Questions tagged [pumps]

For questions about the design, classification and working principle of pumps. A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action.

218 questions
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Is it possible to "pump" a powder?

Is it possible to "pump" a powder the same way liquids can be pumped? If so, what are the challenges? If not, what are some alternatives?
peterh
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Replace mercury with silicone oil in diffusion pump

We have obtained an old mercury-vapor diffusion pump for high vacuum. However, we do not want to operate it with mercury in our lab due to health concerns (which is presumably the reason it was scrapped by the original owner). Instead, we plan to…
dominecf
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Low cost, moderately accurate water depth measurement

tl;dr: After an extended conversation with an old-timer, I realized a few things: The single most valuable measurement for the majority of people will be water-depth-in-well. The second most valuable will be water-flow-from-well. The "bubbler"…
8
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3 answers

Motor for a hydraulic pump in a hydraulic system

I am a complete beginner to hydraulic systems, and I've wanted to learn more about this area. I'm designing a hydraulic system that involves using hydraulics to push/pull objects using pistons. I have looked at what the basic requirements are for a…
Tom
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8
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What is the physical meaning of pulse rate and blood pressure, from a turbo machinery point of view?

Our hearts are peristaltic pumps, which has a periodic compression and expansion. The head developed can be taken as blood pressure. There are situation when the blood pressure is normal while the pulse rate is high. What is the physical meaning of…
7
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2 answers

What is a PD pump that I can use as an immersion pump for a slurry?

I need to pump a thick slurry from a tank. The slurry can be pumped, but won't flow well enough that I can use a suction pump from outside the tank. Normally, I'd use a centrifugal immersion pump that can be drawn from the tank for service. But with…
mart
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7
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Calculating the ultimate achievable vacuum pressure of a diaphragm pump

I am looking to design a diaphragm pump for a device. I know that I would need to achieve a (negative) vacuum pressure of ~ 350-400 mmHg. I know from standard rotary pump design the pump rate should be dictated by stroke volume and speed, and…
daFireman
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What are the benefits of a diaphragm pump vs a simplex pump?

What are the benefits of a diaphragm pump over a simplex pump? Is there any specific design criteria that should be used/stated in an engineering specification for a diaphragm pump?
6
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3 answers

How do I calculate the max flow rate for a pump with no power restrictions?

Let's assume we have a pump and it can draw as much power as it needs. As the pump speeds up, it creates vacuum in the intake. At some point it draws the gas/liquid so fast, the intake pressure is so close to 0. At that point, no matter how much…
5
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1 answer

PWM flow control and thrust

If I have a water pump and a fast solenoid valve (can be open or closed) and turn on my pump at a constant voltage and apply pulse width modulation to my valve. Would the resulting thrust created at the water output be constant and can it be…
Mehdi
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What will happen if I run a submersible pump without water?

I have a submersible pump and it's clearly stated in the user manual that it should not be operated without water. But what will happen if it's not adhered to? The obvious answer is that it will malfunction. But I want to know what causes the…
5
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2 answers

What does 'Open Flow' mean for a pump flow rate?

I have specifications for a positive displacement pump where, in the data table on the last page, the given flow rate is referred to in the column header as 'Open Flow.' Is this the maximum flow generated by the pump?
James Izzard
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Why is my Venturi pump much weaker than expected?

I'm trying to make a simple Venturi tee which will have air flow through it while sucking some water from down below (like paint sprayers do). I want the device to pull the water to a height of 1 meter. That means that I need 0.1 atmospheres (104…
dactylo
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2 answers

Gigapascal pressures in a small package

How small/compact can a pump or other mechanism be, that would allow compressing gas (or liquid) to pressures of excess of 10GPa, continuously? Throughput may be minuscule, of order of milligrams per hour; even lower is acceptable. Also, for "size…
SF.
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What are the predominant types of concrete pumps and what are their working mechanisms?

I've looked around for different types of concrete pumps and simply don't know if there are many different types, what their mechanisms are and which ones are the most predominant ones. What I've found: This video explains how a pump with an…
JHK
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