US2576253A

US2576253A - Concentration control system

Info

Publication number: US2576253A
Application number: US653475A
Authority: US
Inventors: James K Farrell; Paul A Keene
Original assignee: Allied Chemical and Dye Corp
Current assignee: Honeywell International Inc
Priority date: 1946-03-11
Filing date: 1946-03-11
Publication date: 1951-11-27
Anticipated expiration: 1968-11-27

Description

Nov..27, 1951 J. K. FARRELL ETAL 2,576,253

CONCENTRATION CONTROL SYSTEM Filed March 11, 1946 2 SHEETS-SHEET 1 INVENTOR James firuzeZ/z Farrell Paa)! Ajfeene Nov. 27, 1951 J. K. FARRELL VET AL CONCENTRATION CONTROL SYSTEM 2 SHEETS-SHEET 2 Filed March 11, 1946 v INVENTOR James flxzneih Farm awl AJfeene BY Z ATTO NEY Patented Nov. 27, 1951 CONCENTRATION CONTROL SYSTEM James K. Farrell and Paul A. Keene, Syracuse,

N. Y., assignors to Allied Chemical & Dye Corporation, a corporation of New York Application March 11, 1946, Serial No. 653,475

Claims. (Cl. 137-78) This invention relates to a detergent dispenser,

and more particularly to a detergent dispenser for washing machines such as dish or can washing machines.

One type of dispenser heretofore used for can and dish washing machines has required the compressing of the detergents into hard pellets or tablets which were placed in the dispenser, and water then dripped slowly thereover, the rate of Water feed being adjusted to supply the normal demand for the detergent. Other types involved the formation of solutions of the detergent and the addition of such solution to the washliquid by operation of a valve actuated by movement of the cans or trays of dishes, ,or the addition of such solution by allowing it to flow by gravity from a tank to the body of wash liquid. Still another type of dispenser involved the disposition of the solid detergent in a perforated container over which a stream of water continually flows, the drip from this container flowing into the body of wash solution. These dispensers have generally been unsuccessful for a number of reasons, among which may be mentioned:

(1) The rate at which detergent is consumed in the operation of the washing machines varies, widely in some cases, during the course of normal operation; hence, all dispensers which operate on a fixed rate of addition are unsatisfactory because they result in the concentration of the detergent in the wash solution varying widely.

For best results the concentration of detergent in the wash solution should be maintained within fairly narrow limits; concentrations below the predetermined limit produce ineflicient washing, and concentrations above this limit result in unnecessarily large losses of detergents;

, (2) When solutions are added from a tank,

the rate of addition constantly changes due'to struction and hence relatively inexpensive; in-

volves few moving parts so that the maintenance cost is small; can readily be installed upon any can or dish washer by an ordinary mechanic,

without special tools, in a very short time; is so designed that plugging of the discharge conduit or pipe lines by crystallization of detergent cannot take place in operation; and is unusually efficient, particularly in that it maintains the concentration of the body of wash solution in the washer within fairly narrow limits. Other objects and advantages of this invention will be apparent from the following detailed description thereof.

In the preferred embodiment illustrated on the drawings, the invention is shown incorporated in a dish washing machine and the present description will be confined to the present illustrated embodiment of the invention. It will be understood, however, that the novel features and improvements are susceptible to other applications such, for example, as can washing machines or other machines in which it is desired to maintain within narrow limits the concentration p f a solution which tends to foam in use. Hence,

the scope of this invention is not confined to th

sprays

24, 25. 5

embodiment herein described.

