Reverse osmosis (RO) generated water is a very pure form of water and is free of granules and other contaminants that could be in regular clean water, or even softened water. RO is the process of pushing a solution through a membrane leaving the solute on the back side of the membrane and retaining the solvent, in this case, water. An RO system can be used as a final rinse in the wash. Because it is so pure, it leaves nothing behind as it evaporates. Typically this is referred to as a spot-free rinse. Without the aid of an RO system, hand drying would be required unless spotted windows and vehicles are acceptable.
The alternate solution would be burst air drying. This solution not only takes up valuable floor space at the end of the wash, but also consumes energy to drive the motors in the blowers, and heat energy if required. In addition, it typically requires more maintenance than an RO rinse.
An owner-controllable system is of the utmost importance. It allows adjustability within the wash cycle to match specific needs. Northern climates have to contend with salt during the winter months but are not concerned with it in the summer months. Transit authorities like The Rapid need the ability to increase or decrease the amount of washing agent distributed on the vehicle as it moves through the wash depending on the season. More washing agent can be used in the winter, and then dialed back in the summer. Wash agent use in the warm months may be 1 part soap per 40 parts water versus 1 part soap to 20 parts water in the winter. This indicates that the soap use in the summer months is cut in half.
To have a system that the owner can control with only knowledge of a standard personal computer, and without having to attend training classes, saves them time and money. If a vendor-employed technician had to be called every time an adjustment was required, it could be days before a simple adjustment was complete, not to mention costs that could be incurred. The ability to decrease soap when a high soap content is not needed can add up to a large cost saving.
In addition, the ability to modify the output of the RO system can be helpful. Using as little RO water as possible will help keep operating costs low.
The new system was required to fit in the same space as the old system. This was one reason they elected to use an RO water rinse in lieu of burst air drying.
Other space-saving techniques included keeping brush modules as compact as possible, yet allowing for enough space to remain between the chemical arch and high pressure sprayers to allow time for the wash agent to work properly. Space was at a premium, but all elements of the new wash fit into the old wash location without much difficulty.
The Rapid now has a bus wash that does the job it needs it to. It is a hybrid system, is capable of washing all its vehicles, utilizes a reclaim system, operates with a reverse osmosis final rinse and offers owner controllability. Thanks to its nightly maintenance wash with this new system, the fleet meets The Rapid’s cleanliness expectations. The end result is the first step to offering a clean and healthy environment for its passengers.
Seth Horton is a project manager with Progressive AE.