Drying machine basic introduction

Such as wood in front of the production of wooden, wood drying can prevent deformation of products, ceramic blank before calcining drying can prevent crack. After drying of material also facilitate transportation and storage, such as the grain dry to a moisture content of the following, in order to prevent mildew. Due to the natural drying far cannot satisfy the needs of the development of production, all kinds of mechanical dryer has been applied more and more widely. Dryer in the refrigeration system of freeze drying machine, evaporator is conveying cold quantity of equipment, in which refrigerant absorbs heat of compressed air, achieve the goal of dehydration. Compressor is the heart, plays a suction, compression, the role of the refrigerant vapor. Condenser is exothermic equipment, will be absorbed in the evaporator heat along with the quantity of heat of compressor power input is passed to the cooling medium ( Such as water or air) Take away. Expansion valve/valve throttling depressurization effect to the refrigerant, at the same time control and adjust the number of flows into the evaporator refrigerant liquid, and the system is divided into the high side and low voltage side of two parts. Development and classification of modem dryer using the intermittent operation of the fixed bed drying machine. The middle of the 19th century, the use of trunk type dryer, marked the dryer by intermittent operation to continuous operation in the direction of development. Rotary drum dryer is better realized the granular material agitation, drying ability and strength to improve. Some industry respectively developed to adapt to the industry requires the continuous operation of the dryer, such as textile, paper making industry of drum drying machine. In the early 20th century, dairy production application of spray drier, provides a powerful tool for large-scale drying liquid material. In the 40 s, with the development of fluidization technology, high strength, high productivity of the ebullated bed gas flow dryer appeared. While frozen, radiation and dielectric type dryer provides a new means to meet the special requirements. In the 60 s developed far infrared and microwave drying machine. A lot of mechanical equipment types used for drying operation, according to the operating pressure can be divided into normal pressure and decompression ( Decompression drying machine is also called the vacuum drying machine) 。 According to the method can be divided into intermittent and continuous operation. According to the drying medium can be divided into the air, dry flue gas or other media. According to the movement, Material movement and drying medium flow) Way can be divided into the flow and countercurrent and cross-flow. According to the operating pressure, drying machine is divided into two categories, atmospheric pressure drying machine and vacuum drying machine, operation can reduce the moisture of the space in the vacuum steam partial pressure and speed up drying process, and can reduce moisture boiling point and material drying temperature, steam is not easy to leak, so the vacuum drying machine is suitable for drying heat sensitive, easy oxidation, explosive and toxic materials, and moisture vapor recovery. Advantages: 1, well-designed adsorption tower body 2, 3 high-performance activated alumina adsorbent, the silencer 4, the unique power of the effect is good and durable two characteristics of imported pneumatic control, 5, and can accurately adjust flow of gas regulator according to the heating mode, the drying machine is divided into convection, conduction, radiation type, dielectric type etc. Convection drying machine is also called the direct dryer, is using thermal drying medium, direct contact with the wet material in convective heat transfer, and the generated steam away; Conduction type dryer is also called the indirect dryer, it USES the conduction way by heat transfer heat to the wet material through metal partition, the generated moisture vapor available vacuum suction and ventilation with a small amount of purge gas or in a separate set of low-temperature condensation on the condenser surface method. This kind of dryer does not use the drying medium, high thermal efficiency, the product is not contaminated, but drying ability of metal wall heat transfer area, structure is more complex, often operating under a vacuum; Radiation type dryer is the use of a variety of radiator emits a certain wavelength range of electromagnetic waves, after being absorbed by the wet material surface selectively into dry heat; Dielectric type dryer is the use of high frequency electric field, the internal heating for drying wet material. Advantage: 1, using high-performance evaporator, large heat transfer area, heat transfer temperature difference is small, the evaporator outlet air temperature is more stable 2, high-efficiency gas water separation structure, high separation efficiency;