US3570717A

US3570717A - System for fluent material dispensing with electrical controls

Info

Publication number: US3570717A
Application number: US789781A
Authority: US
Inventors: Kenneth R Olson
Original assignee: Stauffer Chemical Co
Current assignee: Diversey Corp USA
Priority date: 1969-01-08
Filing date: 1969-01-08
Publication date: 1971-03-16
Anticipated expiration: 1988-03-16

Abstract

A system for automatically preparing an aqueous dispersion of difficulty-soluble, solid detergent material and delivering the dispersion to the wash wheels of automatic washing machines, comprising means for separately delivering controlled amounts of detergent and water to a mixing tank, means for transferring the detergent-water mix to a storage vessel having stirring and circulating means, and means for dispensing quantities of the mix as needed to the various washwheels.

Description

United States Patent [72] Inventor Kenneth R. Olson Chagrin Falls, Ohio [21] Appl. No. 789,781 [22] Filed Jan. 8, 1969 [45] Patented Mar. 16, 1971 [73] Assignee Stauffer Chemical Company New York, N.Y.

[54] SYSTEM FOR FLUENT MATERIAL DISPENSING WITH ELECTRICAL CONTROLS 8 Claims, 1 Drawing Fig.

[52] [1.5. CI 222/76, 222/148, 222/236, 222/318 [51] Int. Cl B67d 5/06 [50] Field of Search 222/70, 76, 148,318, 226, 233-236 [56] References Cited UNITED STATES PATENTS 1,954,261 4/1934 Pierce 222/70x 2,137,928 III] 938 Tanqueray 222/70x HOPPER Primary Examiner-Samuel F. Coleman Attorneys- Robert C. Sullivan, Donald MacKay, Daniel C.

Block and Paul J. Juettner ABSTRACT: A system for automatically preparing an aqueous dispersion of difficulty-soluble, solid detergent material and delivering the dispersion to the wash wheels of automaticwashing machines, comprising means for separately delivering controlled amounts of detergent and water to a mixing tank, means for transferring the detergent-water mix to a storage vessel having stirring and circulating, means, and means for dispensing quantities of the mix as needed to the various washwheels.

SYSTEM FOR FLUENT MATERIAL DISPENSING WITH ELEETRICAL CONTROLS BACKGROUND OF THE INVENTION 1. Field of the Invention My invention relates to a system for automatic mixing of a granular solid with a diluent liquid, for storing of the resulting dispersion, and for conveying of the dispersion to stations of use as required. More particularly, it relates to such a system for preparing and storing a dispersion of a difficulty-soluble, granular, laundry detergent material in water and for conveying the dispersion to the washwheels of automatic washing machines as needed.

i'ligh labor costs in the modern laundry have led to the increased use of automatic devices. Thus, automatic controls are incorporated into most laundries to control the washing operation. These are largely timing devices which control automatically the various operations in the washing cycle such as the break, suds, rinses, bleach and sour. Generally, however, the addition of the detergent to the washwheel has remained a manual operation. Thus, the washman has added detergent and other supplies such as bleach and sour by hand, and since the presence of the washman is required, much of the cost saving aspects of'automation have not been realized.

2. Description of the Prior Art Efforts have been made to add detergent automatically to the washwheel at the appropriate time in the cycle. Thus, separate pumps have been set up to feed basic liquid detergent components such as waterglass, caustic soda, and a nonionic surfactant, separately and simultaneously. This process, however, is cumbersome and undesirable; even with three pumps feeding three liquids from three storage vessels, the system does not provide for the automatic addition of solid components such as brighteners and anti-redeposition agents that frequently are desired in the modern laundry detergent formulation.

The use of the liquid laundry detergent formulations has, moreover, a further disadvantage resulting in generally poor performance. Due to solubility limitations, it has not been found possible as yet to provide a detergent solution of sufficient concentration for high performance. At the present time, only detergents in the solid form have shown maximum detergency per unit of cost. Liquid detergents, while more convenient to use, have not been able to offer competitive detergency. Besides the problem of being limited to. only highly soluble components, the liquid detergent necessarily entails the cost of packaging and shipping an inert diluent, e.g., water.

