The accumulation of buildup (fouling) causes heat generating facilities (boilers or heaters) to operate significantly less designed efficiency and capacity with increasing of pollution emissions.
Thus, the economic losses caused by clogging of the boilers and subsequent more frequent plant shutdowns have reached an unacceptable level. The disadvantages of conventional on-line cleaning systems such as steam or air soot blowers, acoustic horns, etc. lead to unscheduled downtime for manual cleaning of boilers, which is the most difficult, dirty, costly and harmful operation.
All known and prevalent traditional soot blowers are not effective enough and have their specific shortcomings.
SootGone™ is amazingly effective and less expensive (purchase, installation, operation & maintenance) than alternatives by an exponential factor.
TRADITIONAL SOOT BLOWERS
Electric power generation plants usually have dozens of soot blowers in operation. Until recently there were limited choices on how to regulate and effectively clean boilers, with the most common technologies being steam and compressed air soot blowers.
These were the most well-known traditional soot blowers to combat fouling accumulations:
steam soot blowers
air soot blowers
acoustic (sonic) horns
STEAM SOOT BLOWER
A common application at oil, coal, or multi-fuel source power plants is retractable or rotary steam soot blowers. Several steam soot blowers are usually found at each level of the boiler tower. A traveling lance with nozzle jets penetrates narrow openings in the boiler tube banks to blast the tubes clean.
The primary elements of the typical steam soot blower:
a means to convey the nozzle-conveying mechanism, including the lance tube, carriage, and drive motor;
a means to supply the blowing medium into the nozzle-poppet valve, feed tube, packing gland, and lance tube;
a means to support and contain the lower component, which is a canopy-type beam with a two-point suspension;
integral components protected by the beam control the blowing cycle and supply power to the drive motor.
Typical soot blower operation begins with the blower in the retracted position. At startup, the carriage moves along guide rails or rollers located on each side of a beam to insert the lance tube into the boiler. The carriage then begins the cleaning cycle. The carriage continues to move and the lance tube rotates through the boiler tube banks. At the furthermost point, the carriage reverses its direction and the lance tube starts to return on a different nozzle path. The carriage continues to retract until the nozzle reaches the boiler wall, at which point the blower shuts off. The carriage continues to the start position.
From this brief description we can understand why these very complicated mechanical devices are so expensive.
Steam potentially introduces excessive moisture and condensation in the boiler, with accompanying damage to the pipes, supports, and refractories (thermos shock phenomena). If steam soot blowers are installed outside, provisions for heating and drainage to prevent thermos shocks must be made, thereby adding maintenance hours.
1. high capital, operational, and maintenance costs;
2. steam yields corrosion and thermal shocks damaging pipes, boiler structure and refractories inside the boiler;
3. huge devices make it impossible to install them in all the desired places;
4. large service platforms are required;
5. low cleaning effectiveness;
6. hundreds of spare parts must continuously be kept in stock;
7. the steam consumption costs five to ten dollars per cleaning cycle.
The requirements for regular maintenance and operation of the steam soot blower require frequent inspection and replacement of parts:
blown and damaged nozzles
worm and damaged carriage housing
warped, melted and corroded lance tubes
entangled cable and power cords
failed gearbox seals
corroded Feed tubes
loose packing tensioner
worn motors, gears, steam traps, refractories, pipes, and supports
AIR SOOT BLOWER
Air has less kinetic energy than steam at a given pressure (air pressure is normally 180 psig or 1.24 Mpa). The use of air soot blowers requires the installation of plant compressors to provide the necessary pressure.
Disadvantages when compared to the SootGone™ system:
requires a high pressure compressor with the dryer system;
carries a high capital, operational, and maintenance cost.
WATER CANNON SOOT BLOWER
The application of water cannon soot blowers is a relatively new development and is significantly different from the conventional wall blowers. The water cannon directs a water jet across the furnace ox where it impinges on and removes slag from the opposite boiler wall.
Cleaning is performed by sweeping the water jet across the boiler wall. The primary mechanism of slag removal is the penetration of water into the outer slag layer and its expansion into steam, although thermal shock may also play a role. The concern regarding thermal shock and its long-term effect on water tubes is currently being evaluated.
Water is used as a medium for wall blowers, and almost never for long retractable soot blowers. The density of a water jet has the potential to provide very high-impact energy and efficient cleaning, although there is great concern about tube, refractory, and boiler structure damage and failure due to thermal shock.
Disadvantages compared to the SootGone™ system:
in the short-term, affects the boiler structure, pipes, and refractories;
in the long-term, ruins the equipment;
high maintenance costs.
SONIC HORNS SOOT CLEANING
Acoustic horns, sometimes referred to as sonic horns, have become widely utilized in the last 25 years. The operating principle is to use intense sound pressure to dislodge ash. The horns operate with sound pressure up to 150 dB.
Acoustic horns are utilized in the economizer, air heater, electrostatic precipitator (ESP), and baghouse regions of the boiler. They also clean Selective Catalytic Reduction (SCR) reactors, which are used for NOx control.
The major advantage of acoustic horn blowers is their relatively low operating and capital cost.
Disadvantages compared to the SootGone™ system:
inefficient in removing the deposits off the heat transfer surfaces;
potentially resonant vibration of boiler structure.