The grain dryers produced by Dingli Machinery can be divided into cross-flow, mixed-flow, co-current, counter-flow, forward-counter-flow, mixed-counter-flow, and forward-mixed flow types according to the relative movement direction of grain and air flow.

⒈Cross flow grain dryer

The cross-flow grain dryer is one of the first models introduced in my country. It is mostly a cylindrical mesh type or a square tower mesh type structure. Advantages of cross-flow grain dryer: simple manufacturing process, easy installation, low cost and high productivity. Disadvantages: grain drying uniformity is poor, unit heat consumption is high, one machine is limited in drying multiple grains, the quality of some grains after drying is difficult to meet requirements, and the inner and outer sieve holes need to be cleaned frequently. But a small circulation dryer can avoid some of the above shortcomings.

⒉Mixed flow grain dryer

Mixed flow dryers are mostly tower structures composed of triangular or pentagonal boxes arranged in a staggered (cross) arrangement. There are more domestic manufacturers of this type of machine than cross-flow machines. Compared with cross-flow machines, its advantages are: (1) The hot air supply is uniform, and the moisture content of the grain after drying is more uniform; (2) The unit heat consumption is 5% to 15% lower; (3) Under the same conditions, the The required fan power is small, and the unit consumption of drying medium is also small; ⑷ There is a wide variety of dried grains, and it can dry both grain and seeds; ⑸ It is easy to clean and difficult to mix seeds. The disadvantages are: ⑴ The structure is complex and the manufacturing cost is slightly higher under the same productivity conditions; ⑵ A small part of the grains at the four corners of the dryer precipitation is slower.

⒊Downflow grain dryer

Downflow dryers are mostly tower-type structures that combine funnel-type air inlets and angular box exhaust ducts. Unlike mixed-flow dryers, which have one main air duct to supply hot air, they have multiple (stages) The hot air duct supplies different or partially the same hot air. Its advantages are: ⑴ The temperature of the hot air used is high, and generally the temperature in the Class A high-temperature section can reach 150~250℃; ⑵ The unit heat consumption is low, which can ensure the quality of the dried grain; ⑶ The dryers with three-level downstream flow and above have the ability to reduce large amounts of water. ⑷ The rainfall range is large during continuous drying, generally up to 10% to 15%; ⑸ It is more suitable for drying food crops and seeds with large moisture content. The disadvantages are: ⑴ The structure is relatively complex, and the manufacturing cost is close to or slightly higher than that of a mixed flow dryer; ⑵ The thickness of the grain layer is large, the high-pressure fan power required is high, and the price is high.

⒋Flow and counter flow, mixed and counter flow and forward and mixed flow dryers

Pure counter-flow dryers are rarely produced and used. Most of them are used in conjunction with other air-flow dryers, that is, they are used in the cooling section of co-flow or mixed-flow dryers to form co-flow and mixed-counter-flow dryers. The advantage of countercurrent cooling is that the natural cold wind can fully contact the grain, which can increase the cooling speed and appropriately reduce the height of the cooling section. The forward and counter flow, mixed and counter flow and forward mixed flow dryers respectively take advantage of their respective advantages to achieve high temperature and rapid drying, improve drying capacity, without increasing unit heat consumption, and ensure uniform grain quality and moisture content.