Patent Publication Number: US-8984678-B2

Title: Air injection system for a hydro-massaging bath

Description:
TECHNICAL FIELD 
     The present invention relates to an air injection system for a hydro-massaging bath to eliminate the effect of coolness on the body of a user person immersed in hot water within the bath and in close proximity to air injecting orifices. 
     BACKGROUND ART 
     It is well known to inject air in the hot water contained in a bathtub to provide a turbulence of the water whereby a user person receives a massaging therapy by the turbulent water. A plurality of orifices are distributed in the side walls of the bathtub in areas where a water massage is required such as in the back wall and lower side wall areas of the bathtub. Various hydro massaging baths are known and such comprise adjustable nozzle assemblies mounted on the wall of a bathtub to discharge high velocity jets of water to impinge upon the body of a user person. However, when injecting air within the hot water, the user person is subjected to a sensation of coolness where the air jets impact its wet body. This sensation is the result of an adiabatic reaction which is caused by air which is relatively dry, and which enters in contact with the water. This sensation is felt even if the air is heated to about 60° C. Increasing the temperature of the air is not the solution to resolve the problem as this would burn a user person&#39;s skin. Accordingly, the prior art has opted to mix the air with recirculated water from the bathtub or with heated water such that the injectors comprise a large quantity of water mixed with air. 
     Another problem of injecting air in the water to cause turbulence is that the air cools the water in the bathtub prematurely because of the large surface contact area of turbulent water with the air. It is therefore desirable to eliminate this cool sensation when injecting air in a bathtub through air injecting orifices or air injectors. 
     In British Patent GB 2 224 203 published on May 2, 1990, there is disclosed a spa bath in which an air/water mixture is injected via injectors into the water contained within the bath. In that patent, water is taken from the bottom of the bath, heated in a heater and the heated water is supplied to jets within a manifold through which compressed air is blown. The water is injected through venturi orifices which cause water to be sucked through the jets to form fine droplets which are then discharged through the injectors. The droplets of heated water humidify and heat the air immediately before the air/water mixture is injected into the bath, therefore reducing discomfort to the user and maintaining the water temperature in the bath at a desired level. There are several disadvantages of this method, one being that the injector assembly is very expensive and troublesome. In a system as described, it is likely that the injectors will not all operate in a uniform fashion due to variation in pressure along the injector line. The clogging of the venturi gaps due to the fact that the recirculating water entering the nozzles may clog up the nozzles due to the various products and impurities in the water, particularly when water is extracted from the bottom end of the bathtub. Such decalibrates the operation of the injectors. However, this reference confirms that hot bath water is subjected to accelerated cooling when the water is agitated in contact with ambient atmosphere and that unless water is heated to about 50° C., injected air entering the bath will feel cool to a user person&#39;s body close to the nozzle creating a “chill effect” caused by blown air in contact with wet skin. 
     SUMMARY OF INVENTION 
     It is a feature of the present invention to provide an air injection system for a hydro-massaging bath which substantially overcomes the above-mentioned disadvantages of the prior art. 
     Another feature of the present invention is to provide an air injection system for a hydro-massaging bath having air injecting orifices to which is fed hot humid air under pressure such that when the hot humid air is injected in the bathtub the cool sensation against a user person&#39;s body is eliminated or substantially reduced. 
     Another feature of the present invention is to provide an air injection system for a hydro-massaging bath wherein hot humid air is injected into the bathtub through an air distribution conduit in which is injected a waterspray to humidify air under pressure and wherein a heater is provided in the conduit to heat the hot humid air to a desired temperature for injection through air injecting orifices formed in the peripheral side walls of the bath. 
     Another feature of the present invention is to provide an air injection system for a hydro-massaging bath wherein water injected within the pressurized air in the air convecting conduit is regulated by a pressure reducing valve containing a removable filtered cartridge to remove impurities from the spray of water injected in the air to prevent clogging of the injection orifices. 
     Another feature of the present invention is to control the temperature of hot humid air injected in a hydro-massaging bath whereby to create a heat sensation in the area of the air jets provided in the peripheral side walls of the bath. 
     According to the above features, from a broad aspect, the present invention provides an air injection system for a hydro-massaging bath. The bath has a bottom wall and peripheral side walls. A plurality of air injecting orifices are distributed in at least some of the peripheral side walls. An air convecting conduit is in communication with the air injecting orifices. An air blower is provided for injecting air under pressure and in an entry opening of the air convecting conduit. A water spray injector is provided in the air convecting conduit downstream of the entry opening and upstream of the air injecting orifices to inject a spray of a predetermined volume of water in the injected air. A water supply conduit is connected to the water spray injector and has a flow regulating valve to regulate the volume of water spray injected in the heated air to saturate the air with water. A shut-off valve is provided in the water supply conduit. A heater is provided in the air convecting conduit downstream of the water spray injector and upstream of the air injecting orifices. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which: 
         FIG. 1  is a fragmented perspective view illustrating the construction of an air injection system coupled to a side wall of a bathtub and in communication with an air convecting conduit molded within the side wall; 
         FIG. 2  is a schematic illustration of the air injection system of the present invention; 
         FIG. 3  is a simplified schematic side view showing modifications to the air injection system of the present invention as coupled to a hydro-massaging bathtub; 
         FIG. 4A  is a fragmented section view showing one embodiment of the air injecting orifices distributed in the peripheral side walls of the bathtub; and 
         FIG. 4B  is a view similar to  FIG. 4A  but showing a further embodiment wherein the air injecting orifices are provided with adjustable injection nozzles. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to the drawings and more particularly to  FIGS. 1 to 3 , there is shown generally at  10  an air injection system for a hydro-massaging bath  11  constructed in accordance with the present invention. A hydro-massaging bath also includes indoor and outdoor spas having a hybrid system. The bath  11  has a bottom wall  12  and peripheral side walls  13 . A plurality of air injecting orifices  14  are provided and distributed at least along some of the peripheral side walls  13 . An air convecting conduit  15  surrounds the air injecting orifices  14 . Accordingly, when air under pressure by a blower  16  is injected within the air convecting conduit  15  air will enter under pressure into the hot water  17  contained within the bathtub and create a turbulence in the water. 
