US3147041A - Method and apparatus for shipping incompatible materials in the same compartment - Google Patents

Description

Sept. 1, 1964 M. D. HOWCROFT 3,147,041

METHOD AND APPARATUS FOR SHIPPING INCOMPATIBLE MATERIALS IN THE SAME COMPARTMENT Filed May 29, 1961 INVENTOR. E I E. z MAX D. HOWCROFT AT TORNEYS United States Patent 3,147,041 METHOD AND APPARATUS FOR SHEPING IN- COMPATIBLE MATERIALS IN THE SAME COM- PARTMENT Max D. Howcroft, 1716 Crestview Drive, Modesto, Calif. Filed May 29, 1961, Ser. No. 113,353 8 Claims. (Cl. 30253) This invention relates to improvements in a method and apparatus for shipping incompatible materials in the same compartment.

A serious economic problem has arisen in connection with certain carriers such as railway tankcars, tanker ships, tank trucks, gondola cars, and the like which are used to transport oily, corrosive, odoriferous and similar materials. Because these materials are incompatible with and tend to contaminate many other materials normally shipped in the same type of carrier, it is often necessary for the carrier to return empty. For example oil and other refinery products are often shipped in tankcars from the Texas oil fields to the Midwest and the tankcars are subsequently returned empty. At the same time grain is shipped in boxcars or other types of railway cars to Texas, and because of lack of suitable cargo return empty to the Midwest. Obviously, if the grain could be shipped in the tankcars returning to Texas, significant savings would be effected. This has heretofore been impractical due to the well known propensity of grain to take on the strong odors of oil and like products.

The same situation applies to other types of carriers moving between other areas. Likewise, storing of commodities would be greatly simplified and expedited if they could be stored at different times in the same compartment.

The present invention contemplates a method and apparatus for shipping flowable materials in the same compartment either at the same time or at diiferent times in such manner that the materials are protected from contamination. For this purpose the invention envisions a bag-like liner separate from but insertible into the compartment and adapted to contain and protect the material being shipped. For low cost and strength combined with imperviousness to odors, etc., I prefer to form the bag liners of readily available synthetic resin plastics.

Where an elongated compartment such as that provided by tankcars is being used, problems arise in filling the relatively inaccessible ends of the compartment so as to utilize completely its full volumetric capacity. It is necessary to convey the material into the ends of the compartment and I have found the bag liner has a strong tendency to interfere with this procedure. To overcome this problem I inflate the bag with air so as to support the walls thereof in distended condition out of the way of whatever conveying means is being used.

Another problem arises in emptying the bag liners, also as a result of the thin, flexible nature of the bag walls. Unless otherwise supported, the bag tends to collapse upon and interfere with the operation of the removal conveyor. I have found that I can completely eliminate this problem by adding sufiicient air to maintain the bag in inflated condition during the removal of the material therefrom.

Accordingly it is a principal object of the present invention to provide a method and apparatus for shipping flowable materials in the same compartment in which the material being shipped may be quickly and easily loaded and removed but will be completely sealed off from the inner surfaces of the compartment.

Another object of the invention is to provide a method and apparatus of the character described incorporating a flexible bag liner not directly connected to the compartment walls but which is supported thereagainst during the loading and unloading operations.

A further object of the invention is to provide an apparatus of the character described in which air is introduced into the bag liner and the latter is maintained in inflated condition by restricting the flow of air from the liner.

A still further object of the invention is to provide an apparatus of the character described in which the air supply is provided by the pneumatic conveyor used to load the flowable material into the bag.

Another object of the invention is to provide an apparatus of the character described which incorporates additional means for aiding in removing the flowable material from the ends of elongated compartments.

Further objects and advantages of my invention will be apparent as the specification progresses, and the new and useful features of my method and apparatus for shipping incompatible materials in the same compartment will be fully defined in the claims attached hereto.

