System for controlling electrostatic level in fluidized bed

Abstract

The invention provides a system for controlling electrostatic level in a fluidized bed and is applied to the technical field of electrostatic control. The system comprises at least two electrostatic control sub-systems which are arranged at different bed layer heights, wherein each electrostatic control sub-system comprises electrostatic measurement equipment, a controller and ionic wind equipment; each piece of electrostatic measurement equipment detects an electrostatic potential at the corresponding bed layer height; each controller calculates a difference value of the detected electrostatic potential and a target electrostatic potential, and generates a control signal according to the positive-negative property and size of the difference value; the ionic wind equipment generates ionic wind according to the control signal and feeds the ionic wind into the fluidized bed, so that the ionic wind contacts fluidized particles in the fluidized bed, the electrification situation of the fluidized particles is changed, and the electrostatic potential level at the corresponding bed layer height of each electrostatic control sub-system reaches the target electrostatic potential. According to the system, the characteristic that the electrostatic potential in the fluidized bed is likely to be changed along the axial direction of the fluidized bed is taken into full consideration, and static electricity at different bed layer heights is eliminated in a targeted manner. The system is safe, environment-friendly, and high in electrostatic elimination efficiency.

Description

technical field [0001] The invention relates to the technical field of static electricity control, in particular to a system for controlling the static electricity level in a fluidized bed. Background technique [0002] Gas-solid fluidization technology is widely used in petrochemical, chemical, metallurgy, energy, materials, environmental protection, pharmaceutical and other fields. Static electricity is a technical problem that has plagued the production and operation of gas-solid fluidized bed reactors for a long time. The existence of static electricity will not only affect the hydrodynamic behavior in the fluidized bed, but also cause problems such as sheeting, blockage of the distribution plate, and even shutdown, which seriously affect the continuous operation of the device. [0003] At present, in order to reduce and eliminate the electrostatic hazard in the process of gas-solid fluidization, a series of solutions have been proposed, such as adding antistatic additi...

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Problems solved by technology

[0005] 1. The disadvantage of using antistatic agents is that in the production process of gas-solid fluidized bed reactors, antistatic agents usually have the property of inhibiting the activity of catalysts in the reactor, or have the problem of changing the properties and quality of products; even if a certain type of antistatic The antistatic agent has no toxic effect on a specific catalyst, and it is difficult to adapt to a wider range of production processes; and in the food and drug related industries, the added antistatic agent must meet the product specification requirements, and it needs to be approved by the National Food and Drug Administration. departmental approval

[0006] 2. The electrostatic elimination effect of the surface treatment of the vessel wall is not obvious, and it is difficult to implement in large-scale industrial reactors, and the effect is poor

[0007] 3. Changing the operating conditions to reduce or eliminate the static electricity in the fluidized bed reactor has great limitations, limited by the process requirements and quality requirements of product production, the operating conditions can only be changed within a certain range, so the static electricity The elimination effect is not obvious, and the adjustment range of static electricity level is narrow

[0008] 4. Increasing the humidity of the gas is an effective way to reduce the static level in the fluidized bed reactor, but because water is a poison of some catalysts, the scope of application of this method is limited, and in a high temperature environment, increasing the relative humidity The method is not effective in reducing and eliminating static electricity

However, this intrusive power dissipation device will damage the flow field in the fluidized bed, easily form dead zones, and induce flakes or agglomerations; in addition, studies have shown that the static electricity level in the fluidized bed is distributed along the axial direction , and sometimes polarity reversal may even occur, but the above-mentioned patent scheme cannot adjust the corona discharge parameters at the corresponding positions according to the static electricity levels at different positions in the fluidized bed reactor, and the efficiency of electricity removal is limited

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