In the accompanying drawings,

Fig. l is a diagrammatic vertical section, partly in elevation, illustrating a conventional type of dish washing machine with which the dispenser of this invention may be used, the dispenser being shown diagrammatically, and one possible location of the dispenser relative to the washer being depicted;

Fig. 2 is a wiring diagram showing a bridgetype of electrical control which may be used to control the operation of the dispenser embodying this invention; v r V Fig. 3 is a plan view partly broken away to show the interior structure of a dispenser embodying this invention; and v I Fig. 4 is a vertical section partly in elevation, which section is broken away to enable showing the parts on a somewhat larger scale than would otherwise be possible, of a dispenser embodying this invention. 1 w

Referring to Fig. 1, the dish washing machine comprises a housing ID in which racks of dishes H are placed on perforated supports [2. 'Top and bottom wash sprays l3, I4 are arranged to be supplied with wash solution under pressure through branch pipes l5, 16 from a motor driven pump H, the suction intake l8 of which is in communication with a bodyof' detergent solution 19 disposed in a tank 20 positioned near the bottom of the washing machine. Hot rinse water is supplied from a pipe 2| having

branches

22, 23 extending to the top and'bottom rinse It will be understood that the washer shown in thendrawing represents one desired concentration. The presence of foam between plates 63, 64 in effect short circuits the control electrode 6|, i. e. materially decreases the resistance in the arm 58'of the'Wheatstone bridge. As shown in Fig. 1, electrode 62 is located at a point above the normal level of body of solution l9 where the foam will reach it quickly. Consequently, in operation the dispensing of detergent solution willbe stopped when foam reaches the electrode 62, which will take place before enough detergent is added to cause the solution to overflow the machine. As soon as the foam dies down due, for example, to the presence of soil in the wash water, the'electrode 62 is left free and clear, becoming an infinite resistance, and consequently exerting no further effect on the control electrode 6|. 7

Secondary coils

65, 68 of transformer 53 are connected by conductors with points 66, 6'! of the Wheatstone bridge. Secondary coil 68 supplies current to the filaments 69, 10 of electronic tubes H, 12. Tube H desirably is of a conventional triode or pliotron, and tube 12 desirably is of'a type to produce a higher emission of electrons, such as the well known Thyratron. Tube H, as conventional, comprises a cathode 12, a grid 13 and an anode 14. The tube 12 comprises a cathode 15, a grid 16, a screen electrode 11 and an anode 18. a

Secondary coil 19 of the transformer 53 in circuit with points 86, 8| of the Wheatstone bridge. Located in this circuit is the grid circuit of the tube H as shown in Fig. 2. The output anode circuit of the tube H includes a resistance 14 across which the input circuit of the tube 12 is shunted. In the output anode circuit of tube 12 is disposed relay 82 for operating switch 54 in the main circuit 5|. Resistance 14' is such that when the current flowing through the output anode circuit of tube 1| reaches a certain value, the potential drop across the resistance 14' causes the tube 12 to pass sufficient current through its anode circuit to operate the relay 82, to close switch 54.

The control circuit hereinabove described, except for the electrodes 6|, 62 and the lead wires connected thereto, and the parts of the main circuit except for the solenoid 48 and signal lamp 55, are all preferably disposed in a control box 83 which may be positioned on support 28 next to dispenser 21. The control is, therefore, readily applicable to existing washers not equipped with controls, particularly in cases where it is desired to supply such washers with dispensers of the type herein described. When modifying a washer to embody this invention, it is only necessary to install the dispenser and control box on the side of the washer, connect the discharge of the dispenser with the washer, and place the electrodes 6|, 64 within the washer in the relative positions shown.

