A detection method for fluid flow state in overflow pipe of multi-layer fluidized bed

Abstract

The invention discloses an acoustic detection method of a blanking state of a multi-layer fluidized bed reactor overflow pipe. An acoustic emission signal at the multi-layer fluidized bed reactor overflow pipe is received; the received acoustic emission signal is analyzed, and energy fractions of friction and collision signals in the acoustic signals are observed to distinguish the blanking stateof the multi-layer fluidized bed reactor overflow pipe. When the multi-layer fluidized bed reactor overflow pipe performs normal blanking, particles are transmitted in a dense phase, a flow state is aplunger flow, and interaction between particles and a wall surface focuses on friction. Under this state, in the received acoustic signal, Dcollision / Dfriction<=3. When the multi-layer fluidized bedreactor overflow pipe performs non-normal blanking, air moves upwardly through overflow pipe, air speed is too large so as to prevent the solid particles from moving downwardly, even carry particles to rise. Under this state, particles are transmitted in a dilute phase, interaction between particles and a wall surface focuses on collision, and in the received acoustic signal, Dcollision / Dfriction>3. The method disclosed by the invention has the characteristics of sensitivity, security and environmental protection, simplicity and quickness, can timely and correctly perform on-line analysis andcontrols production data through analysis results.

Description

technical field [0001] The invention relates to the detection of the feeding state of the overflow pipe of a multilayer fluidized bed reactor, in particular to a detection method for the fluid flow state of the overflow pipe of a multilayer fluidized bed reactor. Background technique [0002] The multi-layer fluidized bed can establish concentration gradient and temperature gradient vertically along the bed height, and reduce the axial back-mixing of particles and gas in the fluidized bed. The redistribution of gas through the distribution plates of each layer can inhibit the coalescence and growth of bubbles, effectively reduce the diffusion resistance, and improve the heat transfer and mass transfer rates. Therefore, as an important way to strengthen fluidized operation, multi-layer fluidized bed has been applied in various scales in catalytic cracking, iron ore gas reduction, calcination and drying of particles, production of activated carbon and carbon nanotubes, ion exc...

AI Technical Summary

Problems solved by technology

[0007] 1) The pressure monitoring is easy to be blocked during the monitoring process, and it is difficult to maintain

[0008] 2) Both pressure pulsation monitoring and capacitance monitoring are plug-in, and holes must be drilled on the wall of the fluidized bed during installation. certain influence

[0009] 3) The environmental requirements are relatively high. For relatively harsh factory environments, such as high temperature, high pressure, dust and other environments, signal distortion may be caused, and the dynamic information of the fluid in the fluidized bed overflow pipe cannot be truly reflected.

Images