Chemical apparatus and process disinfecting – deodorizing – preser – Physical type apparatus – Means separating or dissolving a material constituent
Reexamination Certificate
1998-10-29
2002-07-23
Warden, Sr., Robert J. (Department: 1744)
Chemical apparatus and process disinfecting, deodorizing, preser
Physical type apparatus
Means separating or dissolving a material constituent
C134S093000, C134S099200, C137S268000, C422S110000, C422S114000, C422S115000, C422S261000, C422S263000, C422S275000
Reexamination Certificate
active
06423280
ABSTRACT:
FIELD OF THE INVENTION
The invention relates generally to the dissolution and dilution of concentrated solid materials and more specifically to the controlled dissolution and dilution of concentrated solid warewashing detergents to form concentrated liquid solutions. Detergent concentration control is provided exclusively via hydraulic means with no electronic detection of water usage or level, electronic control of detergent content or usage or electronic control of mechanical components.
BACKGROUND OF THE INVENTION
A number of different techniques have been developed and used for converting solid chemicals used in cleaning processes into a aqueous concentrated solution. For example, devices designed for a powdered, flaked or granular detergent are disclosed in Daley et al, U.S. Pat. No. 3,595,438, issued Jul. 27, 1991; Moffet et al, U.S. Pat. No. 4,020,865, issued May 3, 1977; and Larson et al, U.S. Pat. No. 4,063,663, issued Dec. 20, 1977. Another form of solid detergent is the pre-shaped detergent briquette. Dispensing systems for dissolving detergent briquettes are known in the art. See, for example, U.S. Pat. Nos. 2,382,163; 2,382,164; and 2,382,165 all issued Aug. 14, 1945 to MacMahon; and U.S. Pat. No. 2,412,819, issued Dec. 17, 1946 to MacMahon.
One recent form of solid detergent is the solid block form. The detergent block may comprise a detergent extruded or cast within a mold or container or as a detergent block which is free-standing. Dispensing systems for these solids are known in the art. See, for example, U.S. Pat. No. 4,426,362, issued to Copeland et al and commonly owned U.S. Pat. Nos. 4,569,781 and 4,569,780, issued Feb. 11, 1986, to Fernholz et al. The cast detergent is dispensed by spraying a solvent onto the detergent block within the container, thereby dissolving the exposed surface of the detergent to form a concentrated working solution. The concentrated working solution falls into a reservoir or is directed by a conduit to the wash tank of a washing apparatus. When the chemical compound within the container is completely utilized, the exhausted container may be simply discarded and a fully charged container may be placed in the dispenser.
Solid, cast chemicals used in cleaning processes are preferably cast in a sturdy container which can act as a mold, a shipping and storage container, and a dispenser housing. The cast chemical may be dispensed by inverting the container over a spray nozzle and impinging solvent directly onto the exposed surface or surfaces of the chemical contained therein. The container may either be retained within the dispenser as the chemical is being used, or the chemical may be removed from the container and placed into the dispenser. However, hazardous chemicals used in cleaning processes such as highly alkaline detergents are preferably packaged such that they can be dispensed without coming into physical contact with the human body.
Known dispensing devices have sought to maintain a relatively constant rate of the chemical being dispensed, or a constant concentration, by maintaining a fixed distance between the dissolving spray nozzle and the exposed and erodible surface of the solid block of chemical. See, for example, commonly owned U.S. Pat. No. 4,687,121, issued to Copeland on Aug. 18, 1987; U.S. Pat. No. 4,690,305, issued to Copeland on Sep. 1, 1987, and U.S. Pat. No. 4,826,661, issued to Copeland et al May 2, 1988. Alternatively, a separate control system has regulated the amount of detergent dispensed and has maintained a constant concentration, thereby making it unnecessary to control the nozzle to-eroding surface distance.
