In Part III we reviewed a few of the many applications for cleaning with dry steam, which has a moisture content of about 8%, flow rates measured in litres/hour, and pressures generally below 70 PSI, making it ideal for detailing and precision cleaning, where moisture and drainage are a concern. Let’s now look at wet steam, which has a moisture content above 35%, flows measured in gallons/minute and pressures generally above 100 PSI.
When the challenge is on a large scale, especially outdoors, the power of wet steam will make short work of cleaning chewing gum from sidewalks, graffiti from walls, bird droppings from statues, ornaments and other public surfaces, moss and mildew from footpaths, and weeds from curbs, patios, berms, fence lines, playing fields and road shoulders.
Weed control with steam is gaining a lot of attention with the introduction of no-spray policies by provinces and municipalities who are concerned about the potentially harmful effects of pesticides and herbicides entering our water supply.
An interesting fringe benefit of controlling weeds with steam is that the steam can also sterilize the soil that is being treated. Of course, public works departments throughout Canada have long used steam in winter for thawing frozen pipes and hydrants, de-icing bridges, tracks, roofs and decks, and clearing ice-blocked culverts. The modern delivery of steam with more effective flow and pressure extends those winter applications throughout the year, and across environments.
Maintaining facilities such as arenas, parks, and shopping centres becomes easier with steam, which can sanitize the compactors and waste bins at the food court, the spills at the loading docks and in the parking garage, the public washrooms and showers at the campground, swimming pools, locker rooms, the boats at the marina, and the buses and trains that make up our transit system. Steam can clean the exterior walls of the buildings, and, given adequate drainage can also clean vast floor areas. While cleaning, steam also disinfects, reduces water usage, reduces chemical usage, and makes for a safer and easier process for the operator. As stewards of our natural environment, we all benefit from this truly green approach to cleaning.
Steam is also the preferred method of sanitizing production equipment and facilities in the food manufacturing industries, including bakeries, beverages, meats, cereals, and ready-to-serve packaged foods. Similarly, clean room standards in pharmaceutical production or electronic component processing are readily met with steam. Melting grease and oils makes steam useful in other industrial processes as well, including surface preparation of fabricated goods before painting or coating to ensure good adherence of the finish on a thoroughly cleaned substrate.
Steam cleans construction equipment, vehicles, and agricultural implements, and de-greases industrial components being serviced and repaired. Whether rebuilding an engine block, removing salt from the blades of a snowplough or tar from a grader and a roller, the elimination of solvents from the process reduces wastewater treatment costs.
We all know that hospitals use steam to clean their surgical instruments, but modern technology now makes it practical to clean the entire operating room, the beds, the wheelchairs, and indeed the patient rooms, with steam, and thereby to reduce the use of chemical disinfectants which have begun to contribute, along with antibiotics, to the mutation of pathogens into new and tougher superbugs.
Steam cleaning also reduces cross-contamination risks in the transportation and storage of raw materials. Tanker trucks, tanker railcars, tank farms, large vessels in wineries, breweries and dairies, and liquid totes can all be safely re-used for different products if they are cleaned and de-gassed with steam between uses. The same holds for live animal transport cages and trucks.
As with dry steam, I discover new uses for wet steam regularly. This year I learned that steam is used to cure a liner material that repairs broken sewer mains in place, to disinfect fish nets, and to unclog drains. Steam is also used to cure concrete in winter and to extract oil from the tarsands. Perhaps one day we will see the return of a steam-powered automobile.
Serving Canada since 1997