LIQUID METERING AND INJECTION SYSTEM
A liquid metering system for a commercial or industrial laundry operation includes a dosing tank supported by a weight sensor that can measure the weight of cleaning solution transferred into the dosing tank. A valve assembly is operable to transfer the measured cleaning solution from the dosing tank to a transport tank, and a discharge pump is operable to pump the measured cleaning solution from the transport tank to downstream equipment. Measured quantities of different cleaning solutions can also be mixed in the transport tank before being delivered to downstream equipment. A control system regulates operation of the various pumps, valves, and manifolds, and monitors the readings from the weight sensor.
Latest Gurtler Industries Patents:
This claims priority to U.S. Provisional Patent Application No. 61/564,038, filed on Nov. 28, 2011, the content of which is herein fully incorporated by reference.
BACKGROUNDThe present invention relates to liquid metering, measuring, and dispensing, and particularly to metering and measuring liquid products for use in industrial or commercial laundry facilities.
Large capacity industrial and commercial laundry facilities utilize washing machines having capacities on the order of 100 lbs. or more of laundry. Depending upon the type of laundry, different types and amounts of detergent, chemicals, and cleaning solutions are used during different stages in the washing operation. Because the sizes of washers and the sizes of individual loads of laundry can vary throughout a commercial washing facility and from load to load, it is desirable to have an automated system for dispensing the correct amount of detergent and cleaning solutions for each system and each load.
Known systems for regulating the various chemicals and liquids used in commercial laundry facilities rely upon in-line flow meters to measure the flow rate of a given liquid through a given conduit. When the flow rate is known, the total amount of liquid dispensed by the system can be controlled by regulating the duration of the flow. Because different liquids have different viscosities and are carried by different conduits, it generally is required to have individual flow meters for each type of liquid that is to be supplied to the washing machine. As a result, each flow meter must be individually calibrated for the specific liquid being measured. Moreover, because flow meters are highly sensitive to pressure changes, cavitation, and other flow irregularities, the pumps used to initiate the flow of the liquids through the conduits must be of a type that provides a uniform and relatively consistent output flow. For example, peristaltic pumps have been successfully used in commercial laundry facilities.
SUMMARYDuring use in commercial laundry facilities, a flow meter may introduce errors as air enters the delivery tubes or if the supply pump connected to the flow meter generates a back pressure to the flow meter. Errors in the flow meter may result in under-delivering or over-delivering the chemicals and liquids. Under-delivering the chemicals and liquids may result in ineffective cleaning, while over-delivering may result in wasting the chemicals and liquids, and potentially damage the loads of laundry.
In an aspect the disclosure relates to a liquid metering system for a commercial or industrial laundry operation that can measure a weight of a cleaning solution that is being transferred. The system generally includes a dosing tank configured to receive the cleaning solution, a weight sensor configured to measure a weight of the cleaning solution received by the dosing tank, and a discharge pump operable to pump the measured cleaning solution from the transport tank to downstream equipment.
In another aspect the disclosure relates to a metering assembly for a commercial or industrial laundry operation that can measure a weight of a cleaning solution that is being transferred. The metering assembly generally includes a dosing tank configured to receive the cleaning solution, and a weight sensor configured to measure a weight of the cleaning solution received by the dosing tank.
Aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
It is to be understood that the invention is not limited in its application to the details of the construction and the arrangements of components set forth in the following description or illustrated in the drawings. The present invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTIONThe pumping cabinet 14 includes an upper shelf 26 and a middle shelf 30 each supporting a plurality (e.g., six as illustrated) of pumps 34 configured to pump cleaning solution. Each pump 34 is coupled to a supply tank (not shown) for a different cleaning solution and is operable to pump its respective cleaning solution to the metering assembly 22. The pumping cabinet 14 also includes a lower shelf 38 that supports three additional pumps, including a first water flush pump 42, a second water flush pump 46, and a discharge pump 50. In the illustrated construction, the pumps 34, 42, 46, and 50 are diaphragm pumps, chosen based at least in part upon their relatively low cost, long life, and good reliability. Those skilled in the art will readily appreciate that other types of pumps could also be used without departing from the spirit and scope of the present invention. A plurality of manifolds 54 are mounted below the middle shelf 30 and to the left of the discharge pump 50. The discharge pump 50 is coupled at its input to the metering assembly 22 for receiving metered amounts of cleaning solution(s) therefrom, and is coupled at its output to the manifolds 54 for controlling distribution of the metered cleaning solution(s) to the downstream commercial washing equipment.
