| Our common dryer types spray dryer, fluid bed dryer, air dryer, fluidized bed dryer, fluid bed spray granulation dryer.
Spray Dryer spray drying is one of the most advanced equipment in the drying equipment. There are three kinds of conventional atomization methods: rotary atomization, pressure atomization and gas atomization.
Fluid bed dryer during the drying process to consume large amounts of energy, in order to save energy, some of the high moisture content of materials containing solid matter suspension or solution the mechanical dehydration or heat evaporation, and then dried in the dryer to obtain dry solids.
Need to complete the drying process of heat and mass transfer at the same time, ensure that the material surface wet steam pressure at concentrations higher than the wet steam partial pressure in outer space, the material guarantee of the heat source temperature is higher than body temperature. The heat from the boiling heat source in a variety of different ways to pass to the wet material, surface evaporation and escape the outside space, resulting in surface and internal moisture content differences. Water to reduce the surface diffusion and evaporation, the material moisture content, the gradual completion of the drying material.
The drying rate of the fluid bed dryer depends on the surface evaporation rate and moisture diffusivity. Drying rate, the rate of diffusion from the inside and falling, and moisture content to reduce this stage is called the falling rate drying stage. Early drying rate of surface evaporation rate control is usually dry; then, as long as the dry external conditions remain unchanged, drying rate and surface temperature stability of this phase is called the constant drying stage; proliferation of material moisture content is reduced to a certain extent, the surface water The reduction in the rate, and less than surface vaporization rate.
The rotary atomizer spray drying is characterized by stand-alone production capacity (spray volume of up to 200t / h), the feed rate is easy to control, operating flexibility, used widely.
Pressure atomizer spray drying is characterized by the manufacture of coarse particles, and easy maintenance. The nozzle hole is very small, easy to plug, so the feed solution must be strictly filtered. Nozzle hole easy to wear, shall use in the manufacture of wear-resistant materials. Pressure nozzle, there is a new structure, called the pressure - flow nozzle. It is characterized as the center is a pressure nozzle gap of the surrounding environment for the air-nozzle. Atomization in two stages: pressure nozzles formed first film, this liquid film airflow second atomization and finer droplets. Advantages of this type of nozzle as follows: (1) adjust the pressure of compressed air, can adjust the droplet diameter, easy to operate; (2) production, the material liquid of high viscosity, can also be atomized fine droplets; 3 If you disable the compressed air pressure nozzle can also be used.
Gas atomization is mainly used for laboratory and pilot plant, its power consumption. The first two atomizer atomized liquid, air-blast atomizer may be atomized. The high viscosity paste, cream and cake material, three-fluid nozzle can be used to atomization.
Air dryer air drying technology is mature, if operational data can be directly designed. Currently, there are a lot of drying equipment manufacturer able to provide this type of equipment.
Fluidized bed dryer fluidized bed dryer is second only to the spray dryer. Divided into the fluidized bed dryer of the feeding site set blender and heat transfer within a fluidized bed dryer. Easy-to-unity or agglomeration of the powder material with fluidized bed drying, relatively large water feed zone fluidized difficult phenomenon, this time set the stirrer in the feed zone, eliminating the problem of knot groups, can achieve normal flow of. The latter is the heat conduction and convection heat transfer combination, when used for the normal flow of the state the amount of hot air is far from satisfying the heat needed to dry, set up within the heat exchanger, supply part or most of the heat, which The operating modes can be significant energy savings. Within the heat exchanger takes many forms. The fluidized bed is also often used for the combination of dry second and third stages of the drying machine.
Imposed in the ordinary fluidized bed vibration, said vibration fluidized bed. Vibration fluidized generate local oscillator can be divided into two categories: one for the vibration motor drive; and the other for normal motor excitation box spring vibration. Vibration fluidized bed size is large, the latter is better.
The process of fluidized bed spray granulation dryer fluidization technology, organic combination of the atomization and drying technology. It is the atomization of solid to liquid spray to the seed of the fluidized bed, so that the seed has grown up and dry, to be grown up to the required size when discharged. The device's small footprint, large capacity, can produce large particles. The equipment for industrial applications has been increasing.