Tunnel washer
A tunnel washer, also called a continuous batch washer, is an industrial washing machine designed specifically to handle heavy loads of laundry.
The screw is made of perforated metal, so items can progress through the washer in one direction, while water and washing chemicals move through in the opposite direction. Thus, the linen moves through pockets of progressively cleaner water and fresher chemicals. Soiled linen can be continuously fed into one end of the tunnel while clean linen emerges from the other.<ref>"Tunnel Washers | Laundry Consulting". Laundry Consulting. Water Energy Technologies. Retrieved 23 May 2021.</ref>
Originally, one of the machine's major drawbacks was the necessity of using one wash formula for all items. Modern computerized tunnel washers can monitor and adjust the chemical levels in individual pockets, effectively overcoming this problem.<ref>Poe, Matt (11 December 2018). "Efficient, Flexible Tunnel Washers". American Laundry News. American Trade Magazines. Retrieved 23 May 2021.</ref>
