As an ideal machine and equipment for liquid high-precision metrological verification and dosing, metering pump has now been widely used in all walks of life including pharmaceutical industry, food industry and petrochemical equipment. In the whole process of processing technology, it shoulders the metrological verification of strong corrosion, harmful, high viscosity and high pressure substances plus daily tasks. After more than half a century of practice and technical improvement, metering pump has already entered its high-speed development period.

Nowadays, the perfect driving force driver method and the raw material technology of liquid transport end (pump impeller) make the new metering pump basically able to transport all the basic and special substances, and its pressure and volume can also meet most of the requirements of industrial production.

With the general improvement of the production process index value and automation technology level, as the final actuator of the metrological verification and addition stage of organic chemical drugs, the safety factor and divisional planning of the metering pump are becoming more and more critical. Petrochemical equipment and other fields have always been famous for the high aspect ratio automation technology of production process, and it is also one of the industries in which the centralized and distributed system, the distributed system and the intelligent computer automatic control system are widely used. Therefore, it is stipulated that the matching electric actuator metering pump should also have various operation modes, It can easily form a variety of control circuits with computer software to complete more complicated process management.

In order to meet this new development trend, international metering pump manufacturers, such as Prometheus of France, are once again leading the way in ensuring the traditional characteristics of their products. In addition, with the help of embedded microcontroller system software, they integrate a variety of adjustment and control functions and data communication protocols into metering pumps, truly completing the two-dimensional adjustment from four stroke frequency to four stroke length, Make its products into a good innovative intelligent high precision metering pump.

Basic principle of metering pump

As we all know, the key of metering pump is composed of driving force driver, liquid transportation and adjustment control. The driving force driver equipment drives the liquid transport diaphragm (piston rod) to complete repeated movement through the mechanical equipment linkage system software: the diaphragm (piston rod) self induced electromotive force before the four stroke will be absorbed by the transport liquid, and the self induced electromotive force after the four stroke will discharge the liquid out of the pump impeller; Therefore, the liquid transportation capacity can be adjusted by changing the frequency of four strokes or the length of each four strokes. The high precision machining accuracy ensures the pump luminosity every time, so as to complete the high precision metrological verification of transported materials.

Because of the different driving force driver and liquid transportation method, metering pump can be roughly divided into plunger pump type and diaphragm type.

1. There are two key types of piston pump metering pump: valve pump and valveless pump. Plunger pump metering pump is widely used in petrochemical equipment industry because of its advantages of simple structure and heat resistance and high pressure. For low viscosity substances, the general gear pump is not enough under high working pressure. A valveless rotary piston pump metering pump has received more and more attention, and is widely used in the metrological verification of low viscosity substances such as sugar paddle, chocolate and petroleum additives. Due to the structural defect that there is no complete protection between the material to be measured and verified and the lubricating fluid in the pump, the piston pump metering pump is subject to many restrictions in the application of liquid measurement and verification in high pollution control regulations.

2. Diaphragm pump to put it bluntly, diaphragm pump uses a specially designed soft diaphragm instead of piston rod to complete the repeated movement under the effect of actuator organization and carry out the whole process of suction and discharge. Because of the isolation effect of the diaphragm, the structure type truly completes the protection between the liquid to be measured and verified and the wetted tissue of the actuator. The overall design of new technology and the use of new materials have already further improved the service life of the diaphragm. Coupled with the excellent anti-corrosion characteristics of polymer materials, the diaphragm metering pump has become the main type of pump in the application of liquid metering verification at this stage. Among the members of the diaphragm metering pump family, the hydraulic drive diaphragm pump uses gear oil to drive the diaphragm evenly, which gets rid of the defect that the bearing force of the diaphragm is too centralized under the immediate drive method of mechanical equipment, and improves the service life and pressure limit of the diaphragm. In order to get rid of the common faults of single diaphragm metering pump caused by diaphragm damage, some metering pumps are equipped with diaphragm damage sensor to complete the automatic interlocking maintenance when the diaphragm is cracked; The metrological verification of the pump impeller with double diaphragm structure further improves its safety factor, which is suitable for the application places that are particularly sensitive to safety maintenance.

As a kind of diaphragm metering pump, the electromagnetic driven metering pump uses the electromagnetic coil to cause pulsating driving force, which saves the motor and speed control organization, and makes the system software delicate and compact. It is the key branch of the small measuring range bottom pressure metering pump.

Now, the technology of high precision metering pump has been very perfect. Its liquid measurement and verification transportation capacity is large, which can reach 0-100000l / h, and the pressure can reach 4000bar. The scope of work covers the requirements of all industries of industrial production.