Conduction drying, also known as contact with dry, well adapted for the wet grain, while conducting a high thermal efficiency dryer. Evaporation of water vapor or organic solvents or by vacuum out of a small amount of air emissions, air is the main carrier of moisture, heat-sensitive granular material is recommended for vacuum operation. In the conduction drying machine, paddle dryer used for drying paste material. Within the flow tube with a rotary dryer has been designed and has been put into use. Vacuum drying operations are expensive, but materials must be in the low-temperature drying, or hypoxia, or materials in the heating medium and high temperature drying will be degenerate only when recommended by vacuum drying. For a certain degree of evaporation efficiency, high-temperature operation more efficient, so that can reduce the gas flow rate, reducing equipment size. For the low-temperature drying operation, you can select the appropriate low-temperature waste heat or solar collectors as heat source, but the relatively large size dryer. Vacuum freeze-drying is a special case under the conditions of drying. Here, the temperature of the tri-state point in the water under the water (or ice) direct sublimation of water vapor. Despite the heat required for sublimation is many times lower than the evaporation, and other aspects of a larger power consumption, so the cost is still high vacuum drying.

    Conduction heat transfer from the jacket, mixing, heat transfer tubes, and heat supply of dry materials, with hot coal rather than hot air. Typical device is a slotted cylinder dryer. Conical mixing dryer, jacket and built-in heating tube rotary dryer, drum dryer, harrow dryer, vacuum belt drying machine, vacuum freeze-drying machine. In hot air drying, the constant speed drying period the temperature is equivalent to wet bulb temperature. Conduction heat transfer in the dry, you need to create an artificial heating surface, so that heat transfer area is small and heat transfer coefficient increases. In this way, the structure is more complex, investment in equipment than the big hot air dryer.

    Conduction drying method through a metal surface such as Sichuan indirect transfer of heat needed to dry. Drying rate lower than the direct drying method. Constant speed drying temperature and the heat source during the product temperature does not matter, generally with the installation of gas pressure within the same saturation temperature. In order to improve the drying rate and to prevent uneven drying, usually by mechanical stirring or to the container itself is rotated to increase or heat transfer surface continuously updated material, it is necessary to in-depth study of heat transfer body attachment issue. Drying device itself is expensive, but its dust collection system, the load is characterized by small, high heat efficiency, easy solvent recovery, the total cost is much cheaper than direct drying method.

    (1) Hollow Paddle Dryer (leaf drying machine)

    Hollow Paddle Dryer Dryer also known as blades, mainly by the W-shaped shell with a jacket and two hollow paddle shaft and gear component. Axis lined with hollow blades, shaft equipped with a heat medium into the rotary joint. The heat required for drying moisture from the W-shaped groove with a jacket inside and hollow blade wall conduction to the material. Material during the drying process, with the hollow shaft in the hollow blade to the material heated at the same time to stir the material, thus heating surface updates. Is a continuous conduction heating dryer. Heating medium is steam, hot water or heat conducting oil. Heating medium pass into the shell folder kit, and two hollow blade shaft in order to conduction heating means for heating and drying of materials, different materials hollow blade shaft structure is different.

    Machine is appropriate for dealing with all kinds of cream paste, granular, powder such as good thermal stability of materials under special conditions can also be dry and heat-sensitive materials and recovery of solvents in the drying process. Commonly used in carbon black, precipitated calcium carbonate, titanium dioxide, barium carbonate, acrylic acid, gypsum, clay, manganese dioxide, nylon and polyester chips, polyethylene, polypropylene (recycling of solvents) such as drying or cooling of materials.

    (2) vacuum rake dryer

    Dry materials from the vacuum rake dryer shell on the side is the middle, in the constant rotation of the rake teeth of the stirring, the material in contact with the shell wall, the surface constantly updated material has been dried by the steam (or hot water, heat conduction oil ) indirect heating, but the material moisture vaporization, evaporation of water pumped from the vacuum pump in time. Material was dried by indirect heat carrier heating, so that material in the water vaporization, evaporation of water discharged from the vacuum pump and timely. As the operation of a high vacuum, generally within 400 ~ 700mmHg was dried material is much larger than the surface of the water vapor pressure inside the dryer shell evaporation of the water vapor pressure of space. Thus facilitating the material being dried and surface water within the water discharge, have been dried material is conducive to water molecules movement, to achieve drying purposes. Vacuum rake dryer for heat-sensitive, easily oxidized at high temperatures or dry the material easy to harden the material, and dry in the discharge of steam to be recycled materials. Typical drying materials are acrylic acid sodium salt, CMC, phthalocyanine blue, dyes intermediates, carboxymethyl starch, malt dextrin, anthraquinone sulfonic acid and so on.

