Surface Condenser | Types Of Surface Condenser
What is Surface Condenser
Working principle of surface condenser is completely different from jet condenser.In surface condenser exhaust steam and cooling water does not mix up with each other. So condensate remains pure and can be reused in the boiler. Surface condenser is widely used where limited quantity of water is available like ship, land installation etc. To use such a condenser, limited quantity of water feed to the boiler again and again.
In the diagram below, we can see the cylindrical shape surface condenser which is made off cast iron. In the condenser, some vessel packed with water tubes. Two vertical perforated tubes are placed two sides of the condenser and water tubes are fixed with these plates. In the tube, water flows from one direction to another direction. Cooling water flows in one direction to through the lower half of the tubes and returns in opposite direction through the upper half of the tubes.
Advantages and Disadvantages Of Surface Condenser
Advantages Of Surface Condenser:-
1. Pure condensation is possible by the surface condenser.
2. Low quality cooling water can be used for condensation.
3. High vacuum eficiency.
Disadvantages Of Surface Condenser:-
1. Large floor area is required.
2. Large amount of water is required.
3. Construction is not simple.
4. It's need to be operate by the skilled labour.
5. Maintenance cost is high.
Types Of Surface Condenser
According to the direction of flow and arrangement of tubing system, types of surface condenser can be classified the following four categories.
1. Downflow surface condenser
2. Centralflow surface condenser
3. Regenerative surface condenser
4. Evaporative surface condenser
Downflow surface condenser
In downflow surface condenser, exhaust steam enters the top of the condenser. Steam's direction is downside of the condenser due to gravitational force and an extraction suction pump fitted at the bottom of the condenser. The condensate is collected at the bottom and then pumped by the extraction pump. A dry air pump suction pipe is also fitted at the bottom. It is covered by a baffte to prevent the entry of condensed steam into it.
Centralflow surface condenser
Central flow surface condenser is an improvement of downflow surface condenser. In this condenser, exhaust steam enters at the top of the condenser and flow downwards due to gravitational force. But suction pipe of the extraction pump is placed at the center of this condenser. So the steam flows radially inwards over the tubes towards the suction pipe. The condensate is collected at the bottom and pumped by the extraction pump.
Regenerative surface condenser
In regenerative surface condenser, regenerative method is used for condensation. The condensate after leaving the tubes is passed through the exhaust steam from the engine. It improves its temperature for use as feed water for the bottom.
Evaporative surface condenser
In evaporative surface condenser, a circulated gilled pipes are placed inside of the condenser. Now the steam enters at the top of the pipe for condensation. When steam passes through the circulating pipe, cold water is continuously spray over the pipe. As a result of this, steam is condensed into the pipe and some steam is evaporated into the condenser. Remaining water which is now higher temperature stored in the downside collecting tank.Some requisite quantity of cold water is mixed with this water for reuse.