Detonation cleaning - controlled shock-wave cleaning of boiler internals

Detonation cleaning uses a controlled pulse-detonation device - a small chamber where a gaseous fuel-air mixture is ignited - to generate high-energy shock waves projected into the boiler. The shock waves dislodge consolidated deposits that lighter cleaning methods cannot remove. The best-known commercial offering is the Swiss-based Bang & Clean system, marketed primarily for WtE, biomass, and lignite-fired boilers with persistent fouling.

Trade-offs vs sonic horns

Attribute	Detonation cleaning	Sonic horn
Energy per shot	Very high	Low
Frequency	Episodic (per shift)	Continuous (every few minutes)
Damage potential	Documented on weld points if mis-targeted	None
Capital cost per unit	Higher	Lower
Best application	Hard consolidated deposits, periodic remediation	Continuous prevention
Operator presence required	Yes for each shot	No, fully automatic

The two technologies are complementary: sonic horns prevent the buildup that detonation cleaning is otherwise needed to remove, allowing detonation cycles to be reduced in frequency.

How it is applied

Detonation cleaning is normally performed through installed ports or temporary access points. A controlled fuel and oxidant charge is fired in a device that directs a shock wave into the fouled space. The wave fractures brittle or thick deposits through rapid pressure loading and vibration. It is closer to a cleaning event than to continuous conditioning.

Applications include waste-to-energy boilers, biomass boilers, lignite units and other furnaces where deposits become too hard for normal sootblowing. The method can be effective on slag and consolidated ash, but it requires careful targeting, exclusion zones and trained personnel.

Safety and design implications

The high-energy pulse can stress tube attachments, refractory, casing, welds and instruments if poorly aimed or overused. Sites must manage combustible gases, ignition sources, pressure waves, noise and access control. The cleaning provider usually defines charge size, firing angle, standoff distance and permitted frequency.

Detonation cleaning is often scheduled after online cleaning has failed to maintain heat transfer or draft. It can recover a dirty boiler, but it does not stop the next deposit from forming. If fuel chemistry and surface temperature remain unchanged, deposits return.

Relationship to acoustic cleaning

Sonic horns and detonation cleaning sit at opposite ends of the energy and timing spectrum. Horns apply frequent low-energy acoustic pulses to prevent soft deposits from becoming hard. Detonation applies occasional high-energy shock waves to remove deposits that have already consolidated. A good cleaning strategy may use horns to reduce how often detonation is needed and to keep the unit stable between major cleaning events.

Field checks

Detonation cleaning is assessed as an intermittent high-energy method. It can remove heavy deposits that ordinary acoustic horns cannot move, but it creates strong pressure loads, noise, vibration and ignition-control requirements. Before use, engineers review casing strength, refractory condition, access doors, expansion joints, nearby instruments and any combustible atmosphere risk. The cleaning zone also needs clear exclusion controls because the pressure pulse and falling deposits can be hazardous.

Maintenance teams compare it with sootblowing, explosive deslagging, water lancing and continuous acoustic cleaning. Detonation cleaning may be suitable for hard ash bridges or slag masses in robust equipment, while sonic horns are better for frequent low-energy prevention. The two approaches can coexist: continuous acoustic cleaning reduces deposit growth, and detonation cleaning is reserved for exceptional accumulations. It is not a routine substitute for solving poor combustion, ash chemistry, gas maldistribution or inadequate online cleaning coverage.