Saltation ash conveying control method

Abstract

The invention discloses a saltation ash conveying control method which is characterized in that on the basis of not replacing a conveying pipeline and not increasing the conveyed air quantity, through respectively comparing the current conveying pressure with a preset first conveying pressure upper limit, a preset second conveying pressure upper limit, a preset first conveying pressure lower limit and a preset second conveying pressure lower limit, when the current conveying pressure meets preset conditions, a corresponding air valve is controlled to be opened or closed so as to control the length of a solid plug and the total length of the solid plugs in the conveying pipeline, thereby avoiding the pipeline wear and system energy consumption caused by that a pneumatic conveying system is frequently blocked and unblocked.

Description

technical field [0001] The present application relates to the technical field of pneumatic conveying, in particular to a method for controlling the conveying of settled ash. Background technique [0002] Pneumatic conveying, also known as airflow conveying, uses the energy of airflow to convey granular materials along the direction of airflow in a closed pipeline, which is an application of fluidization technology. Pneumatic conveying system is widely used in industrial and agricultural production because of its simple structure, strong airtightness, and suitable for long-distance transportation. [0003] Taking the application of the pneumatic conveying system in a thermal power plant as an example, the pneumatic conveying system applied in the thermal power plant is used to transport the fly ash collected by each electric field of the electrostatic precipitator. Large, generally accounts for about 80% of the total ash collected by each electric field of the electrostatic ...

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Problems solved by technology

[0004] When the high voltage of the first electric field of the electrostatic precipitator cannot be put into normal operation for some reason (such as short circuit of cathode and anode inside the electric field, broken damping resistance, system abnormality, etc. may cause the high voltage to fail to be put into normal operation), all the fly ash collected by the ash hopper of the first electric field It is a relatively coarse and heavy fly ash that settles down by its own weight. The amount of this kind of settled ash is less than that of high-pressure normal operation (accounting for about 10%-15% of the total ash), but due to its relatively coarse and heavy , the transportation is more difficult, and the final speed required for transportation generally needs to be 18m / s-20m / s

[0005] Since the conveying pipelines of the pneumatic conveying system corresponding to an electric field have been laid out, it is impossible to replace the conveying pipelines in order to transport this kind of sedimentation ash stably, because the cost will be very high. Ash, the conveying speed of this kind of settled ash needs to reach 18m / s-20m / s, which requires a lot of air volume, but the large increase in air volume not only accelerates the wear of the conveying pipeline, but also damages the air source of the whole system (also Air compressors) have adverse effects; moreover, due to insufficient spare air compressors and other reasons, there will be situations where the gas volume required to transport this kind of sedimentation ash cannot be reached, and the conveying system will frequently block pipes. When pipe blockages occur When the phenomenon occurs, it is generally necessary to start the automatic blockage removal program to clear the blockage, but because the sedimentation ash is relatively thick and heavy, it takes a long time to clear the blockage, and because the pneumatic conveying system is in the state of blockage removal for a long time and cannot be transported normally, the system output is severely affected At the same time, it also increases the wear of the pipeline and increases the energy consumption of the system.

Therefore, at present, when the high voltage of the first electric field of the electrostatic precipitator cannot be put into operation for some reason, the settled ash produced is basically discharged by manually opening the emergency ash discharge port on the ash hopper, which will not only cause serious environmental pollution and There are potential safety hazards, and a lot of manpower and material resources will be consumed in the process of cleaning and transshipment

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