     As more clearly shown in  FIG. 2 , the blower  16  injects air under pressure in an entry opening  18  of the air convecting conduit  15  and a water spray injector  19  spaced from the entry opening  18  injects a spray of water within the pressurized air flow  20 . The spray injector  19  is positioned downstream of the entry opening  18  and upstream of the air injecting orifices  14 . 
     The water spray injector  19  is provided water from the domestic water line  25 . i.e., a water supply line generally provided in homes and/or households, via a flow regulating valve  27  and a solenoid valve  26  whereby to regulate the pressure and/or volume of water sprayed into the air flow  20  to assure that the air is fully saturated with humidity. 
     As also shown in  FIG. 2 , a resistive heating element  28  is mounted within the air convecting conduit  15  downstream of the water spray injector  19  and upstream of the air injecting orifices  14  whereby to quickly heat and vaporize the saturated air to a desired temperature. As shown in  FIG. 2 , a heating coil  29  or a further resistive heating element (not shown) may be interposed in the air flow path  20  between the blower and the entrance opening to pre-heat the injected air within the air convecting conduit  15 . 
     In  FIGS. 1 and 2 , it can be seen that the flow regulating valve  27  is disconnectably secured in the water supply conduit  25  by lock nuts  29 ′ to give access to a filter cartridge  30  housed within the flow regulating valve  27 . The cartridge  30  filters impurities from the water supply line  25 . This is particularly useful, as shown in  FIG. 3 , when the water supply line is a recirculating conduit  31  which recirculates the water  17  from the bath  11  through a pump  32 . The pump  32  draws the water from the bottom of the bath  11  through a conduit  33  and feeds it to the flow regulating valve  27 . In such an arrangement the solenoid valve  26  would not be necessary as the controller  35  would control the operation of the pump  32  to stop the flow of recirculating water. 
     As also shown in  FIG. 3 , the controller  35  controls the blower  16 , the electrical supply terminal  28 ′ of the resistive heating element  28  and the solenoid valve  26  when a recirculating conduit  31  is not provided. 
     In order to completely saturate the air flow  20  it has been found that the flow regulating valve needs to be adjusted to inject between 4 gallons per hour (GPH) to 15 GPH of water into the air flow  20 . By controlling the adjustment of the solenoid valve  26  the volume of water injected in the air flow can be controlled. The water spray injector  19  is herein constituted by a small air injecting orifice formed in a side wall of the air convecting conduit  15  and has an orifice size of about 2 mm. The controller  35  also controls the blower speed  16  to control the air flow displacement and therefore pressure of air injected in the bath through the air injecting orifices. Accordingly, the control circuit  35  can regulate the temperature and pressure of hot saturated air injected in the water  17  contained within the bath  11 . 
     A thermostat  36  is conveniently secured to the air convecting conduit  15  to feed temperature signals to the control device  35  via its connection  37  whereby the control device  35  can automatically make the necessary adjustments to regulate the temperature and saturation of the air under pressure in the air convecting conduit  15 . The temperature of the heated saturated air, when injected into the water within the bath, is in the range of about 34° C. to 45° C. and at such temperature there is no harm to the skin of a user person bathing in the bath while the “chill effect” sensation is substantially eliminated. In fact, when the temperature is in the higher range, a sensation of warmer water is felt on a user skin without fear of burning the skin of the user person. 
     Referring to  FIGS. 4A and 4B , there are shown two versions of the air injecting orifices  14 . As shown in  FIG. 4A , the air injecting orifice  14  is simply a hole formed in the peripheral wall  13  of the bathtub and in communication with the air convecting conduit  15 . The size and dimension of this hole is described in previous patents of Bain Ultra and does not form part of the present invention. Also, as shown in  FIG. 4B , the air injecting orifices may be constituted by adjustable injection nozzles  38  disposed in communication with the air convecting conduit  15 . The bath  11  may be a therapeutic bathtub incorporating various therapeutic treatments such as lumino therapy, hydro therapy and thermal therapy. Another advantage of the air injection system of the present invention is that the water within the bathtub can stay hot longer and the water is cleaner and sterilized by the use of removable filter cartridges provided in the flow regulating valve such cartridges being accessible for replacement. 
     Another advantage of the present invention is that after use, the controller can automatically engage a cleaning and drying cycle wherein the solenoid valve  26  is shut-off and the air blower is engaged whereby to flush out any residual humidity within the air convecting conduit  15  and the injectors to dry out the air convecting conduit and injector orifices. The heater  28  may also be actuated to accelerate the drying cycle if the resistive heating elements  29  within the blower are not sufficient. 
     It is within the ambit of the present invention to cover any obvious modification of a preferred embodiment described herein provided such modifications fall within this scope of the appended claims.