Ice blast cleaning systems and methods

Abstract

The present application provides an ice blast cleaning method for a layer of slag on a surface. The ice blast cleaning method may include the steps of maintaining the surface with the layer of slag thereon at an elevated temperature, shooting a number of ice pellets at the layer of slag on the surface, and loosening the layer of slag on the surface via a mechanical impact of the ice pellets on the layer of slag and a thermal shock caused by a temperature differential between the ice pellets and the layer of slag.

Description

TECHNICAL FIELD[0001]The present application relates generally to ice blast cleaning systems and methods and more particularly relates to high pressure ice blast cleaning systems and methods to clean slag and the like from industrial boiler tubes via mechanical impact and thermal stress.BACKGROUND OF THE INVENTION[0002]Generally described, industrial boilers operate by using a heat source to create steam from water or another type of a working fluid. The steam may be used to drive a turbine or another type of load. The heat source may be a combustor that burns a fuel-air mixture therein. Heat may be transferred to the working fluid from the combustor via a heat exchanger. Burning the fuel-air mixture, however, may generate residue on the surface of the combustor, the heat exchanger, and the like. Such deposits of soot, ash, slag, dust, and / or other types of residues on the heat exchanger surfaces may inhibit the efficient transfer of heat to the working fluid. This reduction in effi...

AI Technical Summary

Benefits of technology

"The present patent application describes an ice blast cleaning method for removing layers of slag from surfaces, such as heat exchangers and boilers. The method involves maintaining the surface with the slag layer at an elevated temperature, and then shooting a stream of ice pellets at the slag layer. The ice pellets create a mechanical impact and a thermal shock, resulting in the loosening of the slag layer. This method can improve the efficiency and lifespan of heat exchangers and boilers by reducing the need for maintenance and repair. The patent also describes a heat exchanger system and a boiler system that includes an ice blast system for removing slag layers."

Problems solved by technology

Burning the fuel-air mixture, however, may generate residue on the surface of the combustor, the heat exchanger, and the like.

Such deposits of soot, ash, slag, dust, and / or other types of residues on the heat exchanger surfaces may inhibit the efficient transfer of heat to the working fluid.

This reduction in efficiency may be reflected by an increase in exhaust gas temperatures from the backend of the process as well as an increase in the fuel burn rate required to maintain steady steam production and energy output.

Such cleaning processes thus may be relatively time consuming and costly at least in terms of boiler downtime.

The use of pressurized steam and / or water may blow the accumulated ash off of the tube banks but generally will not eliminate a hard layer of slag.

Moreover, the abrasive particle methods may add more hard particles of materials into the boiler, which also may cause a blockage.

Images