Electric heating – Heating devices – With heating unit structure
Reexamination Certificate
1999-08-23
2001-03-13
Walberg, Teresa (Department: 3742)
Electric heating
Heating devices
With heating unit structure
C392S397000, C392S482000
Reexamination Certificate
active
06201223
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to a humidity regulating unit and to a method of manufacturing a humidity regulating unit.
2. Description of the Related Art
Japanese Unexamined Patent Appl. No. 62-26076 discloses a humidity regulating unit in which a tube is used to carry water over a heating element. The tube has a porous retaining wall as the main wall through which water does not pass but steam passes. This humidity regulating unit is designed such that an electric heating element (with a diameter of at least 3 mm) is arranged inside the tube by preparing one tube with a somewhat large diameter. During use, this water carrying tube is connected to a water supply source such that the tube is always filled with water. Steam is expelled through the porous retaining wall of the water carrying tube by the heat of the electric heating element.
When this type of humidity regulating unit is used inside the inhalation route (inhalation circuit) of an artificial respirator, for example, not only can it assure humidifying performance, but using the fact that the outer shape of the humidity regulating unit is a tube, the humidity regulating unit can be arranged in the inhalation route and does not require a large-volume chamber for a humidifier.
However, in the humidity regulating unit described above, from considerations such as assuring adequate steam generation and the size of the heating element, a water carrying tube that has a somewhat large diameter must be used. If the water carrying tube is broken, an impermissible amount of water inevitably leaks which can cause various problems. When the humidity regulating unit is used in the inhalation route of an artificial respirator, for example, water leakage has the undesirable effect of reducing humidifying performance and the leaking water itself can flow to the inhalation side of the inhalation circuit, which is the side where the user of the artificial respirator is located.
SUMMARY OF THE INVENTION
This invention was developed upon reflecting on the situation described above. Its first object is to offer a humidity regulating unit that even if it breaks, can markedly reduce problems caused by leakage while maintaining previous humidifying performance.
A second object of this invention is to offer a method for manufacturing such a humidity regulating unit.
These objects are achieved by providing a humidity regulating unit that includes a heating element housed in a covering that has a porous retaining wall through which water does not pass but steam passes. Several independent water routes are formed in succession between the outer wall of the above-mentioned heating element and the above-mentioned covering by cooperative action between the outer wall of the heating element and the covering where open spaces between the covering and the heating element are provided along the circumference of the heating element.
The latter object is achieved by providing a method of manufacturing a humidity regulating unit that includes preparing two halves of a covering defined by a porous retaining wall through which water cannot pass but steam passes. The two halves are laminated onto opposing sides of a heating element such that at least one independent water route is formed between each half and the outer wall of the heating element by cooperative action between each half and the outer wall of the heating element, where open spaces between the covering and the heating element are provided along the circumference of the heating element.
Then each of the above-mentioned halves of the covering and the outer wall of the above-mentioned heating element are bonded to define the water routes along the heating element.
The latter object is also achieved by providing a method of manufacturing a humidity regulating unit that includes providing a tubular covering defined by a porous retaining wall through which water cannot pass but steam passes and a cap that can cover an open side of the covering.
A heating element is placed within the above-mentioned covering and several independent water routes are formed in succession between the covering and the outer wall of the heating element by cooperative action between the covering and the outer wall of the heating element, such that open spaces are provided between the covering and the heating element along the circumference of the heating element.
The above-mentioned covering and the outer wall of the above-mentioned heating element are bonded to define water routes between the bulges in the heating element. The open side of the above-mentioned covering is then covered by the abovementioned cap. Because a heating element is housed in a covering that has a porous retaining wall through which water does not pass but steam passes and independent water routes are formed between the outer wall of the heating element and the covering by cooperative action between the outer wall of the heating element and the covering by providing spaces along the circumference of the heating element, when water is supplied into each water route and heated by the heating element, steam is expelled from each water route through the porous retaining wall, and the desired humidifying performance can be achieved under optimum conditions.
In addition, because the outer surface of the heating element is used as part of the wall of the water routes and the heating element does not have to be housed inside the water routes, the size of the heating element does not restrict making the cross section of each water route as small as possible. As a result, even if the covering breaks or is damaged, the amount of water leaking from the water routes that this covering covers is minimized, and water leakage can be reduced to the extent that there is no substantial decrease in humidifying performance or problems associated with excessive water leakage.
Because the humidifying unit in one embodiment of this invention has several bulges in the covering along the circumference of the heating element that protrudes outward from the outer surface of the heating element, each water route is comprised of a bulge and the outer surface of the heating element that covers the open base end of the bulge. In addition to having the desirable leak minimization effects described above, the surface area of the steam emitting surface is increased by each bulge, and humidifying performance is improved.
In another embodiment of the present invention, channels are formed in the outer surface of the heating element by providing spaces along the circumference of the heating element. In this embodiment, each water route is defined by the channel and the covering that covers the opening of the channel. In addition to having the desirable leak minimizing effects described above, the proportion of the outer wall of the heating element that comprises the side walls of each water route is increased, and by making the shape of the water routes more stable, the stability of humidifying performance can be increased. As a result, this humidity regulating unit can be used in regions that have higher speed flow.
In yet another embodiment of the present invention, the covering and the outer surface of the heating element are bonded between adjacent water routes, the independence of each water route can be assured and the leak minimizing effects described above can be achieved more securely.
The present invention also contemplates that the outer surface of the heating element is formed by a coating resin and the covering is welded to the coating resin of the heating element. By taking advantage of the easy bonding between these two (the covering generally is formed by a resin such as polytetrafluoroethylene), the covering and the outer surface of the heating element can be bonded easily.
In a further embodiment, the heating element is an electric heating element and the coating resin is an insulator for this electric heating element. The covering is welded to the outer surface of the heating element using the insulator of the electric h
Dahbour Fadi M.
Reed Smith LLP
Respironics Inc.
Walberg Teresa
LandOfFree
Humidification control unit and method of manufacturing same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Humidification control unit and method of manufacturing same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Humidification control unit and method of manufacturing same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2548463