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1. Field of the Invention
The present invention relates to washer extractors, more particularly to an improved washer extractor that uses overflow rinsing to eliminate most or all of the fill and drain steps typically associated with prior art washer extractors. Even more particularly, the present invention relates to an improved washer extractor wherein the liquor ratio (pounds or kilograms water or liquor to pounds or kilograms of fabric articles) can be varied to suit different levels of soiled linen or other fabric articles.
2. General Background of the Invention
Prior art washer extractor machines wash and rinse fabric articles such as linen with successive fill and drain steps. A typical wash formula comprises between 6 and 20 steps, depending on linen soil classification.
Because each step drains the wash/rinse liquor, water consumption is generally between two (2) and four (4) gallons (16 and 33 liters) per pound (kg) ofprocessed linen. In prior art washer extractors, all of the liquid is drained to sewer or to recycling/filtering systems.
The design of the present invention provides an improved washer extractor. The present invention uses high velocity overflow rinsing to eliminate many, if not all, fill and drain steps. The high velocity of the water increases the hydraulic pressure on the soil in the linen and suspended in the wash liquor, thus reducing the amount of rinse water required.
Typical water consumption with this system is between about one-half (½) and two (2) gallons (4-16 liters) per pound (kg) of processed linen.
The present invention provides a method and apparatus for achieving a desired overflow rinsing while flowing liquid into the fabric articles at a high rate. The method of the present invention provides a variable level arrangement that enables variable programmable liquor ratios which are useful when processing different levels of soiled linen.
Normally, the liquor ratio (pounds or kilograms water or liquor to pounds or kilograms of fabric articles) is about 4:1 during the standing bath portion of a washer extractor cycle.
During rinsing, a high volume of water or other fluid is thrust into the drum of the washer extractor. As part of the method of the present invention, pumps are used to vary the level of water contained within the drum. The level of water in the drum thus rises to achieve a liquor ratio that is higher than the usual 4:1 ratio used during a standing bath portion of the cycle. Liquor ratio can be defined as the ratio of the pounds (or kilograms) of water to the pounds (or kilograms) of fabric articles being washed. This fluid level rise and higher liquor ratio preferably produces a liquor ratio of between about 5:1 and 10:1 or higher.
A level sensor can be used to determine the water level within the drum of the washer extractor. The level sensor can determine if the water level is high enough to reach a preprogrammed ratio such as between about 5:1 and 10:1 for the liquor ratio. At that time, a pump turns on. The flow rate of the pump can be varied (for example, using a frequency inverter) to maintain the desired preprogrammed liquor ratio. An advantage of the method of the present invention is that it easily provides the user with variable programmable liquor ratios which is useful when processing different levels of soiled linen.
The present invention provides a method of washing fabric articles. The method includes providing a reservoir of washing liquid and a washer extractor having an interior for holding fabric articles.
The fabric articles to be washed are placed in the interior of the washer extractor.
The washing liquid is pumped from the reservoir to the washer extractor interior.
Washing chemicals are added to the washer extractor interior.
Rinse water is transmitted to the washer extractor interior within a selected time interval.
As part of the method, the liquor ratio increases. This increase can be to a value of between 5:1 and 10:1.
Liquid is then extracted from the washer extractor.
In one embodiment, a chemical such as alkali can be added to the wash.
In one embodiment, one of the added chemicals is a detergent.
In one embodiment, one of the added chemicals is a sour solution.
In one embodiment, water consumption is between about ½ and 2 gallons (4-16 liters) per pound (kg) of processed fabric articles.
In one embodiment, the water temperature is in excess of 100 degrees F. (38 degrees C.).
In one embodiment, the water temperature is in excess of 120 degrees F. (49 degrees C.).
In one embodiment, the time interval is about one minute.
In one embodiment, the time interval is about four minutes.
In one embodiment, the ratio of pounds or kilograms of washing liquid to pounds or kilograms of fabric articles is about 4 to 1, plus absorbed water.
The present invention includes a method of washing fabric articles, comprising the steps of providing a reservoir of washing liquid, providing a washer extractor having an interior for holding fabric articles, placing fabric articles to be washed in the interior of the washer extractor, pumping the washing liquid from the reservoir to the washer extractor interior with a first pump, adding washing chemicals to the washer extractor interior while it is filled with washing liquid and fabric articles, transmitting rinse water to the washing extractor interior within a selected time interval with said first pump, and withdrawing the rinse water from the washer extractor interior with a second pump.
