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Publication numberUS3246758 A
Publication typeGrant
Publication dateApr 19, 1966
Filing dateJan 30, 1963
Priority dateJan 30, 1963
Publication numberUS 3246758 A, US 3246758A, US-A-3246758, US3246758 A, US3246758A
InventorsWagner William
Original AssigneeWatsco Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Hygrometric indicator for desiccants
US 3246758 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

April 19, 1966 w. WAGNER HYGRMETRIC INDICATOR FOR DESICCANTS Filed' Jan. 5o, 1965 INVENTOR WiLLl AM WAGNER Bf United States Patent O y 3,246,758 HYGROMETRIC INDICATOR FOR DESICCANTS William Wagner, Miami Beach, Fla., assigner t Watsco, Inc., Dade County, Fla.

Fired Jan. 30, 1963, ser. No. 255,018 4 Claims.` (Cl. 210-94) The present invention relates to an indicator of the moisture content of desiccants as generally used in refrige-ration systems.

In the conventional `type of refrigeration unit there is a sealed, pressurized system containing a refrigerant, typically Freon. In spite of advanced methods for sealing, this sys-tem'may contain a small amount of moisture from condensation. This moisture may freeze and clog the pressurized system thereby causing malfunction of, or even damage to, the refrigeration unit. To avoid this problem inlarge and/or` strategic refrigeration units it is common practice toinclude in the pressurized system a desiccant, or lchemical dryer, which absorbs the moisture in the're-friger-ant. Since the desiccant retainsv the moisture it absorbs, it cannot continue absorbing indefinitely. When the desiccant becomes fully saturated, it is unable to absorb additional moisture and is therefore useless. The satura-ted desiccant must then be' replaced with a ffresh, dry desiccant from stock.

Desiccants to be used in large refrigeration systems are generally packaged in ya cylindrical copper container having two standard tube fittings, one -at each end, such that the container can be placed directly in the refrigeration line. Before use, while in storage, the container must be sealed so as to keep the desiccant therein fresh and dry, the seals for such purpose .commonly being solderor screw-on caps or plugs for the end fittings of the container. Unfortunately, such seals may be imperfect or become damaged when kept in stock for a lengthy period of time before use, thereby permitting moisture to enter the container, be absorbed by the desiccant therein, and consequently render the desiccant useless.

Heretofore it has been impossible to determine the condition of a desiccant to packaged before its use -as above described. Accordingly, an object of the present invention is to provide a simple, economical, effective method of determining the moisture content of a des-iccant packaged as above described before use.

Another object of the present invention is to provide a simple, economical, effective method of sealing a desiccant container for storage before use.

A further object of the present invention is to provide stock control and rotation means for stockroo-ms having large quantities of packaged desiccants which may be stored for considerable periods of time.

In the accompanying drawing:

FIGURE 1 i-s a pictorial representation of the hygrometric indicator herein claimed.

FIGURE 2 is a pictorial representation of the indicator of FIGURE 1, showing the sealing means thereof.

FIGURE 3 is a side view of the indicator of FIGURE l.

FIGURE 4 is a cross-sectional view of the indicator of FIGURE 1, as taken across line 4--4 of FIGURE 3.

FIGURE 5 is a side cross-sectional view of the desiccant container and showing indicators as shown in FIG- URE 1 in position the-rein.

FIGURE 6 is a cross-sectional View of the desiccant container as taken across line 6-6 of FIGURE 5.

FIGURE 7 is a pictorial representation of a modified embodiment of the hygrometr-ic indicator as claimed herein.

FIGURE 8 is a cross-sectional view of one end of a desiccant container and showin-g the modified embodiment of the hygrometric indicator as shown -in FIGURE 7 in position therein.


Referring to the drawing, the hygrometric indicator for desiccants comprises a transparent plastic plug having three portions thereof, a at viewing portion 10, a shoulder portion 12 having a configuration similar to that of a fiat washer, and a hollow cylindrical portion =14 having its outside' surface tapered substantially as shown in FIGURE 4. Inside the plug, at the closed end olf cylindrical portion 14 and against the inside of viewing portion 10, is a small disk of Ian absorbent material 16 such as gauze, cotton or filter paper, such absorbent material 16 being impregnated with a chemical moisture indicator, such as -a salt of cobalt fluoride. Such a chemical indicator is normally a blue color when it is not in the presence of moisture or water Ivapo-r, the salt being in its anhydrous state; however, when moisture or water vapor' comes in contact with the chemical indicator, said indicator changes to a pink hue, the salt now being in its hydrated state. 'Ihe amount of change from blue to pink is proportional to the quantity of moisture or water vapor present, thereby providing visual indication of the dampne-ss of the adjacent material or the humidity of the surrounding atmosphere.

