US2244302A

US2244302A - Fumigant container

Info

Publication number: US2244302A
Application number: US296447A
Authority: US
Inventors: George E Lynn; Fred W Fletcher
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1939-09-25
Filing date: 1939-09-25
Publication date: 1941-06-03
Anticipated expiration: 1958-06-03

Description

June 3, EMPL G. E. LYNN ETAL 22,302

- FUMIGANT CONTAINER Filed sept. 25, 1959 j; j@ f5 5 EL INVENTORS ATTORNEY Patented .lune 3, 1941 FUMIGANT CONTAINER gall Application September 25, 1939, Serial No. 296,447

6 Claims.

This invention relates to containers, and is particularly concerned with a novel can structure adapted to be employed for dispensing fumi-gants.

Fumigants such as hydrocyanic acid,` methyl bromide, sulphur dioxide, and the like are commonly distributed as liquids in pressure containers. Such liquid fumigants frequently boil at temperatures below 30 C. and tend to vaporize readily in air, even when cooled to below their boiling temperature. The vapors and fumes of such materials are toxic to humans if inhaled in any appreciable amount. It is essential, therefore, that care be exercised in the'handling of these materials, it being impractical to transfer them in open containers unless the operator is equipped with a gas mask or is otherwise protected.

In Carrying out fumigating operations, the doors, windows and other openings oi' the room or chamber to be treated are tightly sealed, the fumigant being commonly introduced in such a haphazard manner as to endanger the health of the operator. For example, where it is desired to treat one or several rooms or closets, as for the control of moths, bedbugs, or other household pests, it has been common practice to vaporize the desired amount of the fumigant from a shallow open vessel. A further unsatisfactory procedure has been to spray, atomize, or otherwise distribute the liquid product by hand from an open container. To avoid the inconveniences, losses of material, and danger inherent to such practice', many applicators and dispensing devices have been developed. Such devices have not been particularly satisfactory, however, since almost without exception the presence of an operator and certain manual operations are required to accomplish the fumigant distribution.

Among the objects of this invention are (l) to provide an improved pressure receptacle for fumigant liquids in the form of a portable sealed container embodying automatic ydispensing means, and (2) to provide a fumigant receptacle adapted for household use which does not require the presence of an operator or manual operation to vent the fumigant.

According to our invention, a container is provided with a tube extending from within and near its bottom through the top of the container. At the outer end, this tube is sealed wih a plug of W-melting metal alloy or the like which, when melted, provides a vent for the release of pressure generated by fumigant previously conned in the container. As the pressure is releasedthe liquid fumigant is forced up through the tube-and out of the container and vaporizes, More specincally, the invention provides the Icombination of a can structure in which the top and bottoniare concave, a tube therein, and a fusible external closure for the tube.

Referringnow to the drawing:

Fig. 1 is a cross-sectional elevation or a container embodying the invention.

Fig. 2 is an elevation largely in section of a can embodying a modication of the invention.

Fig. 3 is a part sectional elevation showing a further modification of the fusible closure illustratedr in Fig. 2.

Fig. 4 is a plan view of the top oi the can structure shownv in Fig. 3.

In each of the gures illustrated in the drawing, the container shell I I is closed at the bottom I2 and at the top I3. The top member I3 carries a concentrically disposed tube Id extending nearly to the bottom I2 of the container. The end of the tube I4 projecting through the top member I3 is provided with a fusible sealing closure, illustrated in Fig. 1 as a simple cap plug I5. In Fig. 2 the closure comprises a plate nozzle i5 xedly attached, as by brazing, to the container top I3. The plate nozzle I6 is counterbored I'i to fit over the protruding end of the tube It within the container. The orice I9 in the nozzle I6 is sealed with a fusible cap plug I5. In Fig. 3 the nozzle IE is counterbored from each end, whereby a recess !8 is provided to accommodate the fusible sealing means I5. In Figs. 3 and 4, there is shown a molded ring 2li disposed around the plate nozzle I6. and consisting of a thermogenic material.

