MODULAR DRAIN PAN ASSEMBLY, WITH SEAMLESS FLOOR, FOR HORIZONTALLY POSITIONED DUAL-PASS COOLING COILS
A modular drain pan assembly with one-piece construction, having no seams in the condensate collection area and using multiple small drain pans with drip caps to avoid leakage between individual pans.
This application is a continuation-in-part of application Ser. No. 13/317,660, filed Oct. 25, 2011 and claims priority in part under 35 U.S.C. §120 therefrom, which application is incorporated by reference therefrom.
FIELD OF THE INVENTIONThe present invention relates to drip pans for substantially horizontally oriented dehumidification cooling coils.
BACKGROUND OF THE INVENTIONThe purpose of a cooling coil drain pan is to capture condensed water from a cooling coil, and route it to a drain, without leaving areas of stagnant water behind. Drain pans are a potential source of microbial contamination. Until recently, most air handlers and terminal units with cooling coils were designed with flat drain pans. However, ASHRAE Standard 62 now stipulates regarding drain pans that pans intended to collect and drain liquid water shall be sloped at least 0.125 inches per foot or shall be otherwise designed to ensure that water drains freely from the pan whether the fan is on or off.
Vertically positioned cooling coils are mounted in a vertical or near vertical position. Horizontally positioned cooling coils are mounted in a horizontal, or near horizontal position. In both cases, condensate flows downward with gravity, into the drain pan.
The prior art reveals applications of permanently installable horizontally positioned dual pass cooling coils. In U.S. Pat. No. 5,816,315 of Stark, horizontally extending cooling coils are used with plate-type cross flow air-to-air heat exchangers in a dehumidification application. In U.S. Pat. No. 5,913,360 of Stark, horizontally extending cooling coils are used in conjunction with air flow dampers in another dehumidification application.
The prior art also discloses vertical or near vertical positioned cooling coils with narrow drain pans. For example, U.S. Pat. No. 4,135,370 of Hosoda describes a dehumidification system with a vertically oriented evaporator 4 with a single drip pan 7 below the evaporator 4. U.S. Pat. No. 6,203,036 of LaVaute describes a Busing Cart with separate drip pans in general for transporting non-analogous dishes. U.S. Pat. No. 6,484,512 of Anderson describes temperature controlled drawers that use a plurality of drip pans, such as disclosed in two separate non-integral drip pans 89 and 148 below a vertically oriented heat sink 124 in
Unlike vertical or near vertical positioned cooling coils, such as in Hosada '370, that require relatively narrow drain pans, horizontal, or near horizontal positioned, cooling coils, such as cooling coils 66 of Stark '315 and Stark '360, have a larger drip surface area and therefore require larger drain pans for collecting condensed moisture and routing it to drainage connection(s).
Problems with single large drain pans under horizontally extended cooling coils are that they exceed the width of traditional construction materials and therefore require seams in the drain pan floor to join pieces together. This joining results in potential for leaks, added assembly labor, uneven and non-uniform pan surfaces which thereby increases the required slope to ensure full drainage with no areas of stagnant water.
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- a. Seams in the pan floor increase the possibility of leaks, increase cost of manufacturing and, in the case of stainless steel; heat from welding changes the properties of the metal at the weld joint, causing rust and accelerated deterioration. Welding long seams of a drain pan material is known to cause “buckling” which leads to pockets of trapped stagnant condensate. The remedy using single large drain pans is to increase the height dimension, to ensure complete drainage.
- b. Increased slope means the pan height dimension must increase and consequently, the height of the entire apparatus must increase to ensure full drainage to the low point or drainage connection(s). Without proper slope, areas of stagnant water form on the surface of large pans. These areas of stagnant water are caused by a non-uniform surface that is a natural tendency over large surfaces. Thick material and/or stiffeners are needed to ensure a uniform flat and adequately sloped surface.
- c. Therefore, there is a need to provide efficient drainage of water underneath horizontally extending cooling coils.
It is therefore an object of the present invention to provide efficient drainage of water underneath horizontally extended cooling coils.
It is also an object of the present invention to provide horizontal cooling coils having large horizontal drip surfaces with multiple drain pans.
It is yet another object of the present invention to create a drain pan, made of a single piece of material, with no floor seams and no stagnant water.
It is also an object of the present invention to provide a plurality of adjacent horizontal cooling coils, acting together as a module, each with at least one drain pan.
