The surface of the heat exchanger plate is pressed into a corrugated or groove type to increase the stiffness of the plate, increase the degree of turbulence of the fluid and improve the heat transfer efficiency. The material is mostly stainless steel, copper, aluminium, aluminium alloy, titanium, nickel, etc. The corner holes at the corners of the plates play the role of connecting channels. The working medium flows through the narrow and tortuous channels formed between the plates respectively for heat transfer. As the plates are installed upside down on each other, the thousands of contacts formed by the corrugated cross are staggered and evenly distributed so that the fluid flows back around these contacts, creating a strong disturbance and forming a very high heat transfer coefficient, giving the heat exchanger a very high heat transfer efficiency and pressure-bearing capacity.
"Then the plate heat exchanger plate for different scaling And how to clean the plate?"
Oil residues
Scaling substances: leachate and fat.
Cleaning method: open the device for mechanical cleaning.
1、Sulphonated hydrogen precipitates can be washed off with sintered naphtha solution (e.g. KEROSINE) and soft brush.
2. Wipe dry with a dry cloth or rinse with water.
Note: Gaskets made of natural rubber, butyl rubber and EPDM rubber will swell when in contact with the above solution. The contact time should be limited to 0.5 hours.
Large fouling
Fouling substances: seaweed, mussel, wood chips, fibres.
Treatment: Open the unit for mechanical cleaning.
1. Gently brush with running water, taking care to avoid damaging the gasket.
2、High pressure hose rinsing.
3、Backwashing of unopened heat exchangers is sometimes more effective.
Scale
Scaling material: calcium carbonate, calcium sulphate, silicate. Treatment: Open the unit for mechanical cleaning.
1. Gently brush with flowing water. Take care to avoid damaging the gaskets.
2、Flush with high pressure hose.
3、Chemical cleaning with the following cleaning agents.
Nitric acid
Amino acid
Citric acid
Phosphoric acid
Compounding agents (NDTA, NTA)
Sodium polyphosphate
Maximum concentration 4%, maximum temperature 60°C.
Microorganisms
Scaling material: Worm winding, protozoa
Treatment: Open the device for mechanical cleaning
1. Gently brush with flowing water. Take care to avoid damaging the gasket.
2、High pressure hose rinsing.
3、Chemical cleaning with the following cleaning agents.
Sodium hydroxide
Sodium carbonate
The cleaning effect will be better if a small amount of hyposalts or agents that can generate synthetics and surfactants are added to the cleaning solution. Maximum concentration 4%, the highest temperature 60 ℃.
Precipitates
Scaling material: corrosion products, iron oxide, sediment, aluminium oxide, diatomic organic matter
Cleaning method: open the device for mechanical cleaning
1. Gently brush with flowing water. Please note: avoid damaging the gaskets.
2. High pressure hose rinse.
3、Chemical cleaning with the following cleaning agents.
Nitric acid
Amino acid
Citric acid
Phosphoric acid
Compound agents (NDTA, NTA)
Sodium polyphosphate
Maximum concentration 4 %, maximum temperature 60°C
Note: Under no circumstances should hydrochloric acid be used to clean stainless steel sheets. When preparing cleaning solutions, do not use if the chlorine content in the water exceeds 300 PPm.
