When choosing drying equipment, we must take into account ancillary equipment. That`s because the drying system is composed of drying equipment and ancillary equipment. Ancillary equipment is also critical to choose whether or appropriate link. Under normal circumstances, drying system mainly consists of ventilation equipment, heating equipment, the host (drying equipment), gas-solid separation equipment, feeding equipment, etc. The provision of the rise of energy expense and of pollution restriction, working condition and safe operation directly affect the design and choosing of the drying equipment. Some of these design factors (especially the suspended drying machine design, such as spray, flash and fluid bed drying machine) has given a full discussion of the various types of drying machines in the selection phase is also necessary to take into account the these factors. Sometimes, different materials and different occasions, can be dried for processing device, one must put in the design phase of these factors into account. For the gas, due to exclude dust, drying equipment can cause pollution. In some places, not even the steam is not permissible. The general requirement is to remove the dust of the exhaust concentrations below 20 ~ 50mg/Nm3, and that they may have to set up efficient dust collector. Importantly, under certain conditions, suitable for drying of rough particles. On the other hand, particles larger the longer the drying time. In the dry powder materials in the aggregation of dust and gas purification commonly used cyclone separator, bag filter or electrostatic precipitator, etc. In other forms, such as paste, sheet materials such as dry, dust only in the convective drying of materials occurred. In order to remove harmful gas pollution, people can by means of absorption, adsorption or incineration and other means.