EnglishViews: 16 Author: Site Editor Publish Time: 2025-06-05 Origin: Site
Plate heat exchangers have become increasingly popular over the past few decades compared to shell and tube heat exchangers. Generally speaking, plate heat exchangers are more efficient at transferring heat and take up less space. These factors have led to breweries' interest in plate heat exchangers as an alternative to shell and tube heat exchangers. There are two methods for cleaning plate heat exchangers: cleaning in place (accomplished by circulating chemicals through the channels of the plate heat exchanger) or manual cleaning (removing the plates from the frame and cleaning the plates one by one using a pressurized water gun).
This method allows a chemical solution to circulate through the heat exchanger, dissolving and removing scale from the plate surface. This method eliminates the need to separate the heat exchanger, simplifies the cleaning process, and reduces cleaning labor. Chemical cleaning is ideal because the corrugated plates clean turbulent liquids and help dissolvescale.
The CIP cleaning method combines time, temperature, and concentration. CIP systems provide chemical and mechanical cleaning of heat exchangers. If the brewery equipment does not allow CIP cleaning, the operator must perform manual cleaning.
Remove scale deposits.
Passivate surfaces to reduce corrosion susceptibility.
Neutralize cleaning chemicals before draining.
The cleaning process is faster.
The labor intensity is low.
Parts that cannot be cleaned by mechanical cleaning can be cleaned.
Alkaline cleaning: Removes organic buildup.
Rinse: Usually uses a high-flow water rinser to remove loose debris and residue from the alkaline step.
Acid cleaning: Helps dissolve and soften scale at a deeper level.
Final rinse: Finally rinses the plate heat exchanger with clean water.
If the plate heat exchanger does not support CIP cleaning, manual cleaning is required.
The first step in maintaining a heat exchanger is to disassemble the plate heat exchanger, which requires a professional technician to shut off all fluids in and out of the heat exchanger (make sure to follow the lockout procedure).
To be able to drain fluid from the heat exchanger, you need to open the valve to release all pressure. You need to complete the cooling before the heat exchanger is opened, to do this you need to:
Loosen the acid on the heat exchanger before moving the next bolt, about 0.6 meters at a time. To ensure effective loosening of the bolts, do not over-loosen the bolts, otherwise you may damage the bolt heads.
Once the bolts are removed, slide each removable bolt head back to expose the hot plate set.
To facilitate reinstallation, all plates need to be numbered in reverse order with the number displayed on the top of each plate.
Any good plate heat exchanger maintenance plan includes cleaning services. Follow these steps to ensure you don't miss any steps:
First, remove the gasket. Whether the gasket is reusable depends on its current condition. To check if the gasket is intact, simply pinch it. If you need to reuse the gasket, wash it with soap and water and hang it in a clean and dry place.
If there is loose debris on the plate, you need to clean it with soap, water and a soft brush or pressure washer (not an abrasive or hard brush).
Clean the plate until all debris is removed.
You need to be very careful when cleaning the grooves of the gasket, and in severe cases, hot acids and caustics are needed to break down stubborn adhesives and scale.
During this inspection, be sure to test and inspect the plates throughout the facility for cracks and pinholes.
Visually inspect the heat exchanger for defects, paying close attention to where the plates touch each other. You can use a light to aid in the visual inspection.
It is also a good idea to perform a dye test to find any pinholes that the visual inspection missed. If more than 10% of the plates are defective, the plates must be replaced. If the plates pass the dye test, they can be cleaned and put back into service.
Before inspecting and preparing the heat exchanger plates, the plate frame must be cleaned and prepared before reassembly:
First inspect the nozzle area and pay close attention to the weld areas where corrosion and defects may occur.
Check the straightness of the fixed and movable heads with a ruler. For painted and powder-coated carbon steel frames, it is necessary to check whether the coating is in a satisfactory condition.
Check the connection points of the upper and lower rails.
Polishing may interfere with serious defects in the plate.
After completing the above steps, start reinstalling the plate, install the plate directly into the frame, and check whether the gasket is properly seated. Finally, install the port ring into the frame.
After the heat exchanger is assembled, always perform a hydrostatic test to check for leaks.
Fill the system or other water source (such as the heat exchanger) with water.
Allow the water to flow for a while to expel excess air.
Slowly reduce the water outlet to increase the pressure, but do not exceed the design pressure.
Air dry the outside of the heat exchanger to remove any residual moisture.
While the heat exchanger is under pressure, check the plate pack for leaks.
Some common causes of leaks include:
Debris in the gasket groove
Gasket aging
Gasket damage
Holes in the plate