Referring also to
The upper extension 68 also includes a central support member 80 extending substantially parallel to the side legs 72 from the cross beam 66 of the frame to the base leg 74. The central support member 80 is substantially centered between the side legs 72 and is coupled (e.g., by welding) to the undersides of the cross beam 66 and the base leg 74. The central support member 80 includes a pair of mounting holes 82 on an underside thereof (the mounting holes 82 are showing facing upwardly in
Referring also to
Referring also to
Although in the illustrated embodiment includes two sidewalls 96 each defining the upwardly opening slot 102, other embodiments may include a single sidewall 96 defining the upwardly opening slot 102. An open side (not shown) of the dosing cap 90 may then face toward the pumping cabinet 14 when the dosing cap 90 is coupled to the upper extension 68 and accommodate the various conduits extending between the pumps 34 and the nozzles that are received by the apertures 94 of the dosing cap 90. In the illustrated embodiment without the open side, one of the sidewalls 96 defining the upwardly opening slot 102 also defines a plurality of apertures 94 formed therein sized and arranged to accommodate the various conduits and nozzles.
Each sidewall 96 defines a pair of holes 106 along an upper edge thereof that are configured for alignment with the inwardly-facing side holes 78 in the upper extension. Fasteners (not shown) extend through the holes 106 and into the side holes 78 secure the dosing cap 90 to the upper extension 68. A dosing lid 107 covers the dosing cap 90. The dosing lid 107 fits over and is coupled to the top holes 88 provided in the side legs 84 of the upper extension 68.
Referring also to
A weight sensor bracket or load cell bracket 120 (
The load cell bracket 120 supports a dosing tank 130 that receives and contains the cleaning solutions dispensed from the nozzles that are coupled to the dosing cap 90. As shown in
With reference also to
Although in the illustrated embodiment the weight sensor 108 is a load cell coupled to the load cell bracket 120, in other embodiments other structures performing the same function as the load cell 108 disclosed herein can be used instead. For example, in some embodiments the weight of the cleaning solution received by the dosing tank 130 may be measured by a sensor pad supporting an underside of the dosing tank 130. In some embodiments, the weight sensor 108 may include any mechanical assembly configured to measure the weight of the cleaning solution received by the dosing tank 130. In other embodiments, the weight sensor 108 may include a piezoelectric compression sensor or any other electric sensors depending on the usage requirements or preferences for the liquid metering and injection system 10. Moreover, although the illustrated embodiment includes a single weight sensor 108, other embodiments may include a plurality of weight sensors 108, for example so as to reliably and accurately measure the weight of the cleaning solution.
As shown in
Referring also to
In the above-described metering assembly 22, the load cell 108 supports the load cell bracket 120, the dosing tank 130, and the valve assembly 148. The dosing cap 90 and dosing lid 107 are supported by the upper extension 68, and the transport tank 154 and transport lid 156 are supported by the lower extension 70. Thus, as cleaning solution is dispensed into the dosing tank 130, the weight supported by the load cell 108 increases in proportion to the volume of solution that is dispensed, allowing for an accurate measurement of cleaning solution volume for subsequent discharge to downstream equipment.
In use, the control system housed in the control cabinet 18 responds to operator or automated requests for dispensing a specific cleaning solution by operating the metering assembly 22 to measure the appropriate quantity of the specific cleaning solution. To measure a specific quantity of a given cleaning solution, the diaphragm valve 150 is closed and the pump 34 associated with the cleaning solution is turned on. Turning on the pump 34 pumps cleaning solution through conduits in the pumping cabinet 14 to the corresponding discharge nozzle (not shown) that is coupled to the floor 92 of the dosing cap 90. The cleaning solution is then discharged into the dosing tank 130. Because the diaphragm valve 150 is closed, the cleaning solution begins to accumulate in the dosing tank 130, and the load on the load cell 108 begins to increase.
