What happens to the Heat Exchanger Unit?
The slab-type heat exchange unit is a type of Heat Exchanger made by pressing thin metal plates into heat exchange plates with a certain corrugated shape, then stacking them and fastening them with plywood and bolts. A thin rectangular channel is formed between the various plates, and heat exchange is performed through half of the plates. The working fluid flows through narrow and curved channels formed between the two plates. The hot and cold fluids pass through the flow channel in sequence, and there is an interlayer plate in the middle to separate the fluid, and the plate is used for heat exchange.
The detachable plate heat exchange unit is made up of a number of stamped corrugated thin plates at a certain interval, sealed by gaskets around them, and superimposed and compressed by a frame and a compression spiral. The four corner holes of the plate and gasket constitute the fluid separation. The piping and the gathering tube also rationally separate the hot and cold fluids so that they flow in the flow channels on each side of each plate, and perform thermal communication through the plate.
The Heat exchanger unit is divided into three types: detachable (seal type), full welding type and string welding type. They work on the same principle.
Heat exchange equipment (also known as heat exchanger, heat exchanger or heat exchange equipment) is a device used to transfer heat from a hot fluid to a cold fluid to meet specified process requirements. It is a convective heat transfer and heat conduction device. Industrial use. The primary heat transfer method is partition heat transfer. Common (semi) volumetric heat exchangers are heat exchangers, plate heat exchangers, U-tube heat exchangers, row-tube heat exchangers, and preheating. Device, cooler, flue gas waste heat recovery device, etc.
Working principle
Coil: The centrifugal force caused by the heat medium entering the spiral floating coil causes the coil to vibrate at high frequency, and changes the free elasticity with the temperature of the water. Progress, the heat transfer coefficient K≥3000W / m2. ℃, which is three times that of the general Shell And Tube Heat Exchanger unit. The high-frequency oscillation and free elasticity of the coil tube make it difficult for the scale to implant and then achieve the purpose of self-descaling.
Equipment: cold water enters the tank through the cold water inlet, and the heat medium enters the coil through the heat medium inlet. The heat exchange between the two walls, the cold water is heated to the set temperature and then sent to the pipe network through the hot water port. The heat medium returns to the boiler through the heat medium outlet to reheat, and returns to the heat exchanger for heat release again.
The heat exchanger unit is more used in various industries because of its own advantages. However, plate heat exchangers often suffer from corrosion during use:
1. The harmful elements in the bottom of the sealed tank are often precipitated by the Cl- in the adhesive due to the temperature rise. Such as neoprene adhesives and compacted asbestos, under the conditions of water and steam, the precipitated Cl- and H + constitute HCl, which causes severe stress corrosion cracking at the bottom of the tank, and through a certain period of corrosion incubation There may be stress corrosion cracking. Trying to damage any of the above conditions during the selection, installation and use of the Plate heat exchanger can effectively prevent or delay the onset of corrosion and make the equipment operate normally and safely.
2. The stainless steel heat transfer plate is mechanically stamped, and a certain amount of external residual stress will inevitably remain. For stainless steel sheets that do not contain molybdenum, it is difficult or even impossible to eliminate the external residual stress.
3. Plates of the Plate Heat Exchanger constitute a multi-gap structure after assembly, such as the contacts between the plates and the bottom of the sealing groove. The simple cause of the gap is often far beyond the ability of stainless steel to resist stress corrosion.
4. When the dirt on the surface of the plate is severe, the corrosive elements in the medium may be attached to the dirt in a large amount and in the gap at the bottom of the dirt.
Heat exchanger unit
