Application of dehumidifier in industrial process

Foundry industry

          During the process, wax mould is repeatedly immersed in clay, and these outer layers form mold. After wax is melted, molten metal can be poured into it. Dry air (very low steam pressure) is more often used to dry clay layer than other heating sources, because dry air will not make wax mold form when heated. The moisture absorption dehumidifier can make the foundry operation cost stable and increase the manufacturing quantity, without slowing down the production pace in wet months, and the drying time of the process can be reduced by 50%.

  Drying of plastic resin

          All plastic resins have some degree of moisture absorption. When the plastic raw material particles are extruded, the moisture is heated and evaporated. These vapors can make the plastic structure and appearance slit. Dehumidifier can reduce the humidity in plastic raw materials, improve the quality of finished products, reduce waste and increase the manufacturing speed.

  Candy cladding

          The process of dressing sugar is very important to the candy industry, and it is also a difficult process. The product is placed in the rotating cylinder, and the material to be covered in the outer layer is sprayed in the rotating cylinder for about an hour, so that the outer layer has a certain thickness. The longer the process, the higher the chance of damaging the product. If chocolate is used as the base or a temperature sensitive formula, the coated surface can be dried with dry air while spraying the coating material to cool the surface. If the air is pre dried by the dehumidifier, the heat will not be added to the product surface and the pressure difference of the surface vapor will increase. This allows manufacturers to maintain a fixed production rate throughout the year without paying attention to changes in foreign gas.

  The object reabsorbs moisture

          Almost every substance has some moisture, and even products such as plastic resin nylon can absorb 6-10% of its dry weight. Generally speaking, this is not a big problem, but sometimes moisture can cause the change of product size and the problem of mutual adhesion.

          The traditional domestic salt can explain this phenomenon. In wet weather, salt will be stuck to the opening of the pot due to moisture absorption. It is not a serious problem on the table, but it will cause a big problem for the product packaging machine.

          Hygroscopic products are more sensitive to relative humidity than absolute humidity, and high relative humidity may occur at any time of the year, in fact, it is often higher in winter than in summer. When the product is stored or manufactured in low temperature, the problem is especially serious.   Here are some examples of typical industrial processes to prevent moisture re suction.

  Packaging of candy

          Candy usually contains sugar and glucose, both of which are hygroscopic. When the relative humidity is high, the product will absorb moisture and become sticky. It is easy to stick to high-speed packaging machine and packaging materials and break the production line. The temperature and humidity control of the candy packaging area is very economical for the candy industry. The standard design conditions for this application are: 35% relative humidity at comfortable temperature.

  Semiconductor and pharmaceutical cleanroom           When making microcircuit, hygroscopic polymer called photoresist is used to etch the mask circuit line. If moisture is absorbed, the microcircuit will be cut off or shorted to cause circuit failure.

          In addition, many powders are hygroscopic in the pharmaceutical process. When the humidity is high, it is difficult to deal with and shorten the storage time. For these factors, the closed control of relative humidity can improve the production speed and maintain the product quality. The typical design conditions are 20 ℃ and 25% respectively.

  Safety glass production           The transparent thin plastic sheet in the safety glass interlayer has very strong moisture absorption. Film that absorbs moisture will produce water vapor bubbles during the process. It is very important to control relative humidity in the process. The standard design conditions for this application are: 25% relative humidity at comfortable temperature.

  Air delivery

          The influence of the storage and transportation system operators on high humidity is more impressive. The results are the blockage of the conveying pipe, the poor product quality and the increase of maintenance times. Compressed air increases the possibility of condensation of water in the air. When the components in the product absorb moisture, they become more viscous and accumulate in the conveyor line, resulting in the above results.

  In order to solve the above problems, moisture absorption agent is widely used in industry as pre drying air. The standard design conditions are that the relative humidity is less than 50% at any dry bulb temperature.