Fluid handling – With cleaner – lubrication added to fluid or liquid sealing... – Cleaning or steam sterilizing
Reexamination Certificate
1998-01-30
2002-01-08
Walton, George L. (Department: 3753)
Fluid handling
With cleaner, lubrication added to fluid or liquid sealing...
Cleaning or steam sterilizing
C134S103100, C134S104100, C134S16900A, C134S171000, C068S01700R, C068S207000, C137S240000, C137S266000, C137S565010, C137S015050, C222S144500, C222S148000
Reexamination Certificate
active
06336468
ABSTRACT:
BACKGROUND
1. Field of Invention
This invention relates generally to chemical dispensing systems and specifically to a method and system for flushing chemicals from a liquid chemical delivery system.
2. Description of Related Art
Liquid chemical delivery systems are used to automatically deliver a plurality of viscous chemicals to one or more destinations. Examples of a liquid chemical delivery system having a single manifold and a single distribution tube and the advantages thereof are described in commonly owned U.S. Pat. No. 5,014,211, incorporated herein by reference.
FIG. 1
shows a chemical delivery system
100
of the type disclosed in U.S. Pat. No. 5,014,211. When it is desired to deliver a chemical stored within the container
102
to, for instance, the washer
110
, the chemical pump
142
is operated in a forward direction so as to pump the chemical from the container
102
into the manifold
130
. The transport pump
132
pumps the chemical from the manifold
130
to the destination washer
110
via the feed tube
150
. In some embodiments, the transport pump
132
has a larger pumping capacity than the chemical pump
142
and therefore draws water into the manifold
130
from the break tank
116
while pumping the chemical from the manifold
130
to the feed tube
150
. In this manner, chemicals from the container
102
are diluted before being delivered to the washers
110
-
112
.
After one or more chemicals are successfully delivered to the washers
110
-
112
, it is desirable to flush the chemical pumps
142
-
146
with water to remove residual chemicals therein. Thus, after delivery of a chemical from the container
102
to the washer
110
, the corresponding chemical pump
142
is operated in a reverse direction to pull water from the manifold into the chemical pump
142
and thereby remove any chemical residual within the pump
142
. Minimizing the time that the pump
142
is exposed to chemicals sourced from the container
102
maximizes the useful life of both the chemical pump
142
and its associated pump tube.
In an industrial laundry system such as, for instance, system
100
of
FIG. 1
, it is desirable to use highly concentrated detergents in order to minimize storage and transportation costs. However, high concentration detergents such as, for instance, the commercially available detergent “CLAX Ultima,” are non-ionic surfactant chemicals that tend to thicken or “gel” when exposed to water. Thus, flushing the chemical delivery system
100
with water immediately after a non-ionic surfactant detergent is delivered using the system
100
may be problematic. Specifically, water is likely to flow into the chemical supply containers
102
-
106
, and therefore likely to come into contact with the detergent therein, while respective pumps
142
-
146
are operated in the reverse direction. The resultant gelling of a non-ionic surfactant detergent at or near the outlet of the containers
102
-
106
may not only compromise the proper concentration of the detergents therein but also lead to a blockage of that outlet and, thus, disrupt subsequent detergent flow from the supply containers
102
.
Prior “solutions” to problems resulting from this “gelling” of non-ionic detergents are not entirely satisfactory. Some solutions simply avoid the use of chemicals that gel upon contact with water. This approach, however, undesirably limits the range of chemicals that may be used with the delivery system
100
. Other solutions include using a non-flushed chemical injection system, or using steam injection systems, to flush the chemical pumps
142
-
146
. These approaches, however, are complicated and expensive.
SUMMARY
A supply tube isolation system is disclosed for use with a chemical delivery system having a manifold connected to one or more chemical pumps which, in turn, are connected to corresponding supply containers via supply tubes. Present embodiments include feedback tubes connected between the manifold and each of the supply tubes of the delivery system. A controllable valve means is provided at or near the junction of the feedback tube and the supply tube so as to effectively segment the supply tube into first and second portions, where the first supply tube portion is that which is connected between the valve means and the manifold, and the second tube portion is that which is connected between the valve means and the supply container.
While one or more chemicals are being delivered to predetermined destinations within the delivery system, the valve means is positioned so as to allow a forward pumping action of the chemical pumps to effect chemical flow from corresponding supply containers to the manifold via the supply tubes and chemical pumps, and thereafter to the predetermined destinations via a feed tube. After the chemical is successfully delivered, the valve means is positioned so as to allow a reverse pumping action of the chemical pumps to draw water from the manifold into the chemical pumps and then back to the manifold via the first portions of the supply tube and the feedback tube. The second portions of the supply tubes are closed and thereby isolate the chemicals stored in the supply containers from the water. In this manner, present embodiments allow the chemical pumps and supply tubes of a suitable chemical delivery system to be flushed with water without exposing chemicals stored within the supply containers to water and, therefore, without an undesirable gelling of non-ionic surfactant chemicals.
REFERENCES:
patent: 856948 (1907-06-01), Fetta
patent: 1149164 (1915-08-01), Richter
patent: 2029232 (1936-01-01), Green
patent: 2526286 (1950-10-01), Schwarzkopf et al.
patent: 2718481 (1955-09-01), Tuthill
patent: 2827070 (1958-03-01), Gatz
patent: 3154087 (1964-10-01), Beaver
patent: 3258792 (1966-07-01), Rickel
patent: 3572366 (1971-03-01), Wiggins
patent: 3674205 (1972-07-01), Kock
patent: 3982666 (1976-09-01), Kleimola et al.
patent: 4390049 (1983-06-01), Albertson
patent: 4845965 (1989-07-01), Copeland et al.
patent: 4932227 (1990-06-01), Hogrefe
patent: 5014211 (1991-05-01), Turner et al.
patent: 480 490 (1992-04-01), None
patent: 787 849 (1997-06-01), None
Diverseylever, Inc.
Pennie & Edmonds LLP
Walton George L.
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