Patent Application
20090102073
The present invention is directed, in general, to humidifiers and, more specifically, to a water distribution tray for use in a pad-type humidifier.
In cold climates, particularly where occupied spaces must be heated, air in these spaces tends to have low relative humidity. This is uncomfortable, encourages static electricity discharges and is sometimes even unhealthy. Humidifiers are routinely used in heating, ventilation and air conditioning (HVAC) systems to add moisture to the air being conditioned to enhance the comfort of the occupants of the conditioned air space. The current relative humidity and the temperature of the air being conditioned dictate the amount of moisture added.
Humidifiers have a variety of different designs. There are small stand-alone units intended for a single room. Larger units are designed for permanent installation as a component of a central heating/HVAC system. These add moisture to the stream of heated air passing through the furnace duct to the conditioned space. The latter type of humidifier will hereafter be referred to as an “in-duct” humidifier. The humidifier whose description follows is an improvement to one common type of in-duct humidifier.
There are a number of different designs for in-duct humidifiers. The kind which is presently of interest has an air-permeable pad, typically made from a number of similarly-sized layers of thin, expanded aluminum sheet stacked to a thickness of perhaps 1.5 in. The layers of aluminum sheet are bonded to each other so as to create a pad structure having a rectangular box-like shape. The pad is placed in or near the furnace duct so that air warmed by the furnace can flow through the pad. Water is caused to drip onto the top surface of the pad at a rate which keeps the pad moist from top to bottom when humidity is demanded. The warm air passing through the pad evaporates water in the pad, adding humidity to the air and thereby raising the relative humidity.
The water flows onto the pad from what is known as a water distribution tray, or simply a tray. The tray extends along the top surface of the pad and has a reservoir for directing water flow over the pad. Water is fed to the tray from the building water supply and flow is controlled by a solenoid valve. Apertures spaced along the tray bottom permit the water flowing into the tray to fall onto the top of the pad. By properly selecting the rate at which water is added to the tray, the pad can be kept moist from top to bottom. The pad, the tray, and a frame supporting the pad and tray in the proper spatial relationship comprise the most important elements of an in-duct humidifier. It is very important, for efficient operation, that the tray evenly distributes water across the entire width of the pad.
There are water distribution trays now known which have a number of apertures spaced apart along the length of the tray and that use individual ducts, or channels, for conducting water to each aperture. Ideally, sizing and positioning the individual channels to conduct water to the apertures allows each aperture to receive an equal measure of the water; thereby assuring that the pad is evenly soaked across its width in accordance with the water demanded. These designs do not always fully realize these goals and indeed may sometimes cause further problems. For example, problems may arise that still prevent uniform saturation of the pad. This may happen if the tray is not perfectly level, thereby preventing an equal amount of water from flowing to each part of the pad's top surface. This is a fairly common problem as there is generally little need to accurately level other elements of the heating/HVAC system. Thus, when the humidifier is installed, it will usually be only as level as the air duct at that location. Water distribution will then likely favor one end of the tray over the other end.
It is also very important for all of the water in the tray to promptly drain onto the pad when the water flow stops. This eliminates un-drained pools of water standing in the tray which will evaporate leaving behind minerals, originally dissolved in the water, pooled on the tray surfaces. Over time, these mineral deposits can build up to a level which interferes with the operation of the tray itself. The use of a number of individual channels to supply water to individual holes tends to exacerbate this problem.
Accordingly, what is needed in the art is a water distribution tray that does not suffer the limitations of the prior art.
To address the above-discussed deficiencies of the prior art, the present invention provides a water distribution tray having an improvement comprising a first downwardly inclined surface therein commencing at a base of a water impingement pedestal within a first of a plurality of channels and ending at a corresponding first of a plurality of discharge apertures, wherein the first downwardly inclined surface has a first declension angle associated therewith, and a second downwardly inclined surface commencing at the base within a second of the plurality of channels and ending at a corresponding second of the plurality of discharge apertures, wherein the second downwardly inclined surface has a second declension angle associated therewith different from the first declension angle. A method of manufacturing is also provided.
The foregoing has outlined preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention.
Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention.
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
Referring initially to
The plurality of discharge apertures 140a-140h are each associated with the plurality of channels 130a-130h. Each of the plurality of channels 130a-130h is defined by one or more of the continuous vertical walls 150a-150h in combination or combined with at least a portion of the first and second outer walls 110a, 110b, or the end walls 111, 112. For example, the eighth channel 130h is defined as the area bounded by: inner vertical wall 150h, first outer wall 110a, second end wall 112, second outer wall 110b and inner vertical wall 150g. At the central water-impingement pedestal 120, each of the plurality of channels 130a-130h comprises corresponding equal angles 131a-131h of about 45°.
