1.Cause of plate heat exchanger scaling
The fouling of a plate heat exchanger refers to the solid substance that gradually accumulates on the solid surface when the heat exchanger contacts the unclean fluid. The main influences of scaling on heat exchange equipment are: because the fouling layer has a very low thermal conductivity, which increases the heat transfer resistance and reduces the heat transfer efficiency of the heat exchange equipment; when the scale layer is formed on the surface of the heat exchange equipment The flow area of the fluid passage in the heat exchange device will be reduced, resulting in an increase in the resistance of the fluid as it flows through the device, thereby consuming more pump power and increasing production costs. According to the mechanism of fouling layer deposition, the scale can be divided into granular dirt, crystal fouling, chemical reaction fouling, corrosive dirt, biofouling.
2.Plate heat exchanger blockage and scaling
(1)Plate heat exchanger blocked
Particles larger than 1.5~3mm in diameter tend to block the passage of the plate, and the flow passage gap of the plate heat exchanger is small, which causes the heat exchange capacity of the equipment to be greatly reduced due to clogging, which seriously causes continuous production interruption of the device. Therefore, a coarse filter or a backwashing device can be provided at the inlet of the medium as needed to effectively prevent clogging of the plate heat exchanger.
(2)Plate type heat exchanger scaling
In severe cases, the plate passage is blocked. The plate heat exchanger plate is designed with a large number of support points. The scaling can cause the heat transfer coefficient of the heat transfer device to decrease, aiming to disturb the medium (to make the medium turbulent to improve heat transfer coefficient) and pressure bearing, where solid debris is easy to accumulate, the side effect is that the fluid forms a local stagnation to generate dirt, and the calcium and magnesium ions in the medium are easily formed into a honeycomb after being precipitated at a suitable temperature scale.