US 3435834 A
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Description (OCR text may contain errors)
April 1, 1969 H. c. COOPER 3,435,834
ARRANGEMENTS FOR IN-PLACE CLEANING Filed March 17, 1967 United States Patent 3,435,834 ARRANGEMENTS FOR IN-PLAC'E CLEANING Harry Christopher Cooper, Crawley, England, asslgnor to The A.P.V. Company Limited, Crawley, England, a British company Filed Mar. 17, 1967, Ser. No. 623,964 Claims priority, application Great Britain, Apr. 25, 1966, 18,031/66 Int. Cl. B0811 3/04 US. Cl. 134-98 2 Claims ABSTRACT OF THE DISCLOSURE A distribution arrangement for an in-place cleaning system comprising main supply lines for cleaning liquids and rinsing water fed by pumps from storage tanks and a suitable water source, and return lines to the tanks, each individual cleaning circuit or part thereof being adapted to be connected between each main supply line and the corresponding return line or drain line by individually operable valves.
This invention relates to the in-place cleaning of plant and equipment, particularl as used in the potable liquid industry.
In the potable liquid industries, where in-place cleaning is employed, it is frequently necessary to clean several pieces of equipment at the same time. In this case it is common practice to provide a number of separate cleaning units, each storage detergent and sterilant (the cleaning solutions) and having a Water supply and a circulating pump. The provision of several units is, however, expensive, and as an alternative a single unit may be used in which the cleaning solution storage tanks are common to a number of circuits. In this case a separate circulating pump is used for each circuit and automatic valves are provided on each cleaning solution storage tank. For example, the circuits to be cleaned could include respectively a road tanker, a storage tank and a pipeline. They could also include other types of process plant, or alternatively all the circuits could include the same type of equipment. In man installations it is, for example, necessary to clean a number of road tankers or storage tanks at the same time.
The cleaning solutions are pumped through the circuits by the respective circulating pumps and the valves admit water, sterilant and detergent selectively to the circuit. In a typical cleaning cycle these valves would be opened and closed in sequence to perform the following programme:
Water rinse Detergent circulation Water rinse Sterilant circulation Water rinse In the lines connecting each piece of process plant back to the cleaning unit valves are used to direct the water rinse to drain and also to return the detergent and sterilant to the appropriate storage tanks for re-use.
In order to recover the maximum quantity of sterilant and detergent in such systems it is necessary to prevent intermixing in the circuits when one solution follows immediately after another. Where a solution is displaced by another, the programme must be arranged so that storage tanks are drained of the first solution before the second enters. Also the pipeline from the cleaning unit to the storage tank must be cleared of the first solution and the tank allowed to drain before the second enters. As an alternative to this method of operation all the lines may be drained of one solution before the next enters, and in this case use is frequently made of compressed air to blow the lines clear of liquid.
These operations are complicated by the normally considerable length of the lines between the cleaning unit and the plant being cleaned, as these lines then contain substantial quantities of solution which take a long time to displace.
A further disadvantage of this arrangement is that the line from the cleaning unit to each circuit carries all the solutions and where, as is usually the case, hot detergent is used, this leads to considerable heat loss as the line is heated and cooled by the successive fluids.
The invention consists in a distribution arrangement for an in-place cleaning system comprising storage tanks for cleaning liquids, a source of rinsing water, pumps for pumping cleaning liquids and water along separate main supply lines, return lines for returning the cleaning liquids to the respective storage tanks, and individual supply and return conduits for a plurality of cleaning circuits connectable by valves to the main supply lines and the return lines respectively.
This arrangement reduces the total length of the cleaning circuits, simplifies the programming and reduces cleaning times. Also each main supply and return line can be arranged specifically for the fluid it carries, for example the hot detergent line can be insulated to conserve heat and the water line may be made of wroughtiron or similar material to reduce cost.
The invention will be further described with reference to the accompanying drawing, which drawing is a flow diagram of a preferred form of the invention.
The drawing illustrates a common distribution arrangement for three cleaning circuits, shown as a road tanker 1, a storage tank 2 and a pipeline 3. Each cleaning circuit includes a supply line 4 and return line 5. Each supply line 4 is selectively connectable by remotely controlled valves 4a, 4b and 4c to a water line 6, a sterilant supply line 7 and a detergent suppl line 8. Each return conduit 5 is connectable selectively by remote controlled valves 5a, 5b, 50 to a drain connection, a sterilant return line 9 and a detergent return line 10.
Sterilant and detergent solutions are stored in tanks 11 and 12 and supplied by pumps 13 and 14 to the lines 7 and 8 respectively. Water from a main supply is pumped by pump 15 to line 6.
Lines 9 and 10 drain into tanks 11 and 12 respectively.
The detergent is normally used hot and the lines 7 and 10 may be insulated to conserve heat.
The valves 4a, 4b, 40, 5a, 5b, 5c are opened and closed in sequence to provide the cleaning programme described previously.
In this system none of the cleaning solution circulating pumps will operate unless a circuit is selected for cleaning. In large installations the pumps used for circulating cleaning solutions may have other pumps connected in series or parallel with them to boost the pressure or flow of solutions when a number of circuits are operating at the same time. Such booster pumps would be brought into operation by automatic control.
Recirculation may be provided "through relief or check valves (not shown) between the lines 7 and 8 and the lines 9 and 10 respectively.
Various modifications may be made within the scope of the invention. Thus, additional or alternative cleaning solutions may be used, such as acids.
1. A distribution arrangement for an in-place cleaning system comprising a plurality of circuits, the arrangement comprising storage tanks for cleaning solutions a source of rinsing water, and pumping means for supplying the cleaning solutions and water to the circuits according to a desired programme, the arrangement having the improvements of comprising separate main supply lines for each of the cleaning solutions and the water, individual pumps feeding the respective main supply lines from the storage tanks, return lines for returning the cleaning solutions to the respective storage tanks, a drain connection, individual supply conduits and individual return conduits for each of the plurality of circuits, and valves adapted to connect each of the main supply lines to each of the individual supply conduits and each of the return conduits to each of the return lines and to the drain connection.
2. A distribution arrangement as claimed in claim 1,
4 wherein at least one of the mainsupply lines and the corresponding return line are thermally insulated.
References Cited UNITED STATES PATENTS 2,558,628 6/1951 Redin 134-95 2,718,481 9/1955 Tuthill 13495 XR 3,046,163 7/1962 Kearney et al. 134-99 XR 10 ROBERT L. BLEUTGE, Primary Examiner.
US. Cl. X.R.