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.

Filter by
Sorted by
Tagged with
1
vote
0answers
33 views

Calculate Power for pump

I did a Civil Engineering course some years ago and from my textbook I had a question on a pump with hoses. Unfortunately I haven't been able to find a solution to this yet. A pump feeds two hoses, ...
0
votes
0answers
14 views

Comparing power requirements of centrifugal pump installations

Hi, I am stuck with a question related to the centrifugal pumps. There are two centrifugal pump installations and it is asked to compare the power requirements for two installations. As in Pa>Pb or ...
0
votes
0answers
17 views

How can I confirm nL Volume Measurement for Pump and Sensor Calibration

I'm dispensing around 1uL of volume with 1% accuracy. Although I'm confident in my pump, I'd like to be able to routinely confirm that I'm getting the exact volume I'm requesting every time. How can ...
0
votes
0answers
37 views

Grad student needing help with a fluid mechanics issue in project

BROUGHT OVER FROM PHYSICS STACK EXCHANGE As the subject states I have hit a wall in a fluid mechanics associated problem in designing an experiment for my grad project. Long story short, I'm an ...
1
vote
1answer
65 views

How are the modern hydraulic cylinders very precisely controlled?

My guess is that they use brushless Motors that in turn powers the hydraulic pump. But there must be some kind of valve that could help in the process. Still the burning question is just by adjusting ...
1
vote
2answers
74 views

Calculating the torque required by an Archimedes screw pump

Given an Archimedes screw pump (shown below) how would you go about calculating the torque required to operate it? I'm assuming a situation where you have to design for a given flow rate, Q (m^3/s) ...
0
votes
0answers
33 views

What type of pump is recommended for pumping gasoline/petrol in vapor phase?

I would really like to know your input, perhaps there are regulations on this that I'm not aware of that can help out regarding the overall safety of the process.
0
votes
1answer
21 views

Pushing fluid through microfluidics

my team is working on a project where fluid (mostly water) need to be pushed through small channels (like small pipes) in order to reach larger reservoir. We were considering using air to push the ...
2
votes
1answer
36 views

Swash Plate Pump Design

My understanding of swash plates led me to believe that the pistons in a swash plate pump rotate around with the driving shaft along with the chambers in which they aspirate (e.g. M&S Hydraulic ...
0
votes
0answers
13 views

can submersible pumps be used for leachate from landfill that may have some solid particles of size 15-20mm?

I would like to know if submersible pumps can be used to extract leachate from leachate wells. The leachate is likely to contain solids of size 15-20mm. Further the pump should have diameter less than ...
1
vote
0answers
26 views

Low pressure Diesel pumping with High pressure Gasoline pump?

We are in desperate search of suitable pumps for one of our applications. We need to be able to pump Diesel fuel in a range going from 5bars to 125bars. To do such thing, I've been looking at Bosch ...
0
votes
0answers
20 views

Borewell motor water outlet adjustment

Recently we put 500 feet borewell in our area, it's hot summer season now. Person who drilled the borewell told me that we can get 1.5 inch of water now. During winter season we can expect at least 2 ...
0
votes
1answer
32 views

When finding flow generated by a pump, where do points A and B go?

I tried to find the answer in past posts, but couldn't locate it. I have a pump (100% efficient, for simplicity) that runs on 100kW and follows the equation: Power(pump) = (Specific Weight)(Flow)(...
0
votes
2answers
39 views

Is this pump design possible? (NPSH Question)

I have been assigned a hands-on project with an adequate budget. The client has given a minimal but adequate description of what they want. The problem is, it seems impossible, especially at certain (...
0
votes
1answer
33 views

head coefficient and volume coefficient for centrifugal pump

If I need to calculate the head coefficient using $c_h=\dfrac{gH}{N^2D^2}$ and the volume coefficient using $c_q= \dfrac{v}{ND^3}$ while keeping $N$ (impeller rotational speed in rpm), how can I make ...
0
votes
0answers
14 views

Extrapolating BHP values for fixed speed and impeller diameter

currently i have a composite pump curve (RIGHT) where the BHP lines are embeded in the performance curve. I would like to extract out the data and create a graph of BHP vs capacity shown on the LEFT. ...
3
votes
2answers
46 views

