1. The physical and chemical properties of materials - shape, water content, water properties, crystal water, particle size, density, viscosity, heat-sensitive, softening point, phase transition point, thixotropy, toxic, corrosive, odor, flammable, explosive dry electrostatic characteristics, air permeability, reunion, crystals or granules friable nature ... 2. material - drying curve to be selected in dry conditions, the critical moisture content, equilibrium moisture content. 3. Drying production requirements and long-term planning. 4. The value of the goods and material drying effect on them. If the product moisture, pollution, temperature, wear, powder, crushed, rehydration ... and so impact on the value of commodities. 5. Material recovery requirements. 6. Order process materials up and down the drying process. (Relating to, the discharge of state method) 7. drying method or material past the drying method similar products. 8. The heat source can be used (coal, fuel oil, electricity, gas, liquefied petroleum gas, natural gas) 9. Install the size of the venue, any special requirements. 10. The environmental requirements - for dust emissions, noise, vibration, odor, volatile matter ... like restrictions. 11. The amount of money may be invested in procurement, local labor, land, energy prices. 12. The operator user level and maintenance capabilities. 13. The local average annual temperature and humidity. 

keywords: Drying equipment, a new drying, dryer,