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Methods of reducing the resistance of plate heat exchangers

Release time:

2022-08-01

Passivation: After pickling, most of the scale and metal oxides on the surface of the plate heat exchanger will dissolve and fall off, revealing a brand new metal, which is very easy to be corroded. Therefore, the heat exchange should be passivated immediately after pickling device board.

Methods for reducing the resistance of plate heat exchangers

Methods to reduce the resistance of plate heat exchangers

Plate heat exchangers have certain requirements for resistance during use. In general, the average flow rate of the medium in the channel is 0.3~0.6m/s, and the resistance is not more than 100kPa. In order to better control the resistance, it is necessary to Take some measures to assist, here are some ways to reduce heat exchanger resistance.

1. Heat exchanger bypass pipe: When the flow of cold and hot medium is relatively large, a bypass pipe can be set between the inlet and outlet of the large flow side to reduce the flow into the heat exchanger and reduce the resistance.

2. Selection of heat exchanger form

The medium in the flow channel between the plates of the plate heat exchanger should have an average flow rate of 0, 3~0, 6m/s and a resistance of not more than 100kPa. Different types of heat exchangers can be selected according to the flow ratio of the cold and hot medium. , regardless of whether symmetrical or asymmetrical, single-process or multi-process heat exchangers are used, heat exchanger bypass pipes can be set, but detailed thermal calculations should be carried out.

3. Multi-process combination: When the flow rate of the cold and hot medium is large, a multi-process combination arrangement can be used, and more processes can be used on the small flow side to increase the flow rate and obtain a higher heat transfer coefficient.

4. Use hot-mixed plate: the geometrical structure of the corrugations on both sides of the hot-mixed plate is the same, and is divided into hard plate (H) and soft plate (L) according to the angle of the herringbone corrugation, and the included angle is greater than 90 (generally 120 about).

5. Adopt asymmetric heat exchanger: The symmetrical plate heat exchanger is composed of plates with the same corrugated geometric structure on both sides of the plate, forming a heat exchanger with the same cross-sectional area of the cold and hot runners.

Cleaning method of plate heat exchanger

Plate heat exchanger is a kind of equipment used for heat exchange. It has the characteristics of low heat loss and high efficiency. In order to keep the heat exchanger running effectively, regular cleaning is an inevitable task, so what are its cleaning methods? What?

1. Pickling method and time: The pickling method should be carried out by a combination of static soaking and dynamic circulation. The pickling time is static soaking for 2 hours, and then dynamic circulation for 3-4 hours. During the pickling process, it is necessary to frequently Sampling to detect the pickling concentration, when the concentration difference between two adjacent tests is less than 0.2%, the pickling reaction can be considered complete.

2. Increase the pickling temperature: Increasing the pickling temperature can improve the descaling effect. If the temperature is too high, it will aggravate the corrosion of the pickling solution to the plate heat exchanger. Through repeated tests, it is found that the pickling temperature should be controlled at 60 .

3. Passivation: After pickling, most of the scale and metal oxides on the surface of the plate heat exchanger will dissolve and fall off, revealing a brand new metal, which is very easy to be corroded. Therefore, the heat exchange should be passivated immediately after pickling device board.

Well, that's all for today, thank you for watching, let's see you next time.