Pump Placement Question

I build an awesome skating rink for the kids. Now I have to flood it. I have the rink built 450 feet from the lake. The rink is 7 feet higher than the water. I have a 1.5-inch polyurethane rigid hose ...
0
votes
1answer
48 views

Best affordable food grade hot water pump

I am currently building a pour over coffee maker(personal use), but I am having trouble sourcing a water pump to use. I am hoping to create something that performs similar to the Poursteady commercial ...
1
vote
1answer
104 views

What is the point of this valve that only allows air in and not liquid?

I'm looking at googles mocktails maker. And it puts 2 holes in a container. 1 hole is connected to a pump that will take water out and the other connects to a backflow prevention valve that only ...
3
votes
1answer
52 views

How to resolve the interruptions in the screw pump operation due to air trap?

In one of my application, there is a requirement to dispense the concrete paste at the required rate continuously. some technical details of the application given below Dispense rate 5-50 LPM ...
1
vote
2answers
520 views

What does a stalled hydraulic pump mean?

What does it mean when a pump stalls? I could not find a useful explanation with the search terms pump stalling and hydraulic pump stalling. I'm trying to understand what Elon's tweet means. Maybe an ...
0
votes
1answer
236 views

Am I calculating the power required and power out for a peristaltic pump correctly?

I am trying to design a peristaltic pump, in a spreadsheet where I can alter the tube and casing diameter, pump RPM and some other parameters, I'm wondering if anyone can spot anything odd in this ...
1
vote
0answers
34 views

Choosing a blower for a Pneumatic Conveyor

Basically we are designing a pneumatic conveyor system for transferring 11 tons of beans per hour. We need to decide on the specifications of the blower. What are the calculations necessary to decide ...
1
vote
0answers
30 views

Where to put the booster pump at customer substation in a district heating system?

In a district heating system, one of the houses in the distribution net is not getting the desired heat into their house. This is because the pipes of this customer which connects them to the ...
2
votes
2answers
115 views

Why is the Current to Motor less than Motor Rated Current?

I have a motor for a submersible pump with a Rated Current of 8.4A as given in the motor's electrical data. However, when it is running, I record a current of 3.4-3.9A. Is there a fault I am supposed ...
1
vote
1answer
95 views

Gear pump has backflow and does not stop forced flow

I have a "Micropump GB-P25.JVS.A" gear pump. I pump in the range between 100 and 500 ml/min up to a column about 10 cm above the pump level. The column is filled from the top and has a bottom outlet. ...
8
votes
1answer
620 views

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 ...
1
vote
2answers
104 views

Submersible sump pump life in pit without water?

What can happen to a pump in a pit without water for many months, then the fall heavy rains start adding water to the pit, will the pump be efficient to do its job? Should water be added to the pit to ...
2
votes
0answers
51 views

Analytical shape of a pump curve

I'm looking for a formula to arrive at a pump curve for a centrifugal pump: $H(Q, n)$ - total head delivered as a function of flow and speed (rpm), and of course some pump specific parameters. I find ...
0
votes
1answer
18 views

Calculating NPSHa for a pump

NPSHa formula - h(sp) +/- h(s) - h(f) - h(vp) h(sp)- static pressure head (absolute) applied to the fluid h(s)- elevation difference between fluid level in reservoir to pump inlet h(f) - friction ...
0
votes
2answers
57 views

How does bell housing guarantee the concentricity of the shafts?

I'm talking about IEC motors-gearbox alignement. Here are an example: I found the drawing in cross hydraulic website, so it's quite reliable. What i don't understand, is, how this design makes sure ...
1
vote
0answers
16 views

Does impeller design have a specific cause on how the fluid will flow in a centrifugal pump?

I am a student learning about centrifugal pumps in my studies. I’ve learnt about the 3 different type of flows - axial, radial and mixed. I’ve also learnt about different impeller designs - mainly ...
1
vote
1answer
69 views

Pump with high pressure, low delta pressure

I'm looking for a circulation pump in a very high pressure loop and having trouble finding one. I'm hoping I just don't know the correct search term and someone can point me to it. The absolute ...
1
vote
2answers
76 views

What happens when pumps are blocked off?

