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2018

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08

Metering pump knowledge explanation

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Metering pumps are also called quantitative pumps or proportional pumps. The metering pump is a special volumetric pump that can meet the needs of various strict technological processes. The flow rate can be infinitely adjusted within the range of 0-99.99%. It is used to transport liquids (especially corrosive liquids). The metering pump is a type of fluid conveying machinery. Its outstanding feature is that it can maintain a constant flow rate independent of the discharge pressure. The use of metering pumps can complete the functions of conveying, measuring and regulating at the same time, thus simplifying the production process. Using multiple metering pumps, several media can be input into the process flow in accurate proportions for mixing. Due to its own prominence, metering pumps have now been widely used in various industrial fields such as petrochemical, pharmaceutical, and food.

Metering pumps are also called quantitative pumps or proportional pumps. The metering pump is a special volumetric pump that can meet the needs of various strict technological processes. The flow rate can be infinitely adjusted within the range of 0-99.99%. It is used to transport liquids (especially corrosive liquids). The metering pump is a type of fluid conveying machinery. Its outstanding feature is that it can maintain a constant flow rate independent of the discharge pressure. The use of metering pumps can complete the functions of conveying, measuring and regulating at the same time, thus simplifying the production process. Using multiple metering pumps, several media can be input into the process flow in accurate proportions for mixing. Due to its own prominence, metering pumps have now been widely used in various industrial fields such as petrochemical, pharmaceutical, and food.

 

Classification of metering pumps

⒈ According to the flow-passing part: ⑴Plunger, piston type ⑵Mechanical diaphragm type ⑶Hydraulic diaphragm type

⒉ According to the driving mode: ⑴ Motor drive ⑵ Electromagnetic drive

⒊ According to the working mode: ⑴ reciprocating type ⑵ rotary type ⑶ gear type

4. According to the characteristics of the pump: ⑴ Extra large base ⑵ Large base ⑶ Medium base ⑷ Small base ⑸ Micro base.

Other classification methods: electronic control type, air control type, thermal insulation type, heating type, high viscosity type and other principle characteristics

 

Metering pump structure

The pump consists of three parts: motor, transmission box, and cylinder. The transmission box component is composed of a worm gear mechanism, a stroke adjustment mechanism and a crank connecting rod mechanism; the high adjustment stroke is achieved by rotating the adjustment handwheel, thereby changing the eccentricity of the moving shaft to achieve the purpose of changing the plunger (piston) stroke. The cylinder components are composed of pump head, suction valve group, discharge valve group, plunger and packing seal.

 

The principle of metering pump

The motor drives the worm through the coupling and reduces the speed of the worm gear to cause the main shaft and the eccentric to rotate. The eccentric drives the sliding adjustment seat of the bow-shaped connecting rod to reciprocate. When the plunger moves to the rear dead center, a vacuum is gradually formed in the pump chamber, the suction valve opens, and the liquid is sucked in; when the plunger moves to the forward dead center, the suction valve closes, the discharge valve opens, and the liquid moves further through the plunger. Expelled during exercise. The reciprocating and sequential operation of the pump forms a continuous, pressured and quantitative discharge of liquid.