In operation, resistance 51 is set at a point previously determined by calibration, which point is dependent upon the desired concentration of the detergent used. Resistance 56 is likewise set at a point previously determined by calibration, which point is dependent upon the temperature of the body of wash solution I9. Since the grid 13 and plate 14 of tube H are approximately 180 out of phase, an increase in the resistance of the solution, due to a decrease in concentration, causes a gradual increase in the instantaneous voltages between the grid 13 and cath ode 12 which in turn causes a decrease in the curr n flo hrou h theresjst 1 3 'Ihecon- 6. trolvoltage developed across resistor 14, applied across the control grid 16 and cathode 15 of tube 12,- is suflicientzto prevent tube I2 from firing before the concentration of the solution starts to decrease. When the decrease in voltage drop across-resistor 14', resulting from the increase in resistance'across the electrode 6|, reaches a critical value, depending upon the tube employed, the'control grid 16 loses control and the tube 12 fires which causes current to flow through the relay 82 which effects closing of the switch 54 causing current to flow through the solenoid 48. The armature 48 of the solenoid 48 is thus raised against the action of spring 49, to move plug 43 from its seat 42.. Water in reservoir 40 along with that supplied thereto through line flows through opening42 and spout 44, to the distributor plate 31, and flows in contact with the I detergent, the resultant solution passing through passageway 35 into and through passageway 34, into the washer where it collects in tank 20. 7

As the concentration of the solution in tank 20 increases, the resistance across the electrode 6! decreases, and agradual decrease in the instantaneous voltages between the grid 13 and cathode I2 of tube ll occurs, which causes an increase in the current flowing through resistor 14'. The resultant increase in voltage appearing across the control grid 16 and cathode 15 of tube 12 finally reaches a point where the control grid 16 resumes control and extinguishes the tube, stopping the current flow through the relay 82, deenergizing it, and opening the switch 54, whereupon, under the influence of spring 49, valve stem 46 returns valve plug 43 to its seat 42. Water thereafter supplied through line 45 flows fromreservoir 46 through overflow pipe 4| into and through passage 35 and not to the body of detergent maintained in compartment 36 of the dispenser 21.

' If the controller has an auxiliary electrode as disclosed in said co-pending application of Paul A. Keene, which type of controller should 1 be used when using detergents which tend to foam,when the foam rises to a point such that it enters between the plates 63, 64 of the auxiliary electrode 62, the resistance in the arm 58 of the Wheatstone bridge is thereby reduced so that, as hereinabove described, valve plug 43 is seated in seat 42 and the water flows through channel 35 and not through the body of deter gent. Hence, as long as foam is present at a level such that it contacts the auxiliary electrode 62, no detergent is fed to the washer. When the foam dies down, the auxiliary electrode 62 is left free'and clear, exerting no further effect on the control electrode 6| and permitting this electrode to maintain the concentration of the detergent in the washer within the desired narrow limits.

It will be noted the dispenser of this invention uses solid detergent in compartment 36, as obtained from the package or barrel, thus avoiding the necessity of preparing solutions or special physical forms of detergents such as pellets or tablets required in the operation of some dispensers. It will be further noted the dispenser is simple in design and can easily be fabricated; hence, it is of relatively low cost. The only mechanical movements involved in the dispenser are the movement of the valve plug 43 from a position where the water is discharged so that it flows in contact with the solid detergent in compartment 36 to a position where the water OW d r t y and thrOll 91 31 1 3 5; h nc the maintenance: cost of: the dispenser; is: very smallt. Since the, supply of detergent is controlled by small changes the;concen=tration orthebody of: wash solution, the concentration. is maintained within narrowlimits, determined. to;v be most efiective for producinggeflicient-washing; This results ina substantial saving of. detergent since feeding thereof does not take place: unless there is av demand for the detergent, In. other words, if. the demand for the detergent falls: off, the controller operates to interrupt. detergent feed if, on the.- other hand the demand for the detergent increases, then the controller operates to increase the time interval during which detergent is fed: to the washer, to maintain the: desired concentration.