What will be the result if the pipe losses is greater than head produced by the pump? What will be the result if outlet is closed?
1
vote
2answers
56 views

How does a Vibratory Pump (“Schwingankerpumpe”) work?

in my aquarium Ive got a little pump for bubbling air through the water so it is substained with enough oxygen. Internaly the pump works fairly similar to old door bells, where the mains is flowing ...
3
votes
1answer
23 views

Would too small tubing reduce the max head of a pump?

I got a mini-project: I want to automatically get rid of the water produced by an indoor air conditioner unit. Since the unit is underground, the water needs to climb ~2m to get to the outside. I ...
3
votes
1answer
36 views

Why does my VFD and pump configuration stop pumping?

I recently installed a VFD to reduce the speed of my pump, however, occasionally the configuration will stop pumping liquid through the system. The pump is a three phase 60 Hz and this issue has ...
0
votes
1answer
210 views

Pump power and fluid viscosity

I used to calculate the power needed by a pump using Bernoulli equation, $ W =(p_2-p_1) + {1 \over 2}\rho(u_2^2-u_1^2) + g\rho(h_2-h_1) + R $ where $\rho$ is fluid density (and assuming it is ...
0
votes
1answer
130 views

Can the same diaphragm pump be used to pressurize a container?

If the output of a diaphragm pump is impeded in any way, or meant to be at higher pressure than the input of the diaphragm pump, will it work, or will it stall out and fail to pump? In addition to ...
2
votes
1answer
50 views

How were multiple vacuum pumps used to raise water over 10m (e.g. by a steam engine)?

I can imagine a steam engine driving multiple regular old vacuum pumps, which each raise water ~10m. I would think that someone would combine the multiple pumps into a single piece of machinery for ...
2
votes
1answer
54 views

Designing for a specific flowrate

I have a simple, practical engineering question. I'm trying to design a hot water circulation system with a constant flow rate of 1.3 L/min. I'm having trouble finding any pumps that will do the job ...
2
votes
1answer
65 views

Simplest Way to Make A Pressurized Water Reservoir

I have a vapor system that requires a 50 psi feed of DI water. Without getting fancy, is there a simple commercial off-the-shelf part I can buy, fill with water and hand-pressurize? Or something with ...
1
vote
1answer
232 views

Can my total dynamic head (TDH) be more than the “Rated Head” on the pump?

I have just received a recommendation to use a pump with a "Rated Flow" of 1cu.m/h and a "Rated Head" of 91m. I am realizing I am actually not familiar with these two terms (Rated Flow and Head). My ...
4
votes
3answers
101 views

Power in a continuous flow pump

I work with left ventricular assist devices in patients with heart failure. These devices operate by maintaining a fixed speed of a centrifugal or axial rotor. The native heart continues to contract ...
1
vote
2answers
139 views

How to make water go into my house, from a lake without energy?

Basically, I'm thinking about a system, that filtrates, and makes a lake's water drinkable, drives water into my house's faucets without electricity, and all these should be able to work when it is -...
1
vote
0answers
91 views

What happens, when the pump discharge velocity is faster than 3 m/s?

I am doing a gerotor pump application design. I know the velocity of the suction port should be 1 ~ 2 m/s to avoid cavitation. Since I have enough space for suction port, it is not a problem. Yet, ...
2
votes
1answer
70 views

Are pumps used in geothermal systems

The water held underground in a geothermal system is under high temperature and pressure. Are pumps used to raise the very hot underground water to the surface or does the water rise under its own ...
1
vote
2answers
100 views

Why does net positive suction head (NSPH) include velocity head?

When the absolute pressure dips below the vapour pressure, cavitation occurs. Why would dynamic pressure be taken into account in this case?
1
vote
1answer
67 views

High pressure water pumps filling a container. How long does it take to obtain P pressure?

The problem I have at hand is the following: I have a container C with a given volume V. I need to fill it with water, fast, up to a given pressure P. I have a number of high pressure hydropneumatic ...