Method for extracting, regenerating and returning particles in magnetically stabilized fluidized bed

Abstract

The invention provides a method for extracting, regenerating and returning particles in a magnetically stabilized fluidized bed, which mainly comprises the following steps of: 1) performing gas-solid countercurrent contact in the magnetically stabilized fluidized bed, treating gas A in an upward movement process and discharging the gas A from the top, and gradually inactivating / saturating the particles in a downward movement process; (2) at the lower part of the magnetically stabilized fluidized bed, the inactivated / saturated particles flow into an ascending bed through a lower orifice; (3) gas B is introduced into the bottom of the ascending bed to perform regeneration treatment on the particles, the bed layer is in a magnetic control bubbling state, and generated tail gas is discharged from the top; and 4) returning the regenerated particles to the magnetically stabilized fluidized bed in an overflow form through an upper orifice on the upper part of the ascending bed. The method is simple in process flow, the required equipment is compact in structure, the investment cost is relatively low, the operation is flexible, inactivated / saturated particles in the magnetically stabilized fluidized bed can be continuously extracted for regeneration, and meanwhile, the regenerated particles are returned, so that the continuity of gas A treatment is ensured.

Description

technical field [0001] The invention relates to the technical field of fluidized bed reactors, in particular to a method for extracting, regenerating and returning particles in a magnetically stable fluidized bed. Background technique [0002] Bubbling fluidized beds are often used for contact operations between the process gas and the particle population. However, when the operating gas velocity exceeds the minimum bubbling speed of the particle population, the excess gas will short-circuit through the bed in the form of bubbles, resulting in gas-solid The contact conditions are poor, and the one-way conversion of the gas is small. [0003] When the bed material in the bubbling fluidized bed is a binary mixture of magnetic particles or non-magnetic particles, a magnetic field is often used to suppress the formation of bubbles, creating the famous magnetically stable fluidized bed. figure 1 For the magnetically stabilized fluidized bed reported in U.S. Patent US4115927, fi...

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Problems solved by technology

However, this method has the following disadvantages: 1) the thin and tall riser makes the whole equipment large-scale, the advantages of compact structure of the magnetically stable fluidized bed no longer exist, and the investment cost is high; 2) the particles in the riser are in dilute phase In the fluidized state, the solid content rate is low (<10%), and the residence time of the particles in the riser is very short, which is not convenient for regulating the regeneration process of the particles; 3) The relationship between the particles and the inner wall of the riser and the cyclone separator 4) The fine powder produced by particle wear will increase the subsequent dust removal load of gases B and A, increasing the risk of environmental pollution

[0006] All in all, so far, there is still no method that can continuously extract and regenerate the deactivated / saturated particles and return the regenerated particles on the basis of maintaining the compact structure of the magnetically stable fluidized bed, which severely limits the magnetically stable fluidized bed. Industrial application of chemical bed

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