GB1573820A - Method of and chute for transferring particulate loose material between two levels - Google Patents

Description

(54) METHOD OF AND CHUTE FOR TRANSFERRING PARTICULATE LOOSE MATERIAL BETWEEN TWO LEVELS (71) We, MITSUI ENGINEERING & SHIPBUILDING CO., Lid., a Japanese Company of 6 4 5-chome, Tsukiji, Chuo- ku, Tokyo, Japan and KAWASAKI STEEL CORPORATION, a Japanese Body Corporate of 1-28 l-chome, Kitahonmachi-dori, Fukiai-ku, Kobe City, Hyogo Pref.Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a method of transferring between two levels, particulate material such as ores, or grain, particularly such material which may be of a type relatively easily crushed or similarly broken upon shock. The invention also concerns a chute for transferring such materials between two levels. The chute may for instance be installed in a bulk carrier, such as an ore and/or grain freighter, for either marine or overland transport, for use in loading the bulky cargo into the carrier.

When loading loose material such as crushed ores, for example into holds of a cargo ship, it is general practice to dispose a conveyor device in the vicinity of and above the hold and let the cargo fall into the hold from a high level. Such a loading method causes the cargo to be crushed. Particularly, in the instance of porous ores, the method permits the cargo to be so finely pulverised that it can no longer retain its original commercial value. At the same time, it is then made difficult to carry out later the prescribed treatment or processing of the goods.

It is also currently a common practice to utilise a chute in loading loose goods. However, generally the chute is installed in the hold at an angle of inclination much greater than the angle of repose of a particular material to be handled, so the material is allowed to fall by sliding along the chute at so high a speed that the material becomes crushed or ground. Another difficulty, in this case, is that due to friction caused when the material slides own the chute at high velocity, the chute undergoes abrasive damage or wear within a relatively short time of use.If on the other hand the angle of inclination of the chute installation is smaller than the angle of repose of the cargo material, it is likely that upon unloading the cargo a considerable amount will be left deposited on the chute, requiring manual operation of removing the portion of cargo remaining on the chute.

Accordingly one aspect of the present invention provides a method of transferring loose particulate material from a first level to a lower level by controlled falling, comprising passing the material onto a chute between the said levels, said chute comprising a pair of side wall members and a bottom wall member connecting said side wall members, the bottom wall member being disposed with an angle of inclination to the horizontal which is greater than the angle of repose of the particulate material to be transferred, and said side wall members having a height sufficient to allow the particulate material to accumulate in the chute to form a layer whose upper surface is inclined substantially at the angle of repose of the material; placing the particulate material on the chute to build up to form such a layer; and placing more of the particulate material on the chute so it flows down said inclined surface of the layer at a rate controlled by the sliding or rolling action as it passes along said surface of the layer.

Thus, when the chute has had such a layer built up thereon, further conveyed material can flow on or along the surface of said reposed layer of material, said surface having an inclination parallel to the angle of repose of the cargo. This controls the movement to prevent the material from falling at a high speed down the chute, and may also prevent material at a high position on the chute from pouring over the side walls of the chute, so that difficulties with the current chute struc tures such as undesirable crush of the cargo and early wear of the chute can be effectively cancelled.

Preferably said layer is formed in such a way that it is able to disperse under the effect of its own weight when transferred particulate material from around the bottom of the chute is removed. This is greatly con ducive to ease of operation for unloading the cargo which can be automatically removed from the chute (with virtually none of it left remaining on the chute since the chute is inclined at a greater angle than the angle at which the chargo reposes).

The method of the invention offers utmost advantage, in cases where the cargo chute required is of a great length, and consequently the cargo passing down the chute is more likely to fall down the chute in large cascades.

Another aspect of the invention provides a cargo chute for use in transferring loose particulate material between a first level and a lower level, comprising: a pair of laterally positioned side wall members; a bottom wall member interconnecting said side wall memhers; and means for decelerating the flow of loose particulate material down said chute, said decelerating means comprising a plurality of flow control plates extending between the laterally positioned side walls and at spaced locations down the chute, each said flow control plate defining with said bottom wall a gap at that particular location, and having an upper edge above which said laterally positioned side wall members project at that location, the upper edges being lower for each successive flow control plate down the chute, whereby an initial charge portion of said loose particulate material can be transferred to a downstream end portion of said cargo chute through the gaps formed between said obstruction plates and said bottom wall at said locations and the material can then build up as an inclined layer of particulate material on the said bottom wall between every two successive flow control plates.

