How to solve it if pressure drop of heat exchanger is very high?

- Jul 05, 2018-

Excessive pressure drop of the heat exchanger is one of the common faults. If you encounter the fault before you encounter the relevant processing knowledge,

Then you can restore the cooler operation in time and reduce the loss as much as possible.

1. It is better to use soft water after softening treatment for the secondary circulating water. Generally, the mass concentration of suspended solids in water is not more than 5 mg/L, the impurity diameter is not more than 3 mm, and pH is ≥7.

When the water temperature is not more than 95 ° C, the concentration of Ca and Mg should be no more than 2 mmol / L;

When the water temperature is greater than 95 °C, the concentration of Ca and Mg should be no more than 0.3 mmol/L, and the concentration of dissolved oxygen should be no more than 0.1 mg/L.

2. For the central heating system, a method of replenishing water to the secondary can be used once.

3. Remove dirt or slab fouling in the runner flow path. For newly operated systems, clean once a week according to actual conditions.

When cleaning the scale on the surface of the plate (mainly CaCO3), use a 0.3 sulfamic acid solution or a 0.8 nitric acid solution containing 0.3 urotropin, 0.2 aniline, 0.1 potassium thiocyanate as the cleaning solution, and the cleaning temperature is 40-60 °C.

When disassembling the equipment for chemical immersion cleaning, open the cold medium inlet and outlet of the cooler, or install the DN25 cleaning port on the medium inlet and outlet nozzles when installing the equipment, inject the prepared cleaning liquid into the equipment, and wash it with water after soaking. Residual acid to make pH ≥ 7.

When disassembling the cleaning, soak the plate in the cleaning solution for 30 min, then use a soft brush to lightly rub the scale and finally clean it with water.

4. Avoid damage to the plate and rubber pad during the cleaning process.

If the mechanical backwashing method is not disassembled, a nozzle should be connected to the medium inlet and outlet pipes in advance to connect the equipment to the mechanical cleaning vehicle, and the cleaning liquid is injected into the equipment in the opposite direction of the medium flow.

The cycle cleaning time is 10 to 15 minutes, and the medium flow rate is controlled at 0.05 to 0.15 m/s. Finally, recycle with water several times to control the mass concentration of Cl in the water below 25 mg/I.