Flexible control device for pneumatically conveying tobacco shreds and control method

Abstract

The invention provides a flexible control device for pneumatically conveying tobacco shreds and a control method, which starts a tobacco shred pneumatic conveying system in a soft start manner to reduce the break rate of the tobacco shreds when starting. After started, the device directly measures and controls the tobacco conveying speed, and combines the flexible control manner, to make the tobacco shreds in a horizontal pipeline to generate continuous and stable dense phase flow, thereby reducing the break rate in the pneumatic conveying process, and reducing the energy consumption of the pneumatic conveying system. In the dormant period and stopping period in the tobacco shred conveying process for a cigarette making machine, the wind complementing and regulating valve is controlled to complement wind by simulating the shred conveying condition for stabilizing the pressure and the wind amount in a dust removing pipe, and then the wind complementing and regulating valve is finely regulated by measuring the pressure in the dust removing pipe to increase or reduce the wind complementing flow amount for further stabilizing the pressure in the dust removing pipe, thereby greatly reducing the pressure fluctuation cased by intermittence, randomness and temporary stoppage in the tobacco shred conveying process in the tobacco shred pneumatic conveying system.

Description

technical field [0001] The invention relates to the technical field of pneumatic conveying, in particular to a flexible control device and control method for pneumatic conveying shredded tobacco speed. Background technique [0002] At present, pneumatic conveying and related technologies are widely used in building materials, chemical industry, grain, metallurgy, mining, environmental protection, light industry, energy and other departments. Fibrous and leaf-like materials, such as cement, lime, flour, grain, coal powder, explosives, chemical fertilizers, chemical raw materials, molding sand, cotton, wool, shredded tobacco, tea, carbon black, wood chips, etc., are more and more widely used The method of pneumatic conveying. [0003] In cigarette production, pneumatic conveying of shredded tobacco is widely used. Pneumatic conveying of shredded tobacco has the advantages of low investment, flexible layout, high reliability, and easy maintenance and management. However, the ...

AI Technical Summary

Problems solved by technology

The wire feeding process of the cigarette machine is intermittent and random, and sometimes it will be stopped temporarily, which will cause pressure and air volume fluctuations in the tobacco pneumatic conveying system, and will also affect the stability of the air velocity of the pneumatic conveying, which in turn affects the flow of the tobacco pneumatic conveying. state

[0006] At present, the cut tobacco pneumatic conveying system used in domestic cigarette production is to indirectly control the cut tobacco flow speed by detecting the air velocity. ~8m / s, but at present there is no reliable theoretical formula to calculate the optimal delivery air velocity, therefore, the delivery air velocity can only be determined by experience or experimental data, in order to avoid pipeline blockage, sometimes the delivery air velocity is even as high as 30m / s , under such working conditions, the crushing rate of shredded tobacco is very high

Moreover, due to the gap, randomness, and temporary shutdown of the wire feeding process of the cigarette machine, the pressure and air volume of the tobacco pneumatic conveying system are constantly changing, making it difficult for the conventional tobacco pneumatic conveying system to achieve an optimally designed two-phase flow. state (group flow), and cannot stabilize the flow state

That is to say, even if a reasonable conveying air velocity is obtained, the stability of the conveying air velocity cannot be guaranteed, let alone the stability of the flow velocity of shredded tobacco.

At the same time, because the wire feeding process of the cigarette machine is intermittent and random, sometimes it will temporarily stop, resulting in pressure and air volume fluctuations in the tobacco pneumatic conveying system, which will also affect the stability of the conveying air velocity

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