In order that the present invention may more readily be understood the following description is given, merely by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic view taken in a vertical plane parallel to the longitudinal axis of a bulk carrier, showing a hold thereof equipped with a cargo chute in accordance with the present invention; Figure 2 is a transverse cross-sectional view of the hold illustrated in Figure 1; Figures 3 and 4 are fragmentary sectional views, giving an illustration of the manner in which particulate bulk is being piled near the lower end portion of the chute; Figures 5, 6 and 7 are fragmentary perspective views, illustrating various different structures of the lower end portion of the chute; Figures 8 and 9 are fragmentary perspective views, showing spiral chute structures;; Figure 10 is a cross-sectional view similar to Figure 2, showing a hold provided with a further modified example of the chute structure; Figure 11 is a fragmentary side elevational view illustrating the manner in which particulate loose material flows on the chute; Figures 12 and 13 similarly are fragmentary side elevational views showing two modified configurations of the side wall members of the chute; Figures 14, 15, 16 and 17 are crosssectional views, as an illustration of further examples of the chute; Figures 18 and 19 are a longitudinal sectional view and a cross-sectional view, respectively, of a hold equipped with a further modified chute which includes a plurality of flow control members for controlling free acceleration of the cargo fall;; Figures 20 and 21 are fragmentary longitudinal sectional views, showing two modified examples of the chute provided with the flow control members; Figures 22 to 26, inclusive, show crosssectional views illustrating several chute structures having modified flow control members; Figure 27 is a fragmentary perspective view of a chute provided with further modified flow control members; Figure 28 similarly Is a fragmentary perspective view, showing the manner in which the cargo flows on the chute illustrated in Figure 27; and Figures 29 and 30 are fragmentary perspective views, illustrating two modified forms of structure of the flow control members.

Referring now to the drawings, and in particular to Figures 1 and 2 initially, a bulk freighter 1 such as an ore and grain carrier has a plurality of individually partitioned holds 2 covered by a deck 3 provided with hatchways 4 which have individual hatch covers 5. Near a bulkhead or- partition wall 6 of hold 2 there is installed a cargo chute 7 in an inclined manner as shown in Figure 2. Near the lower end or discharge end portion of chute 7, is a cargo receiving plate member 8 of the hold 2.

Chute 7, which is composed of side wall members 9 and 9a and a bottom wall 10 integrally fabricated in a trough-like structure substantially having a U-shaped cross-section, has near its upper end portion a stepped section comprising horizontal shelves 11 and vertical walls 1 lea, and from the lowermost one of the horizontal shelves 11 the bottom wall plate 10 extends downwardly.

The bottom wall 10 of chute 7 is disposed at an angle of inclination relative to a hori zontal plane appreciably greater than the angle of repose of particulate matter to be conveyed by the chute.

With reference to Figures 3 and 4, in which the lower discharge end portion of the chute is shown, the bottom plate 10 has an angle of inclination indicated at a, which is appreciably greater than the angle of repose b which the material 12 adopts at its layer surface 12a. Further, the side walls 9 and 9a have a depth or height sufficient to permit a first conveyed portion of particulate material 12 to become piled, forming a layer substantially reposed on the bottom wall 10 at the angle b at its layer surface 12a, and also permit a subsequently conveyed portion of material 12 to flow down substantially along said surface 12a of the layer.

In determining the height and configuration of side walls 9 and 9a, consideration should be given to ensuring that the particulate loose matter to be conveyed in a certain great amount can flow down into the hold from as low a position on the chute as possible, as later to be described in greaer detail.

