If the surfaces you are cleaning have any kind of grease or oil, you will need a high temperature eg. steam cleaner or hot water pressure washer to clean them.
Steam cleaning is an entirely different process from pressure washing. The key to steam cleaning is vapor expansion. The steam cleaner uses steam’s expansion to accelerate water droplets, at the boiling point, to a high velocity. The closer the steam cleaner’s nozzle is to the surface to be cleaned, the higher the temperature and velocity of the water/steam mixture, and the more rapid the cleaning action. The temperature of the water/steam mixture drops quickly as the distance between the nozzle and the surface to be cleaned increases. Consequently, for many cleaning applications, the nozzle should be held close to the soiled surface to achieve the best results. Steam cleaners are excellent for cleaning grease and oil, sterilizing, disinfecting, degreasing, dissolving resins, de-icing, flushing away chemicals and poisons, degassing, and for preparing surfaces for painting or other treatments.
Water in a steam cleaner is heated to 320°F at relatively low pressure (in the 100 to 250 PSI range vs. 2,000 to 4,000 psi for the most common pressure washers), depending on the model.
Water at atmospheric pressure boils at 212°F. At higher pressure, it takes more energy to convert water molecules into steam, so the boiling temperature increases. Water in a steam cleaner is compressed to 250 PSI by the pump, and heated to 320°F prior to nozzle discharge. Water at this temperature remains a liquid at any pressure over 89.7 PSI. After the 320°F water in a steam cleaner passes through the restrictive nozzle it is no longer under the additional pressure of the water pump and cannot remain a liquid. Fifteen percent of the water instantly flashes into steam, cooling the mixture of steam and water from 320°F to 212°F. This steam vapor, used with a properly designed steam cleaning nozzle, also accelerates the remaining water droplets. Unlike a pressure washer nozzle, the steam cleaning nozzle has an expansion zone placed past the pressure orifice, which directs the water vapor energy to a smaller area, instead of dissipating in all directions. The tremendous expansion is directed by the conical steam nozzle, accelerating the water droplets. The expansion nozzle’s effect can be compared to that of the choke of a shotgun. Not only does the expansion nozzle direct the steam cleaner’s output, it serves as a propulsion chamber. The expansion nozzle both directs and accelerates the output.
The cleaning action of steam is not accomplished by a cloud of steam vapor, but by very hot water droplets accelerated by steam expansion in the nozzle. This process allows the water to reach the surface to be cleaned at a temperature as near the boiling point of water as is possible, enhancing the aggressiveness of most cleaning chemicals and making the task of thoroughly removing grease and oil much easier and faster.
Typical applications for steam cleaners include:
• Cleaning engines, transmissions, drive trains, and other equipment prior to performing service and maintenance work.
• Thawing drains, tanks, piping systems or culverts, for street and highway departments, manufacturing and processing plants, pipelines, and other industries.
• Thawing railroad tank cars to accelerate removal of viscous liquid contents, while ensuring that the maximum temperature is less than the boiling point of water (to prevent fires and other high temperature damage).
• Removing chewing gum from sidewalks, tables, stadiums or entryways.
• Degassing tanks prior to welding or other maintenance work, especially gasoline, oil, and petrochemical
tanks.
• Preparing surfaces for painting, especially for removal of cutting oils, grease, or other oily/greasy
substances.
• Degreasing dies and tools in manufacturing operations.
• Removing fats, grease, oils, and substances from surfaces and equipment in food processing plants.
• Melting and removing paraffin, wax or grease from traps and drains in waste water treatment plants,
petroleum refineries, and other industries.
• Cleaning and restoring brick, block, stone and other masonry surfaces for maintenance or restoration projects, (monuments, cemeteries, and similar applications), where steam is more gentle and less intrusive and damaging than high pressure cleaning.
• Wide range of other specialty applications.
Many industrial steam cleaners today are electric in nature, although older models still ran on gasoline. Electric models have the advantage not having to maintain the burner (burner is the #1 source of problems in traditional models). Electric steam cleaners are excellent for use in areas that cannot tolerate contaminants in the air. These machines produce no fumes or exhaust.