The present invention includes a washer extractor apparatus, comprising a washer extractor for holding fabric articles to be washed in a volume of a washing liquid having an associated reservoir and a washer drum with an extractor interior. A reservoir having a flow line enables transmission of washing liquid from the reservoir to the washer extractor interior. A first pump at a first elevation enables flowing of rinse fluid to the combination of fabric articles and washing liquid at a rate of between about 30 to 700 gallons (114 to 2,650 liters) per minute for a selected time interval. A second pump at a second elevation lower than said first elevation enables extraction of excess liquid from the washer extractor in order to maintain a selected volume of liquid in said interior. A controller enables a change in the volume of fluid being pumped by the second pump to a flow value that is different from the volume of fluid pumped by the first pump so that the fluid level in the drum can be changed to a new and different liquor ratio.
The present invention includes a method of washing fabric articles, comprising the steps of providing a reservoir of liquid, providing a washer extractor having an interior for holding fabric articles, placing fabric articles to be washed in the interior of the washer extractor, pumping the liquid from the reservoir to the washer extractor interior with a first pump, wherein the washer extractor interior has a liquid upper surface, adding washing chemicals to the washer extractor interior, transmitting rinse water to the washing extractor interior at a rate of between about thirty and seven hundred gallons (114 to 2,650 liters) per minute, and extracting liquid from the washer extractor, wherein excess liquid that has been added is discharged via an effluent flow line.
In one embodiment, at least some of the withdrawn liquid is re-circulated to the reservoir.
In one embodiment, the present invention further comprises a re-circulation flow line connecting the washer extractor to the reservoir, wherein said re-circulation flow line enables transmission of at least some of the extracted liquid to the reservoir and wherein the said second pump is in said re-circulation flow line.
In one embodiment, at least some of the extracted liquid is re-circulated to comprise at least a part of the rinse water.
In one embodiment, the present invention further comprises a re-circulation flow line that conveys all or part of said excess liquid to said reservoir.
In one embodiment, the present invention further comprises placing the second pump below the first pump.
In one embodiment, the present invention further comprises placing the washer extractor interior below the first pump.
In one embodiment, the second pump is a column pump.
In one embodiment, the second pump is below the washer drum.
In one embodiment, the present invention further comprises placing a second pump below the first pump.
In one embodiment, the reservoir is refilled with rinse water.
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
Machine 11 provides a drum 12 interior 13 for holding fabric articles (e.g., linen articles) to be washed and rinsed. Tank or sump 14 can be used to mix fresh cold water via line 17 and fresh hot water via line 20. The mixture of hot/cold water in tank 14 can be pumped to drum 12 interior 13 via flow line 15. Tank 14 provides tank interior 16 where hot and cold source water is mixed to provide fresh water having a selected temperature.
In
In
Table 1 below provides examples of flow rates, quantity of rinse water and rinse time in minutes for washer extractors of differing capacity. Washer extractor capacity is given in pounds (lbs) and kilograms (kg). Quantity of rinse is given in gallons (gal) and liters. Flow rates are in gallons per minute (GPM) and liters per minute (LPM).
Rinsing or “pulse flow” rinsing is shown in
In
The comparison between a Standard washer and a Pulse Rinse washer (single bath; light soil; no bleach) is seen in the following tables:
The conventional formula uses fresh water for all fills; each rinse is drained to a sewer and then refilled with fresh water, using extra fresh water and more time; and the extracted water goes to a sewer. The PulseRinse formula reuses water for all fills; combines all three drains into one step, therefore saving time and water; and the water from the sour and extract step are reclaimed.
The comparison between a Standard washer and a Pulse Rinse washer (heavy soil; with bleach) is seen in the following table:
The conventional method requires 11 fill/drain steps, whereas the PulseRinse method requires 2 fill/drain steps.
The following tables show a comparison of parameters for different washing programs and different types of soil:
indicates data missing or illegible when filed
indicates data missing or illegible when filed
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
This is a nonprovisional patent application of U.S. Provisional Patent Application Ser. No. 61/691,532, filed 21 Aug. 2012, which is hereby incorporated herein by reference. Priority of U.S. Provisional Patent Application Ser. No. 61/691,532, filed 21 Aug. 2012, incorporated herein by reference, is hereby claimed.
Number | Date | Country | |
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61691532 | Aug 2012 | US |