1, drum dryer, the minimum diameter of this model is 600x8000mm, and it can dry about10t in 24 hours. Because of friction, it will damage the appearance and the quality is not good.
2. Three-drum dryer, the minimum size of this model is 1800x3500mm, and its 24-hour drying capacity is the same as that of the drum dryer, with the same drying quality and higher heat utilization rate.
Model features:
According to the relative movement direction of grain and airflow, dryers can be divided into cross flow, mixed flow, parallel flow, countercurrent and parallel flow, mixed countercurrent and parallel flow.
Folding cross-flow dryer
Cross-flow dryer is the first model imported from China, which is mostly cylindrical or square-tower. At present, there are still many domestic manufacturers. The advantages of this machine are simple manufacturing process, convenient installation, low cost and high productivity. The disadvantages are: poor uniformity of grain drying, high unit heat consumption, limited drying of many kinds of grains by one machine, poor quality of some grains after drying, and frequent cleaning of internal and external sieve holes. However, a small circulating dryer can avoid some of the above disadvantages.
Folding mixed-flow dryer
Mixed-flow dryers are mostly tower-shaped structures with triangular or pentagonal boxes staggered (crossed). There are more domestic manufacturers of this model than Crossflow. Compared with cross-flow, it has the advantages that (1) the hot air supply is even, and the moisture of the dried grain is even; (2) unit heat consumption is reduced by 5% ~15%; (3) Under the same conditions, the required fan power is small, and the unit consumption of drying medium is also small; (4) There are many kinds of dried grains, which can dry both grains and seeds; (5) Easy to clean and not easy to hybridize. Disadvantages are: (1) the structure is complicated, and the manufacturing cost is slightly higher at the same productivity; (2) A small part of grain in the four corners of the dryer precipitates slowly.
Folding downstream dryer
Parallel-flow dryers are mostly tower-shaped, with funnel-shaped air inlet and angular air outlet. The difference from mixed-flow dryers is that one main air duct supplies hot air, while different or partially the same hot air is supplied by multiple (stage) hot air ducts. The number of domestic manufacturers is less than that of mixed-flow dryer manufacturers, and its advantages are: (1) high hot air temperature, and the temperature of the first-stage high temperature section can reach150 ~ 250℃; (2) the unit heat consumption is low, which can ensure the quality of dried granules; (3) Dryers with more than three downstream stages have the advantages of reducing water content and obtaining higher productivity; (4) During continuous drying, the primary precipitation is relatively large, generally reaching10% ~15%; (5) It is most suitable for drying grain crops and seeds with high water content. Disadvantages are: (1) the structure is complex, and the manufacturing cost is close to or slightly higher than that of mixed-flow dryer; (2) The thickness of the granular layer is large, the required high-pressure fan power is high, and the price is high.
Folding downstream dryer
Pure counter-current dryers are rarely produced and used, and most of them are used in conjunction with other air dryers, that is, they are used in the cooling section of parallel or mixed-flow dryers to form parallel and mixed counter-current dryers. The advantage of counter-current cooling is that the natural cold air fully contacts the grain, which can improve the cooling speed and appropriately reduce the height of the cooling section. Countercurrent dryer, mixed counter-current dryer and advection dryer make use of their respective advantages to realize high-temperature rapid drying, improve drying capacity, and ensure grain quality and moisture uniformity without increasing unit heat consumption.