Air Tank Drain

This invention relates generally to air storage tank drains and more particularly to an automatic venturi drain which expelled accumulated liquid in the tank along with the stored air withdrawn from the tank. Current engine air starter storage tanks utilize a pet-cock located at the low point of the tank for periodic removal of liquids. Typically this is a maintenance item which is forgotten. Various schemes exist for automatically activating a valve to keep the liquids out of the tank. These are complicated, requiring electric or pneumatic control valves and are, therefore, prone to failures.

The foregoing illustrates limitations known to exist in present devices and methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.

In one aspect of the present invention this is accomplished by providing an air tank venturi drain comprising a tank for receiving and storing a compressible pressure fluid; a port means in the tank for delivery of the pressure fluid to a conduit extending from the tank; a suction conduit extending from the port means to a selected point within the tank; and a venturi means formed in the port means for producing suction to educt liquid from the suction conduit and the selected point within the tank.

The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.

FIG. 1 is a partial sectioned view of a vertically orientated air tank containing a venturi drain according to the present invention;

FIG. 2 is a partial sectioned view of an air tank according to the present invention shown in a horizontal position; and

FIG. 3 is a detailed cross section showing the venturi design according to the present invention.

Referring to FIG. 1, an air tank for a pneumatic engine starter or the like is shown and generally referred to by reference numeral 1. The tank is provided with a port 2 which in the present case is utilized to fill and extract pressure fluid which may, for example, be compressed air or other suitable gas. The tank 1 is further provided with a flexible suction tube 3 extending from the nozzle or port 2 to a low position in the tank where it is open terminated and held in position by a gravity weight 4.

The suction tube 3 is positioned within the nozzle 2 in a groove 5 formed within the interior of the nozzle. The tube or hose 3 is secured within the groove 5 by means of a snap ring 6 or the like (best seen in FIG. 3). The construction shown permits the drain to be readily assembled in the nozzle by simply feeding the flexible conduit into the groove formed in the nozzle and securing it therein by insertion of a snap ring in a groove formed within the nozzle. The open end 10 of the conduit or hose 5 is positioned within the nozzle and formed so as to create a venturi effect as pressure fluid is delivered from the storage tank. The venturi effect creates a suction in the conduit or hose 3 which in turn withdraws any liquid at the bottom of the tank.

The gravity weight 4 is shown attached to the bottom end of the suction tube 3 and is provided for the purpose of assisting the suction tube to find the low portion of the tank in service. This permits the tank to be installed in a vertical position as shown in FIG. 1 or in a horizontal position as shown in FIG. 2. The gravity weight 4 and the suction hose 3 are provided with a notch and bias cuts (of the hose) 11 to permit fluid to be drawn into the suction hose when the gravity weight 4 is on the bottom of the tank.

Further, as shown in FIG. 3, the tank may be constructed of a metallic outer shell 1 having a suitable corrosion resistant inner coating 8 of plastic or fiberglass or similar material. A nozzle reinforcement 9 may be utilized and may be made of metal or similar structurally sufficient material to resist the nozzle forces created by the piping connections to the tank.

Thus, it should be now apparent to one skilled in the art that any unwanted liquid in the pressure fluid storage tank will be withdrawn and delivered with the pressure fluid exiting the tank upon withdrawal demand of pressure fluid.