The densities of the various cleaning solutions pumped by the system 10 are pre-programmed into the control system. As such, the control system is able to monitor the weight of the cleaning solution via the load readings provided by the load cell 108, and can then convert the weight of the cleaning solution into a volume of cleaning solution that has been dispensed. In some applications, overall cycle time of the system 10 can be reduced by constantly monitoring the load on the load cell 108 and adjusting the speed of the pump 34 on the fly. For example, at the beginning of a discharge cycle the pump 34 can be operated at maximum speed to rapidly fill the dosing tank 130. However, as the desired quantity of cleaning solution is approached, the speed of the pump 34 can be reduced to allow the final amount of cleaning solution dispensed to be controlled more precisely.
Once the desired amount of cleaning solution has been transferred to the dosing tank 130, the pump 34 is turned off and the diaphragm valve 150 is opened. The cleaning solution then flows by gravity through the discharge tube 152 and into the transport tank 154. As the cleaning solution is flowing into the transport tank 154, the control system can continue to monitor the load on the load cell 108 and thus be able to detect when the dosing tank 130 is completely empty. When the dosing tank 130 is empty, the diaphragm valve 150 is closed and another metered dose of cleaning solution can be prepared, potentially before the previously-metered dose of cleaning solution has been pumped from the transport tank 154 by the discharge pump 50. For certain operating parameters, it may also be desirable to mix metered amounts of different cleaning solutions in the transport tank 154 before the transport tank 154 is emptied by the discharge pump 50. Once the final desired amount of cleaning solution or solutions have been transferred to the transport tank 154, the discharge pump 50 is operated and the manifolds 54 are controlled to supply the metered and optionally pre-mixed cleaning solution(s) to the appropriate downstream equipment.
The system 10 is advantageously configured to dispense a plurality of different cleaning solutions (e.g., twelve in the illustrated embodiment). In some circumstances, these different cleaning solutions may be dangerously reactive with one another. To reduce potential risks associated with the mixing of incompatible cleaning solutions, the first and second water flush pumps 42, 46 can be used to rinse the dosing tank 130 and the transport tank 154, respectively. The first water flush pump 42 is connected via conduits to the dosing cap 90 and is operable to pump rinse water into the dosing tank 130. The second water flush pump 46 is connected via conduits to the transport tank 154 or transport tank lid 156, and is operable to pump rinse water into the transport tank 154. In some embodiments, the control system can be pre-programmed to recognize potentially dangerous combinations of cleaning solutions and to rinse the dosing tank 130 and/or the transport tank 154 as needed between metering operations.
The system 10 may also include a self-calibration feature that utilizes a float assembly mounted to the dosing cap 90. The float assembly extends or can be adjusted to extend downwardly from the dosing cap 90 to sense a location of the free surface of any liquid contained within the dosing tank 130. Thus, the control system can fill the dosing tank 130 with a liquid of known density (e.g., water) to a predetermined calibration level having a known volume by sensing the level of the liquid with the float assembly. The control system can then compare the reading of the load cell 108 with the expected reading based upon the known volume and known density of the liquid that held in the dosing tank, and can adjust the calibration level of the load cell 108 as necessary. In other embodiments, the self-calibration feature may utilize an ultra sonic sensor or a sight glass instead of a float assembly. In still other embodiments, the system 10 may not include a self-calibration feature. For example, a known amount of liquid may be injected so as to eliminate the need for a self-calibration feature. The apparatus and articles of manufacture described herein are not limited in this regard.
In view of the foregoing, the system 10 is operable to meter and dispense a desired amount of cleaning solution by measuring the weight of the cleaning solution before dispensing the cleaning solution to downstream equipment. The system 10 includes a dosing tank 130 supported by a load cell 108. The system 10 is configured to minimize possible interference with readings of the load cell 108 by supporting at least the dosing cap 90 and the transport tank 154 by separate structure, such as the upper and lower extensions 68, 70. Because the system 10 includes two tanks, namely the dosing tank 130 and the transport tank 154, a first measured quantity of cleaning solution can be prepared in the dosing tank 130 and transferred to the transport tank 154. Then, before the first measured quantity of cleaning solution is transferred from the transport tank 154, a second measured quantity of cleaning solution can begin to be prepared in the now-empty dosing tank 130, thereby reducing overall cycle time of the system. The two tank arrangement also allow for the pre-mixing of multiple measured quantities of cleaning solutions in the transport tank 154. The system is also capable of performing self-calibration of the load cell 108 using a float assembly mounted to the dosing cap 90.