Due to the. howof water, preferably at. a. temperature of; about. 10.05 F. or higher through: the discharge conduit 34. when there is nodemand for. detergent, crystallization of detergent. within thedischarge. conduit is avoided since this water washes out any residual detergent solution the discharge conduit 34= leading to-thei washer, thus preventing this line from becoming plugged by crystallization,

In the operation of the. dispenser, ithas been found, the water fed to the distributor plate 31 seldompenetrates, the body of solid detergent therebelow to azdepth exceeding V2 to A; Accordingly, recrystallization of detergent within the body of. solid detergentv inthe: dispenser is limited'tothi depth of the body or solid. detergent, Since the recrystallized: detergentis inall cases more. diiiicultly soluble than the original solid detergent, it will. be appreciated it is highly advantageous to limit the formation of. recrystallizeddetergent. to such small depth;. if: the; recrystallized detergent were to extend all of the way to the base. of the: dispenser, this would materially reduce the efiiciency of the operation of the dispenser. Since certain changes may be madein the aboveconstructionand different embodiments of theinvention could be made. without departing from the scope thereof, it is intended that all matter contained in. the above description or shown-in the accompanying; drawing shall. be interpreted as illustrative and not in. a. limiting sense.

What is claimed is: r r

1. In; a washer, receiving means for. a" body, of detergent solution, a dispenser for supplying; detergent solution to said receiving meansv to maintainthe concentration: of the bodyof detergent solution. therein within narrow limits; said; dispenser. comprising in.cmbination, a container for solid detergent, a passageway communicating with said receiving means; a. sidewall: 01 said container having a portion. thereof provided: with ascreen. to place said container in. communication with said passageway, awater. reservoir'having an overflow pipe; leading; into. said. passage;- wayand a valve controlled v outlet. in: communication with said container; a; water. pipehaving its discharge outlet: disposed: to supply water to said water reservoir, means for: operating; said valve to cause water supplied to said; reservoir to flow therefrom through.- said: container in contact with the. solid; detergent, the: resultant. solution flowingthrough. said screen: into, saidpassagewayand thence into saidlreceivingsmeams means for closing said valve so that the waterfflows from said reservoir through said overflow pipe directly 'tosaid passagewayand flows-therethrough into said receiving means and a controller responsive to changes in the concentration of. saidbody of solutionto effect the operation of: said valve. to cause the water tofiow in con,- tact with saidgsolid, detergent and. the resultant solution to flow into said receiving means when the concentration of said-body of solution. falls below a. predetermined value, and to cause said water to flow through said overflow pipe, into and through said passageway; and thence into said receiving means when the. concentration. of said body of solution.- isrestored to said predetermined value:

2. A dispenser for detergenttomaintain the concentration of a. body of detergent solution within: narrow limits; comprising, in combination, receiving means. for saidbody of detergent. solution, a container for soliddetergent, a passage.- way communicating with said. receiving, means, aside wall ofsaid container. having a portion thereof provided with a. screen to place said container in communication with said passage.- way, meansfor supplying water to said container whereby the water dissolves a portion of said solid detergent and the resultant solution flows through said screen; into said passageway and thence: into: said receiving means for said body of detergent solution, means for diverting said water supply so. that the water is fed directly to said passageway and flows therethrough into said receiving means, the ratev of supply of water to said. passageway being; such that the volume of water passed directly into said passageway and thence into said receiving means has no appreciable efiect. on the concentration of said body or" detergent solution in. said receiving means, and a controller responsive to-changes in the concentration of said, bodyofv detergent solution to affect. the operation of said water supply to cause water to flow in. contact with said. solid detergent when: theconcentration of said body of detergent solution falls. below a predetermined value and-zto cause the water to flow directly toand. through said passageway into said. receiving means for said body of' detergent solution when the, concentration of-:'said body of detergent solution" is; restored tosaid predetermined value.

