Pumps Definition and 114 Threads

  1. LEO31

    System curve and centrifugal pump suitability

    I’m trying to calculate the system curve of an already existing plant, the complexity lies in having 2 different lines, each with its respective pump 1- A substance contained in a closed tank with a liquid level of 40 ft connected to pump 1. 2- a closed tank of pure water connected to pump 2...
  2. RCH

    Which Pump Can Safely Circulate Fluid with Glass Spheres?

    Hello -- I am working on a project where I need to recirculate a fluid which has a large quantity of glass spheres of say, 1mm diameter suspended in it, but without the pump crushing the spheres. I would appreciate any advice. To give a simple description of the desired function: it will be a...
  3. S

    Solving the Problem of Capillary Action in Tiny Peristaltic Pumps

    Hello, I designed a tiny peristaltic pump which works really fine. I am using a very thin tubing of 0.5mm diameter, which makes me struggle with capillary action, unfortunately. When my pump is not working, sometimes liquid still flows into the tubing because of capillary action. Do you have...
  4. Elizabeth111

    Vacuum Pumps in Labs: Applications and Types

    Summary: Research about the different vacuums used in labs and their applications. Hello, I am currently seeking assistance from people who work in labs. I am researching about the the different types of vacuums used in labs and their applications. Any information that you may have, please...
  5. Bill McC

    B Heat Pumps And The Peltier Effect

    I had seen a few topics from this forum while searching for information on the temperature differential possible in a reverse polarity thermocouple junction. I was reading some of the replies and I am wondering if the heat pump is understood. It uses a refrigerant that can be anything that...
  6. J

    I Possibility of PCB Oils in old Diffusion Pumps?

    I recently found three old vintage diffusion pumps left over by the previous lab owners: 1. Veeco EP 2A 2. Veeco EP 2A-1 3. Edwards Speedivac F203 Is there a possibility that these pumps have PCB based oil inside? I do not have access to PCB oil testing at the moment. Also any further...
  7. M

    Maximum number of microchannels in parallel for a syringe pump

    Basically, I want to determine how many microchannels I can have in parallel to drive a fluid (for now assume water),without the syringe pump stalling. Let's say a syringe pump have a maximum linear force of 50 lbf. and I want to drive the fluid at 60 ml/hr. So if I have 4 parallel channels...
  8. R

    How do we maintain the RPM of turbo pumps in liquid rocket engines?

    How do we maintain the RPM of turbo pumps in liquid rocket engine ? and how do we control it ? and in the case of electric pump fed engine (like rocket labs's rutherford engine) is easy but how we do it for other liquid propellant engines ?
  9. F

    How Do Pumps Increase Pressure According to Bernoulli's Equation?

    Hello, My understanding is that pumps (whatever type) add energy to the fluid and cause the fluid to move. The fluid can be either brought to a higher elevation or not. I am unclear on how pumps "provide a larger pressure". Do they? If so, in what sense? Are pumps simply speeding up, i.e...
  10. AbdullahS

    Pressure setpoints for a set of pumps (Affininity Laws)

    Hi Guys, The problem I am facing at the moment is to calculate the appropriate setpoint for a set of pumps supplying cold water to a building so that electricity and cost savings can be achieved. Here is the situation: There are three pumps connected in parallel. They are located on the ground...
  11. Steven Bolgiano

    Potentiometer or Closing Valve for Regulating 12V DC Pump Flow?

    Using as an example a 12v pump typical of aquarium, to regulate flow is better to use a potentiometer or a closing valve to affect a rate of flow?
  12. S

    Pressurizing Argon Gas: Pump or Compressor Options?

    I need to pressurized argon gas from 1 bar pressure to 2 bar pressure. Flow rate outlet is 0.5 LPM. Can anybody suggest me a pump or compressor which is small in size? Minitiarised diaphragm seems good option but is it right one?
  13. P

    Why are centrifugal pumps so inefficient?

