answersLogoWhite

0


Best Answer

centrifugal chiller

User Avatar

Wiki User

10y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: What type of chiller uses a screw type impeller?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Continue Learning about Mechanical Engineering

What are specialized tools.?

Specialised tools have a limited number of uses. For instance, a pipe wrench can only be used for gripping a particular range of pipe sizes. A tri-wing screwdriver can only be used on one type of security screw,


Which type of compressor uses belts to turn the compressor?

Open drive.


What is volute centrifual pump?

The volute of a centrifugal pump is the tank that holds the liquid being pumped. The centrifugal pump is a type of pump that uses a swirling motion to pump liquid.


What is a non-positive displacement pump?

A hydraulic pump that uses an impeller or propeller to move fluid by momentum, as opposed to a positive displacement pump, which moves discrete quantities of fluid with each rotation. A typical application of a non-positive displacement pump is the coolant pump, or water pump, on a radiator-cooled engine.The most common types of mobile hydraulic (hydraulic oil systems) pumps that one might come across are:Vane type (positive displacement, open center system)Gee Roller (positive displacement, open center system)Gear type (positive displacement, open-center system)Radial piston (positive displacement, closed center, destroking and pressure compensating)Axial piston (positive displacement, closed center, destroking, pressure compensating and load sensing)The open center system pumps being positive displacement must have a dump valve, bypass, or pressure relief on the outlet side of the pump because of constant flow production. For example, if you were to put an on-off valve on the outlet side of a positive displacement open-center system and if you turned that valve to "off" You would either hit a system "stall" pressure or have a broken housing and/or lines.The closed center systems will "destroke" (stop pumping) when there is no demand for pressure oil. This allows for decreased horsepower demands and lower sump oil temperature.Examples of non-positive displacement pumps are:Turbine pumpsImpeller (centrifugal) found in engine cooling systems, liquid transfer pumps, and dredging systems.Any pump that does not require a relief, dump, or bypass valve when outlet flow or pressure is restricted or stopped.With these examples it is easy to assume that they are open center systems, however, being non-positive displacement an individual could shut off a valve on the outlet side of these systems and avoid system damage. This is due in most part to larger clearances within the pump, which allow for a certain amount of a "calculated leak" or "slippage" as another individual stated. Shutting off the outlet side will strain the system a little but it should be accepted to system specifications. This examples plays out in the cooling system of a vehicle every time the engine temperature is below operating temp. The water pump is being turned whenever the engine is running but until the thermostat (our hypothetical valve) opens, the impeller of the water pump must slip as it continues to try and build flow.


Why cavitation will occur in Centrifugal Pumps and not in displacement pumps?

Cavitation occurs when the pressure on a liquid drops below the vapor pressure for the liquid or when gas is otherwise introduced to a pump such that it disrupts the flow of the liquid through the pump.Positive displacement pumps trap a quantity of liquid (or gas) and then increase the pressure by pushing (displacing) it into the discharge pipe. External pressure pushes the liquid into the pump chamber which then is made smaller before the pump chamber discharges its contents. If any gas enters the pump chamber along with a liquid it is simply compressed along with the liquid. Positive displacement pumps work just fine with both gases and liquids - although when gases are being compressed it is usually necessary to cool the pump chamber which heats up quite a bit during the almost adiabatic compression step of the pump. Cavitation does not occur in part because the pressure in the pump chamber is almost completely uniform. If the compression chamber drops below the vapor pressure of a liquid being pushed into it, the external pressure will continue to push the liquid in, then when the pump begins to decrease the volume, the valve allowing the liquid to enter will close and the volume of the contents is decreased until the pressure rises back above the vapor pressure of the liquid and it condenses in the pump chamber.A centrifugal pump uses a rotating impeller to increase the pressure and flow rate of a fluid. In centrifugal pumps, pressure is added by increasing the kinetic energy of the liquid and then, in essence, "throwing" the liquid into the discharge pipe where the higher kinetic energy liquid pushes on the liquid ahead of it to increase pressure. As the impeller moves through the liquid being pumped, it pushes on the liquid ahead of it, imparting additional kinetic energy to it. The liquid behind the impeller, however, actually experiences a little bit of a drop in pressure as the impeller tries to move away from it. Because liquids are fairly incompressible, this usually does not create any problem and the internal pressure of the liquid is sufficient to keep it in contact with the backside of the impeller. If the drop in pressure is low enough that the pressure drops below the vapor pressure of the liquid at the temperature present in the pump, the liquid will begin to vaporize. Once gas is present in the pump, it begins to cavitate - the liquid separates from the back of the impeller - especially near the tips. For this reason, introducing air or other gas into the liquid can cause cavitation, even if the pressure never drops below the vapor pressure of the liquid being pumped. This is also why centrifugal pumps are usually "primed" prior to being started up - to get all, or at least most, of the gas out of the line so that the pump won't cavitate.

Related questions

What chiller that uses a screw type impeller is the?

centrifugal


An impeller pump in an outboard motor uses an impeller made of?

Synthetic Rubber


What is the difference between vrv system and chiller?

Chiller uses chilled water while vrv uses refrigerant directly


What is the difference between centrifugal compressor and screw compressors?

A rotary compressor is like a car engine, with pistons, rods, sleeves, valves, etc. A screw compressor has two screw type rotating parts that squeeze the refrigerant as the screw threads get tighter and tighter. They have long life potential.


What is the relation between ahu and chiller?

The AHU uses the cooled refrigerant incoming through pipes from Chiller to cool the supply air of the cooled area.


What the uses of screw?

to screw in something that needs to be screwed in the wall or anywere !


What are the uses of a screwdriver?

To screw screws'!


What is a turbo in the pt cruiser?

It is a turbo charger. A turbo charger uses exhaust gases to turn an impeller that is attached to a shaft and another impeller that forces more air into the intake system of the engine. This increases power and engine efficiency.


What are the uses of micrometer screw gauge?

mafanta


What uses the flow of exhaust gasses out of the engine to pressurize the air entering the intake manifold?

a turbocharger uses exhaust gas to spin an impeller that boost atmospheric pressure and feeds it into engine


What are the uses in construction for a ball screw jack?

There are several uses for a balll screw jack. Ball screw jack assemblies use small balls to roll between the nut and the lifting ball screw. It creates less friction and increases use life.


What are uses of the first class levers?

a hammernand a screw