3. A dispenser for detergent to, maintain the concentration of abody of detergent solution within. narrow limits, comprising, in combination, receiving means .for saidbody of detergent solution-,a container having a compartment for solid detergent, a passageway contiguous to: said compartment. and. separated from said compartment bya perforated wall thereby placing said compartment inscommunication with: said passageway through said perforations, a discharge conduit leading. from. said passageway to said receiving means for said body: of. detergent solution, means for'supplying a stream ofv liquid" to the body of solid detergent in said compartment, the liquid flowing in contact: with. saidsolid detergent; and. the resultant solution flowing into andthrough saidpassageway and said discharge conduit: an'dthence. intosaid receiving means for said.- body of; detergentsolution, means for, diverting. the; flow or said stream. of liquid to cause said liquid tofiow through saidxpassageway With.- out. flowing in contact with said. solid detergent insaid compartment, the liquid flowing from said passagewaythrough said discharge conduit into said receiving means for said body of detergent solution and thus flushing out and removing from said passageway and said discharge conduit any solid --'detergent deposited therein, and acon- 9 troller responsive to changes in the concentration of said body of detergent solution to affect the operation of said liquid supply to cause the liquid to flow in contact with said solid detergent when the concentration of said body of detergent solution falls below a predetermined Value and to cause the liquid to flow directly to and through said passageway and discharge conduit into said receiving means for said body of detergent solution when the concentration of said body of detergent solution is restored to said predetermined value.

4. A dispenser for detergent, comprising, in combination, a cylindrical container, an arcuate perforated wall disposed in said container to separate the container into a compartment and a contiguous passageway, said compartment occupying a major portion of the volume of said container and adapted to receive solid detergent, receiving means for a body of detergent solution, a discharge conduit leading from said passageway to said receiving means, means positioned above said passageway for supplying water to the top surface of the body of solid detergent, said water flowing in contact with said solid detergent and the resultant solution flowing into and through said passageway and discharge conduit into said receiving means for said body of detergent solution, means for diverting the water flow to cause it to flow through said passageway and said discharge conduit into said receiving means without flowing in contact with the solid detergent in said compartment, whereby said water flushes out and removes from said passage- Way and said discharge conduit any solid detergent deposited therein, and a controller responsive to changes in the concentration of said body of detergent solution to aifect operation of said water supply to cause the water to flow in contact with said solid detergent when the concentration of said body of detergent solution falls below a predetermined value and to cause the water to flow directly to and through said passageway and said discharge conduit into said receiving means for said body of detergent solution when the concentration of said body of detergent solution is restored to said predetermined value.

5. A dispenser for detergent to maintain the concentration of a body of detergent solution wthin narrow limits, comprising, in combination, receiving means for said body of detergent solution, means for supplying water to said dispenser, a container for solid detergent, a passageway communicating with said receiving means, a side wall of said container having a portion thereof 16 provided with a screen to place said container in communication with said passageway, water conduitmeans for passage of water from said water supply means directly to said passageway and to said container for solid detergent, said water conduit means which supplies water directly to said passageway supplying said water in amount such that the volume of water delivered to said receiving means has no appreciable effect on the concentration of said body of detergent solution in said receiving means, means for controlling passage of water through said water conduit means, whereby water supplied to said container for detergent dissolves a portion of said solid detergent and the resultant solution flows through said screen into said passageway and thence into said receiving means for said body of detergent solution and water supplied from said water supply means directly to said passageway flows therethrough and into -said receiving means, and a controller responsive to changes in the concentration of said body of detergent solution and effecting the operation of said means for controlling the passage of water through that portion of said water conduit means supplying water to said container for detergent to cause water to flow in contact with said detergent when the concentration of said body of detergent solution falls below a pre determined value and to discontinue this flow of water in contact with the solid detergent so the water from said water supply flows directly to and through said passageway and into said receiving means for said body of detergent solution when the concentration of said body of detergent solution is restored to said predetermined value.

JAMES K. FARRELL.

PAUL A. KEENE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,799,051 Le Baron Mar. 31, 1931 1,928,128 Guth Sept. 26, 1933 1,945,351 Grafton Jan. 30, 1934 1,951,426 Littler Mar. 20, 1934 1,991,388 Healy Feb. 19, 1935 1,995,318 Merrill Mar. 26, 1935 2,278,769 Chayie Apr. 7, 1942 2,370,609 Wilson et al Feb. 27, 1945 2,377,363 Noble June 5, 1945 2,392,026 Cram Jan. 1, 1946