DE AERATOR IN BOILER

DE AERATOR IN BOILER



USE OF DE AERATOR-:

1. It is used to remove dissolved gases from the feed water to the boiler.
2. It also pre heat the feed water  and increase the efficiency of boiler.
3. Prevent corrosion by removing oxygen .

TYPE OF DE AERATOR-:

TRAY TYPE DEAERATOR
* It contain perforated trays in the top of the Deaeration section. The bottom section acts as storage for boiler feed water.
* Feed water to deaerator enters into the perforated trays where the surface area and residence time is increased to contact with steam.
* Then the water goes to the horizontal storage section where steam is passed in sparger pipe to remove the remaining traces of dissolved gases * keep the stored water at its saturation temperature.

SPRAY TYPE DEAERATOR
*It contains spray nozzle in feed water entry area. 
*It is then preheated and deaerated and sent to storage section. 
*In storage section also steam is added to keep the water at its saturation temperature.



WORKING PRINCIPLE -:


The deaerator work on HENRY'S LAW of partial pressure it states that the solubility of  in a liquid is directly proportional to the partial pressure and when a liquid is heated up to saturation limit under pressure then the solubility decreases.


WORKING-:

SPRAY TYPE -



1. condensate enters the devapouriser, gaining heat from the rising air from the de-aerator body which passes over the outside of the tubes. 

2.From the devapouriser the condensate enters into the sprayer compartment

3. This condensate is then sprayed through nozzles into the main body of the deaerator where it is  heated by direct contact with hot drain exhaust. 

4. The sudden pressure drop and heat gain  effectively liberates the air. 

5. Condensate and exhaust steam finally mix and flow down to the elevated feed tank at a temperature approximately that equal to the saturation temperature of  the steam.

DE AERATOR FITTED AT HEIGHT WHY -:

To provide sufficient Positive head at feed pump suction to prevent vapour forming as When it heating water under pressure ,there is a high chance of steaming of water at suction side of boiler feed water pump which lead to cavitation.

Comments

Post a Comment

Open for Suggestions and Corrections

Popular posts from this blog

SLIDING FEET ARRANGEMENT IN BOILER

Image
SLIDING FEET ARRANGEMENT IN BOILERS 1.The boiler expands and contracts as it heats up and cools down, sliding feet are installed to allow the boiler to move easily.  2.The sliding feet are located below the boiler, usually under the front end of the sidewall header and water drum.  3.There is a brass liner or a greased phosphor-bronze friction plate on which these feet will move.  4. Failure of sliding feet to move can cause cracks in the air casing and can cause header handhole plug leaks. 5. Movement indicators are installed on the sliding feet, which have to be checked before lighting off, during warm up and after the boiler is on line to ensure positive movement of the sliding feet.
Read more

BASIC DESIGN OF WATER WALLS USED IN WATER TUBE BOILER

Image
USE - Water walls are used in water tube boilers to contain the heat of the furnace and reduce the amount of refractory material required. They also contribute to the evaporation rate by receiving radiant heat; indeed, in radiant heat boilers the water walls provide the bulk of steam generation. TYPE    1. PARTIALLY STUDDED The partially studded water wall has a relatively wide pitch and so does not unduly weaken the tube plates or headers, but to seal the gaps between the tubes a refractory material must be used, this being keyed in place by steel studs resistance-welded to the water wall tubes. 2. TANGENTIAL  In the case of the tangential type water wall a much smaller pitch is used, the off-set tube ends allowing the use of staggered holes to prevent undue weakening of tube plates and headers. However, some radiant heat can still penetrate the wall and a layer of suitable refactory material must be placed behind the water to protect the boiler casing. 3. DIA
Read more

13 IMPORTANT PARTS OF MARINE DIESEL ENGINE

Image
The size ,shape  of particular parts will vary according to engine type and manufacturer. BASIC PARTS OF MARINE DIESEL ENGINE 1. BEDPLATE > The Bedplate form the structural base which houses the heavy crankshaft and support the cylinder block. > It is a platform on which other structural components such as frames or columns and guides may be accurately mounted to support the engine cylinders and ensure the alignment of all working parts. > The bedplate is seated on stool made above the tank top and secured by foundation bolts. > Bedplate  withstand heavy, fluctuating stresses from working parts.  > Bedplate transmit the engine loads, including the propeller thrust, to the  ship's structure, distributing these over the necessary area, and may complement the ship's strength and propeller shaft alignment. Construction -:  > Bedplate generally fabricated from steel plates and casting welding together. > Longitudinal girder wi
Read more