How to Deal with Fouled Condenser?

2024-09-23

The condenser is extremely prone to scaling. Normally, daily water treatment should be carried out during the cooling supply period. Otherwise, when operating in an environment with high-hardness water quality, the inorganic salts dissolved in the circulating water system will crystallize and precipitate as the temperature rises, forming scale on the tube wall of the heat exchange surface of the condenser, resulting in reduced heat exchange efficiency. At the same time, as hard scale increases, energy consumption rises. When hard scale is 1mm thick, it will increase by 6% to 10%.
Due to dirt formed by soil, silt, and humus in water, combined with biological slime formed by bacteria, algae and other microorganisms and their secretions, it will adhere to the heat exchange tube wall of the condenser to form sludge, and in severe cases, cause pipeline blockage. Dirt and slime will affect heat exchange efficiency, consume more electrical energy, cause high-pressure operation, and in severe cases, cause overpressure shutdown. All these seriously affect the normal operation of the condenser.
Condenser cleaning is divided into physical cleaning and chemical cleaning.
Physical cleaning method:
Physical cleaning mainly uses a flexible shaft brush for cleaning. The flexible shaft is driven to rotate by the motor of the cleaning machine. At the front of the flexible shaft is a nylon brush. When in use, insert the flexible shaft and brush into the copper tube of the condenser. The dirt in the copper tube is removed by the high-speed rotating brush. Finally, rinse with clean water. This machine is called a tube cleaner.
The advantages of physical cleaning are that it saves the cost of chemical cleaning solution, avoids the problem of treating waste liquid after chemical cleaning, and is not easy to cause corrosion of the copper tube of the condenser.

How to Deal with Fouled Condenser?1727064256102

The disadvantage is that for hard scale and corrosion products with strong adhesion, the cleaning effect is not good, and the cleaning operation is relatively time-consuming and labor-intensive.
If the scale is hard water scale, chemical cleaning should be carried out. Physical methods cannot remove the scale. In order to make the condenser operate in an optimized state, it is necessary to carry out special chemical treatment on the condenser to remove scale, rust, slime, sterilize and prevent corrosion, and restore it to a clean metal surface.
Chemical cleaning process:

Tighten the valves for cooling water entering and leaving the condenser, and use the thermometer tube, pressure gauge tube or sewage discharge tube to connect the anti-corrosion pump and liquid preparation tank to form a small circulation system for circulation cleaning.
First add an acid pickling corrosion inhibitor. This agent is a special copper corrosion inhibitor. It adheres to the metal inner wall of the condenser to prevent acid from reacting with metal.
Add solid acid pickling cleaning agent, which is used to clean scale with calcium carbonate scale as the main component.
The cleaning agent is a composite solid organic acid, white crystal, non-corrosive to metal, and is a weak acid. The dosage of the cleaning agent depends on the amount of scale on the equipment.
Add a sludge stripping agent (optional). If the condenser equipment is thickly scaled, a sludge stripping agent needs to be added to promote the rapid dissolution of the reaction products of scale in water and accelerate the reaction of deep scale.
Add a neutralizing passivating agent. After chemical cleaning of the condenser, neutralize residual acid to prevent secondary floating rust from being generated due to oxidation of the metal surface.
Cleaning process:
A. Cleaning temperature: Generally, normal temperature cleaning is adopted. If the scale is thick, it can be cleaned at 40℃ - 50℃ to improve the cleaning speed.
B. Close the valves of the unit for entering and leaving, and use the pressure gauge or thermometer tube, anti-corrosion pump, and acid tank to connect into a cleaning circulation system. When cleaning, add a corrosion inhibitor first. After the corrosion inhibitor is evenly circulated, slowly add organic acid. During cleaning, the reaction situation should be detected regularly. When the cleaning agent is insufficient, it needs to be replenished to ensure that there is enough acid solution to react with scale. During cleaning, according to the scale reaction situation, an appropriate amount of sludge stripping agent, defoaming agent, etc. can be added.
C. After cleaning, discharge the remaining liquid and add clean water for rinsing.
D. After cleaning the condenser, a neutralizing passivating agent needs to be added to neutralize residual acid to prevent oxidation of the metal inner wall.
E. The cleaning time of the condenser is about 5 to 10 hours, depending on the actual situation.