    I have been playing around with pump curves a bit and have noticed that in general, the best operating point yields a pretty poor efficiency relative to the pump input power (75% max). From a second law perspective, there shouldn't be any losses. Where is all of this energy being lost? Is it in...
  14. G

    Efficient Pump Usage in Fuel Oil Supply System: Solving for Tank Fill Time

    Homework Statement A fuel oil supply system consists of two tanks (Tank A and Tank B) and two transfer pumps (Pump A and Pump B) to supply a Bunker C fuel oil to a heating boiler. Pump A can fill up a Tank A from the minimum level in 15 hours and 20 minutes Pump B can fill up a Tank B from the...
  15. E

    How to pump liquid from vacuum to atmosphere

    Greetings, The application is a wiped film evaporator (~1.2-1.5 kg/hr throughput). The concentrate and the distillate gravity feed round bottom flasks. I'm not worried about the cold-trap waste. The evaporator volume is under vacuum (~0.003Torr). I want to pump the liquid from the...
  16. S

    Bernoulli Equation and its application to turbines and pumps

    Hi, I have never found a satisfactory explanation for why the Bernoulli equation is not valid when the streamline passes through a turbine, pump or another work transferring device. I have read many books that simply state this limitation without providing a convincing reason. Bernoulli...
  17. C

    Calculating Flow Rates for Cascading Heat Pumps

    Homework Statement I am given that a Chemical Company wants to implement a cascading refrideration cycle to provide 1 MM Btu/hr of cooling. We are given the three compounds we are using. Evaporator Temperature (F) Compresspr Out Pressure(psia) Cycle 1...
  18. R

    How Do I Calculate the Change in Head When Reducing Discharge Line Size?

    I have a pump running at 400rpm with 8" inlet and outlet with head 30 ft 500 gpm. Now I am planning to reduce the discharge line to 6" . Assuming the flow rate and speed constant the velocity in the pipe will increase. How do I calculate the change in head?
  19. W

    I Variable displacement hydraulic pumps

    In online examples of variable displacement systems with swash-plate pumps, the input pump & motor are usually of equal size. When the constant RPM input pump is at full tilt (max displacement) the fixed displacement motor is at the same RPM for a 1:1 ratio, and when the pump is at no tilt (no...
  20. J

    Two Pumps on one system flow question

    I am hoping this is the right place to post this. I have a hydraulic system that uses two pumps. Each pump is capable of producing 22.5 gpm. With out taking into account the different valves, restrictors, and pipe sizing, my question is, does my gpm double to 45 gpm or stay at 22.5? the pumps...
  21. industria77

    How do you run vacuum pumps in series?

    can anyone refer me to a graphical representation of how this works so i can build one?
  22. S

    Use of Bernoulli equation for pumps

    I have a doubt on the use of Bernoulli equation for pumps. Consider the situation in the picture. I marked different points: ##1## on the surface of first tank, ##2## in the exit from first tank, ##3## just before the pump, ##4## just after the pump and ##5## entering the second tank. Now...
  23. M

    A Understanding the Up-Left Quadrant of Pump Function: Q>0 and n<0

    Hi Could anyone describe each quadrant (of four quadrants) of pump function which includes combination of Q (fluid) & N (rotation) duration transient analysis? (second quadrant especially which Q>0 and n<0)
  24. Mingsliced

    Centrifugal/Reciprocating Pump Efficiency

    Homework Statement It is proposed to pump 1500 m3 of a liquid (density 1100 kg m–3) each day through a total head of 10 m (including all losses) by using either a centrifugal pump or a reciprocating pump. The centrifugal pump discharges 2.0 m3 min–1 when driven by an electric motor supplying...
  25. S

