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When I should specify a Solenoid dosing pump and a Motor dosing pump? 3

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cempass

Petroleum
May 12, 2006
2
I have to specify an acid / basic dosing pumps as a neutralization system. The flows are 0.07 and 0.005 l/h respectivaly. The discharge pressure is atmospheric (to a basin pod). Shall I specify a motor dosing pump or a solenoid dosing pump? and why? I have seen in the market that motor pumps go down as low as 0.15 l/h, so, it seems that a solenoid dosing pump sounds to be the right choise for such low flow and pressure. With this problem in mind the final question to answer is : when to use a Solenoid dosing pump Vs to use a Motor dosing pump? Can anyone help me on this regard? Thsnks...
 
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Solenoid diaphragm metering pumps are available in capacities ranging from 0.74 to 75 l/h at a back pressure of 16 to 2 bar. To be able to meter almost any liquid chemicals, ProMinent uses a very extensive range of materials. (ProMinent).

The flow is very low contact your local dosing pump supplier for better result as per the design.
 
It is a personal preference. Motor driven pumps are more expensive and reliable, but many are not familiar enough with the equipment to know the difference. Many do not want to spend the extra money for better quality.

Solenoid pumps are considered to be throwaways instead of being repairable. Solenoid pumps won't stand up to 24/7 service. If the application is critical, you would need a spare for the solenoid pump plus additional parts inventory to repair the solenoid pump.

For the small flows that you mentioned, you may consider diluting the products. It will be easier to pump a larger flow and will improve the accuracy of pumping.
 
I prefer using a motor based dosing pump in almost all the applications except for clients that are extremely cost sensitive. The motor based pumps are more reliable and last longer. Your flow rates are very low, I would suggest diluting the solution in water and have a flow rate of around 500 mL/h. If your discharging into a basin pond, how are you going to ensure that the chemical is mixed properly into the liquid in the pond?
 
For such small flowrates, Solenoid will give you a better value for money. You do not need high pressure, so a motor is not needed in my opinion. Prominent (as cited before) has an extended range, but for such low flowrates, Grundfos also make very good and reliable equipment that can dose down from 0.008 l/h to 8 l/h with one pump model (step by step motor system). You can find less expensive pumps of course, but then beware of the quality. With Prominent or Grunfos you will find pumps with sophisticated electronics, able to regulate directly from a 4-20 mA signal (pH). Parikshithm remark is to the point, I would be careful on how to inject the chemicals to ensure good mixing.
 
Why do you have to specify the one or the other?

For such a use the performance, price and dependability (Eg. price/lifetime cost) should be the deciding factor. Describe performance / operation and open for suppliers argumentation and documentation of their product The quality of performance, support, service, cost/lifetime and future availability should then give the final decision.

 
I go with Mr. Bimr and Mr.Parik

That motor driven pump is a better idea. Because it's more reliable and can run 24/7 perHr.
About the dossage of your chemical injection. Try to dilute it first before injecting. It is easier solution than you must search for the spesific dosing pump (I never heard of a dosing pump that will give that small of amuount of chemical dosing though)

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