Abstract: An air gap, venturi-type mixer for mixing a liquid chemical with water includes a readily field-exchangeable collimator, water seal and venturi unit to accommodate different flow rates. The venturi unit includes a funnel with slightly inclined walls that direct a misaligned collimated water stream into the vena contracta of the venturi without reducing its speed or entraining any air.

Abstract: A system is provided for managing washing machines, and controlling laundry chemical dispensers. The system enables a user to choose controls, such as: automatically select, change, increment and monitor formulations used in a specific washing machine, or in a group of machines; flush out chemicals to the washing machine in conjunction with a low level indicator; select a specific washing machine out of a group of machines for a different operation; a power reset following a spike detection, power surge or a brownout; readings for: hot and cold water consumption, drain output, and steam output; the use of a plurality of machines to perform a series of washings using a sequence of chemicals; and, print-out times, and dates associated with the operation of each machine in a series of machines. The control system is regulated by an input keyboard, and specific operations may be recorded by a printout, viewed on a screen, or both.