    Maximizing Heat Output from Electrical Energy: Heat Pumps vs Heaters

    I have read that when we directly use 'W' Joules of electrical energy to heat a liquid,the maximum heat we can use to heat the liquid is W. However, when we use a heat pump Q=[COP+1]*W , and that means Q > W. Hence heat pump is more efficient and is preferred over electrical heater. Doesn't this...
  26. D

    Understanding Fuel Pump Performance: Factors, Measurements, and Potential Risks

    I am not talking about the mechanics of them, I am talking about what factors influence how much fuel they pump in a given system(EFI return style) at a given time. What do numbers such as maximum pressure and free flow rate mean? Can you have a pump that is too powerful for a system like say...
  27. Ben Reade

    Can Heat Pumps Be Used to Cool Water for Heat Exchangers?

    Hello there, So with say a Ground Source Heat Pump you have a source of warm-ish water coming in at 10 - 15 degrees C or so, and using a Heat Pump you are able to get a central heating temperature of about 40 degrees for your central heating system. Could you in theory, use a inlet water...
  28. E

    Why are centrifugal pumps generally used to move water?

    Well the question says it all. On several websites I have found main 2 categories of pumps for air - diaphragm pumps for water - centrifugal pumps Why are centrifugal pumps not used generally for air applications?
  29. M

    Calculating the Cost of Heating with a Less Efficient Heat Pump

    Homework Statement Assume that you heat your home with a heat pump whose heat exchanger is at Tc=2∘C, and which maintains the baseboard radiators at Th=47∘C. If it would cost $1000 to heat the house for one winter with ideal electric heaters (which have a coefficient of performance of 1), how...
  30. SmokeyMTNJim

    Biological Machinery i.e. living pumps

    In my exercise physiology class we are discussing the amazing work that the human heart performs over a lifetime, even over a single day. My textbook says that the fluid output of the heart exceeds that of a household faucet turned wide open (Katch, McArdle, Katch). With the invention of the 3-D...
  31. R

    Why aren't there more heat pumps in process plants?

    In process plants many heating applications will use steam at approx 120 C whereas the standard cooling utility is cooling water at approx. 30 C. In the dozens of plants I've seen I cannot recall having seen even one Heat Pump. Why is this so? Is the capex too high? Or are compressors too...
  32. T

    How to find Best Efficiency Point for pumps in series?

    Homework Statement I read here http://www.engineeringtoolbox.com/pump-system-curves-d_635.html that this is where the system curve and the pump performance curve intersect. But if the situation involves pumps in series, what will the system curve be a plot of? Is it flow rate and the total...
  33. S

    Can I Use Aluminum for DIY Diffusion Pumps?

    Can I make diffusion pumps from aluminum? I am going to create parallel connected diffusion pumps for many UHV purposes. I see that aluminum that is treated to prevent outgassing is used for UHV valves, chambers, and reactors. I'd like to know what temperature diffusion pumps boil their...
  34. B

    Help Building AC Pumps: Is It Realistic?

    So I'm trying my hand at engineering, and I thought "maybe an air conditioner would be a good place to start, that doesn't sound too hard". Stupid idea. Of course it's too hard. But I'm going to try anyways. So what do you guys think about this as a pump? I want to find a very clean cut...
  35. C

    Why Does COP in Heat Pumps Depend on Time?

    Hi experts... I'm new to this forum and want to know that why does COP(Coefficient of Performance) in heat pumps depend on time?
  36. G

    Quietly Pump Water 11ft - Ideas for Sump Pump Solutions

    I need help with ideas on how to pump water our of a sump pump that is always filling up. Using a sump pump when the float is tripped is really load. I need something that quietly pumps the water out steadily while not using up huge power...but it needs to be quiet! I see these aquarium...
  37. M

    Understanding the Carnot Cycle: Heat Pumps & Engines

    Greetings, Here is my thought process on the carnot cycle, regarding heat pumps and engines. I'd much appreciate it if you can clear up any misconceptions and answer my question at the very end. So my book states that there is no change in internal energy in a heat engine, but neither confirm...
  38. steves1080

