Drying and gas or vapor contact with solids – Apparatus – Houses – kilns – and containers
Reexamination Certificate
1999-09-22
2001-02-13
Wilson, Pamela (Department: 3749)
Drying and gas or vapor contact with solids
Apparatus
Houses, kilns, and containers
C392S380000, C392S381000
Reexamination Certificate
active
06185838
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to hand driers such as are used in institutional and commercial washrooms, and in some public facilities, and in particular to such hand driers in which the air is warmed to procure rapid drying of the hands after washing.
BACKGROUND OF THE INVENTION
Hand driers usually consist of a housing containing a fan and a heater, usually powered by electricity. An air outlet or nozzle ejects a stream of heated air over the hands, usually from one end of the housing, or through a nozzle which can in many cases be swivelled around so that the air is directed to a desired location. Fresh air is usually inducted into the housing at a location remote from the air outlet. In this way the heated air is continuously dissipated into the ambient air in the room and its calorific values are lost, or in summer months simply add to the load on the air conditioning facilities in the building. The fresh air inducted is at ambient temperatures and must be rapidly warmed to the desired drying temperature. There is in effect a continuous demand for heat energy for the incoming air which is then immediately dissipated again. While it is true that such driers incorporate timers so that the actual duration of operation is cut off after the time has expired, there is none the less a considerable waste of energy. It also well known that persons may need to extend the timed operation, and simply repeatedly press the operating switch.
There is an additional disadvantage to conventional hand driers, in that the location of the air outlet is often so designed that the heated air flow stream spreads widely as it exits into the atmosphere, and much of the calorific value in the heated air stream never even reach the hands at all. Some designs have more efficient outlets so as to guide the air stream more narrowly, but in these cases the air stream may be so narrow that it impinges on only a portion of the hands and the user may have to move the hands so as to direct the air onto all areas of the skin. In all cases the direction of airflow is one way ie from the outlet towards the hands and out into the atmosphere. Thus the hands are dried only from one direction. The hands must be turned around and wiped over each other, as is well known. Unless this is done the hands will remain wet on the sides that do not face the air stream.
Clearly it is desirable to provide a hand drier which is both more efficient in its use of electrical energy, and in which the calorific value of the heated air is to some extent recovered by recycling the heated air, and in which the heated air stream is at the same time directed in such a manner as to dry all areas of the hands simultaneously, and quickly, and with a minimum of loss of heated air, and consequent loss of calories, to the atmosphere.
BRIEF SUMMARY OF THE INVENTION
With a view to providing a hand drier which addresses these conflicting problems the invention provides a hand drier having a housing, a fan in the housing and means for dividing the air flowing from the fan into at least two streams, and heating means for heating the air, and having at least two air outlets spaced apart from one another for receiving respective air streams from the housing, and being oriented so as to direct two air streams from opposite directions in opposition to one another so as to produce a turbulent air flow region therebetween in which the hands can be placed for drying, and having an air induction inlet located substantially intermediate the outlets through which air is inducted by the fan, thereby causing the fan to re-induct a substantial proportion of the already heated air flowing from the outlets and thus continuously recycling warm air and recovering at least some of the calorific value in the warm air, and having thermal control means in the housing for maintaining a constant internal air temperature during operation to prevent overheating caused by induction and reheating of already heated air.
The invention provides in one embodiment a housing with a central induction inlet opening and two outlets at opposite ends of the housing, directing two air streams across the exterior of the housing from opposite sides and procuring turbulent air circulation adjacent a region intermediate the two outlets, and in the general region of the air inlet opening so that turbulent warm air is inducted from the region of turbulence created by the opposition of the two air streams.
Preferably the two outlets are located below the housing and the inlet opening is located in an underside of the housing, between the outlets.
In one form the fan is a centrifugal fan mounted within the housing to rotate on a vertical axis, and there are two scrolls or air collectors within the housing to collect air flowing from around the fan and to direct the air into two air streams flowing towards opposite ends of the housing.
In a particularly convenient design one outlet, and one end wall of the housing, are molded integrally together out of thermoplastic material, and the outlet and end walls are of identical design for both ends of the housing so as to provide an economical form of construction.
Each molding will preferably incorporate a support flange for supporting an air intake grill, to still further save in construction.
The various features of novelty which characterize the invention are pointed out with more particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
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patent: 5974685 (1999-11-01), Hironaka
Joyce Andrea M.
Wilson Pamela
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