In Figures 5 and 6, the structure of the lower discharge end portion of chute 7 is illustrated in detail. In the arrangement illustrated in Figure 5, chute 7 has a forward end wall member 9b and a downwardly facing discharge opening 13, which is provided by making the bottom wall 10 suitably shorter than side wall 9 and 9a. In the modified example shown in Figure 6, it is the side wall 9a, instead of bottom wall 10, which has a reduced length to provide a side outlet 13a. The forward end wall 9b in Figure 5, or that indicated at 9c in Figure 6, serves as a bumper member to prevent crushing of the material 12 that would otherwise be permitted to flow down the chute at a greater velocity and easily tend to be damaged by impact against the bottom wall of the hold. The provision of such a bumper member is also effective for greatly suppressing wear of the bottom wall 10 of the chute.It will be readily understood that the discharge opening 13 or 13a should be located as near the hold bottom as possible.

Figure 7 illustrates such an arrangement in which the chute 7 is devoid of the forward end wall considered above. In this instance, the cargo receiver plate member 8 is slantingly disposed close to the discharge end 13b of the chute so that an initially charged portion of cargo 12 can accumulate on the plate 8 as indicated at 12b.

Figures 8 and 9 show modified chute structures or spiral chute structures, as opposed to the straight type chutes considered above in conjunction with Figures 1 and 2.

The chute generally represented by 7 in Figure 8 comprises a plurality of straight chute sections, which are connected successively at an angle to define a continuous but zigzag path for the flow of particulate material passing down the chute. In Figure 9, the spiral chute 7 is provided virtually by coiling the side wall 9a and bottom wall 10 about a pillar member 14. It will be appreciated that with structures as proposed in Figures 8 and 9 the space required for installation of the chute can be advantageously reduced.

Various particular configurations and/or dimensions of the side wall members, are possible. For example Figure 10 schematically shows a cross-section of a cargo ship hold equipped with the chute.

As illustrated, the lines of upper edges of.

the side walls of the chute 7 have an angle of inclination greater than the angle of a plane parallel to the upper surface 12a of material 12 piled in a layer on the bottom wall 10. The chute 7 in this instance includes also an upper stepped portion formed by horizontal shelves 11 and vertical walls 1 la.

Whereas partlculate material Il;conveyed by a loader 15 is sent into the hold through a port 16 it is occasionally difficult, due to a particular construction of the hold, to obtain beneath the port 16 an angle of inclination large enough for installation of chute 7. In that event, it is possible to suitably dispose a horizontal plate member 17 in addition to the horizontal shelves 11 of the chute so that there can be a plurality of relatively small falls provided in the path of the particulate material and, more particularly, at an area beneath port 16. With the chute of the foregoing arrangement, particulate loose material 12 loaded through the port 16 becomes piled on the plate 17 and the shelves 11 at its angle of repose.

In Figure 11, the chute 7 has a horizontal forward end wall 10a, whereby the particulate material 12 can be gradually accumulated on the bottom plate 10 and can repose at the angle b, forming a layer having the inclined surface 12a. When this situation has arisen, a subsequently charged portion 12a' of particulate material can slide or roll down substantially over said surface 12a. Also in Figure 11, the side wall 9a is so made as to define with respect to the line of its upper edge an angle 8 with respect to a horizontal plane which is greater than the angle of repose b of the loose particulate material 12, so that flow of the particulate material sideways over plates 9 and 9a of the chute can begin from only a lowermost part of the chute.As the heap of cargo then grows on the bottom of the hold 2, the point where the particulate material floods over the side wall plates oi the chute becomes gradually higher.

Figure 12 illustrates another embodiment of the chute and in this embodiment the vertical walls 9 and 9a of chute 7 have their upper edges stepped to include portions parallel to the line of angle of repose a of cargo 12 and some vertical portions. Qíth this chute 7, transverse flooding of cargo occurs initially at the portion indicated at X of the side wall plates and then successively over the portions Y, Z and so on.

Figure 13 shows still another embodiment of this invention, in which upper edges of walls 9 and 9a are suitably curved so tbat the depth of the chute structure gradually increases at successive locations up the chute, whereby the point of transverse flooding of particulate material can transfer gradually from a lowest position to a highest position.

It will be understood that with this embodiment the likelihood of particulate material falling over the side walls can be effectively reduced at upper portions of the chute and that this device is most advantageously utilised in loading material which tends to pile in conical heaps since, with such material, flooding over the side walls at an upper portion of chute is quite likely.

