How to choose the head of the shell and tube heat exchanger?

How to choose the head of the shell and tube heat exchanger?

Selection principle of heat exchanger head

1. Whether the shell side needs to be cleaned;

2. Whether it is necessary to move the tube bundle;

3. Whether thermal expansion needs to be considered;

Front head type: A, B, C, D, N

Rear head type: L, M, N, P, S, T, W Rear head is divided into fixed type, floating head type and U-shaped tube. Compared with the fixed type, the floating head type is more expensive and requires a larger shell diameter, low heat transfer effect (due to the existence of leakage flow C), the advantage is that one end has a degree of freedom to handle the problem of thermal expansion.

Front head

Type A head: suitable for the situation where the tube side fluid is dirty and needs to be cleaned frequently.

B-type head: single-flange economical type is the best, because it is easy to purchase, it is the most commonly used head

C-type head: with tube plate and detachable cover, easy to clean on the tube side, can handle high pressure and high-risk media on the tube side (appropriate), suitable for heavy tube bundles on the shell side and cleaning of the shell side.

D-type head: special high-pressure type, suitable for special high-pressure working conditions (the tube box is welded on the tube sheet)

N-type head: with tube sheet and detachable cover, the tube bundle is not removable, this type of head is the most economical and easy to access the tube sheet; it can handle high-risk media on the shell side.

Compared with the B-type head, the A-type head has one more flange, and its pressure resistance is not as good as the B-type head. Its advantage is that the head cannot be removed during the maintenance of the heat exchanger. Compared with the B-type head It is more convenient to say. The tube bundles in C-type head and N-type head heat exchangers can be drawn out, and the tube sheet and tube box in the C-type head heat exchanger are welded together.

rear head

L-shaped rear head: the same as the A-shaped front head;

M-type rear head: same as B-type front head;

N-type rear head: same as N-type front head;

U-shaped: U-shaped tube bundle, the tube bundle can be moved, and the shell side is easy to clean; thermal expansion treatment is excellent, economical (no flange); the disadvantage is that the tube side cannot be cleaned, it is difficult to replace the tube bundle, and the elbow is easy to be damaged by erosion.

S-shaped head: Its size characteristic is that the diameter of the rear head is larger than the diameter of the shell. The advantage is that it can solve two problems in the design process of the heat exchanger. One is to eliminate the thermal stress of the heat exchanger; Both shell and tube sides of the heater can be cleaned.

The T-shaped head is similar to the S-shaped head, but the size of the rear head is the same as the shell diameter, and the inner head and the tube bundle can be drawn out directly, but compared with the S-shaped head, the force of the T-shaped head is different. It is not as good as the S-shaped head. The only advantage is that it is convenient to pull the core. T is generally not used in engineering design.