Pneumatic conveying of grain, application in tobacco industry
? ? ?The application of grain and tobacco industries in the grain processing process requires chemical technology inspection of raw materials and semi-finished products. Throughout the production process, samples are continuously taken and analyzed through pneumatic conveying in container containers. Milk products and margarine both require sampling and testing, which can be conveyed using a double connected container pneumatic conveying device. The weight of this container does not exceed 0.4kg, with a maximum diameter of 69mm and an airflow velocity of 13m/s. The use of pneumatic conveying can reduce the manual transfer of samples and improve the efficiency of chemical testing. The former Soviet Union designed a pneumatic sample delivery system for grain processing as shown in Figure 1. The grain production rate of the processing plant is 300t/d. The device has 9 workshop receiving and transmitting stations and laboratory receiving and transmitting stations. This conveying pipeline is used to transport empty and sample containing containers (capsules). After the samples are taken out from the laboratory, the empty containers are sent along the pipeline to the given workshop receiving and dispatching station. After the sampling mechanism of each workshop loads the samples into the empty container, the container is then transported to the laboratory through a conveyor pipe. The weight of the general sample is 0.2~2.0kg, and the diameter of the pneumatic conveying device for the container does not exceed 150mm. The geometric dimensions of the container depend on the maximum weight and size of the sample.
Figure 1
? ? Container pneumatic conveying is also widely used in the tobacco industry. More than 300 factories in the United States use this method to transport cigarettes in packs, with a conveying distance of 20-100m and stainless steel rectangular pipes. Italy also has pneumatic conveying production lines for assembling cigarettes, and the conveying pipes are transparent rectangular plastic pipes.