Fooooks
Mechanical
- Sep 15, 2016
- 48
Hi all, I just joined and am a new hire at a bulk liquid storage facility. No previous experience outside of college.
I have a basic question that I'm trying to understand physically. I cannot grasp what is happening to a fluid throughout a pipe and how it relates to the discharge pressure of a pump. Does it mean that if the pump requires more pressure (such as going uphill, discharging to atmosphere), the flow rate will be less? Does this apply to Bernoulli's Equation, which says a higher pressure decreases flow? But then if I run the pump at a higher pressure, my mind thinks the flow will increase, as there is a larger difference between discharge pressure of the pump and the atmosphere.
For example, if there is a pump with a discharge pressure of 100 psi, the fluid has a certain flow rate through 100' of pipe, assuming releasing to atmosphere. However, if I add a valve that has a high pressure drop into the pipeline, doesn't that mean the pressure drops? But this pressure decrease does not result in a higher flow, instead you would need a higher pressure from the pump to maintain the original flow rate. But a higher pressure is supposed to mean a slower flow rate if I look at a pump curve, I thought.
I must be missing something for this example. But I am having trouble understanding how losses and pressure drops downstream affect the pump-driven flow rate. I hope my thoughts are coming out appropriately.
I have a basic question that I'm trying to understand physically. I cannot grasp what is happening to a fluid throughout a pipe and how it relates to the discharge pressure of a pump. Does it mean that if the pump requires more pressure (such as going uphill, discharging to atmosphere), the flow rate will be less? Does this apply to Bernoulli's Equation, which says a higher pressure decreases flow? But then if I run the pump at a higher pressure, my mind thinks the flow will increase, as there is a larger difference between discharge pressure of the pump and the atmosphere.
For example, if there is a pump with a discharge pressure of 100 psi, the fluid has a certain flow rate through 100' of pipe, assuming releasing to atmosphere. However, if I add a valve that has a high pressure drop into the pipeline, doesn't that mean the pressure drops? But this pressure decrease does not result in a higher flow, instead you would need a higher pressure from the pump to maintain the original flow rate. But a higher pressure is supposed to mean a slower flow rate if I look at a pump curve, I thought.
I must be missing something for this example. But I am having trouble understanding how losses and pressure drops downstream affect the pump-driven flow rate. I hope my thoughts are coming out appropriately.