pipe is blocked or the outlet valve is not open, the pressure at the pump outlet and in the pump chamber area surrounding it rises rapidly. Therefore, a safety valve is needed to limit the pressure at that location.