SUMMARY OF THE INVENTION Myinvention provides a system for the automatic addition of a difficulty-soluble, solid detergent formulation in precisely measured quantity to a washwheel. The detergent formulation is uniformly dispersed in water to facilitate dispensing in more precisely measured quantities than is possible with undispersed granular material, yet the system is such that complete solution of the detergent is unnecessary; thus, the desired high concentration of detergent can be automatically supplied to the washwheels with the facility of low concentration liquid detergents, but without the inherent inaccuracies, cloggings, etc, of handling an entirely solid material.

The construction and mode of use of the system will be readily apparent from the drawing and the following detailed description.

DETAILED DESCRIPTION OF THE INVENTION With reference to the drawing, a system for the automatic dispersing of a granular detergent in water, for storing of the resulting dispersion, and for conveying the dispersion, as needed, to the washwheels of various washing machines in readied for operation by supplying warm water, e.g., at about 150 li, through supply line 10, valve 11, solenoid valve 12 and lines 13 and M to mixing tank 15. Water is introduced into the mixing tank, which may be provided with a glass lining 18, until it reaches upper level control electrode 19 whereupon conductivity controller 56 effects the closing of solenoid valve 12, the starting of the mixing tank stirrer 20, the starting scale contact 25 and effecting shutoff of the vibrating feeder 21, and the starting of timing clock 26. To insure complete dispersion of the detergent, the mixing tank stirring device 20 is kept in operation by timer 26 for a preset period of time, advantageously about l0 minutes, after termination of the addition of granular detergent to mixing tank 15. Generally, the dispersion formed is about 5 to 20 percent solid detergent in water.

Upon completion of the preset stirring period, timer 26 effects the opening of automatic valve 27 and the starting of" pump 28, thereby effecting discharge of the detergent-inwater dispersion, via flexible hose 29, pump 28, line 30, automatic valve 27 and manual ball valve 3l, into storage vesse I Transfer of the dispersion from the mixing tank to storage vessel 32 is continued until the liquid level in mixing tank 15 falls below lower level control electrodes 33, thus breaking the circuit and causing the closing of automatic valve 27, the shutting off of pump 28, and the opening of solenoid valve 12: With the opening of valve 12 is caused the renewed introduction of warm water, via line 14, into the mixing tank, which water introduction, as mentioned above, will continue until the liquid level reaches upper level control electrode 19; thus, is effected the beginning of another mixing cycle. The transferof dispersion from mixing tank 15 to storage vessel 32 is also automatically discontinued by the liquid level in storage vessel 32 reaching upper level control electrode 34, whereupon conductivity controller 57 effects the closing of automatic valve 27 and the shutting off of pump 28.

The mixing tank stirring device 20 may remain in operation throughout the mixing and transfer cycle, or it may be automatically inactivated during transfer of the dispersion and/or during water addition to the mixing tank, in response, for example, to level control electrodes 19 and 33 or to timer 26.

Storage vessel 32 also may have a glass lining 35 and stirring device 36. The dispersion contained therein is continuously circulated through manual ball valve 37 and circulating pump 38 through lines 39 and 30, past outlet lines 41, and back to the storage vessel 32'via pressure reduction valve 42 and valve 43 and line 40.

Each outlet line 41 carries a portion of the circulating dispersion to the washwheel of a washing machine 44 when automatic valve 45 is opened by demand of the washing machines individual cycle. Ball valves 46 are positioned in outlet lines 41 and may be manually adjusted to vary the size of the orifices in the outlet lines.

Pressure control valve 42 dilates and constricts automatically to compensate for the varying amounts of dispersion drawoff in outlet lines 41 and to maintain a constant pressure in that portion of the circulating line 40 which runs between pump 38 and valve 42. Pressure gauge 49 is mounted in circulating line 40 for purposes of visually reading the pressure in the line and ascertaining whether it is being maintained at the desired level, e.g., about 20 p.s.i.g.

