Measuring apparatus and measuring method for gas-solid fluidized bed particle mixing

Abstract

Disclosed are a device and a method for measuring air-solid fluidized bed particle mixture. The device comprises a microwave reflecting screen (7) set on the two sides of the fluidized bed (1); a microwave transmitting device is comprised with cascading the microwave generating device (4), a transmitting antenna (5) and a waveguide (6), wherein the waveguide (6) is installed in the middle of the microwave reflecting screen (7); a microwave receiving and processing device is comprised with an optical imaging object lens (8), a infrared probe (9), an amplifier (10) and a computer (11), wherein the optical imaging object lens (8) is locate on the other side of the fluidized bed (1) between two microwave reflecting screens (7). The method comprises that the microwave transmits to the fluidized bed layer via the guidance of the antenna and the waveguide; the tracking particles with polar H2O molecule are heated and employs the optical imaging object lens to receive the infrared radiation power distribution graph and reflect it to the infrared probe.

Description

technical field [0001] The invention relates to a measuring device and a measuring method for particle mixing in a gas-solid fluidized bed, belonging to the technical field of fluidized bed and multiphase flow measurement. Background technique [0002] The mixing behavior of particles in a gas-solid fluidized bed reflects the movement and transfer characteristics of particles in the bed. It is the key to understanding the gas-solid heat transfer and mass transfer mechanism of the fluidized bed. It is important for the design of the fluidized bed reactor and the optimization of structural parameters. significance. As pointed out in the literature: It is precisely because of the study of particle mixing characteristics that the riser can effectively reduce the gas-solid backmixing compared with the turbulent fluidized bed, which makes the catalytic cracking process transition from the traditional fluidized bed to the riser reaction Device produced a qualitative leap [Referenc...

AI Technical Summary

Problems solved by technology

These tracer methods are more or less deficient, making the repeatability and reliability of the measurement results less than ideal:

[0004] (1) Magnetic particle tracking is generally only suitable for a single tracer particle, and the movement of a single tracer particle in the flow field is very random; if more tracer particles are used, the same polarity will occur between the tracer particles Mutual exclusion phenomenon, the movement of tracer particles cannot reflect the real movement of particles

[0005] (2) The biggest disadvantage of thermal particle tracing is that the temperature of thermal tracer particles decays rapidly under the action of cold air flow; in addition, for dense gas-solid fluidized beds, thermal tracer particles are often easily blocked by dense bed materials, resulting in Undetectable by sensitive thermocouples

[0006] (3) The biggest disadvantage of colored particle tracking is that in a dense gas-solid fluidized bed, colored particles are easily blocked by dense bed materials and cannot be captured by a fast digital image acquisition device

[0007] (4) Phosphorescent particle tracking is similar to hot particle tracking and colored particle tracking, and is not suitable for gas-solid fluidized beds with large particle concentrations

However, the safety issues involved in the preparation, storage and use of radioactive tracer particles are strictly restricted by relevant laws and regulations; the equipment of radiation monitors or radiation cameras is expensive and the operation is complicated, which prevents this method from being widely used

[0009] Conventional particle tracer methods have become increasingly difficult to measure complex particle mixing in gas-solid fluidized beds, especially dense gas-solid fluidized beds

Images