In Figures 14, 15, 16 and 17, the method of this invention is further illustrated.

In the embodiment of the invention shown in Figure 14, the chute 7 has shelf plates 18 suitably provided at intermediate points down the entire length of the chute. To install the chute 7 in the ship's hold at an angle of inclination greater than the angle of repose of material 12 inevitably gives rise to a problem regarding the length of the incline, but such problem can be completely cancelled by providing the chute with the intermediate shelves shown by 18 in Figure 14.

In Figure 15, a plurality of shelf plates 17 is provided, disposed in a vertically spaced manner and in an oppositely projecting arrangement, so as to provide a zigzag course in which the material 12 falls with the acceleration of its fall controlled or suppressed.

Figure 16 also shows a zigzag path for the particulate material, and the embodiment in this instance comprises a plurality of relatively short chute members 7a and 7b, which are vertically spaced and in an oppositely projecting arrangement as shown. This material 12 will be transferred down a zigzag path from the upper chute member 7a to the lower member 7b and so on. In particular, this arrangement can realise an economy in respect to the space required for installation of the chute.

The embodiment illustrated in Figure 17 is useful where a hold has a relatively large cargo capacity and it is therefore deemed advisable to install a plurality of separate feed chutes to discharge at the same time.

As shown, two chute members 7c and 7d are provided beneath the cargo port 16.

As mentioned before in this specification, by allowing particulate material to be transferred while a portion thereof is maintained in a condition piled up to its angle of repose on the bottom wall of chute, the material can be prevented from destruction such as by crushing, and at the same time wear of the chute itself can be minimised. This situatiqn can be established by providing the chute with a flow control member capable of checking undesirable sliding of the cargo and of controlling the cargo flow to a prescribed flow rate.Several embodiments of such a system are illustrated in Figures 18 to 30. Referring first to Figures 18 and 19, it will be seen that the chute 7 includes longitudinally spaced apart plates 19 (Figure 19) which are transversely disposed between side wall plates 9 and 9a, with the gap maintained between the lower edges of the plates 19 and the chute bottom wall 10, these gaps defining a passageway 20 for the material. Whereas some of the material 12 loaded through port 16 flows downward through this passageway 20, the major portion is obstructed from flowing by members 19 and forms an accumulation layer about each plate 19.Although once the layer of material so formed has grown thick enough, an additional portion of the material begins to flood over the obstruction plate 19, even in such a condition an appreciable amount of the material continues to flow through the passageway 20. If particulate material continues to be loaded at a rate exceeding the flow rate through the passageway, it will begin to pour over an uppermost one of the control or flow obstruction plates 19, and this pouring will take place successively over the lower plates 19 down to the lowermost positioned plate 19. Accordingly, with this embodiment of the chute, material charged subsequent to the formation of an accumulation layer at each flow control plate 19 can flow substantially by sliding or rolling on the surface of each layer which will be inclined substantially at the angle of repose of the particular material to be handled.

Upon unloading, when the portion of cargo located in the vicinity of the lower end portion of chute 7 is removed by an unloader, the material piled on the bottom wall 10 of the chute can spontaneously fall through the passageways 20 because said bottom wall 10 is disposed with inclination at a greater angle than the angle of repose of cargo. Thus, by the provision of passageways 20, the chute 7 is able to be completely unloaded without the need for any manual operation.

It will be readily appreciated that for any given particulate material the chute of Figure 19 will operate in the desired manner provided the plane joining the bottom edge of one plate 19 to the top edge of the next plate 19 is inclined to the horizontal at an angle no greater than the angle of repose of the material, and thus one such chute can accommodate a range of values of the angle of repose of the conveyed material 12 with the desired flow controlling action due to the reposed layer" build-up on the chute between the plates 19.

Figures 20 and 21 illustrate modified arrangements of the flow obstrucfion or control members 19. In Figure 20, the chute 7 includes, in addition to plates 19 of Figure 19 considered above, a plurality of plates 19a, each of which has a shorter depth or height than the plate 19 and which are individually disposed between each adjacent pair of plates 19. With the modification of Figure 21, the bottom wall 10 of chute 17 has a stepped structure and each plate 19 is disposed slightly downstream of each stepped portion of the wall 10, so that accumulation of the particulate material in the chute can build up more quickly.

