Cleaning of ash accumulation in catalytic waste heat boilers
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The waste heat boiler is of modular design, featuring a superheating section, an evaporation section, and upper and lower economizers. As the unit operates, the heat exchange efficiency gradually becomes less satisfactory; it is necessary to remove certain components for cleaning. Using manholes poses the risk that thorough cleaning may not be possible, while using high-pressure water guns to clean the fins could damage the lining at the bottom of the flue. Do anyone have any good suggestions?
1. Acoustic soot blower 2. Shock wave soot blower
The addition of 3.5 MPa superheated steam for soot blowing at our facility has proven to be effective; the furnace temperature rises rapidly after such cleaning
Reply to 2# aqshhsq: We use shock wave soot blowers. The effect on the chimney during soot blowing is acceptable, but the exhaust temperature still rises significantly over time (by about 1 month per year). It’s possible that the fins are blocked by the catalyst. Is there any good way to clean them if we stop operations?
For cleaning dust accumulated in waste boilers, shock wave soot blowers or acoustic soot blowers are commonly used. Our unit also has significant dust accumulation; it’s an older unit, and the outlet of the three-spin critical nozzle is located in front of the waste boiler. Next year we will consider whether it’s possible to move the outlet of the critical nozzle to behind the waste boiler, which would help reduce dust accumulation in that boiler.
In addition to the sound waves, shock waves, and steam cleaning methods mentioned above for removing ash from boilers, there is another approach that makes use of spent catalysts. In this method, the catalyst tank is compressed, and the pressurized catalyst is then blown into the flue duct located behind the smoke extractor and in front of the waste heat boiler. The high-speed impact of the catalyst on the fins causes the vibrational kinetic energy of the dust particles to exceed their adsorption energy, thereby achieving dust removal. However, the obvious drawback is the wear on the fins; nonetheless, the device performs quite well – the flue gas exit temperature drops by fifty to sixty degrees after each soot blowing operation.
We use shock wave soot blowing here, and judging from the flue gas temperature, it seems to be quite effective. However, it’s usually done at night, hehe
Reply to 1# zhaojiong1999: Using sound waves is somewhat better than using shock waves. I do have some information regarding the application of sound waves in boilers; if you provide your email address, I can send it to you for reference.
Shock wave soot blowing is quite effective; however, due to design and installation location constraints, its effectiveness may decline over time to some extent, but not significantly. Steam soot blowing also works very well, but be careful to prevent corrosion and leakage issues. Catalysts with a balancing blowing effect work well, but they may remain inside the furnace over time. Acoustic soot blowing is the least reliable method due to its shock wave drawback, and there are numerous factors that influence it; we removed it after just one cycle of use
Last time, our unit removed the excess boiler and opened the manhole to flush it with fire water, and the result was good. When bringing the excess boiler back into use, it’s necessary to proceed slowly and remove all the water from the system to prevent water hammer!
Reply to 9# ppv: Hello, can we add each other on QQ? I would like to learn more about the disadvantages of using acoustic soot blowing. QQ331837388