In many situations, however, it is desirable for the chemical concentration to be variable. The optimum chemical concentration depends upon such factors as the type of solid chemical being dispensed, the type of surface being cleaned, the amount of soil being removed from the fabric or surface being cleaned, the temperature of the solvent, the degree of mechanical action applied to the fabric or surface being cleaned, and the volume of cleaning solution being produced. In the past, adjusting the concentration of the cleaning solution has typically been done manually by the operator. That is, a certain amount of cleaning solution has been dispensed from the solid chemical, to which a certain amount of water is added. If a higher use solution concentration is desired, then less water is added to the concentrated cleaning solution. However, this procedure does not result in a consistent, precise, and controlled solution concentration, and often results in the use solution having either too much or too little cleaning chemical concentration.
U.S. Pat. No. 2,371,720 to Stine discloses an admixing and dispensing device applied to dishwashing machines. One of the objects of the invention is to “provide a method and device in which the rate of admixture is governed and controlled automatically by the flow of liquid”. An upwardly disposed spray nozzle
10
projects a spray of water against a conical screen
8
. The conical screen
8
supports a mass of caked or powdered chemical detergent. The water to the nozzle is provided by a pipe
20
which is the main rinse water supply. Water is directed to spray nozzle
10
through valve
15
and pipe
11
. Valve
15
is of a design such that it also transmits a flow, proportional to the flow, through to a rinse line.
U.S. Pat. No. 2,308,612 to Lehmkuhl discloses a dissolving apparatus in which water from a spray head
61
falls upon powdered detergent. The detergent is held in an inner container
31
which has a foraminous partition
41
in its center. The concentration of the dissolved powder in the liquid is adjusted by moving the nozzle closer to or further from the detergent powder. Adjusting the height of the nozzle changes the relative proportions of the water sprayed into the inner container holding the detergent and water sprayed into the space between the side walls of the inner and outer containers.
U.S. Pat. No. 3,727,889 to Nagel discloses a fluid conduit
38
provided with a nozzle which projects a jet of liquid against a dry chemical. An automatically controlled valve
44
dispenses a predetermined amount of liquid against the chemical. The disclosure describes the control means
46
by a block diagram labeled “control” and states that “suitable automatic control means [are] well known in the art”. The specification discloses a selector dial to select the amount of dilution water for a given cycle.
U.S. Pat. No. 4,964,185 to Lehn discloses a pressure regulating valve
35
which maintains a constant flow rate of solvent to spray nozzle
31
. The spray nozzle sprays the solvent onto solid or granular chemicals retainably held above the nozzle. The device forms a concentrated chemical solution and controls the amount of chemical dispensed.
U.S. Pat. No. 5,505,915 to Copeland et al. discloses a solid chemical dispenser in which distance between the nozzle and the detergent can be varied. The position of the nozzle can be varied by a mechanical linkage or an automatic means such as a servo system.
U.S. Pat. No. 3,982,666 to Kleimola ct al. discloses a means to sequentially and automatically inject various liquid products into a laundry washing machine. The invention utilizes a signal generating device for generating electrical signals of a predetermined duration.
U.S. Pat. No. Reissue 32,818 to Fernholz et al. discloses a method of using a cast detergent-containing article. The patent describes positioning the solid detergent over “spray means which is connected to a water source”.
There remains a need for a simple, accurate method of dissolving and diluting a concentrated solid warewashing detergent using solely hydraulic control without complicated electronic control of water, chemical or mixing.
BRIEF SUMMARY OF THE INVENTION
Accordingly, the invention involves a hydraulic method for dispensing and controlling detergent and rinse aid use and active concentration in a warewashing machine. Accurate dispensing and control of active detergent c
Davidson Glen W.
Lentsch Steven E.
Tarara James J.
Ecolab Inc.
Merchant & Gould P.C.
Soubra Imad
Warden, Sr. Robert J.
LandOfFree
Hydraulic control of detergent concentration in an automatic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulic control of detergent concentration in an automatic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulic control of detergent concentration in an automatic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2908906