Drying equipment is also called dryer and dryer. The equipment used for drying operation vaporizes and escapes the moisture content (generally refers to moisture or other volatile liquid components) in the material by heating to obtain the solid material with the specified moisture content. The purpose of drying is for the use of materials or further processing. For example, the drying of wood before making wooden molds and woodware can prevent deformation of the product, and the drying of ceramic blanks before calcination can prevent cracking of the finished product. In addition, the dried material is also convenient for transportation and storage, such as drying the harvested grain below a certain moisture content to prevent mildew. As natural drying is far from meeting the needs of production development, various mechanized dryers are increasingly used.
There are many types of drying equipment. Depending on the operating pressure, operating method, heat transfer principle, heating method, structure, etc., drying equipment can be classified into different categories. According to the operating pressure, it can be divided into normal pressure and vacuum type; according to the operation mode, it can be divided into intermittent operation and continuous operation; according to the heat transfer principle, it can be divided into conduction heating, convection heating, radiant heat transfer and high There are several types such as frequency heating; according to the heating method, it can be divided into two types: direct heating and indirect heating.According to the structure, it can be divided into spray dryer, fluidized bed dryer, air dryer, paddle dryer, and box dryer. And rotary flash dryer.
Equipment for drying operations. There are many types. According to the operating pressure, it can be divided into normal pressure and reduced pressure (reduced pressure dryer is also called vacuum dryer). According to the operation method, it can be divided into batch type and continuous type. According to the drying medium, it can be divided into air, flue gas or other drying media. According to the movement (material movement and drying medium flow), it can be divided into co-current, counter-current and cross-current.
According to the operating pressure, the dryer is divided into two types: normal pressure dryer and vacuum dryer. Operating under vacuum can reduce the wet partial vapor partial pressure of the space to accelerate the drying process, and can reduce the wet boiling point and material drying temperature. Leakage, so the vacuum dryer is suitable for drying heat sensitive, oxidizable, explosive and toxic materials as well as occasions where moisture vapor needs to be recovered.
By heating method According to the heating method, the dryer is divided into convection type, conductive type, radiation type, and dielectric type. Convection dryer, also known as direct dryer, is the use of hot drying medium in direct contact with wet materials to transfer heat by convection and take away the generated steam; conductive dryer is also called indirect dryer, it uses conduction The method transfers heat from the heat source to the wet material through the metal partition wall. The generated wet steam can be removed by vacuum suction, a small amount of purge gas, or condensation on the surface of a separately set low-temperature condenser. This type of dryer does not use a drying medium, has high thermal efficiency, and the product is not polluted. However, the drying capacity is limited by the heat transfer area of the metal wall, and the structure is more complicated. It is often operated under vacuum. The dryer emits electromagnetic waves in a certain wavelength range, which are selectively absorbed by the wet material surface and converted into heat for drying; the dielectric dryer uses the high-frequency electric field to dry the wet effect inside the wet material.
By exercise According to the movement method of wet materials, the dryer can be divided into fixed bed type, agitation type, spray type and combined type; according to the structure, the dryer can be divided into a box type dryer, a conveyor type dryer, a drum type dryer, and a standing type. Type dryer, mechanical agitator dryer, rotary dryer, fluidized bed dryer, air-flow dryer, vibration dryer, spray dryer and combined dryer.
Petroleum and chemical industry: polymerization, condensation, distillation, melting, dehydration, forced insulation. Oil industry: fatty acid distillation, oil decomposition, concentration, esterification, vacuum deodorization. Synthetic fiber industry: polymerization, melting, spinning, drawing, drying. Textile printing and dyeing work: heat setting, drying, heat capacity dyeing. Non-woven industry: non-woven fabric. Feed industry: drying. Plastic and rubber industry: hot pressing, calendering, extrusion, vulcanization. Paper industry: Dry, corrugated paper processing. Wood industry: plywood, fiberboard press forming, wood drying. Building materials work: drying of gypsum board, heating of asphalt, curing of concrete components. Machinery industry: painting, printing and drying. Food industry: baking, heating. Air-conditioning industry: heating of industrial plants and civil buildings. Microwave vacuum drying equipment Microwave vacuum drying equipment Road construction industry: Asphalt melting and thermal insulation. Pharmaceutical industry: drying. Light industry: production of inks and washing powders.