Automatic temperature and humidity regulation – Mixing fluid of dissimilar temperature – Mixing valve with temperature motive means
Reexamination Certificate
2000-05-08
2001-08-07
Wayner, William (Department: 3744)
Automatic temperature and humidity regulation
Mixing fluid of dissimilar temperature
Mixing valve with temperature motive means
C236S012120, C004S676000
Reexamination Certificate
active
06270014
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to tempered water blending systems particularly useful on emergency safety showers.
BACKGROUND OF THE INVENTION
Tempered water safety showers are used in a wide range of industries in which workers are exposed to toxic and hazardous chemicals that can cause serious tissue damage upon contact. Occupational Safety and Health Administration regulations require the availability of emergency safety showers for use as a form of first aid treatment. ANSI standard Z358.1 requires that these showers can deliver at least 20 gallons of water per minute for a time period of 15 minutes over the body of a person who has been exposed to an aggressive chemical.
It has been found that there are problems relating to a 15-minute sustained time in cold water for any individual, and particularly for a person who is already in or subject to traumatic shock. The body quickly begins to react to the cold by shivering in order to fight off cold and generate body heat. The sustained flow of cold water increases the loss of body heat beyond the body's ability to maintain adequate temperature levels and further stimulates the metabolic rate to compensate. Ultimately, the user enters thermal shock and/or refuses to remain in the shower for the time required for adequate treatment. Moreover, use of cold water discourages the effective, maximum use of the safety shower temperature for the 15-minute period which is required by the ANSI standard. Users tend to leave the shower much earlier when being deluged with cold water.
Tempered water blending systems usually provide drench water at almost 85° F-90° F., and at the temperature levels sufficient to provide relief to the affected tissue while allowing the user to remain immersed for the required treatment period. Most systems use basically mechanical, temperature-control devices which respond sluggishly to temperature changes with a pressure drop across the system of from about 30 to 40 psi. Even later-model electro-mechanical systems that allow existing plant hot and cold water supplies to be accurately and safely blended to a preset, non-adjustable, safe, utilization temperature leave something to be desired as far as responsiveness and fail-safe operation is concerned. Such systems are readily available in industrial safety catalogs. Because of this and other desires for tempered water safety showers, there exists a need for the development of a tempered water emergency shower that is simpler, more economical and safer to use.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a simple, economical and safe emergency shower apparatus for supplying tempered water having a desired, pre-selected temperature within a fraction of the time required using existing systems. The apparatus of the present invention provides a steady flow of tempered water having a preset temperature without significant temperature fluctuation. Temperature fluctuation is less than about ±3° F. The present invention accomplishes the desired outlet water temperature within a period of time less than about 1 second of the manual opening of a flow valve such as a safety shower head. The time it takes for the establishment of a steady flow of tempered water flow having the desired preset temperature from the sensing of flow after opening the flow control valve by the user is referred hereinafter as the response time. In contrast, current systems generally take much longer to establish a steady water flow having the desired preset temperature.
It is an object of the present invention to provide a tempered water shower apparatus having an infinitesimal probability to fail in hot mode, thereby providing a much safer device than prior art devices. For instance, the present invention apparatus is designed to fail (if such should occur) in the safe, not hot, mode.
These and other objects of the present invention will become apparent to an engineer with ordinary skill in the art of emergency tempered water safety systems from the following discussion. In accomplishing these objects, an apparatus is provided for supplying tempered watercomprising a three-way, thermostatic, self-operated mixing valve for mixing the flow of a cold water stream with a hot water stream at effective proportions to form an output water stream having a temperature of a desired, preset temperature. The apparatus employs a sensor which detects the flow of the cold water stream to cause a normally closed solenoid valve in the tempered water line to open. The system includes a controller programmed to close the tempered water flow upon either a mechanical or electrical failure, or upon the temperature of the tempered water reaching a temperature greater than a predetermined value, while allowing flow to continue through the cold water bypass which is designed to flow about 30 gpm.
REFERENCES:
patent: 4739793 (1988-04-01), Vollmer
patent: 4767052 (1988-08-01), Kostorz et al.
patent: 5058804 (1991-10-01), Yonekubo et al.
patent: 5358177 (1994-10-01), Cashmore
patent: 5647531 (1997-07-01), Kline et al.
patent: 5979776 (1999-11-01), Williams
Bollas Christopher J.
McAdams Charles R.
Nguyen Dai Duc
Encon Safety Products
Jenkens & Gilchrist P.C.
Wayner William
LandOfFree
Tempered water blending system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tempered water blending system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tempered water blending system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2537660