Question

In which condenser, the steam flows in the radial direction? Explain the working of this condenser with step by step and a neat sketch ?

Answer 1

Answer :

In Central flow surface condenser , the steam flows in the radial direction ( i.e radially inward ).

Now lets see what's a surface condenser ? how central flow surface condenser works and what are its advantages and limitation .

Lets get started

Condenser :

1. A condenser is a device which is used for the condensation of exhaust steam to water.

2. It is usually done by circulating cold water or cooling water.

3. It has two types on the basis of cooling action :

a. Jet condensers

b. Surface condensers

4. We will only talk about surface condensers.

Surface condensers :

1. In surface condensers, the basic concept is that there is no physical contact in between cooling water and exhaust steam .

2. They are separated with the help of a heat transfer wall.

3. They are of the following types :

a. Down flow surface condensers

b. Central flow surface condensers

c. Evaporative type

d. Inverted flow surfrace condensers

e. Regenerative type

4. We will only discuss about central flow surface condensers.

Central flow surface condensers

1. It is called "central flow" due to the flow of steam being towards centre.

2. In it at the centre of condenser , there is a pipe of air extraction pump whose function is to create a suction there, due to which the steam comes towards it and that's why the flow of steam is radially inward.

3. The steam comes from the top as shown in the diagram below .

4. Now except the centre , there is tube nest everywhere in the shell . These tubes contains cooling water which is circulating.

5. So when the steam comes and flows from up to down radially , they gets access to the entire periphery of the tubes .

6. Due to this the heat transfer is very effective and the steam gets condensed .

7. Now at the bottom there is an condensate extraction pump which extracts the pure condensate.

8. Diagram:

Steam and Air • Radially inward XOXO - Tuber Next ( contains cooling water) entraction pump To wie To condennate expaction pump surface Central flow Condenser

Advantages :

1.The vacuum efficiency is high .

2.The condensate is pure as there is no mixing thus can be re used .

3. Low quality cooling water can also be used.

Limitations:

1. The floor space needed is large.

2. Maintenance cost is high.

Now if you still have any doubt , do comment

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