Multi-cyclone recovery system for electrostatic coating of powder coatings

[China Aluminum Industry Network] The electrostatic spraying of powder coatings has entered the application field since the 1960s, and it has been rapidly popularized throughout the world, and it has been increasingly favored by people. However, with this spraying method, due to the discontinuity of the workpiece during the spraying process, the quality of the powder itself, and the influence of the spraying stroke, part of the powder may not be fully utilized. If this part of powder is not collected in time, it will easily pollute the environment; if it is treated as waste powder, it will be too wasteful; if it is used for repeated use, it contains a lot of unusable waste powder which will affect the coating quality. This requires a device to collect and separate it, separate the available and unusable parts, and deal with them separately. The function of the powder recovery device is to collect the powder falling from the spraying process, separate it into usable powder and non-utilizable waste powder, and send it to the corresponding device. However, in actual use, due to various factors such as equipment manufacturing, technology, etc., there is always one or the other deficiency in the recovery device. Therefore, people have been looking for an ideal powder recovery system to solve the problem of powder recovery during spraying. This article describes a multi-cyclone powder recovery system. working principle: Multi-cyclone powder recovery system: This device can be divided into four parts: inhalation section, separation section, filtration section and discharge section. The suction section consists of a freely adjustable wind plate, an adjustment system and a tuyere. Its function is to suck powder dust or unutilized powder floating in the air from the spray chamber into the separation system to separate it. During operation, adjust the adjustment system according to specific conditions, adjust the intake air volume by changing the size of the tuyere to improve the environment and collect dust and powder. The adjustment of the tuyere should be based on the height of the spraying chamber, the relative height of the workpiece from the tuyere, and the straight-line distance. to make sure. If the air outlet is too close to the workpiece, due to the suction of the air, the upper powder rate of the workpiece is often not high, and the powder consumption is too large. On the other hand, if the air outlet is too small, it will not be easy to remove the dust in the spraying room in time, and the spraying work environment becomes poor. . The separation section consists of a cyclone separation tube, a filter screen, and an air inlet and outlet. Its role is through a special cyclone cylinder device, so that the available powder enters the original powder box and mixes with the original powder and enters the spraying cycle again, while another part of the powder with very small particles is difficult to adsorb electrons in the spraying electric field. Because it is charged, it is basically impossible to apply it to the workpiece and it is called waste powder. If these waste powders are not added in time and they are continuously added to the original powder, the amount of available powder in the original powder will be less and less, and the amount of effective powder sprayed per unit time will be less and less, resulting in more film thickness of the workpiece being sprayed. The thinner it is. On the other hand, if these waste powders enter the spraying cycle together with the original powder, in order to obtain qualified parts, they must constantly adjust the process parameters, increase the amount of powder per unit time, and waste powder should be coated from the original powder box to the workpiece. After a series of devices, the waste powder runs at a very fast speed, which increases equipment wear and severely affects the service life of the equipment. Therefore, this part of the waste powder should be separated as much as possible and it can no longer participate in the spraying cycle. This process is completed in the separation section. The key equipment here is a cyclone separation drum. The device is a cyclonic structure with an internal involute shape. When the airflow enters the device, it will change direction and form a turbulent flow. The centrifugal force and the gravity together cause the powder therein to be efficiently separated during rotation. The powder and gas mixture from the separation section enters the filtration section, and the filtration section consists of the filtration chamber, the waste powder collection tank and the cleaning gas system. Its role is: the filter chamber consists of a set of filter elements and their accessories, the main role is to filter the mixture coming from the front. The filter element is made of a special material with high strength and micropores. The micropores can pass gas, but the powder can not pass, but as time goes by, there will be a lot of fine powder stuck to the surface of the filter element, blocking the pores of the filter element, on the one hand losing the filtering effect, and on the other hand making the system The internal air flow is not smooth, and the resistance of the exhaust fan is increased, which easily causes the fan to be overloaded and damaged. Therefore, there is a need for a clean air system, which is a freely adjustable pulse air flow system. If its pulse cycle is adjusted to 5s, it will send out a flow of air from the inside of the filter element to the filter element every 5s, so that the powder adhering to the outside of the filter element will drop and enter the collection tank for easy collection. At the same time, the pulse cycle and air flow intensity can be adjusted according to actual production conditions to achieve better recovery. Here, the filter element and pulse gas are more critical. If the filter is not good, it will easily lead to unclean filtration, which will cause the discharged micropowder to enter the atmosphere and affect the surrounding environment. If it is serious, it will cause the local dust concentration to be too high and cause explosion. The discharge section consists of fans, air ducts and screens. Fans are used to exhaust air, which is also the driving force of airflow in the whole system; the wind tunnel determines the wind direction; the filter is a later protection, making the airflow into the atmosphere as clean as possible. summary: Compared with other types of recovery systems, the advantages of the multicyclone powder recovery system are: its structural multi-stage and separation on the set-up ensures that the mixture is rapidly and completely separated after entering. Its unique multi-cyclone separator cartridge and filter core made of special materials ensure high separation efficiency and good results. Each segment cooperates with each other and is separated from each other. The key is the coordinated work of the cyclone separation tube, filter element and backflushing pulse gas system, which not only ensures the high quality of recovery and separation, but also ensures the normal operation of the spray booth. The promotion and popularization of the system will greatly improve the efficiency of powder recovery, improve the quality of spraying and improve the environment.