How to removing scale in shell – tube condenser

There are three ways to prevent and remove scale:

1. Mechanical descaling method: mechanical descaling is a method of descaling the condenser of steel cooling tube with a soft shaft pipe washer, especially for vertical shell and tube condenser.

The operation method:

⑴Extract the refrigerant from the condenser.

⑵Close all valves connected with the condenser and the refrigeration system.

⑶Normally supply cooling water for condenser.

⑷The bevel gear scraper connected with the soft-shaft pipe washer is rolled down the vertical pipe of the condenser from top to bottom to remove scale, and the heat generated by friction between the scraper and the pipe wall is cooled by circulating cooling water. Meanwhile, the water scale, iron rust and other dirt are washed into the sink.

In the process of descaling, according to the scale thickness of the condenser, the corrosion degree of the pipe wall and the length of  used time to determine the appropriate diameter hob.The second descaling is done by using a hob with a diameter close to the inner diameter of the cooling pipe.This double scaling removes more than 95 percent of the scale and rust from the condenser.

This kind of mechanical descaling method is to use bevel gear hob to rotate and vibrate the hob in the cooling pipe ,Remove the scale and rust from the condenser cooling pipe, and remove all water from the condensing pool after the descaling.Clean up the bottom of the pool from the dirt and rust,And refill it with water.

2.Chemical pickling descaling:

• Use the prepared weak acid descaler to clean condenser,It can make scale fall off and improve heat transfer efficiency of condenser.

• The operation method is:
• ⑴Prepare the descaling solution in the pickling tank and start the pickling pump.After the descaling agent solution circulates in the condenser’s condensing tube for 24 hours, the scale is generally removed after 24 hours.
• ⑵After stopping the pickling pump, use circular steel brush to pull back and forth in the tube wall of the condenser, and rinse the scale and rust with water.
• ⑶Wash the remaining descaler solution in the pipe repeatedly with water until it is completely clean.
• Chemical pickling descaling method is suitable for vertical and horizontal shell – tube condenser.

3.Electronic magnetic water descaling method:

The electronic magnetometer works by dissolving calcium, magnesium and other salts in the cooling water flowing through the condenser in a positive and negative ion state at room temperature.

When the cooling water flows through the transverse magnetic field of the device at a certain speed, dissolved calcium and magnesium plasma can obtain induced electric energy and change its charge state, the electrostatic attraction between ions is disturbed and destroyed, thus changing the crystallization conditions,The structure of the crystal is loose and the tensile and compressive strength is reduced.It can not form a hard scale with strong cohesive force, and become loose mud residue to be discharged with the flow of cooling water.

This descaling method can not only effectively prevent the generation of new scale, but also remove the original scale.In addition, the magnetized cooling water has certain inductive power,Because the expansion coefficient of steel tube and scale in condenser is different, the original scale gradually cracks,The magnetized water continuously intrudes into the cracks and damages the adhesion of the original scale, making it loose gradually and fall off on its own and constantly being carried away by the circulating cooling water.

The descaling method of the electronic magnetic water heater is simple and easy to operate, the labor intensity is low, and the descaling and preventing descaling are carried out without affecting the normal operation of the refrigeration system.

Significance of scale removal and energy saving:

Once the condenser has scale, the thermal conductivity increases,So as the thermal resistance increases, the heat transfer coefficient decreases,Because the condensing temperature is inversely proportional to the heat transfer coefficient, the condenser temperature increases and the condensing pressure increases accordingly,And the more serious the scale of the condenser, the faster the condensing pressure will increase, thus increasing the power consumption of the refrigerator.As a result, the power consumption of all operating equipment of the refrigeration system increases correspondingly, resulting in the waste of electric energy.