In the instant invention, absorbing material '16 and the chemical indicator therein impregnated, is positioned as above described, and the color of` said chemical indicator is hence visible through viewing portion 10.

Desiccant 18 is enclosed in a cylindrical copper container 20 havin-g opposite open ends 2v2, 24 of a smaller diameter than the main body thereof and having a circular Icross-section throughout. Ends Z2, 24 are of -a size suitable for soldering into a standard refrigeration line. The container 20 includes means (not shown) for retaining the desiccant therein when said container is placed in the refrigeration line, as -is convention-al in the art.

When packaged for storage and sale, ,copper container 20 is placed in a cardboard box 26 having a square crosssection. The length of box 26 is slightly less than the overall length of copper container 20 and when said container 20 is in box 26, ends 22, Z4 of container 20 protrude very slightly [from box 26 in holes 2-8, 30 provided for the purpose lin the ends of said box 26.

One plastic plug las above described is forced into each open end I22, 24 of copper container 20. In such position said plugs provide an effective seal for said container 20, thereby protecting desiccant 18 enclosed therein from moisture contamination. Furthermore, the color of the chemical indicator impregnated in absorbent material 1-6 is at all times visible through exposed viewing portion 10 at each end of box 26. Since the said chemical indicator is in direct communication with desiccant 1S, a check can easily be made of the moisture content, and therefore usefulness, of said desiccant, by merely observing the color of said chemical indicator.

A modified version of the instant invention consists of a threaded plastic cap 32 having 'a chemical indicator impregnated absorbent material 16a behind -a fla-t viewing portion 10a of said cap 32. Said threaded cap 32 screws onto threaded open ends 22a, 24a of copper container 26a thereby sealing the desiccant 18a contained therein and providing visual indication of the moisture content of said desiccant y18a in a m-anner similar to that hereinabove described for the unmodified version hereof.

What is claimed is:

1. Desiccating means for use in refrigeration systems, comprising a container radapted to be installed in a refrigeration line, said container having -two opposite ports one port |adapted to serve as the inlet port for a refrigerant passing through said line, the opposite port adapted to serve as an outlet port for such refrigerant, a desiccant contained within said container, and a pair of closure members closing said ports and sealing said desiccant within said container and .thereby preventing 3 moisture [from entering the container and hydratinlg the desiccant, at least one of said closu'reimembers being hollow land containing a hygrometric indicator exposed to said desiccant and ysensitive to any moisture that may leak into the container rand hydrate the desiccant, said closure member having a transparent portion through which the hygrornetr-ic indicator may be viewed from the outside to determine whether moisture Ihas entered the container, and a box having a pair of openings formed therein at opposite ends thereof, said container bein'g disposed in said box, and eaoh of said closure members projecting outwardly from a respective ,opening in said box, thereby permitting visual inspection of said hygrolmetric indicator without opening said box.

2. Desicoating means in accordance with claim. l, wherein each of said closure members is hollow and contains a hygrometric indicator exposed to said desiccant and vsensitive to any moisture that may leak into the container and hydrate the desiccant, eac-h said closure member having a transparent portion through which the hygroimetric indicator may be Viewed from t-he outside to determine whether moisture has entered the container.

3. The combination of claim Z, wherein the container is generally tubular, having an enlarged main body porti-on containing the desiccant and reduced end portions suited Afor connection into ia .refrigeration line, one of said lreduced end portions serving las the inlet port for the refrigerant, the other reduced e-nd portion serving as the outlet port for the refrigerant, said closure members 4 comprising hollow plastic plugs tted into said reduced end portions of thelcontai'ner.

4. The combination of claim 2, w-hcrein the container is generally tubular, having an enlarged .main body portion containing the desiccant and reduced end portions suited for connection into a refrigeration line, one of said reduced end portions serving as the inlet port for the refrigerant, the other yreduced end portion serving as the outlet port for the refrigerant, both of said reduced end portions being externally threaded, said closure members comprising internally threaded hollow plastic plugs, threadedly secured to said reduced end portions of the container.

References Cited by the Examiner Jones 73-73 X REUBEN FRIEDMAN, Primary Examiner.

SAAC LISANN, Examiner.

Patent Citations
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Referenced by
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U.S. Classification210/94, 116/206, 210/282, 73/29.5, 96/117.5, 210/446, 210/232, 210/287, 210/DIG.600, 73/73, 73/29.2, 96/108
International ClassificationF25B43/00
Cooperative ClassificationF25B43/003, Y10S210/06
European ClassificationF25B43/00B