Plate heat exchangers are essential equipment in various industrial processes due to their high thermal transfer efficiency and compact design.
Over time, they can accumulate fouling that impacts their performance. Cleaning plate heat exchangers is the solution to maintaining their efficiency over time.
The Importance of Plate Cleaning in Heat Exchangers
The accumulation of fouling on the plates reduces their thermal efficiency, increases energy consumption, and can lead to equipment failures.
Regular cleaning ensures:
- Operational Efficiency: Restoring heat transfer capacity.
- Energy Savings: Reducing energy consumption.
- Equipment Longevity: Preventing damage and wear.
Technical Procedures for Chemical Cleaning
There are two main methods for cleaning plate heat exchangers:
In-Situ Cleaning (CIP – Cleaning In Place):
This method involves circulating chemical solutions through the heat exchanger without the need for disassembly, minimising downtime.
The steps include:
- Preparation: Isolate and drain the heat exchanger.
- Circulation of the Chemical Solution: Circulate a descaling solution appropriate for the type of fouling present.
- Rinsing: Remove chemical residues from the cleaning process using clean water.
- Restoration: Reintegrate the heat exchanger into the system and verify its operation.
Immersion Cleaning of Heat Exchanger Plates:
Immersion cleaning is used when fouling is severe or in-situ methods are insufficient. The procedure is as follows:
- Preparation: Disassemble the heat exchanger and remove the plates.
- Immersion and Cleaning: The plates are submerged in a tank with the chemical solution. Specific techniques, such as agitation or circulation within the tank, are used to enhance efficiency.
- Rinsing and Drying: The plates are removed from the tank and rinsed with clean water to eliminate any chemical solution residues. The plates are thoroughly dried before reassembly.
- Reassembly: The heat exchanger is reassembled, maintaining the original plate order, and pressure tests are conducted.
Technical Considerations
- Chemicals Selection: Choose effective cleaning agents based on the type of fouling present.
- Parameters: Factors such as temperature, chemical solution concentration, contact time, and flow rate.
- Safety: Use appropriate personal protective equipment (PPE) and follow proper protocols for handling chemical products.
Benefits of Regular Plate Heat Exchanger Cleaning
- Performance Optimisation: Maintains the heat exchanger’s thermal efficiency.
- Reduced Operating Costs: By improving heat transfer, energy consumption and associated costs are reduced.
- Failure Prevention: Removing deposits prevents corrosion and other damage that can lead to equipment failure.
- Regulatory Compliance: In industries where hygiene is critical, such as food and pharmaceuticals, regular cleaning ensures compliance with sanitary regulations.
In conclusion, chemical cleaning of plate heat exchangers is an essential practice for maintaining the efficiency, safety, and durability of the equipment. Implementing proper and regular cleaning procedures ensures more efficient operations and extends the equipment’s lifespan.
