What is the key to solving the condenser heat dissipation problem?
In the field of medical equipment, no matter what kind of equipment, the user should pay attention to the maintenance and maintenance of each component after using it for a period of time. Taking the ultra-low temperature refrigerator as an example, it is particularly necessary to pay attention to the scale problem of the shell-and-tube condenser.
It is understood that scale is commonly referred to as "rust", which refers to crystals formed by the constant adhesion and accumulation of impurities in natural water. Its thermal conductivity is very poor, which easily affects the heat dissipation of the equipment. Therefore, in order to prolong the service life of the ultra-low temperature refrigerator, the scale on the surface of the shell-and-tube condenser must be removed in time.
So, what are the methods for removing scale from the shell-and-tube cold trap? The industry introduced three methods of mechanical descaling, chemical pickling and descaling, and electronic magnetic water descaling. Below, Xiaobian will introduce the principle and scope of descaling of these methods.
The tube-type cold suspect mechanical descaling method is a method for descaling the condenser of the cooling tube by using a soft shaft washer, and is particularly suitable for a vertical shell-and-tube condenser.
The specific operation is to first withdraw the refrigerant in the condenser, and then close all the valves connected to the refrigeration system of the condenser to ensure the normal supply of the cooling water of the condenser, and then use the umbrella gear-shaped scraper coupled with the soft shaft washer. The riser of the condenser is rotated and descaled from top to bottom, and the circulating cooling water is used to cool the heat generated by the friction between the scraper and the pipe wall, and the dirt, rust and the like which are removed are flushed into the pool.
The industry reminds that when cleaning the shell and tube condenser of the ultra-low temperature refrigerator, it is necessary to take care to prevent damage to the pipe wall to avoid malfunction of the ultra-low temperature refrigerator.
Chemical pickling and descaling
The chemical pickling and descaling method is to clean the ultra-low temperature condenser of the low-temperature refrigerator by using the prepared weakly acidic descaling agent to make the scale fall off, thereby improving the heat transfer efficiency of the condenser. The chemical pickling and descaling method is suitable for vertical and horizontal shell and tube condensers.
The main step is to first prepare a descaling solution in the pickling tank, start the pickling pump, and let the detergent solution circulate in the condenser of the condenser for 24 hours, then stop the pickling pump and then use a round shape. The steel brush is brushed back and forth in the pipe wall of the condenser pipe, and the scale and rust are rinsed with water, and the detergent solution remaining in the pipe is repeatedly washed with water until it is completely clean.
Electromagnetic water descaling
In addition to the above two methods, the ultra-low temperature refrigerator removes the scale of the shell-and-tube condenser, and there is an electronic magnetic water descaling method.
According to reports, the electronic magnetic water descaling method is to dissolve calcium, magnesium and other salts in the cooling water flowing through the condenser, and dissolve it in water in a positive and negative ion state at normal temperature, thereby effectively preventing the generation of new scale and clearing the original. Some scales. At the same time, because the expansion coefficient of the steel pipe and scale in the condenser is different, the original scale gradually cracks, and the magnetized water invades the crack without interruption, destroying the adhesion of the original scale, making it gradually loose and self-contained. Shedding and constantly being taken away by circulating cooling water.
All in all, once the condenser of the ultra-low temperature refrigerator has scale, its thermal resistance will continue to increase, resulting in a continuous decrease in the heat transfer coefficient, making the refrigeration effect worse and worse. Therefore, it is recommended that the operator check and remove the condenser as soon as it is found to have scale.