Shock wave soot blower

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Waste heat boilers are the most commonly used waste heat recovery devices. It is used to recover the heat from the regenerator exhaust gases, generating steam and heating it to produce superheated steam. Since the catalyst dust carried in the flue gas gets adsorbed on the fins of the tube bundle, this reduces the heat extraction efficiency; shock wave soot blowers are installed to remove this dust and improve the efficiency of the waste heat boiler. The ESW shock wave soot blower generates shocks through the deflagration of gas. The fuel (usually gaseous fuels such as acetylene, natural gas, or propane) is ignited by a high-energy igniter in a special device, resulting in a deflagration ； The intense deflagration causes the combustion gases behind the flame front to reach high pressure instantaneously, resulting in the formation of a shock wave in front of the flame front ； As it passes through the flame duct, the compression wave is continuously amplified, eventually forming a stable shock wave ； Upon entering the shock wave generator, this shock wave serves, on one hand, as an ignition shock wave to ignite the combustible mixture inside the tank; on the other hand, it is further amplified due to the special structure within the tank ； Ultimately, the modulated shock wave is emitted from the shock wave nozzle into the furnace, where it acts on the ash accumulated on the heating surfaces inside the furnace, causing it to break apart and flake off under the impact of the shock wave, thereby detaching from the furnace’s heating surfaces. By controlling the intensity of the shock waves, it is possible to deal with different types of soot accumulation on the boiler’s heating surfaces, causing the soot to break apart under the impact of shock waves of appropriate and sufficient intensity. In practical use, the gaseous fuels that generate shock waves are usually gases such as acetylene, natural gas, and liquefied petroleum gas. Because these gaseous fuels are the easiest to obtain in modern factories and are also inexpensive. These gases have high specific energies and fast combustion rates, making them suitable for generating shock waves. Taking acetylene as an example, after its deflagration, a detonation shock wave with a speed of about 4 to 5 times the speed of sound is generated within the ESW shock wave soot blower. The pressure at the wave front is at atmospheric pressure, while the isochoric combustion pressure behind the wave is approximately 1.0 MPa; the wave speed ranges from 1500 m/s to 1860 m/s. The pressure peak at the shock wave front is related to the structural characteristics of the shock wave generator, and can typically reach several times the steady pressure behind the wave. After the shock wave is emitted from the shock wave nozzle, it undergoes partial spherical diffusion in the fan-shaped area outside the nozzle. Since the pressure behind the diffusing shock wave surface cannot be maintained above normal pressure, a reverse pressure peak is formed behind that surface, with a value lower than the normal pressure in that area. The diffused shock wave is reflected at the physical interfaces within the furnace chamber, and can be guided into the interior of the object through refraction. The intense pressure pulsations of the shock wave exert a pushing followed by pulling effect on the ash accumulation, causing it to break apart and detach from the base of the ash layer ； The refracted shock wave introduced into the accumulated dust also generates shear waves within the dust mass. The interaction between the reflected wave and the incident wave at the base of the accumulated dust creates shear forces at the interface between the dust and the base, leading to the separation of this interface. This post was last edited by Shuichangshou on 2009-4-27 at 18:15.]