Developer of an innovative online detonation cleaning device - SootGone™. Founder, Owner, and CEO at LeonPulse Ltd.
March 1, 2023
Various Methods of Generating Detonation Waves
in Online Boiler Cleaning Devices
As we mentioned earlier, online detonation soot and deposit cleaning technology in most cases has many advantages over other outdated methods.
Let us dwell on the peculiarities, technological methods and design features of various online detonation cleaning systems that currently exist in the industry.
Note: We are not referring to the use of dynamite or a det cord, both of which occur offline and involve significant risk. The force of the blast coupled with its inherent danger of an uncontrolled explosion can damage boilers.
We will review three different principles of generating a detonation wave.
Required conditions: high volume, atmospheric pressure of gas-air mixture, supply of ambient air and various types of fuel gases. Big footprint. Effective.
A detonation wave can be generated in a sufficiently long pipe by igniting a low pressure premixed fuel-oxidant mixture. The combustion products, limited by the pipe walls and the flame front, initially move towards the open end into the unburned mixture at a relatively low propagation velocity, followed by acceleration from deflagration to detonation mode (Deflagration to Detonation Transition - DDT) until the detonation front is established. .
A detonation device based on this principle was successfully implemented for online cleaning of large-scale coal-fired boilers in the United States. It consisted of long pipes tens meters long and about 18 inches in diameter. It was a huge heavy structure with a complex control system.
Required conditions: a high pressure mixture of methane or propane with oxygen and a small size device with a moving piston. Compact and efficient.
Such online boiler cleaning devices based on this principle originated in Europe.
The detonation wave in this device is generated by igniting a mixture of oxygen and methane or propane under high pressure.
Necessary and sufficient conditions: small volume, atmospheric pressure of gas-air mixture, supply of ambient air and various types of fuel gases. Small footprint. Effective.
Further development of detonation cleaning devices has led to the emergence of a fundamentally new small-sized system designed by our team - an online detonation pulse generator SootGone ™.
What makes the compact and efficient SootGone™ detonation system different from other detonation devices? The Flame Front Approach is not just a name, but rather the philosophy and process behind the technology.
The use of the flame front phenomenon as a working medium makes it possible to create / design unique pulse generators without a single moving part. The Flame Front works in this device as a compressor piston and an igniter which makes it more reliable and less costly.
The SootGone™ system consists of a Flame Front generator (FFG), conduit pipes of small diameters, and several pulse generators.
The procedure for SootGone™ operation is as follows:
The initial step of the operation sequence is to fill the FFG, conduit pipes and one or two pulse generators with an air-gas mixture at low pressure.
The flame front (piston) created / generated by the FFG travels through the conduit pipes at high speed and pushes the unreacted gas-air mixture to the pulse generator at a deflagration velocity of about 200-250 m/s with continuous acceleration.
The Flame Front compresses the unburned air-gas mixture in the PulseGenerator.
The FlameFront reaches the Pulse Generator and ignites the compressed gases with an ignition delay of a few microseconds. The transition from deflagration to detonation (DDT) in the pulse generator occurs due to the following factors: temperature increase in the pre-compressed unburned mixture due to adiabatic compression to its self-ignition temperature, high temperature of the flame front and due to the vortices created by the vortex generator blades installed in pulse generators.
Important clarification: the DDT process occurs in Pulse
5. The detonation wave propagates at supersonic speed inside the Pulse Generator and decays ( breaks up) into a powerful sonic omnidirectional shock wave in the boiler space.