LANGUAGE
Modern industrial structures are developing towards intelligence and efficiency. This is also true in the development of grain steel silo. In the entire grain silo system, there is room for performance improvement systems including the feeding and discharging system and the drying system. Because only these two systems need to consume energy, how to reduce the energy they need has become the research and development direction of the entire grain silo system. Today we will explain to you the three effective energy-saving methods of grain silo dryers.
The combustion furnace is an important place for fuel combustion and also the source of heat for the dryer. The heat energy loss of the combustion furnace mainly occurs in the following aspects: ① Mechanical combustion loss; ②Chemical combustion loss; ③Loss during heat transfer, among which the heat loss during heat transfer is more serious. The heat loss in summer is about 5%~6%, while in winter it is 8%~10%, indicating that temperature has a certain influence on the heat transfer loss. When the ambient temperature is low, the heat energy loss of the dryer is more serious. In order to improve the efficiency of thermal energy utilization, it is necessary to improve the completeness of fuel combustion.
Mechanical combustion loss is mainly due to factors such as poor fuel properties, unscientific grate pore size, excess air index, and excessive furnace temperature.
Chemical combustion loss is mainly due to heat loss caused by incomplete combustion of combustible gas, that is, the loss caused by the combustible gas being discharged out of the furnace with the exhaust gas. This is mainly caused by the low furnace temperature or uneven mixing, which leads to the failure to fully introduce the gas fuel in the furnace, which is closely related to the scientific design of the stove.
In order to ensure the quality of grain drying and use the least fuel at the same time, the optimization of the furnace structure is very important. On the one hand, it is necessary to study the reburning problem of solid fuel into gas to improve the extensiveness of fuel, and at the same time, it is also necessary to solve the grain drying quality or adopt coal powder combustion technology to ensure the sufficiency of fuel combustion; on the other hand, the furnace structure developed by the manufacturer needs to ensure that the furnace temperature exceeds 800℃, especially for dryers that directly use flue gas as the drying medium. When the furnace temperature is ≥800℃, the benzopyrene content of the flue gas will be effectively reduced, which can ensure the full combustion of the fuel and effectively ensure the quality of the grain after drying and improve economic benefits. In addition, in the process of furnace design, it is necessary to consider the properties of the pipeline, select pipelines with good insulation effect or add pipeline insulation measures to reduce heat loss.
The recovery and utilization of waste heat from waste gas mainly refers to the recovery of heat in waste gas before and after drying and cooling waste gas. The heat of waste gas almost exceeds half of the total energy. If the heat in the waste heat from waste gas is effectively recovered, the utilization efficiency of heat can be effectively reduced. Therefore, the recovery and utilization of waste heat from waste gas is an important way to save energy and reduce consumption of grain dryers.
There is not much moisture in the grain during the cooling process. For example, the moisture content of corn in the cooling stage is only 0.5~1.0%. Therefore, the moisture content in the cooling exhaust gas is low, and the used cooling exhaust gas is generally 10℃ higher than the ambient temperature. The temperature and humidity of the exhaust gas at this stage are not high, but the available amount is large and can be recycled. The recycled exhaust gas can be combined with flue gas as a drying medium for the flue and air mixed gas, or it can continue to be used as a cooling medium again.
The exhaust gas in the drying stage is usually 15 degrees Celsius higher than the ambient temperature. If the dryer has a preheating stage, the temperature of the dry exhaust gas can be about 5℃ higher. The moisture content of this part is 60%~70%, which can be recycled as a drying medium for the flue gas and air mixed gas, or introduced into the slow refrigeration warehouse for slow refrigeration treatment. The utilization of this part of hot gas heat energy can effectively improve the working efficiency of the dryer, thereby improving the economic benefits of the enterprise.
Over-drying means excessive drying, which makes the moisture content of grain lower than the moisture content specified for safe storage. Over-drying not only easily reduces the quality of grain, but also causes additional energy consumption and economic losses. Take rice as an example. Its moisture content before drying is 25%. As long as it is reduced to 14.5%, it can meet the standard of safe storage. However, due to the error in parameter setting, the moisture content of rice was reduced to 13%, and the moisture content was reduced by 1.5%, which means that more energy was spent to reduce the moisture content by 1.5%, affecting the economic benefits of the enterprise. The economic losses caused by over-drying are also huge. If the moisture content drops by 1.5%, the weight of the rice will also drop by 1.5%, and more energy will be consumed. If the depreciation of the machinery and labor management fees are considered, the total loss will be greater. In addition to saving energy consumption, reducing unnecessary drying also has the following advantages: increasing the capacity of the dryer, improving the working efficiency of the dryer, reducing the loss rate of grain drying, and ensuring the quality of grain drying. In order to reduce the phenomenon of over-drying, the dryer needs to use a high-precision moisture detector to perform online inspection at any time during the drying process to ensure the accuracy of grain drying.
The above are the three effective energy-saving methods of grain steel silo dryer. I hope the above description can bring some help to everyone. Shandong Shelley Storage specializes in the production of various types of steel silos. It has been engaged in the production, research and development and sales of steel silos for many years. If you have any product needs, please feel free to call us for consultation.
Written by
Shandong Shelley Grain Steel Silo Co., Ltd
Editor Jin
www.grainstoragesilos.com
WhatsApp : +86-18653877118
Email : shelley@cnshelley.com
