Also known as a chemical dosing or injection pump depend on the industry it gets utilized in, it is a positive displacement pump designed to pump chemicals at a precise rate of flow.
Chemical metering pumps get employed in many different industries including agriculture, industrial setups, large-scale medical manufacturing as well as in treating swimming pool water.
There are many ways the chemical dosing pump can maintain the precise rate of flow, depending on the type of pump as well as the features it includes. Nonetheless, most metering pumps draw an exact amount of chemical into a chamber before injecting it into a pipe or tank for dosing.
Types of Chemical dosing pumps
There four main types of chemical injection pumps, and they vary concerning their pumping mechanisms, their field of application, types of chemicals pumped as well as pumping pressure.
a) Constant Injection Diaphragm
In this kind of chemical metering pump, the pump chamber gets filled and emptied via a piston, diaphragm, and valves placed on the inlet and outlet of the chamber. When the piston gets pulled, the chamber draws in the chemical to a pre-calibrated amount while the outlet valve gets closed.
When the required volume gets achieved, the piston gets pushed inwards to inject the chemical at a specified rate of flow.
These types of pumps provide a near-accurate rate of flow, and with proper adjustments, it can pump chemical at variable rates of flow.
b) Pulse Injection Diaphragm
In this type of chemical dosing pump, the diaphragm effect works in a similar manner to that of the Constant Injection Diaphragm pump. However, in this pump, the rate of flow gets controlled by a solenoid coil.
Instead of a slow and constant pumping, the solenoid draws chemical into the chamber and pumps it out in pulses. The rate of flow here gets controlled by producing the pulses at timed intervals.
The mechanical and electrical components are quite simple, and hence the pump is less accurate regarding chemical dosage volumes due to the timed pulse injections. If the chemical supply pressure fluctuates, the dosage will also vary as a result of the timed pulses.
As a consequence of the low accuracy, these pumps are quite cheap.
c) Lobe chemical injection pumps
These types of pumps utilize an impeller set of gears to allow fixed volume of chemical to enter the diaphragm. Though the volume measurement is not as accurate as in diaphragm pumps, these types of pumps mostly get used in the dosing chemicals with high viscosity.
Additionally, it is intricate to adjust the pump accurately for low rates of flow. However, one advantage of the pump is that it self-lubricates its gears via the viscous chemicals and hence it has a reduced wear rate.
d) Peristaltic Chemical metering pumps
Peristaltic pumps are quite accurate because they include a semi-circularly bent flexible tube through which the chemical passes flows. A mechanical arm moves along the curved tube, and its purpose is to capture the required volume of a chemical by squeezing the tube and pushing the chemical along the tube into the dosing pipe.
The main disadvantages of these pumps are that they wear quickly, and due to the use of an expandable rubber tube, they are not applicable to high rates of flow.
For more information about chemical pumps, talk to a professional.