Figures 22 to 25 illustrate various crosssectional configurations of the cargo passageway 20.

Whereas in Figure 22 the passageway 20 has a rectangular configuration (as in Figures 18 and 19), the cross-section shown in Figure 23 is modified to a pentagonal shape. In Figure 24, the passageway 20 is further restricted in its width in comparison to those shown in Figures 22 and 23, and is formed at a central portion of the chute 7. In Figure 25, triangular passageways 20 are provided at lower comers of the plate 19. Further, in the example of Figure 26, the floor 10 in Figure 22 is modified to be shaped as triangular section trough.

Figures 27 and 28 show a still further embodiment of this invention, in which the upper edges of the plate members 19 are altemately inclined in opposing directions whereby particulate material loaded after the formation of the reposed build-up in the chute can flow in zigzag manner over the surface of the reposed layer, as can be best seen in Figure 28. The passageways 20 formed under these plate members 19 are asymmetric to define a similar zigzag path for the chute clearance flow.

The embodiment illustrated in Figure 29 is made with a view to reducing the flow rate of cargo at the initiation of loading. In this embodiment, the member 19 has at its central portion the passageway 20 of a restricted width (similar in form to that shown in Figure 24). At the same time, the chute 7 is provided with inner side walls 21 attached to both sides of the passageway 20, defining an inner gutter-like path for flow of material.

With this structure, upon loading, the cargo will first flow through the narrower inner path until it closes the passageway 20, whereby a control can be effectively made of the volume of cargo tending to flow at a high velocity at the outset of loading.

In the embodiment of the invention illustrated in Figure 30, corner plates 22 are provided on each control member plate 19 (which is, for example, of the type shown in Figure 24) so that substantially no particle of the bulk conveyed through the chute may stay at comer portions of the number 19, particularly upon unloading of the cargo.

Whereas the present invention has been described with reference to specific examples of operation, many modifications and alterations will become apparent to those skilled in the art without departing from the scope of the invention as defined in the claims. For example, although the description and illustration of the invention have been made above only in connection with the instance of a bulk carrier or cargo ship, the invention can similarly be advantageously utilised in the case of overland cargo vehicles. Also, it will be obvious that the provision of flow control plate members can be applied not only in the case of straight type chutes illustrated in for example Figures 18 and 19 but also in connection with spiral chutes such as shown in Figures 8 and 9.

WHAT WE CLAIM IS: 1. A method of transferring loose particulate material from a first level to a lower level by controlled falling, comprising passing the material onto a chute between the said levels, said chute comprising a pair of side wall members and a bottom wall member connecting said side wall members, the bottom wall member being disposed with an angle of inclination to the horizontal which is greater than the angle of repose of the particulate material to be transferred, and said side wall members having a height sufficient to allow the particulate material to accumulate in the chute to form a layer whose upper surface is inclined substantially at the angle of repose of the material; placing the particulate material on the chute to build up to form such a layer; and placing more of the particulate material on the chute so it flows down said inclined surface of the layer at a rate controlled by the sliding or rolling action as it passes along said surface of the layer.

2. A method according to claim 1, wherein the said more of the particulate material is caused to follow a zigzag path as it passes down said chute over the said surface of the layer.

3. A method according to claim 1 or 2, wherein said layer is formed in such a way that it is able to disperse under the effect of its own weight when transferred particulate material from around the bottom of the chute is removed.

