Discussion on the method of adding the solution
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This post was last edited by sunjl1981 on 2013-1-6 at 21:49. Suppose solution A is to be added to the pump inlet pipeline of solution B; the point of addition is located about 2 meters away from the suction inlet of the B solution pump (the suction pipeline for B solution is approximately 5 meters long, and the level of B solution is about 2.5 meters high under normal pressure). The flow rate of solution A is 150 L/h, with pipes of DN20 diameter, while the flow rate of solution B must be at least 40 m3/h, using pipes of DN200 diameter. The addition can be carried out either by using a pump for solution A or by using a reservoir for solution A at a higher level. From a process perspective, what are the advantages and disadvantages of each of these two methods? Which method is more appropriate? Please share your opinions actively # hcbbs
This post was last edited by 181128425 on 2010-1-18 23:25. Why can’t it be added directly to the B solution tank?
It is more reasonable to use a metering pump. Reason: The high-level tank also needs to be circulated using a pump; therefore, using a metering pump helps save energy, space, and investment. If the high-level tank is empty, it is possible for the B liquid pump to draw in air and suffer from air locking. With a metering pump, the likelihood of air entering the B liquid pump is lower if the low-level tank is empty.
The advantages of a high-level tank are obvious: the flow rate remains stable, and there is some time for emergency response in the event of an issue with pump A. Pumping is of course more cost-effective; a self-control regulating valve needs to be added to adjust the flow rate. In terms of process control, it is mainly necessary that the pressure of fluid A be higher than that of fluid B. Therefore, if a sump is used, a certain height is required, and this potential energy that is utilized for work represents a certain amount of waste as well. When fluid is introduced at the pump inlet and mixed by the pump, thorough mixing is achieved; if there is a buffer container afterward, then there are no issues at all with the reaction. Therefore, the usefulness of using a head tank is not that obvious.