It is a further object of the present invention to provide insertable and removable horizontal cooling coils which can be replaced or maintained efficiently.
Other objects which become apparent from the following description of the present invention.
SUMMARY OF THE INVENTIONThe concerns raised in the prior art relating to large horizontal drip surfaces are best served with multiple drain pans as in the solution offered by this invention.
In keeping with the Objects of the Invention, it is the intent of this invention to use sloped drain pans, made of a single piece of material, with no floor seams and therefore resulting in no stagnant water for the purpose of capturing and routing condensate to drain connections.
Modular drain pans, with multiple drain connections, mounted under one or more horizontal cooling coils, offer greater slope with less height, minimal stagnant water, minimal height and no base seams.
In one embodiment of this invention, the entire drip surface area of one or more horizontally oriented cooling coils is serviced by two or more drain pans intercepting all drips. The size of each sloping pan is such that it is fabricated of a single sheet of material of commonly available size. This obviates the need for sheet joining and also reduces the pan height as compared to a larger single pan of comparable floor slope.
To prevent leakage between multiple drain pans, an optional drip umbrella or cap with an upside-down “V” cross section bridging the top edges of adjacent pans is used divert any impinging drips into one or the other pan. Where the horizontally positioned cooling coil is actually a plurality of adjacent horizontally oriented coil coils, each horizontally oriented cooling coil can have one or more integrally formed drain pans underneath. If a single drain pan is used under a separate horizontally positioned cooling coil, then the drip umbrellas are not needed, as there are no adjoining drain pans. If, however, one or more integrally formed drain pans are positioned under each separate horizontally positioned cooling coil, then preferably drip umbrellas or caps need to be provided between adjacent drain pans.
In an alternate embodiment, a module can be formed of a plurality of adjacent, side by side, cooling coils in a module, each cooling coil with one or more drain pans underneath.
In another embodiment each of the one or more horizontally mounted cooling coils is inserted from the end of the housing and sealed with flap or bulb gasket seals to the heat exchanger section above. This facilitates ease of initial assembly or service change-out. The gasket seals are selected of materials designed to last the life of the equipment. New gaskets are to be provided to insure sealing integrity in case of re-insertion.
Note that for dual-pass dehumidification applications of this general equipment, a variety of heat exchanger types can be used atop the cooling coils. Specifically, either the plate type heat exchanger described in U.S. Pat. No. 5,816,315 or the heat pipe heat exchanger of Applicant's patent application Ser. No. 13/317,660 can be used, wherein elongated, smaller-diameter tube heat pipes have an airflow arrangement that allows for short distances between evaporating and condensing sections of the heat pipe. The heat pipe is exposed to multiple alternate hot and cold zones adjacent to each other. Each evaporator zone accepts input heat to cause evaporation of the working fluid in the wick of the immediate vicinity. The vapor produced moves to either side by local pressure differences to condense in the two adjacent condenser zones where it is absorbed by the wick as a liquid and flows in the wick back to adjacent evaporator zones at each side. Each evaporator zone creates two fluid loops whereby evaporated working fluid splits up left and right, condenses in adjacent condenser zones and flows back to the evaporator zone as a liquid within the wick. Therefore, the overall tube length can be increased indefinitely, without traditional degradation of performance.
The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
Two or more drain pans 11 of even smaller dimensions can be used. With this flexibility, it is feasible to use non-metallic sloped drain pans which can be molded or vacuum formed of plastic resins which avoid corrosion and reduce cost. Optionally, the sloped drain pans can be formed of a metal sheet bent to form each adjacent sloped drain pan module from a single piece of sheet metal.
In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.
Claims
1. A combination modular drain pan assembly and horizontally positioned cooling coil comprising in combination:
- at least one horizontally positioned cooling coil,
- a single piece of material formed into an integral seamless assembly of at least two adjacent sloped drain pan modules with seamless floors,
- said integral seamless assembly of said at least two adjacent sloped drain pan modules positioned under a substantially horizontally positioned cooling coil,
- said integral seamless assembly of said at least two adjacent sloped drain pan modules capturing and routing condensate to drain connections.
2. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 1 further comprising:
- a respective drip umbrella provided between each said adjacent sloped drain pan modules to prevent water leakage between each said respective adjacent sloped drain pan module of said at least two adjacent sloped drain pan modules.
3. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 2 wherein each said respective drip umbrella has an upside-down “V” cross section bridging the top edges of said adjacent drain pan modules of said at least two adjacent sloped drain pan modules.
4. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 2 wherein each respective drain pan module has a width which is proportionately a portion of a predetermined width of said substantially horizontally positioned cooling coil.
5. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 4 wherein said integral seamless assembly of at least two adjacent sloped drain pan modules with seamless floors is made of metal bent to form said at least two adjacent sloped drain pan modules.
6. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 4 wherein said integral seamless assembly of at least two adjacent sloped drain pan modules with seamless floors is made of plastic.
7. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 6 wherein said plastic integral seamless assembly of at least two adjacent sloped drain pan modules with seamless floors is made of a molded plastic resin.
8. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 6 wherein said plastic integral seamless assembly of at least two adjacent sloped drain pan modules with seamless floors is made of a vacuum formed plastic resin.
9. The modular drain pan assembly as in claim 1 wherein said at least one horizontally positioned cooling coil is a plurality of horizontally positioned cooling coils.
10. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 1 further comprising at least one heat exchanger positioned above said at least one horizontally positioned cooling coil.
11. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 10 further comprising a manifold having respective air inlet and outlet regions, said manifold positioned above said at least one heat exchanger for introduction of said inlet air therein and for expelling said outlet air therefrom, after said inlet air communicates with said at least one cooling coil and said air reversal plenum prior to said inlet air becoming said outlet air by then traversing said cooling coil, said at least one heat exchanger and said manifold.
12. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 10 wherein said at least one heat exchanger is a plate type heat exchanger.
13. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 10 wherein said at least one heat exchanger is a heat pipe heat exchanger.
14. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 1 wherein said housing is a pre-assembled housing having at least one recess for insertion of said at least one horizontal cooling coil therein.
15. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 14 wherein each said horizontal cooling coil is slidably insertable upon side angle profile supports within said recess of said pre-assembled housing.
16. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 15 further comprising said horizontal cooling coil being retained by a plurality of baffles and opposite end plates accommodating said slidably insertable horizontal cooling coil therein; wherein further said end plates and said baffles each having at least one elastomeric seal sealing said end plates and said baffles to an interior surface of said recess of said pre-assembled housing accommodating said insertable horizontal cooling coil therein, whereby said insertable horizontal cooling coil is slidably removable from said recess of said pre-assembled housing for repair or maintenance thereof.
17. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 11 wherein said manifold is triangular in crossection, wherein the apex of said triangular cross sectional manifold extends axially parallel to the longitudinal axis of said at least one cooling coil; said manifold having a series of inlet plenums for inlet of said incoming air stream, said inlet apertures adjacent to a series of outlet plenums, each said inlet plenum and said outlet plenum being triangular in crossection and having an apex extending parallel to the longitudinal axis of said at least one cooling coil, said at least one cooling coil having a coolant manifold extending horizontal and perpendicular to the longitudinal axis of said at least one cooling coil.
18. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 12 wherein said at least one plate type heat exchanger is a plurality of plate type heat exchangers.
19. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 12 wherein said plate type heat exchanger is a cross flow plate type heat exchanger, comprising a heat exchange body having a diamond shaped crossection, said cross flow plate type heat exchanger heat exchanger having a longitudinal axis extending horizontally and perpendicular to the longitudinal axis of said cooling coils, each said cooling coil having at least one drain pan thereunder.
20. The combination modular drain pan assembly and horizontally positioned cooling coil in claim 13 wherein said at least one heat pipe heat exchanger is a plurality of heat pipe heat exchangers.
21. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 16 wherein said at least one elastomeric seal is a plurality of seals providing a sealed fit for each said cooling coil in a variable dimension region between a top of each said cooling coil and a bottom of a respective heat exchange area above each said cooling coil.
22. The combination modular drain pan assembly and horizontally positioned cooling coil as in claim 21 wherein each said variable dimension region has a height taller than a height of each respective seal, wherein when each said cooling coil is inserted above a respective coil support, said respective cooling coil is raised by said respective coil support to provide a tight fit for said respective seal between said top of said respective cooling coil and said bottom of said respective heat exchange area.
Type: Application
Filed: Aug 20, 2012
Publication Date: Apr 25, 2013
Inventor: Walter Stark (Huntington, NY)
Application Number: 13/590,156
International Classification: F25D 21/14 (20060101);