Among the three common condensers, except for air-cooled condensers, the other two, namely water-cooled condensers and evaporative condensers, all use water.

After long-term use, these two condensers are prone to scale formation in the pipes. If not handled in time, these scales will affect the heat exchange effect, causing the condensation temperature of the unit to increase, which in turn leads to a decrease in cooling capacity and an increase in unit power consumption.

Therefore, the condenser should be descaled frequently.

There are three main methods for preventing and removing scale:

1. Mechanical descaling:

Mechanical descaling is a method of using a flexible shaft pipe cleaner to descale the condenser of a steel cooling tube, which is particularly suitable for vertical shell and tube condensers.

The operation method is:

(1) Extract the refrigerant from the condenser.

(2) Close all valves connecting the condenser to the refrigeration system.

(3) Supply cooling water to the condenser normally.

(4) Use the umbrella gear connected to the flexible shaft pipe cleaner to rotate and scrape the scraper from top to bottom in the vertical tube of the condenser to remove scale, and use circulating cooling water to cool the heat generated by the friction between the scraper and the tube wall, while flushing the removed scale, rust and other dirt into the pool.

During the descaling process, the appropriate diameter of the roller is determined according to the thickness of the scale of the condenser, the degree of rust on the tube wall, and the length of time it has been used. However, the diameter of the roller selected for the first descaling should be slightly smaller than the inner diameter of the cooling tube to prevent damage to the tube wall. A roller with a diameter close to the inner diameter of the cooling tube is selected for the second descaling. These two descaling processes can remove more than 95% of the scale and rust in the condenser.

This mechanical descaling method uses the rotation and vibration of the bevel gear-shaped roller in the cooling tube to remove the scale and rust in the condenser cooling tube. After the descaling is completed, all the water in the condenser pool is drained, the scale, rust and other dirt removed from the bottom of the pool are cleaned up, and the water is refilled.

2. Chemical pickling and descaling method:

Use the prepared weak acid descaling agent to clean the condenser to remove the scale and improve the heat transfer efficiency of the condenser.

The operation method is:

(1) Prepare the descaling solution in the pickling tank, start the pickling pump, and circulate the descaling solution in the condenser tube of the condenser for 24 hours. Generally, the scale is basically removed after 24 hours.

(2) After stopping the pickling pump, use a round steel brush to brush back and forth on the tube wall of the condenser tube, and rinse the scale and rust with clean water.

(3) Use clean water to repeatedly clean the descaling solution remaining in the tube until it is completely clean. The chemical pickling and descaling method is suitable for vertical and horizontal shell and tube condensers.

3. Electronic magnetic water descaling method:

(1) The working principle of the electronic magnetic water device is to dissolve calcium, magnesium and other salts in the cooling water flowing through the condenser in the form of positive and negative ions in the water at room temperature.

(2) When the cooling water flows through the transverse magnetic field of the magnetic water device at a certain speed, the dissolved calcium, magnesium and other ions obtain induced electrical energy, causing their charge state to change, and the electrostatic attraction between the ions is disturbed and destroyed, thus changing their crystallization conditions, making the crystal structure loose, and reducing the tensile and compressive resistance. It cannot form hard scale with strong adhesion and becomes loose mud residue that is discharged with the flow of cooling water.

(3) This descaling method can not only effectively prevent the formation of new scale, but also remove the original scale, because after using the electronic magnetic water device, the ions lose their scaling ability, which loses the protective effect on the original scale.

(4) In addition, the magnetized cooling water has a certain amount of induced electrical energy. At the same time, due to the different expansion coefficients of the steel pipe and the scale in the condenser, the original scale gradually cracks, and the magnetized water continuously invades the cracks, destroying the adhesion of the original scale and making it gradually lose. The method of the electronic magnetic water device is simple and easy, with low labor intensity, and it can remove scale and prevent scaling without affecting the normal operation of the refrigeration system.

4. The significance of descaling and energy saving:

Once the condenser is scaled, the thermal resistance of heat conduction increases, so the thermal resistance increases and the heat transfer coefficient value decreases. Because the condensation temperature is inversely proportional to the heat transfer coefficient, the condenser temperature increases and the condensation pressure increases accordingly. The more serious the condenser scaling is, the more significantly the condensation pressure increases, which increases the power consumption of the refrigerator and the power consumption of the various operating equipment in the refrigeration system, resulting in a waste of electricity.