The preferred forms of my invention are illustrated in the accompanying drawing forming part of this application, in which:

FIGURE 1 is a side elevational view of a railway tankcar in which a loading apparatus constructed in accordance with the present invention is operatively positioned and in which portions of the tankcar and apparatus are broken away and shown in section to illustrate internal details;

FIGURE 2, a side elevational view of one end of a tankcar taken similarly to that of FIGURE 1 but illustrating apparatus for removing the flowable material therefrom;

FIGURE 3, an enlarged fragmentary detail view of a device for eifecting an air-tight connection between the bag liner and a pneumatic conveyor conduit; and

FIGURE 4, a fragmentary side elevational view of an end of a tankcar incorporating a modified form of the apparatus of FIGURE 2.

While I have shown only the preferred forms of my invention, it should be understood that various changes or modifications may be made within the scope of the claims attached hereto without departing from the spirit of the invention.

Referring to the drawings in detail, it will be seen that the apparatus of the present invention includes a bag 11 adapted for containing a flowable material such as grain 12 and having thin, flexible walls 13 impervious to odors and contaminants and formed for positioning within the compartment, together with means 14 for supporting the bag walls 13 during movement of the flowable material into and out of the bag. Also incorporated in the apparatus is a conveyor means 16 for selectively moving the material 12 into and out of the bag.

The material of which the bag 11 is formed is important to the successful operation of the invention and preferably consists of a synthetic resin plastic having certain desired properties. The particular properties required will vary somewhat with the nature of the commodity being shipped, the size and shape of the compartment, and special requirements such as corrosion resistance, etc. However, certain properties are common to all forms of the invention.

For economy in manufacture, ease in handling Era space requirements, the walls 13 of the bag should be very thin and flexible. This is made possible by the fact .that the bag walls are supported against outward movement by the walls of the compartment and are supported against inward movement by the means 14 during loading and unloading and by the flowable material during shipping.

For most purposes a polyethylene material several thousandths of an inch thick will be adequate. Where the compartment is large or the material being carried presents sharp and jagged edges, the bag may be formed of the polyester film produced by reacting terephthalic acid With ethylene glycol and commonly known by the Du Pont trade name Mylar. Where increased chemical inertness and resistance to corrosion is required the film may be formed of or coated with polytetrafluoro ethylene, commonly known as Teflon.

The extreme thinness of the wall 13 makes it possible to collapse the bag completely and leave it in place in a compartment such as the interior of a railway tankcar 17 when the latter is being used in its normal capacity for transporting liquids. The collapsed bag takes up very little space and when the car is empty the bag may readily be inflated to assume its correct position in the tankcar.

In accordance with the present invention the means 14 for supporting the bag walls 13 includes a conduit 18 communicating with the interior of the bag 11 and adapted for connection to a source of air under pressure such as a blower 19. The conduit 18 has a flow capacity sufficient for maintaining the bag 11 in inflated condition during the movement of the flowable material 12 into and out of the bag by the conveyor means 16 without obstruction by the bag walls 13. This makes it possible to utilize the full volumetric capacity of elongated compartments such as are found in the tankcars 17.

While any suitable conveyor means 16 may be employed in the apparatus, I have found that a pneumatic conveyor means provides several unexpected advantages. For example in the form of the invention shown in FIG- URE 1 and utilized for filling the tankcar 17 with grain 12 or other flowable material, the functions of the conduit 18 and the conveyor means 16 are combined. As depicted more or less schematically at the upper portion of FIGURE 1, a grain hopper 21 may be mounted to feed into the conduit 18 so that the grain is entrained upon the air blast passing through. The grain is conveyed into the bag 11 by an extension 22 of the conduit 18 which is made flexible so as to direct the stream of grain to the desired location. With this construction the stream of air passing through extension 22 serves both to inflate the bag and to propel the grain into the ends of the compartment.

FIGURE 3 illustrates a convenient method of sealing the bag 11 to the conduit extension 22. As here shown, the bag is formed with a sleeve portion 23 secured to the extension 22 by means of a C clamp 24 having a manually operative thumbscrew 26.

