term1 Definition1term2 Definition2term3 Definition3
Please sign in to your Google account to access your documents:
Blowdown
- The process of opening valves to blow water or steam through a fitting or from a boiler in order to remove any sludge, sediment, or other undesirable particles
- to control high water
- to control chemical concentration
- to drain the boiler for cleaning and inspection
Centrifugal Feedwater Pump
https://m.youtube.com/watch?v=BaEHVpKc-1Q
https://m.youtube.com/watch?v=lmjIQqo8mX4
- A pump that uses the centrifugal force of a rotating element to pressurize water so it can be added to a boiler
- the basic parts are the: casing, impeller, impeller shaft, shaft bearings, and packing glands or mechanical seals.
- a discharge valve on this device cannot be opened until the pump is started.
- high velocity, you need to prime it.
- pressure gauges are on this pump
- it is one of the rotary pumps which uses kinetic energy for the impeller
- it continuously discharges the fluid
- in centrifugal pump the flow rate decreases which increases the pressure.
- it is used for pumping high viscous fluid.
- This pumps discharge is inversely proportional to the viscosity of fluid.
- efficiency of this pump is low compared to reciprocating pump.
- centrifugal pumps have problems with priming
- it uses impellers to transfer energy to fluid.
- they are lighter than reciprocating pumps.
- it gives higher discharge at low heads.
- it is less costly.
- these pumps require less maintenance.
Closed Feedwater Heater
- A shell-and-tube feedwater heater used to capture heat from continuous blowdown water from a boiler or flash steam from a process.
- steam and feedwater do not mix in this heater.
- equipped with a safety valve on the steam side and a relief valve in the feedwater side.
- located on the discharge side of the feedwater pump and therefore applies a higher pressure on the feedwater than the open feedwater heater.
- used to reduce thermal shock on the boiler metal and it also increases plant efficiency.
- the heat in the steam is transferred to the water to raise the water temperature
- the steam that condenses back into water is removed with a steam trap.
Deaerator
- A feedwater heater operating under pressure used to separate oxygen and other gases from the steam before releasing the gases to the atmosphere through a vent
- typically use steam to heat water
-used to hold and preheat boiler feedwater before it is pumped into the boiler. This increases the sensible heat within the boiler water.
- classroom definition: it heats the feedwater and acts as a storage while it removes oxygen and other gases
- three basic types are spray, tray (this one is less important), and column.
- there is a safety valve on this device.
Economizer
- A feedwater heater that heats feedwater by passing it through a finned-tube heat exchanger placed in the order of gases of combustion.
- used to reclaim heat from the hot gases of combustion.
- Increases boiler efficiency.
- located in the breeching between the outlet damper and the chimney, where gases of combustion make their last pass in the boiler.
- sufficient draft is needed to overcome these tubes, typically forced and induced draft are combined.
- the tubes must be kept clean of soot (soot retards heat transfer because it insulates the surface).
Feedwater Heater
- A device used to heat feedwater before it enters the boiler.
- two main reasons to use one is to improve energy efficiency by recovering waste heat and water quality.
- it preheats feedwater thereby reducing thermal shock to the boiler.
- it acts as a reservoir for available feedwater.
- they may be heated by live steam, exhaust steam, or gases of combustion.
- can be located on the suction side or discharge side of the boiler feedwater pump or in the breeching.
Feedwater Line
- The pipeline that carries the feedwater from the feedwater pump to the boiler
- must have a check valve and stop valve located near the shell of the boiler
Feedwater Pump
- A pump that takes water from the feedwater heater and delivers it to the boiler at the proper pressure
- must deliver the quantity of water necessary to maintain the NOWL in the boiler
- may be the centrifugal, turbine, or reciprocating type.
Feedwater Regulator
A device that maintains the water level in a boiler by controlling the amount of feedwater pumped to the boiler
Float Feedwater Regulator
- A feedwater Regulator that contains a steel or copper float ball connected to a switch by a linkage
- found on package firetube or watertube boilers where feedwater pumps run either intermittently or continuously
Need help typing ? See our FAQ (opens in new window)
Please sign in to create this set. We'll bring you back here when you are done.
Discard Changes Sign in
Please sign in to add to folders.
Sign in
Don't have an account? Sign Up »
You have created 2 folders. Please upgrade to Cram Premium to create hundreds of folders!