AU2011101211A4 - A non pressurised, dustless, mass flow, fully emptying, bulk powder, shipping container - Google Patents

Abstract

A purpose designed and built shipping container for bulk powders comprising a non pressurised vessel which is transported in the horizontal position and designed using silo design techniques to ensure mass flow discharge of the powder under gravity when the container is tilted to an appropriate angle to the horizontal to ensure the powder material flows out of the discharge outlet at the bottom. The shipping container incorporates a frame designed to integrate with the silo vessel structure to form a monocoque style of structure. The frame conforms to ISO (International Standards Organisation) standards for shipping containers and includes conforming corner castings. The silo vessel incorporates filling hatches, aerators, vent pipe, isolation valves and quick connect couplings. The shipping container requires an unloading facility to discharge the bulk powder. The unloading facility incorporates a tilting frame with twistlocks, a pneumatic transfer unit with the ability to suck powder from the vessel outlet, a bag house filter and a compressed air supply.

Description

1 NON PRESSURISED, DUSTLESS, MASS FLOW, FULLY EMPTYING, BULK POWDER, SHIPPING CONTAINER TECHNICAL FIELD [0001] The field of this innovation is the transport and unloading of bulk powders in standard dimension shipping containers and particularly relates to a purpose designed non pressurised vessel which incorporates mass flow, gravity discharge principles of bulk storage silo design. BACKGROUND [0002] Shipping containers are available in a number of standard sizes and are used to ship a variety of goods. However standard shipping containers are not suited to the loading and unloading of bulk powders. Standard shipping containers are fundamentally a rectangular enclosed box with a pair of doors at one end. Dry bulk powders such as cement are generally easy flowing and emit dust when disturbed. If such a powder is loaded or unloaded through the open doors of a shipping container large amounts of uncontained dust will be generated and the material is open to contamination from moisture or dust in the atmosphere. [0003] Some current standard shipping containers have been modified to connect with an unloading system. The modifications involve creating a small discharge gate low in one end and. The unloading system is required to tilt the shipping container in order to tip the powder out, collect the powder in a transfer hopper and provide a powder transfer system to move the powder into another container. The disadvantages of modified standard shipping containers are that modifications add weight which increases tare and reduces payload and bulk powders tend to hang up in the ledges and corners resulting in the material not completely emptying and the difficulty in sealing between the shipping container and the unloading system hopper to prevent dust emissions. [0004] Some current shipping containers for bulk powder incorporate a pressure vessel which connects to a pressured discharge transfer system. The disadvantage of 2 these shipping containers is the high capital cost and ongoing maintenance cost of pressure vessels, the ongoing regulation and certification of pressure vessels and the intrinsic safety risk of pressure vessels. SUMMARY OBJECT OF THE INOVATION [0005] It is an object of this innovation to provide a purpose designed vessel for transporting bulk powders incorporated in a frame complying with standard shipping container dimensions and that the vessel is not a pressure vessel and it completely empties when discharged without exposing any of the contents to atmosphere. It is also an object of this innovation that the payload be maximised within the volume of the container dimensions. SOLUTION [0006] A non pressurised, dustless, mass flow, fully emptying, bulk powder, shipping container in accordance with this innovation comprises a purpose designed vessel or silo which incorporates mass flow, gravity discharge principles of bulk storage silo design and integrates the structure of the silo with the frame of the shipping container. The silo vessel is designed to completely empty by gravity when tilted to an angle to the horizontal. The required tilt angle is determined by the angle of the silo cone and the angle at which the transported bulk powder will flow and not hang up. [0007] The silo vessel incorporates aeration devices in the lower section to enable aeration and fluidisation of the contained bulk powders. The aeration devices are connected via piping to an isolation valve and a quick connect coupling which can be connected via a flexible hose to a regulated compressed air supply. The silo vessel incorporates hatches which can be unlatched and pivoted open to provide openings for filling the vessel with bulk powder at a standard filling depot such as included at a cement factory. The silo vessel incorporates a vent pipe with an isolation valve and a quick connect coupling which can be connected via a flexible hose to a bag filter at the unloading station. The silo vessel incorporates a discharge pipe to the side with an 3 isolation valve and a quick connect coupling with can be connected via a flexible hose to a suction operated pneumatic transfer device at the unloading station. [0008] In another form the silo vessel incorporates a discharge opening at the bottom with an isolation valve and a quick connect coupling which can be connected via a flexible hose to another container below and the contents of the silo can be transferred to the lower container by gravity flow of the stored bulk powder. [0009] The silo vessel is transported in the horizontal position. However for unloading the container needs to be elevated to an angle which relates to the angles of the discharge cone of the silo. In its elevated position the angle of the silo discharge cone relative to horizontal must match the required angle to ensure that the bulk powder will flow and not hang up. [0010] The frame of the shipping container is purpose designed to comply with the ISO (International Standards Organisation) standard for shipping containers. The dimensions, load bearing capacity and corner casting fittings are designed to comply with the ISO standard. The structural design of the frame is integrated with the structure of the silo vessel to produce a monocoque assembly which maximises structural efficiency, minimises tare weight and maximises contained volume and payload. When transported by rail, road or sea the container is anchored to standard container twist lock anchors at the corner castings. [0011] The non pressurised, dustless, mass flow, fully emptying, bulk powder, shipping container bulk is emptied at an unloading facility which incorporates a tilting frame assembly which has twist lock fittings to attach the container. The tilting frame tips the container to the required angle from the horizontal to ensure that the material flows down the silo vessel cone. The unloading facility also incorporates a supply of regulated compressed air to connect to the silo vessel aeration system. The unloading facility also incorporates a bag filter to connect to the vessel vent pipe to ensure that air can flow in and out of the silo vessel during discharge without emitting powder dust into the atmosphere. The unloading facility also incorporates a pneumatic transfer unit which has the ability to suck aerated powder materials and transfer the material to another container such as a fixed silo.

