Ice is not the instinctive answer that comes to mind when considering powerful industrial cleaning tools. Industrial cleaning is a challenging task that demands both powerful equipment to handle tough compounds and versatility to achieve standards of cleanliness that vary in different industries. An effective cleaning solution may need the capability to remove precise burrs from manufacturing equipment or the power to strip paint off the hull of a ship. Some cleaning applications are extremely outdated, such as manual decontamination in nuclear power plants, where workers in bio hazard suits use cloths to wipe down surfaces.
The most common cleaning method is blasting using abrasive media, which is using compressed air to propel small particles of a substance (media) to take contaminants off of a surface. Popular media include sand, plastic bead, aluminum oxide, all of which are harmful to the environment and hard to contain. There are some gentler blasting options in using walnut shells or corn cobs, but the inconsistency in size and softness of the media make it a rare practice. When abrasive media is used to remove toxic or hazardous substances, the contaminants become airborne and have a negative effect on workers and the environment.
The last major innovation in industrial cleaning, as a first step towards a greener industry, occurred in 1988 when the first commercial dry-ice blasting machine was created. Dry-ice uses frozen carbon dioxide particles as media, which turns to gas after impact. Dry-ice pellets are relatively soft when compared with abrasive media and have a similar density to frozen water. During blasting, contaminants fall off the surface and the frozen particles and can be swept up. The result is less waste by-products and a lower environmental impact than abrasive blasting methods. However, there are risks of carbon dioxide poisoning when used in areas that are not well-ventilated and an explosion risk if stored improperly.
Despite increasing restrictions on environmental regulations and concern for climate change, industrial cleaning methods have not changed significantly. Many industries persist in using abrasive blasting methods that are an inefficient use of resources, specifically in high-pressure water blasting or sand blasting. Even after the introduction of dry-ice blasting, it is not a commonly accepted method due to the high cost of dry-ice. Abrasive blasting tends to be high in energy and media consumption. Despite regulations that make worker safety concerns a high priority, regulations on the usage of abrasive blasting tends to be poorly regulated in environmental respects.
A recently commercialized technology using frozen water (wet-ice) blasting is challenging the cleaning industry to make an environmentally-friendly change. Wet-ice blasting uses ice particles as an environmentally-friendly and worker-safe media that results in negligible airborne contaminants. As the ice sublimates on impact and turns to water, the process removes and rinses away contaminants. The process is non-abrasive, meaning that the surface underneath contaminants will not be damaged. Using only 27 gallons of water, a fraction of the 180-gallon usage in hydro-blasting, wet-ice blasting conserves valuable resources. Since this blasting technique uses only water, and there is no need for additional media, wet-ice blasting will also reduce transport trucks, used for dry-ice or other media, and reduce waste byproducts in industrial cleaning.
Dry-ice blasting is seen as an environmentally-friendly cleaning solution, as the byproduct is carbon dioxide gas, leaving only the contaminant for disposal. The main differentiation between wet-ice blasting and dry-ice blasting for the cleaning industry is the operation price for each method. Dry-ice incurs purchase, storage, and delivery costs, whereas wet-ice blasting only needs a water supply. In addition, dry-ice is not as environmentally friendly as it appears. Dry-ice must be shipped from production facilities, and at a usage rate of 150 lbs per hour, there is a significant environmental footprint for dry-ice blasting. Styrofoam is the choice packaging material for dry-ice and it is non-biodegradable and a leading source of hazardous waste. This type of packaging is typically used once and then disposed.
Blasting technologies are like tools in a toolbox, each performing a slightly different function. Abrasive blasting tends to be better for tackling tougher contaminants like stripping road paint, but many industries could be served by non-abrasive blasting. The important thing is to find the right tool for companies that will result in an environmentally-conscious solution. Wet-ice blasting is the beginning of a redefinition of industrial cleaning and will hopefully lead to other meaningful inventions.