To prevent crystallization of the dispersion in the various lines, pumps, valves and tanks of this invention when it is shut ofi after working hours, the following procedure is used:

1. Manual valve 11 is shut off before the last draw is made to washwheels 4,4. This interrupts the automatic cycle and prevents a new batch of mix from being started. When the washwheels call for solution the level of the storage tank 32is drawn down so that it is partially empty.

2. After washwheels 44 have completed their final draw of detergent solution from storage tank 32, valve 37 is closed and valve 51 is opened. This puts heated water into pump 38 from line 50 and forces the detergent solution out of line 40 and replaces it with heated water. The detergent solution is forced into storage tank 32 by this'water.

3. After an interval of time, depending on the capacity of pump 38 and the size and length of line 40, virtually all of the detergent solution will be replaced by heated water at which time valve 53 is opened and valve 43 is closed, thereby diverting the flow of this heated flush water through valve 53, line 52 and line 14 into mixture tank 15. The mixture tank 15 is allowed to fill in this manner until about three-quarters of the water necessary for a new batch is in it. At this time, valve 51 is closed to prevent it from filling further and the controller is shut off which shuts off all pumps and mixers.

4. Valve 53 and valve 58 are closed and valve 55 is opened. A flush switch is activated on controller 48 which opens automatic valve 27 and starts pump 28. This pumps the diluted solution in mixture tank 15 through valve 59, pump 28, valve 27, line 30, valve 55, line 54, line 52 and line 14 back into mixture tank 15. This dilutes the concentrated dispersion that was trapped in valve 59, line 29, pump 28, line 30 and valve 27 and makes it about equivalent to the concentration of the diluted dispersion in the tank 15. Each draw off line 41 is now drained by opening each of the valves 45 for a short time to allow any concentrated dispersion that is trapped above the valves to drain to the washwheels. Water or diluted dispersion is in all the vessels, pumps, pipes and valves with the exception of the storage tank which is now isolated from the rest of the system by closed valves 31 and 37. The concentrated dispersion in the storage tank is maintained above the crystallization temperature of the dispersion by a thermostatically controlled heater 56 which is now activated at the control panel. The remainder of the system can now be allowed to cool down without danger of harming or plugging lines, pumps, valves, etc.

The start up of the system is as follows:

1. Operator checks all manually operated valves. Valves ll, 59, 31, 37 and 43 should be open. Valves 17, 55, 53 and 51 should be closed.

2. Operator opens steam valve 17 and allows steam to enter mixture tank 15 through lines 13 and 14 until temperature of the dilute dispersion is above 150 F. When this temperature is reached, steam valve 17 is shut off and activates the start button on the controller. This button shuts off heater 56 and opens 150F. water valve 12 to start a new batch and the system is ready to operate.

Detergents for use in the detergent metering system herein described generally contain surface active agents, such as soaps, alkaryl sulfonates, nonionics and the like, together with builders such as sodium metasilicate, sodium tripolyphosphate, or tetrasodium pyrophosphate. Brighteners, anti-redeposition agents, and foam stabilizing agents may also be included.

A typical formulation that is widely used in the laundry industry and which can be dispensed using the system of the present invention, and for which no other practical centralized automatic distributing system is known, is as follows:

Amount,

weight Component: percent Sodium metasilicate 73 Tetrasodium pyrophosphate 10 Sodium carbonate 12 Tergitol l-S9* 5 A surface active agent produced by condensation of a secondary alcohol with ethylene oxide.