    (3) The belt dryer

    Belt dryer units by several independent blocks. Each unit segment, including circulating fans, heating devices, alone or in common fresh air into the system and the exhaust system. Right amount of drying medium, temperature, humidity and the amount of exhaust gas recycling operating parameters can be independently controlled, thus ensuring the reliability of the work with a drying machine and the optimization of operating conditions. With a drying machine, flexible operation, wet feed, the drying process carried out in fully enclosed cabinets, better working conditions, avoiding the leakage of dust. Sheet for better ventilation, strip, dry granular materials, for dehydrated vegetables, Chinese Herbal Pieces such as high water content and the material does not allow a high temperature material is particularly appropriate.

    (4) Garden & Patio Sets

    Dryer drum scraper through the rotating cylinder to heat conduction of the way, attached to the cylinder outer wall of the liquid material or ribbon materials in a continuous operation of equipment dry. Be dried in liquid flows from the high slot inside the drum dryer by the trough. Drying drum in gear-driven, according to the stipulated rotational speed. Material from the fabric membrane device, the roller material film formed on the wall. Pass into the cylinder with a continuous heating medium, heating cylinder, heat transfer from the cylinder wall, so that the moisture vaporization membrane materials, and through the scraper will reach the requirements of materials scraped dry by screw conveyor to the storage tank, for packaging. Evaporation of moisture removed, depending on their nature can be sealed enclosures, introduced in the corresponding processing units; usually water vapor, can be directly from the hood exhaust pipe placed to the top of the atmosphere. The machine is mainly used for processing of liquid materials can pass into the steam, hot water or hot oil heating and drying, but also pass into the cold water cooling guitar piece. According to the different material properties and process requirements using immersion, spray, grind-assisted methods such as feeding.

    (5) double-cone rotary vacuum dryer

    Double cone rotary vacuum dryer body slightly, such as olive-shaped, covered at both ends, in the middle to set up two-axis bearing the body of. The body of a jacket for heating and drying the body of the rotatable, so that frequent replacement of materials and contact with the wall, to overcome the material in the vacuum oven heating tube conduction on the shortcomings of low thermal efficiency. Rotary Vacuum Dryer in fine chemical industry, medicine, etc. has been used widely, the viscosity or in the rotation during the strong adhesion of materials does not apply. The device is mainly used in pharmaceutical, chemical, food industry, powdered, granular and fibrous materials, concentration, mixing, drying and the need for low-temperature drying of materials (such as biological and chemical products, etc.), more suitable for easily oxidized, volatile, heat-sensitive strong stimulation, toxic materials and do not allow destruction of crystal materials dry.

    (6) Vacuum Oven

    As the decompression after the evaporation of materials containing volatile compounds can reduce the evaporation temperature is suitable for a variety of heat-sensitive, easy-oxide material dry. This device is often the park bearing the vacuum tube or other shell operations, within the heating or hot water, heat conduction oil by heating panels or heating tubes for heating, suitable for small-volume batch production.

    Oven is a universal drying equipment suitable for a wide face, is a dish rack intermittent drying equipment, used in pharmaceutical, chemical, food. Light industry, heavy industry and other industries and products, heat-curing materials, dry dehydrated. Such as raw material medicine, Chinese herbs, Chinese Herbal Pieces, extract, powder, granule, powder, Shuiwan, packing bottle, pigment dyes, dehydrated vegetables, dried fruits, sausages, plastic resin, electric elements, BAKING so.

    (7) freeze-drying machine

    Freeze-drying machine is cooled to freeze the liquid first, followed by decompression to make the ice sublimation to obtain stem material. As the entire process is below the freezing point, commonly used in dry heat-sensitive items. Due to the freezing of the material under vacuum heat more difficult, as well as under vacuum sublimation of water vapor condensing a larger cooling system, so dry and more costly. Frozen water in the high-heat-sensitive materials, and will maintain high vacuum to below freezing temperatures. So that water sublimation with material separation. Material loss of active ingredients in a small, but the drying rate low.

    Over a number of common basic types of drying equipment, we can according to the user as well as material needs of the specific requirements of the drying technology of the original basis of the basic model variant developed them.