Mechanization Technology of drying in Grain producing area

For a long time, the drying method of grain in our country mainly depends on the natural sunlight, and some even occupy the rural road, which is not only limited by climatic conditions but also greatly affected, at the same time, it also directly endangers the traffic safety of rural roads to a large extent. Most of the grain production areas in China, especially in Yingtan City, Jiangxi Province, which is located in the middle and lower reaches of the Yangtze River, are often rainy and wet during the rice harvest season. In the cool weather, it is difficult to dry the rice in time. Every year, due to climate reasons, the loss rate of germination, mildew and insect pests caused by too much time for drying or safe water storage is as high as 5% to 10%. In order to change this passive situation of relying on nature for food and reduce the grain loss that has already been obtained, it is extremely necessary to popularize and develop the mechanization technology of drying in grain producing areas in our city, which is the main rice producing area. The mechanization technology of drying in grain producing areas can not only effectively prevent the losses caused by disastrous weather such as continuous overcast and rain, and ensure the increase of agricultural production and income, but also has obvious advantages compared with natural drying: first, it reduces the use of sun field, which is of great significance to the protection of cultivated land. Second, it is an effective way to prevent farmers from occupying rural roads to dry grain, which can prevent and reduce traffic casualties on rural roads. Third, because of the high degree of automation and simple operation of the drying machinery, the broad masses of farmers are liberated from the traditional heavy manual labor of drying in the sun. Reduce labor intensity, improve working conditions and increase labor productivity. To provide effective means for realizing agricultural modernization, agricultural industrialization and intensification. The fourth is to improve the quality, storability and processability of rice. The mechanical drying time of rice is short, and it will not sprout and mildew in the drying process; the drying temperature is suitable, the drying is uniform, and the waist burst can be controlled in the drying process. These advantages have been proved by production practice at home and abroad. 1. Technical introduction and technical and economic indicators 1. Technical introduction the mechanized technology of drying in grain producing areas is a drying technology that takes machinery as the main means and adopts corresponding technological and technical measures to artificially control temperature, humidity and other factors without harming grain quality. under the premise of not harming grain quality, reduce the water content in grain and make its moisture content reach the national safe storage standard. The drying process of rice is a complex process of heat transfer and moisture transfer, accompanied by the change of biochemical quality of grain itself. In the process of drying, not only the excess moisture in grain should be removed to meet the standard of safe storage, but also the quality of grain should not be reduced and improved as much as possible. The technology of drying mechanization in grain producing areas can be widely used in large-scale farms with certain economic strength, especially in the large grain growers of agricultural mechanization in our city. This practical technology is widely used in grain departments, rural grain processing enterprises and other agricultural products processing enterprises and agricultural mechanization service stations (centers), and is welcomed and praised by the majority of grain farmers and rice processing groups. The drying machinery mainly includes all kinds of drying equipment, and the circulating low temperature hot air tower dryer is commonly used at present. The grain drying process is usually divided into four stages: preheating, water vaporization, slow Su (temperature regulation) and cooling. 2. Technical and economic indicators (l) the use of grain dryers provides a guarantee for agriculture to resist disasters and win a bumper harvest. Grain-producing areas often encounter continuous overcast and rain during the harvest season, and the mildew loss of grain is about 5%, 10%, and the use of dryers ensures a high yield and harvest. Each kilogram of rice is calculated at 1 yuan, and the loss is 8%, which can reduce the grain loss 40kg per mu, worth 40 yuan. (2) the drying of low temperature grain is timely and safe, which shortens the drying time of grain and makes the new rice on the market in advance. The price of rice per kilogram is 0.04 yuan-0.06 yuan / kg, and the income can be increased by 25 yuan / mu. (3) the crushing rate of dried rice was compared and determined. Under the same conditions, the broken rice rate of mechanical drying