What should I Do if the Plate Heat Exchanger Fails?

What should I Do if the Plate Heat Exchanger Fails?

05 Jan 2019

External leakage

It mainly manifests as leakage (small amount, discontinuous water droplets) and leakage (large amount, continuous water droplets). The main parts of the external leakage appear as plates and plates.
The seal between the sheets, the two seal sealing groove portions of the sheet, and the inner end of the end sheet and the pressing plate.
Solution
In the no-pressure state, re-clamp the equipment according to the clamping dimensions provided by the manufacturer, the dimensions should be uniform, the deviation of the compaction size should be no more than ±0.2N (mm) (N is the total number of plates), two compression plates The parallelism should be kept within 2 mm. If it is invalid, it can be marked on the leaky part, then
Disassemble the heat exchangers one by one, reassemble or replace the gaskets and plates.

Liquid leakage

Its main feature is that the medium on the higher side of pressure is in the medium on the lower side of pressure, and there will be abnormal pressure and temperature in the system. If
Medium is corrosive and may cause corrosion of other equipment in pipeline. The liquid string usually occurs in the diversion area or the secondary sealing area.
Solution
1. Replace the plate with cracks or perforations, and find the cracks in the plate by light transmission method in the field.
2. Adjust the operation parameters to meet the design conditions.
3. The clamping size of heat exchanger during maintenance and assembly should meet the requirements, not the smaller the better.

Large pressure drop

The pressure drop of the inlet and outlet of the medium exceeds the design requirements, and even many times higher than the design value, which seriously affects the flow and temperature requirements of the system. in
In the heating system, if the pressure drop on the hot side is too large, the primary side flow rate will be seriously insufficient, that is, the heat source is insufficient, and the secondary side outlet temperature cannot meet the requirements.
Solution
1. Remove dirt or slab fouling in the heat exchanger flow path. For newly operated systems, clean once a week according to actual conditions.
2. For the central heating system, a method of replenishing water to the secondary can be used once.

Heating temperature does not meet the requirements

Solution
1. The flow rate of the primary side medium is insufficient, resulting in a large temperature difference on the hot side and a small pressure drop.
2. The cold side temperature is low, and the cold and hot end temperatures are low.

Steam Waste

Solution
The thermal conductivity of scale is very poor, and its thermal conductivity is several times or even hundreds of times smaller than that of metal. After scaling, the heat transfer on the heated surface will be deteriorated and reduced. Heat transfer efficiency, wasting steam, and regularly cleaning scale.
The above are several common faults of the plate heat exchanger, some of which can be avoided. As long as the maintenance is proper, there will be no situation, and some can be repaired by themselves.