Dispensing a viscous use solution by diluting a less viscous concentrate

An apparatus for diluting a liquid concentrate with a liquid diluent to form a use solution, the apparatus comprising:

• (a) an aspirator comprising a first inlet port for receiving a stream of the liquid diluent said diluent at water service line pressure less than about 60 psi, a second inlet port for receiving a stream of the liquid concentrate having a viscosity of 10-600 cP at 22.degree. C., a nozzle, and venturi comprising a nozzle opening, a throat facing the nozzle and a passageway terminating at an outlet port, wherein the ratio of the area of the throat to the area of the nozzle is greater than 4:1 and effective to cause the liquid concentrate to be aspirated and drawn through the apparatus;
• (b) a liquid diluent conducting means connected to the first inlet port and a liquid concentrated conducting means having a valve, the liquid concentrate conducting means being connected to the second inlet port of the aspirator for supplying thereto the liquid concentrate at atmospheric pressure;
• and
• (c) a liquid conducting outlet means connected to the outlet port for delivering the use solution having a viscosity greater than the liquid concentrate, from the apparatus;
• wherein the outlet port and the second liquid conducting means are adapted for use with a use solution having a viscosity of 200 to 1200 cP at 22.degree. C., the use solution having a viscosity greater than the diluent and the concentrate, the outlet port and the liquid conducting outlet means are shaped and configured to maintain during dispensing a dynamic volume of use solution within the outlet port and the liquid conducting outlet means, sufficient to maintain continuous dispensing and a concentrate to diluent ratio of about 1 part of concentrate to about 3 to 6 parts of diluent, and are sized in relation to the flow rate of the liquid diluent and in relation to the flow rate of the liquid concentrate, through the first inlet port and the second inlet port such that the flow rate of the use solution from the apparatus is substantially unaffected by the viscosity of use solution.

A method of diluting an aqueous liquid concentrate having a viscosity of about 10-1000 cP with an aqueous liquid diluent to form an aqueous use solution having an increased viscosity, when compared to the concentrate, the method comprising:

• (a) combining the liquid diluent said diluent at water service line pressure less than about 60 psi, with the liquid concentrate having a viscosity of about 10-1000 cP, in an aspirator device, to form a liquid use solution of increased viscosity when compared to the liquid concentrate;
• and
• (b) accumulating the aqueous use solution in a container in liquid communication with the aspirator;
• wherein the viscosity of the use solution is greater than both the liquid concentrate and 200 cP.

An apparatus for diluting a liquid concentrate with a liquid diluent to form a use solution, the apparatus comprising:

• (a) an aspirator comprising a first inlet port for receiving a stream of the liquid diluent said diluent at water service line pressure of less than about 60 psi, a nozzle opening for the liquid diluent having a diameter of about 1 to 6 mm, a second inlet port for receiving a stream of the liquid concentrate having a viscosity of about 10 to 1000 cP, and an outlet port for the use solution having a viscosity of about 100 to 4000 cP;
• (b) liquid diluent conducting means connected to the first inlet port and liquid concentrate conducting means connected to the second inlet port of the aspirator for supplying thereto the liquid diluent and the liquid concentrate respectively;
• and
• (c) a liquid conducting outlet means having a throat and a passageway connected to an outlet port for dispensing the use solution having a viscosity greater than the liquid concentrate, from the apparatus;
• wherein the use solution has a higher viscosity than the concentrate and the diluent, the ratio of the diameter of the opening to the throat and the passageway to the diameter of the nozzle opening is greater than about 1.4:1 and the liquid connecting outlet means comprises a variable flow restriction means having a diameter about 3 to 10 mm and smaller than the diameter of the passageway causing the passageway to fill with use solution.