Means 27 is also mounted on the bag and is adapted to provide a restricted passage for egress of the air at a rate of flow not exceeding the rate of flow of the pneumatic conveyor so that the bag will be maintained in inflated condition. Preferably and as here shown, the means 27 consists of a tube 28 secured by a clamp 29 to a sleeve portion 31 in a manner similar to the connection of conduit extension 22 to the bag 11. Mounted in the tube 28 is a butterfly valve 32 which may be manually operated by a handle 33 positioned at the exterior of the tube. The butterfly valve 32 should be regulated to allow air to escape in quantities sutficient to avoid blowing up the bag 11 but not suflicient to permit the bag to deflate.

FIGURE 2 of the drawings illustrates the conveyor means 16a as comprising a pneumatic suction conduit 34 adapted for connection to a blower or the like (not shown). The grain 12 is entrained in the air being drawn into the intake end 36 of conduit 34 and passes through the conduit to a suitable storage bin.

As a feature of the present invention, air is added to the bag 11 in suflicient quantities to maintain the bag in inflated condition while the conduit 34 is removing the grain. This is here accomplished by a smaller conduit 37 through which high-pressure air is forced in sufiicient volume to make up the quantities of air drawn from the bag through the conduit 34.

I have found that the operation of the pneumatic conveyor conduit 34 may be significantly facilitated by providing a nozzle 38 on the end of conduit 37, the nozzle being formed for directing a blast of high-pressure air against the grain 12. This stirs up the grain in the ends of the compartment and aids in entraining it in the air entering the pneumatic conveyor 34.

A modified form of the invention is illustrated in FIG- URE 4 in which the conveyor means 16b is mechanical in nature as contrasted to the pneumatic conveyors illustrated in FIGURES 1 and 2. It should be apparent that the described inflation of the bag 11 is equally effective in connection with mechanical conveyors. The supporting of the walls of the bag in distended condition permits the operator to direct the end of the conveyor to the correct location to effect complete removal of the grain.

The mechanical conveyor means 16b illustrated in FIG- URE 4 is of a conventional type and consists of an auger 39 rotatable in a trough 41. The trough 41 should be mounted for free swinging movement so that its intake end 42 may be moved to correct position for unloading all of the grain. In this connection it should be noted that should the mechanical conveyor means 16b be ineffective for removing the last remnants of the grain, the bag 11 may be collapsed and drawn out through the access hatch 43 in the dome 44 of the railway car 17.

In carrying out the method of the present invention, the compartment to be used is provided with a separate flexible plastic bag liner. The flowable material is then conveyed into the bag liner while the interior of the latter is maintained at a pressure higher than atmospheric pressure so as to support the bag liner in distended condition. At the destination the bag liner is again inflated and held in distended condition while the flowable material is being removed therefrom.

The method and apparatus of the present invention is thus well suited for preventing contamination of materials even though shipped in the same compartment as some incompatible material. Ordinarily it is contemplated that the incompatible materials Will occupy the compartment at different times and the major problem will be to prevent any residue remaining in the compartment from contaminating subsequent shipments. However it should be appreciated that the present invention is also effective to prevent the compartment from becoming contaminated in the first place. Moreover, the present invention can be adapted to permit shipping of incompatihle materials in the same compartment at the same time. This may be done very simply by providing more than one of the bags 11, with each bag having its own conveying and inflating means.

I claim:

1. An apparatus for transporting flowable materials in an elongated tank-like shipping compartment having a limited access, comprising a bag adapted for containing a flowable material and having thin flexible walls impervious to vapors and formed for positioning within the compartment, a pneumatic conveyor having a flexible suction conduit extending into said bag and formed for drawing air and the material entrained thereon from said bag, and means for adding air to the interior of said bag at a rate of flow not less than the rate of flow of said pneumatic conveyor whereby the bag will be maintained in inflated condition during removal of the said material, said conduit incorporating a passage for high-pressure air terminating in a nozzle positioned inside of said bag, said nozzle being formed for directing a blast of high-pressure air issuing therethrough against the mate rial to aid in stirring up the material in the ends of said compartment and entraining it in the air entering said pneumatic conveyor.