It is understood that the disclosure may embody other specific forms without departing from the spirit or central characteristics thereof. The disclosure of aspects and embodiments, therefore, are to be considered as illustrative and not restrictive. While specific embodiments have been illustrated and described, other modifications may be made without significantly departing from the spirit of the invention.
Claims
1. A liquid metering system for a commercial or industrial laundry operation, the system comprising:
- a dosing tank configured to receive a cleaning solution;
- a weight sensor configured to measure a weight of the cleaning solution received by the dosing tank; and
- a discharge pump operable to pump the measured cleaning solution from the dosing tank to downstream equipment.
2. The system of claim 1 further comprising a valve assembly operable to transfer the measured cleaning solution from the dosing tank to the transport tank.
3. The system of claim 1 further comprising a control system operatively connected to the weight sensor and discharge pump, wherein the control system monitors the weight of the cleaning solution and adjusts a speed of the discharge pump.
4. The system of claim 3, wherein the control system regulates the discharge pump at a first speed during a first mode of operation and at a second speed that is slower than the first speed during a second mode of operation.
5. The system of claim 3, wherein the control system is configured to be programmed with a density of the cleaning solution, and whereby the control system monitors a volume of the cleaning solution.
6. The system of claim 5 further comprising a float assembly coupled to the dosing tank, wherein the float assembly is configured to sense a level of the cleaning solution contained within the dosing tank for performing self-calibration of the control system.
7. The system of claim 1 further comprising a manifold configured to receive a plurality of measured cleaning solutions from respective discharge pumps, to mix the plurality of measured cleaning solutions, and to deliver the mixed cleaning solution to the downstream equipment.
8. The system of claim 1 further comprising a weight sensor bracket coupled to the dosing tank, and wherein the dosing tank is supported substantially exclusively by the weight sensor and the weight sensor bracket.
9. The system of claim 8, wherein the weight sensor includes a first end, a second end, and a sensing portion positioned therebetween, and wherein at least one of the first and second ends is coupled to the weight sensor bracket.
10. The system of claim 9, wherein the sensing portion includes a strain gauge.
11. The system of claim 1 further comprising a transport tank configured to receive the measured cleaning solution from the dosing tank.
12. The system of claim 11, wherein the dosing and transport tanks are supported by separate structures.
13. The system of claim 11 further comprising a flush pump connected to at least one of the dosing and transport tanks, wherein the flush pump is operable to rinse water into at least one of the dosing and transport tanks.
14. A metering assembly for a commercial or industrial laundry operation, the metering assembly comprising:
- a dosing tank configured to receive a cleaning solution; and
- a weight sensor configured to measure a weight of the cleaning solution received by the dosing tank.
15. The metering assembly of claim 14 further comprising a weight sensor bracket coupled to the dosing tank, wherein the dosing tank is supported substantially exclusively by the weight sensor and the weight sensor bracket.
16. The metering assembly of claim 15, wherein the weight sensor includes a first end, a second end, and a sensing portion positioned therebetween, and wherein at least one of the first and second ends is coupled to the weight sensor bracket.
17. The metering assembly of claim 16, wherein the sensing portion includes a strain gauge.
18. The metering assembly of claim 14 further comprising a transport tank configured to receive the measured cleaning solution from the dosing tank.
19. The metering assembly of claim 18, wherein the transport tank is configured to receive a plurality of measured cleaning solutions from the dosing tank, and to mix the plurality of measured cleaning solutions.
20. The metering assembly of claim 18, wherein the dosing and transport tanks are supported by separate structures.
Type: Application
Filed: Nov 28, 2012
Publication Date: May 30, 2013
Applicant: Gurtler Industries (South Holland, IL)
Inventor: Gurtler Industries (South Holland, IL)
Application Number: 13/687,812