1 claim: 1. A system for automatically dispersing a granular detergent material in a diluent liquid, for storing of the resulting dispersion, and for conveying the dispersion to stations of use such as washwheels of washing machines, comprising:

a. a mixin tank having a stirrin device therein;

b. means or supplying a flow o diluent liquid into the mixing tank;

c. means responsive to the level of the liquid in the mixing tank for discontinuing the flow of diluent liquid thereinto when said level reaches a predetermined height;

. a supply hopper for granular material;

e. means for supplying a flow of granular material from the supply hopper into the mixing tank;

means for automatically actuating said granular material supplying means upon discontinuance of the flow of diluent liquid into the mixing tank;

g. means responsive to the weight of the contents in the mixing tank for automatically discontinuing the flow of granular material thereinto when said weight reaches a predetermined amount; 7

h. means for automatically actuating the stirring device during the flow of granular material into the mixing tank and for a predetermined period of time thereafter;

. mixing tank discharge means for transferring the dispersion from said mixing tank to a storage vessel;

j. means for preventing the transfer of the dispersion from the mixing tank during the flow of diluent liquid or granular material into the mixing tank and during the predetermined stirring period after discontinuance of the flow of granular material;

k. means for automatically actuating said mixing tank discharge means at the end of said predetermined stirring period and allowing the transfer of the dispersion for the mixing tank to the storage vessel;

1. means for preventing the flow of diluent liquid and granular material into the mixing tank during actuation of said discharge means; and

m. dispensing means for transferring the dispersion from said storage vessel to one or more stations of use as required.

2. The system of claim 1 wherein said storage vessel has a stirring device therein.

3. The system of claim 2 wherein said storage vessel has means for circulating the dispersion contained therein.

4. The system of claim 3 wherein the storage vessel dispensing and circulating means comprise a tubular conduit for passage of the dispersion therethrough, said conduit connecting a discharge port in the storage vessel with a reentry port in the storage vessel and containing, intermediate said discharge port and said reentry port, one or more valve-actuated outlets operable to open on demand from the stations of use and receive a portion of the dispersion passing through said conduit.

5. The system of claim 4, wherein there is disposed in said conduit, intermediate said valve-actuated outlets and said reentry port, a pressure reduction valve operable for maintaining a constant pressure of the dispersion in said conduit between said discharge port and said pressure reduction valve.

6. The system of claim 5, wherein the storage vessel has fluid level control means for preventing the transfer of the dispersion from the mixing tank to the storage vessel when the dispersion in the storage vessel reaches a predetermined height.

7. The system of claim 6, wherein said fluid level control means is operable to prevent actuation of the mixing tank discharge means when the dispersion in the storage vessel reaches said predetermined height.

8. The system of claim 6, wherein said granular material supplying means includes a vibrating ramp operable to transfer a flow of granular material from said supply hopper to said mixing tank.

Claims

1. A system for automatically dispersing a granular detergent material in a diluent liquid, for storing of the resulting dispersion, and for conveying the dispersion to stations of use such as washwheels of washing machines, comprising: a. a mixing tank having a stirring device therein; b. means for supplying a flow of diluent liquid into the mixing tank; c. means responsive to the level of the liquid in the mixing tank for discontinuing the flow of diluent liquid thereinto when said level reaches a predetermined height; d. a supply hopper for granular material; e. means for supplying a flow of granular material from the supply hopper into the mixing tank; f. means for automatically actuating said granular material supplying means upon discontinuance of the flow of diluent liquid into the mixing tank; g. means responsive to the weight of the contents in the mixing tank for automatically discontinuing the flow of granular material thereinto when said weight reaches a predetermined amount; h. means for automatically actuating the stirring device during the flow of granular material into the mixing tank and for a predetermined period of time thereafter; i. mixing tank discharge means for transferring the dispersion from said mixing tank to a storage vessel; j. means for preventing the transfer of the dispersion from the mixing tank during the flow of diluent liquid or granular material into the mixing tank and during the predetermined stirring period after discontinuance of the flow of granular material; k. means for automatically actuating said mixing tank discharge means at the end of said predetermined stirring period and allowing the transfer of the dispersion for the mixing tank to the storage vessel; l. means for preventing the flow of diluent liquid and granular material into the mixing tank during actuation of said discharge means; and m. dispensing means for transferring the dispersion from said storage vessel to one or more stations of use as required.