Surface Condenser

Introduction

Tipo surface condenser mainly consists of a cast iron shell. The shell is cylindrical in shape and closed at both end to form a water box. A tube plate is located between each cover head and the shell. A number of water tubes are fixed to the tube plates. The shell is provided with exhaust steam inlet at the top and condensed steam outlet at the bottom. The hot exhaust steam enters through the top inlet of the surface condenser shell cooling water enters into the inlet water box and then flows through the water tubes runs from one end to other end of the condenser shell as shown. Then it enters into the end water box and returns from this box to outlet water box via return water tubes.
During this circulation, the heat is absorbed from exhaust steam by cooling water through the wall of the tubes. As a result, the steam ultimately becomes condensed and comes out through wet air outlet.

This surface condenser required two pumps-

1. One pumps to circulate cooling water through the water tubes under pressure.
2. One for extracting wet air, condensates from the bottom of the condenser shell.

 

Features of Surface Condensers:

• In surface condensers there is no blending of fumes steam and cooling water. The condensate can be re-utilized in the kettle: In surface condenser even unclean water can be utilized for cooling reason though in fly condensers cooling water must be unadulterated. Despite the fact that the capital cost and the space required is more in surface condensers however it is as yet favored because of its low running expense and high warm productivity of plant.
• Surface condensers can be grouped into changes composes relying on the situation of condensate extraction pump, stream of condensate and course of action of tubes.

 

Advantages of Surface Condensers:  

• The condensate can be used as boiler feed water.
• Cooling water of impure quality can be used because the cooling water does not come in contact with steam.
• High vacuum (about 735 mm of Hg pressure) can be obtained in the surface condenser. This increases the thermal efficiency of the plant.
• Water used for cooling is reused without any treatment.
• For high capacity plants, it is more advantageous.
• In this Condensate losses can be eliminated.
• It required power for air pump is low.
• High vacuum efficiency.
• Pure condensation is possible by the surface condenser.
• Low quality cooling water can be used for condensation

 

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. Down flow surface condenser
2. Central flow surface condenser
3. Regenerative surface condenser
4. Evaporative surface condenser

Applications of Surface Condensers:

• The condensate can be used as boiler feed water.

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