What is a Grain Dryer?

Grain dryer is an assembly of a dryer. Is a collective name for various equipment of grain dryer. It can also be a grain dryer, such as a corn dryer, a rice dryer, a rice dryer, a dregs dryer, etc. We can all call it a grain dryer.

Grain dryer

According to the relative movement direction of grain and air flow, the dryer can be divided into cross flow, mixed flow, forward flow, counter current and forward and reverse flow, mixed counter current, and forward mixed flow.

Cross flow dryer

Cross-flow dryer is the first model introduced in China. Most of them are cylindrical screen or square tower screen structure. There are still many manufacturers in China.

The advantages of this machine are: simple manufacturing process, convenient installation, low cost and high productivity. Disadvantages are: poor uniformity of grain drying, high unit heat consumption, limited drying of multiple grains by one machine, some grain quality is difficult to meet requirements after drying, and internal and external sieve holes need to be cleaned frequently. But a small circulation dryer can avoid some of the above-mentioned shortcomings.

2. Mixed flow dryer

The mixed-flow dryer is mostly a tower structure composed of a triangle (pentagonal) box staggered (fork) arrangement. There are more domestic manufacturers of this model than cross flow. Compared with cross flow, its advantages are: (1) uniform hot air supply, uniform moisture content of grain after drying; (2) unit heat consumption is 5% to 15% lower; ( 3) Under the same conditions, the required fan power is small, and the unit consumption of drying medium is small; (4) The variety of dried cereals is wide, and both grains and seeds can be dried; (5) It is easy to clean and not easy to mix seeds.

The disadvantages are: (1) the structure is complicated and the manufacturing cost is slightly higher under the same productivity; (2) a small part of the cereals at the four corners of the dryer have a slower precipitation.

3. Downstream dryer

Downstream dryers mostly have a tower structure that combines a funnel-type air inlet and an angular box exhaust channel. It is different from a mixed-flow dryer in which one main air pipe is used to supply hot air, but multiple (stage) The hot air pipe supplies different or part of the same hot air.

The number of domestic manufacturers is less than that of mixed-flow dryer manufacturers. Its advantages are: (1) the temperature of hot air is high, and the temperature of the first-stage high temperature section can reach 150-250 ° C; (2) the unit heat consumption is low, which can ensure the grain after baking Quality; (3) dryers with three or more downstream streams have the advantage of reducing large moisture and can obtain higher productivity; (4) the range of primary precipitation during continuous drying is large, which can generally reach 10% to 15% (5) Most suitable for drying large moisture food crops and seeds.

The disadvantages are: (1) the structure is relatively complicated, and the manufacturing cost is close to or slightly higher than that of the mixed-flow dryer; (2) the thickness of the grain layer is large, the required high-pressure fan power is large, and the price is high.

4.Cross-current, counter-current and co-current dryers

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

1. Different types of grains and rice should be dried differently from conventional drying methods. The rice has not been harvested after the expiration date, and there is a pop-up phenomenon or a pop-up variety in the field, there are a lot of cold-damaged rice, broken rice, barley mixed in the rice, and dry beer and wheat. "Slow" or low temperature range, 3-4 ° C lower than the control temperature. For unripe rice with a lot of green grains, a grain dryer with an increase of 5 to 6% of the stop water setting value is adopted.

2. Frequently use cleaning and maintenance when the dryer is idle. Clean up in time, clean up the residual grain, close the inlet and outlet, etc., which is beneficial to the life of the machine and improve the efficiency of the drying operation.

3. Grain loading should meet the requirements, not too much, and not too little. Too much loading is likely to cause clogging; too little loading will not only reduce the operating efficiency, but also affect the drying quality. When the full amount is reached, if there is still a small amount of rice that can not be added any more, it can be recharged within 1 hour after starting the drying, and the feeding within 1 hour will not cause uneven drying of the grain dryer.

4. Extremely high moisture content

After the grain enters from the hopper, the moisture detector is used in the elevator. If the moisture detector does not meet the standards, the elevator enters the upper auger, the quenching and tempering bin, enters the drying bin, and then passes through the grain discharge wheel And enter under the auger

1. When the grain dryer is used in the open air, it should be protected from wind and rain.

2. Mechanized continuous operation, stable performance, convenient operation, saving civil investment.

3. Strong adaptability, can take care of drying multiple varieties of grain.

4. Recycling waste heat and reducing energy consumption.

5. The grain is dried thoroughly and evenly, and the grain can be directly stored in the warehouse.

6. The unit heat consumption is low, which can ensure the quality of the dried grain without pollution.