Plate Air Preheater Common Problems and Overhaul Processing Methods

Plate Air Preheater Common Problems and Overhaul Processing Methods

Plate air preheater is widely used in drying, heating and cooling, drying and other fields, such as textile printing and dyeing, pulling vice sizing, papermaking, starch and other industries. And clogging, leakage and poor heat transfer is a common problem encountered by users and friends.

1, scaling and clogging

In long-term use, due to the use of different environments, there are different cases of scaling, there are several factors:

Fluid flow rate: the flow rate for the impact of dirt should be considered at the same time its impact on the deposition of dirt and dirt stripping, for each of the dirt, due to the flow rate caused by the stripping rate of the rate of large compared to the rate of dirt deposition has a difference, so the rate of increase of dirt with the increase in flow rate and decrease.

Heat transfer wall temperature: temperature for chemical reaction scaling and salt precipitation crystallisation scaling has an important role, the increase in fluid temperature generally leads to an increase in the rate of chemical reaction and crystallisation rate, which has an impact on the amount of dirt deposition, resulting in a higher rate of increase in dirt.

Heat exchanger surface materials and surface quality: on the commonly used carbon and stainless steel tube, carbon steel is more susceptible to corrosion, and then scaling corrosion, so choose a better corrosion-resistant materials can be less fouling. The surface of the material will also affect the generation of dirt, the greater the degree of surface roughness, the easier to scale, so the choice of material is very important.

2, leakage: the main reason is corrosion, material defects and the use of a long cycle.

Treatment: for ordinary leakage point of chemical adhesive patch or playing card patch glue; serious need to change the heat pipe and the whole heat exchanger in a timely manner.

3, poor heat transfer: the main reason is the finned tube wall scaling, bending blockage, fin deformation and serious ash accumulation and fan failure, etc.

Treatment: regular blowing or cleaning of the heat exchanger, inspection and repair of damaged fins and detect whether the fan failure and overhaul.