4 [0012] In another form the tilting frame of the unloading facility may be positioned above a transfer vessel and the container discharges by gravity into the transfer container via a flexible quick lock connected hose. The transfer facility may incorporate pneumatic or mechanical means of conveying the powder to another container such as fixed silo. ADVANTAGES [0013] A non pressurised, dustless, mass flow, fully emptying, bulk powder, shipping container in accordance with this innovation provides the advantages of lower capital cost, lower ongoing maintenance cost and less administration than for pressure vessel units. A shipping container in accordance with this innovation provides the advantages of minimum tare, maximum payload, complete unloading and no dust emissions.

Claims (5)

1. A purpose designed and built shipping container, not a modified standard shipping container being for bulk powders comprising a non pressurised vessel which is transported in the horizontal position and designed using silo design techniques to ensure mass flow discharge under gravity when the container is tilted to an appropriate angle to the horizontal to ensure the powder material flows out of the discharge outlet at the bottom which can be either an outlet pipe to the side to connect to a suction transfer unit or an outlet in the bottom which will gravity discharge into a vessel below.

2. The shipping container as claimed in claim 1, wherein the frame of the container is designed to comply to ISO ( International Standards Organisation) shipping container standards and is structurally integrated with the design of the silo vessel to form a monocoque style structure and is fitted with ISO standard shipping container corner castings.

3. The shipping container as claimed in claim 1 and 2 wherein the silo vessel is fitted with opening hatches in the top (when the container is in its horizontal transport orientation) to facilitate bulk powder loading in a normal loading facility such as a cement factory loading depot.

4. The shipping container as claimed in claim 1, 2 and 3 wherein the silo vessel is fitted with aeration pads in the cone and lower sections to aerate and fluidise the contained bulk powder to assist discharge and the silo vessel is fitted with a vent pipe to connect to a bag filter when unloading and the silo is fitted with isolation valves and quick connect couplings at connections to the unloading facility.

5. The shipping container as claimed in claim 1,2 3 and 4 wherein the vessel can be unloaded when tilted to the appropriate angle that the bulk powder flows either using a pneumatic suction transfer unit which sucks the powder from the discharge outlet of the silo vessel or gravity discharge directly from the silo vessel outlet into a vessel below.