Referring now to
Associated with the second discharge aperture 140b is a second downwardly sloping surface 160b that comprises channel 130b. Around the second discharge aperture 140b, it can again be seen that the slope on each side of the second discharge aperture 140b is identical and is associated with a second declension angle 170b measured from the vertical. That is, the second downwardly sloping surface 160b (i.e., channel 130b) has a constant slope in all 360° around the second discharge aperture 140b. In a like manner as with the first downwardly sloping surface 160a, the second downwardly sloping surface 160b terminates when it intersects inner vertical walls 150a, 150b, 150h, the outer wall 110a, or the central water-impingement pedestal 120. The second declension angle 170b is less than the first declension angle 170a. In a preferred embodiment, the second declension angle 170b is about 104.3°.
One who is of skill in the art will take notice that the third discharge aperture 140c is surrounded by a third downwardly sloping surface 160c that comprises the third channel 130c. The third downwardly sloping surface 160c terminates when it intersects inner vertical walls 150b or 150c, the outer wall 110a, or the central water-impingement pedestal 120. The slope on each side of the third discharge aperture 140c is identical and is associated with a third declension angle 170c measured from the vertical. The third declension angle 170c is less than the second declension angle 170b. In a preferred embodiment, the third declension angle 170c is about 98.8°.
Furthermore, the fourth discharge aperture 140d is surrounded by a fourth downwardly sloping surface 160d that comprises the fourth channel 130d. The fourth downwardly sloping surface 160d terminates when it intersects inner vertical walls 150c, 150d, the outer walls 110a or 110b, the first end wall 111, or the central water-impingement pedestal 120. The slope on each side of the fourth discharge aperture 140d is identical and is associated with a fourth declension angle 170d measured from the vertical. The fourth declension angle 170d is less than the third declension angle 170c. In a preferred embodiment, the fourth declension angle 170d is about 96.0°.
In a like manner, fifth through eighth discharge apertures 140e-140h are arrayed from the central water-impingement pedestal 120 along the centerline 101 toward the second end 103. It should be apparent to one who is of skill in the art that the fifth through eighth discharge apertures 140e-140h and their corresponding channels 130e-130h are analogous to the first through fourth discharge apertures 140a-140d and their corresponding channels 130a-130d. The fifth declension angle 170e is substantially equal to the first declension angle 170a. The sixth declension angle 170f is substantially equal to the second declension angle 170b; and the seventh declension angle 170g is substantially equal to the third declension angle 170c. The eighth declension angle 170h is substantially equal to the fourth declension angle 170d.
With the channel angle 131a-131h for each channel 130a-130h being equal, water impinging on the water impingement pedestal 120 and flowing to the channels 130a-130h should be substantially equal within each channel 130a-130h. Therefore, a substantially equal volume of water is being distributed to each channel 130a-130h. Because the first and fifth discharge apertures 140a, 140e are closest to the water impingement pedestal 120, the first and fifth channels 130a, 130e have the largest declension angles 170a, 170e. Because the second and sixth discharge apertures 140b, 140f are closer to the water impingement pedestal 120 than the third and seventh discharge apertures 140c, 140g, declension angles 170b, 170f for channels 130b, 130f are less than declension angles 170a, 170e, but greater than declension angles 170c, 170g. In a like manner, declension angles 170c, 170g for channels 130c, 130g are less than declension angles 170b, 170f, but greater than declension angles 170d, 170h.
The present invention was successfully tested against the prior art upon which it was based. The general plan design for the present invention is essentially that as disclosed in U.S. Pat. No. 4,125,576 to Kozinski which is incorporated herein by reference. Relationship of the water distribution tray to other elements of the humidifier, e.g., frame, water-retaining pad, etc., may be gleaned from Kozinski and are therefore not included here. However, Kozinski did not employ downwardly sloping channels, but rather a flat bottom surface throughout the tray. Both trays were tested in three conditions: level, 2° of tray tilt (¼ bubble of a carpenter's bubble level), and 3.5° of tray tilt (1 full bubble), simulating installation of the humidifier in normal and abnormal positions. It should be noted that to install a heating duct at one full bubble off of level would likely be an extreme case, although it would likely not affect the functioning of the heating system itself.
Referring now to
Thus, an improved humidifier water distribution tray has been described that provides downwardly sloping surfaces at varying angles of declension to efficiently and reliably deliver water to a humidifier pad for evaporation. Testing shows that the present invention more evenly delivers the water across the width of the humidifier pad and eliminates pooling.
Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.