    Question on positive displacement piston pumps

    This is a very simple question but I am struggling to grasp the answer. My question is in regards to a positive displacement piston pump. http://upload.wikimedia.org/wikipedia/en/thumb/0/0d/Axial_piston_pump.svg/686px-Axial_piston_pump.svg.png Say you are using this machine to pump...
  39. K

    Question about Pumps and Nozzles

    How do I know if a pump I have is strong enough to suck up a pool of mucky water? What equations would I use? And how do I calculate the pressure with which the water would be discharged? Then finally how do I determine the correct nozzle to disperse this water? This is not a homework...
  40. D

    Mechanical Nuclear coolant pumps built on turbine to generator shaft?

    Hello, I'm new to this board. I have a engineering question about the coolant pumps used to maintain reactors. I have been studying the basics of a PWR. I notice the pumps are fed mostly by electricity. While I see the logic and efficiency of that..I am left wondering why the space on...
  41. Low-Q

    Question about the practical benefits of heat pumps

    Hi, I did read an article (Norwegian one) about heat pumps. Several owners claims that the annual costs for operating a heat pump versus a traditional electric stove isn't much different. Even if the heat pump isn't reversed at hot days in the summer (And used solely for heating), these...
  42. J

    AC & Heat Pumps: Motor Vehicle Solutions

    On a hot day the AC in my car starts working immediately pumping cool air, on a cold day I have to wait till the cooling system heats up before I get warm air. It would be perfectly possible (with the aid of a couple of solenoid valves) for the AC unit to run as a heat pump providing immediate...
  43. I

    Catch without to touch, vacuum pumps and sprinklers

    I am interesting in searching several options to catch big size wafer, 1 meter X 2 meter, the wide of this wafer is very thin, only 120 micro meter, the challenge is that it is forbidden to touch the wafer because we don't want to put some finger prints or scrap the wafer, and the mission is to...
  44. T

    Understanding head and NPSH in pumps

    So I know that head is related to energy. And it is just another way to measure the energy at any given point in the flow (although in units of meters/feet/etc). So does that mean the head is equal at all points of a pipe? Since by conservation of energy and mass, and assuming the flow is...
  45. T

    Understanding centrifugal pumps

    In this video, I would like to know why the operator of the centrifugal pump had to fill the pump with water first? Thanks!
  46. J

    Do all reversible engines become heat pumps?

    I have a cycle (and the gas is ideal) that starts at Pressure=4Po Volume=Vo and and Temperature=Th. First step it's cooled at constant volume to Tc and Po; Second step, it is reheated at constant pressure to Th and 4Vo, and lastly it is compressed at constant temperature to Vo and 4Po. For those...
  47. Low-Q

    Alternative expansion valve in heat pumps

    I have been looking at the basic operation of a heat pump. On these pumps there is an expansion valve. This valve is a narrow hole where the condensed working fluid is passing through, then evaporation happens in the low pressure side - after this hole. I assume this valve act as a resistance...
  48. Z

    Automotive Mechanical vs. electric coolant pumps

    Hi everyone, I am conducting a small research on how many manufacturers (if any) use electric water pumps in production vehicles. So far I found that many Audi models have auxiliary electric pumps which help the main mechanical one when needed (and maybe to run for some minute after turning the...
  49. S

    Suggest me please - Water pumps in Thailand

    Suggest me please! -- Water pumps in Thailand I need to motor system for pump. What I sholud have system to motor? For safe motor,for save electricity,for the best performance control and other. My father is planting rice. The water is necessary. I live in Thailand...
  50. rmattila

    Why aren't jet pumps used as main coolant pumps in PWRs?

    Once again reading reports of PWR main coolant pump seal issues, my mind started to wander.. Is there some obvious reason, why jet pumps are not used as PWR main coolant pumps? This would eliminate the non-isolable leak issue and enable a more flexible pump arrangement.
Back
Top