2. An apparatus for transporting flowable materials in an elongated tank-like shipping compartment, comprising a flexible plastic bag adapted for containing a flowable material having Walls impervious to vapors and formed in substantial matching configuration at the end of the compartment, a conveyor for moving materials into and out of said bag through said limited access, and penumatic means associated with said conveyor and simultaneously operative therewith for maintaining the bag in an inflated condition as material is moved into and out of said bag.

3. The apparatus defined in claim 2, in which theconveyor utilized for removal of material is a mechanical conveyor.

4. The apparatus defined in claim 2, in which the conveyor utilized for removal of material is a pneumatic conveyor extending into said bag and formed for blowing air and a flowa-ble material entrained thereon into said bag, and the means for maintaining the bag in inflated condition is a restricted passage for egress of air blown into the bag by the pneumatic conveyor.

5. The apparatus defined in claim 2, in which the conveyor and means for maintaining the bag in inflated condition includes a pneumatic conveyor having a flexible suction conduit extending into said bag and formed for drawing air and the material entrained thereon from said bag, and means for adding air to the interior of said bag at a rate of flow not less than the rate of flow of said pneumatic conveyor whereby the bag will be maintained in inflated condition during removal of the said material, said conduit incorporating a passage for high-pressure air terminating in a nozzle positioned inside of said bag, said nozzle being formed for directing a blast of high-pressure air issuing therethrough against the material to aid in stirring up the material in the ends of said compartment and entraining it in the air entering said pneumatic conveyor.

6. In a railroad tankcar having -a tank with limited access, in combination, a flexible plastic bag adapted for containing a flowable material having walls impervious to vapors and formed in substantial matching configuration at the end of the compartment, a conveyor for moving materials into and out of said bag through said limit ed access, and pneumatic means associated with said conveyor and simultaneously operative therewith for maintaining the bag in an inflated condition as material is moved into and out of said bag.

7. The method of shipping flowable materials in a shipping compartment having a limited access, comprising the steps of inserting an air-tight flexible plastic bag liner in said compartment, inflating the bag liner, adding the material to be shipped while maintaining the bag in inflated condition, transporting the container and contents to a shipping destination, inflating the liner at the shipping destination and removing the material from the bag While the liner is maintained in an inflated condition.

8. The method of shipping flowable materials in a shipping compartment having a limited access, comprising the steps of inserting an air-tight flexible plastic bag liner having matching configuration with the container in said compartment, inflating the bag liner to extend the liner in position against the container, adding the material to be shipped while maintaining the bag in inflated condition, transporting the container and contents to a shipping destination, inflating the liner at the shipping destination and removing the material from the bag with a pneumatic conveyor while blowing a stream of air into the liner to dislodge and entrain material while simultaneously maintaining the liner in an inflated condition.

References Cited in the file of this patent UNITED STATES PATENTS 1,498,612 Collingwood June 24, 1924 2,394,607 Gray Feb. 12, 1946 2,950,146 Lease Aug. 23, 1960 2,991,906 Eligonlachvili July 11, 1961 3,005,317 Bunn Oct. 24, 1961 FOREIGN PATENTS 484,440 Canada July 1, 1952

Claims (1)

1. 2. AN APPARATUS FOR TRANSPORTING FLOWABLE MATERIALS IN AN ELONGATED TANK-LIKE SHIPPING COMPARTMENT, COMPRISING A FLEXIBLE PLASTIC BAG ADAPTED FOR CONTAINING A FLOWABLE MATERIAL HAVING WALLS IMPERVIOUS TO VAPORS AND FORMED IN SUBSTANTIAL MATCHING CONFIGURATION AT THE END OF THE COMPARTMENT, A CONVEYOR FOR MOVING MATERIALS INTO AND OUT OF SAID BAG THROUGH SAID LIMITED ACCESS, AND PENUMATIC MEANS ASSOCIATED WITH SAID CONVEYOR AND SIMULTANEOUSLY OPERATIVE THEREWITH FOR MAINTAINING THE BAG IN AN INFLATED CONDITION AS MATERIAL IS MOVED INTO AND OUT OF SAID BAG.

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