In operation, a container, as described above, is charged with a liquid fumigant, such as methyl bromide, and placed by the operator Within the room to be fumigated. With the preferred embodiment of the invention, illustrated in Figs. 3 and 4, the ring of solid combustible material 20 encircling the closure is then ignited. No further attention by the operator is required. The generated heat fuses the plug of low-melting alloy, whereby the pressure exerted by the confined liquid fumigant forces the fumigant through the discharge tube and out of the can. Where a thermogenic element is not an integral part of the closure, and particularly when a can having a concave top is employed, the fusion of the plug may be accomplished by pouring a.V

ing alloy, such as Woods metal, Roses metal,

Lipowitzs alloy, bismuth solder, or other metal or metallic mixture, provided only that the material selected has a melting point between about 50 and about 125 C.

The plate nozzle, as employed in certain embodiments of the invention, is preferably of brass, although other metals, such as copper, which are adapted to collect the heat emanating from the heat source and transmit the same to the fusible plug, may be substituted. Any desired form of nozzle may be employed. If desired, the nozzle may be fitted over and attached to the discharge tube in such manner as to be out of contact with the container top.

With respect to the heating element, no limitation is made upon its precise composition or form. For example, the element may take the form of a molded ring or pellet of combustible material. Such a product may be conveniently prepared from a mixture of equal parts by weight of metaldehyde and starch or from hexamethylene tetramine. Such molded element is attached adjacent to either the sealed discharge tube or the plate nozzle. Alternately, the combustible material may take the form of a small amount of alcohol or other flammable liquid placed around the fusible seal or nozzle and ignited as the can is employed. In place of the combustible material, an inorganic salt or salt mixture adapted to givel off heat when wet with water may be employed. The only requirement with respect to the heating element is that the temperature developed thereby must supply sufficient heat to melt the plug and liberate the fumigant.

A further application of the present invention resides in a closure comprising the discharge tube and fusible seal, with or without the plate nozzle, xedly positioned through a cap or plug adapted to screw into or onto a threaded aperture in the top of a fumigant container. Such a closure is conveniently employed in the repackaging of liquid fumigants into units of small Weight and volume, since it permits the utilization of inexpensive and commonly available can structures.

We therefore particularly point out and distinctly claim as our invention:

1. A dispensing device for liquid fumigants and the like comprising in combination a fluid-tight pressure container, a discharge tube sealed through the top of said container and extending downwardly to near the bottom of the container, a fusible closure embodying a low-melting metal alloy seal over the outer opening of said tube, and a tliermogenic element adjacent to the closure.

2. A dispensing device for liquid fumigants comprising in combination a fluid-tight pressure container, a discharge tube sealed through the top of said container and extending downwardly to near the bottom of the container, a closure for said tube embodying a counterbored metal plate nozzle adapted to lit over the end of the tube, a fusible seal o'ver the orifice of said nozzle, and a thermogenic element adjacent to the closure.

3. A dispensing device for liquid fumigants comprising in combination a fluid-tight metal container, a discharge tube sealed through the top of said container and extending downwardly to near the bottom of the container, a closure for said tube embodying a counterbored metal plate nozzle adapted to t over'the end of the discharge tube, a fusible seal over the orifice of said nozzle, composed of a low melting alloy, and a thermogenic element adjacent to the closure.

4. A dispensing device for lliquid fumlgants comprising in combination a fluid-tight metal container, a discharge tube sealed through the top of said container and extending downwardly to near the bottom of the container, a closure for said tube embodying a counterbored metal plate nozzle adapted to t over the end of the discharge tube, a fusible metal alloy seal over the orifice of said nozzle, and a molded element of combustible material adjacent to the closure.

5. A fumigant container comprising a can in which the top and bottom are concave, a discharge tube sealed through the top and extending downwardly to near the bottom of the can, and a fusible closure embodying a low-melting metal alloy seal over the outer opening of said tube.

6. A container for liquid fumigants and the like comprising a cylindrical metal shell having concave top and bottom members sealed thereto, a discharge tube sealed through the top extending downwardly Within the shell to near the bottom thereof, and a fusible closure to seal the outer opening of said tube.

GEORGE E. LYNN. FRED W. FLETCHER.