is 5.7% lower than that of manual drying, and the rice yield is 5.9% higher, so that the rice processing gain is 30mur40 yuan / mu. The above three items have a total increase of 100 yuan / mu, deducting the drying cost of 40 yuan / mu, a net increase of 60 yuan / mu. 2. Operating rules 1. Technical specifications the drying quality of grain is related to the extent of primary precipitation, grain humidity and the soothing process of grain. Due to different types and uses of grain, the drying process and parameter settings are also different. The hot air temperature of the circulating low temperature hot air dryer is determined as follows: Rice is easy to burst in the drying process, and its shell has a significant delaying effect on moisture and heat conduction. The waist burst rate of rice is not only related to the initial moisture content, but also closely related to the hot air temperature during drying, so the general hot air humidity is about 45 ℃ during drying. 2. Technical implementation points (l) when dried rice is mixed with a large number of rice stalks and other sundries, it will affect the flow of rice and cause uneven drying, so coarse sieving is needed before drying. (2) the rice after harvest should be loaded into the dryer as soon as possible. Before a batch of required drying capacity is installed, it is best to carry out ventilation circulation and not ignite the burner for the time being. (3) when drying rice with uneven moisture content, it is necessary to ventilate and circulate as long as possible, and then ignite the burner. (4) the drying speed should be reduced when drying explosive waist varieties, rice with explosive waist phenomenon and rice with freezing injury. 3. Technical operation rules Rice drying is different from other grain drying, it is a kind of heat-sensitive grain, the drying speed is too fast or improper parameter selection is easy to cause waist burst. The hardness of rice is higher than that of wheat and corn, and its shell can significantly delay the drying process, so it is easy to burst during drying and cooling. When using fixed bed drying or other static drying equipment to dry rice, the general furnace gas temperature should be 45 ℃; when using fluidized bed drying equipment to dry rice, the general furnace gas temperature should be less than 160℃, the outgoing grain temperature should be lower than 60 ℃, the original moisture content of rice should be 17%, 18%, the in-machine precipitation should be 1%, and the static cooling water should be 1% 1.2%. In this case, the rice basically does not produce a waist burst. Practice has proved that keeping the dried rice stacked for about 4 hours and then cooling by mechanical ventilation is not only beneficial to ensure the quality of rice, but also makes it possible to coordinate the vaporization rate of its surface water with the rate of transfer of water from the inner layer to the outer layer, so as to avoid capillary shrinkage and hardening on the surface layer. 3. Precautions: (1) the power supply voltage used should be within the allowable range; (2) use fuel equipment and check whether there is oil in the fuel tank before starting the burner. whether there is oil leakage in the oil path (mainly check filter valves, tubing, burners, etc.); (3) the fuel used must meet the equipment requirements and do not refuel the fuel tank when the burner is working (4) after starting the dryer, first check whether the air transfer is normal (hoist, fan, upper and lower parts, etc.); (5) when drying, check whether the combustion is normal and whether there is any peculiar smell; (6) when drying different varieties of grain, clean up the grain left in the facility to prevent confusion. (7) do a good job in the maintenance of machinery and facilities, there are many electrical devices and moving parts, it is necessary to do a good job of maintenance and maintenance on a regular basis. Equipped with necessary safety protection equipment; (8) regularly clean the drying part of the dryer, so as not to block the holes in the dryer, so as not to affect the drying effect of the dryer; (9) when checking and cleaning drying, you should first cut off the power supply to avoid personal safety accidents; (10) the dryer operator needs special training and is responsible for it. Use the dryer according to the operation rules; (11) the operation scale of the drying point in the grain producing area should meet the local actual demand, the selected type should be suitable for the dry grain type, and the location of the point should be convenient for transportation. (12) Grain dryers are generally installed indoors with good ventilation and adequate working space to ensure normal operation on rainy days and at night. Models with a large body that can not be installed indoors (such as tower dryers) should also be chosen in well-ventilated, relatively dry places as far as possible. 4. Suitable machines and tools should be Shanghai Sanjiu dryer or Wuxi gold dryer.