4. A method according to claim 3, wherein the chute includes a plurality of spaced vertical flow control plates above each of which the particulate material can build up until it pours over that flow control plate to form a build-up above the next and later

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (13)

**WARNING** start of CLMS field may overlap end of DESC **. desired flow controlling action due to the reposed layer" build-up on the chute between the plates 19. Figures 20 and 21 illustrate modified arrangements of the flow obstrucfion or control members 19. In Figure 20, the chute 7 includes, in addition to plates 19 of Figure 19 considered above, a plurality of plates 19a, each of which has a shorter depth or height than the plate 19 and which are individually disposed between each adjacent pair of plates 19. With the modification of Figure 21, the bottom wall 10 of chute 17 has a stepped structure and each plate 19 is disposed slightly downstream of each stepped portion of the wall 10, so that accumulation of the particulate material in the chute can build up more quickly. Figures 22 to 25 illustrate various crosssectional configurations of the cargo passageway 20. Whereas in Figure 22 the passageway 20 has a rectangular configuration (as in Figures 18 and 19), the cross-section shown in Figure 23 is modified to a pentagonal shape. In Figure 24, the passageway 20 is further restricted in its width in comparison to those shown in Figures 22 and 23, and is formed at a central portion of the chute 7. In Figure 25, triangular passageways 20 are provided at lower comers of the plate 19. Further, in the example of Figure 26, the floor 10 in Figure 22 is modified to be shaped as triangular section trough. Figures 27 and 28 show a still further embodiment of this invention, in which the upper edges of the plate members 19 are altemately inclined in opposing directions whereby particulate material loaded after the formation of the reposed build-up in the chute can flow in zigzag manner over the surface of the reposed layer, as can be best seen in Figure 28. The passageways 20 formed under these plate members 19 are asymmetric to define a similar zigzag path for the chute clearance flow. The embodiment illustrated in Figure 29 is made with a view to reducing the flow rate of cargo at the initiation of loading. In this embodiment, the member 19 has at its central portion the passageway 20 of a restricted width (similar in form to that shown in Figure 24). At the same time, the chute 7 is provided with inner side walls 21 attached to both sides of the passageway 20, defining an inner gutter-like path for flow of material. With this structure, upon loading, the cargo will first flow through the narrower inner path until it closes the passageway 20, whereby a control can be effectively made of the volume of cargo tending to flow at a high velocity at the outset of loading. In the embodiment of the invention illustrated in Figure 30, corner plates 22 are provided on each control member plate 19 (which is, for example, of the type shown in Figure 24) so that substantially no particle of the bulk conveyed through the chute may stay at comer portions of the number 19, particularly upon unloading of the cargo. Whereas the present invention has been described with reference to specific examples of operation, many modifications and alterations will become apparent to those skilled in the art without departing from the scope of the invention as defined in the claims. For example, although the description and illustration of the invention have been made above only in connection with the instance of a bulk carrier or cargo ship, the invention can similarly be advantageously utilised in the case of overland cargo vehicles. Also, it will be obvious that the provision of flow control plate members can be applied not only in the case of straight type chutes illustrated in for example Figures 18 and 19 but also in connection with spiral chutes such as shown in Figures 8 and 9. WHAT WE CLAIM IS:

1. A method of transferring loose particulate material from a first level to a lower level by controlled falling, comprising passing the material onto a chute between the said levels, said chute comprising a pair of side wall members and a bottom wall member connecting said side wall members, the bottom wall member being disposed with an angle of inclination to the horizontal which is greater than the angle of repose of the particulate material to be transferred, and said side wall members having a height sufficient to allow the particulate material to accumulate in the chute to form a layer whose upper surface is inclined substantially at the angle of repose of the material; placing the particulate material on the chute to build up to form such a layer; and placing more of the particulate material on the chute so it flows down said inclined surface of the layer at a rate controlled by the sliding or rolling action as it passes along said surface of the layer.

2. A method according to claim 1, wherein the said more of the particulate material is caused to follow a zigzag path as it passes down said chute over the said surface of the layer.

3. A method according to claim 1 or 2, wherein said layer is formed in such a way that it is able to disperse under the effect of its own weight when transferred particulate material from around the bottom of the chute is removed.

4. A method according to claim 3, wherein the chute includes a plurality of spaced vertical flow control plates above each of which the particulate material can build up until it pours over that flow control plate to form a build-up above the next and later

successive such plates, and each said flow control plate defines with said bottom wall member a gap through which the particulate material of said layer can flow when the area around the bottom of said chute is clear of transferred particulate material.

5. A method according to any one of claims 1 to 4, wherein said bottom wall member has a stepped structure at an upper portion of the chute thereof.

6. A method according to any one of claims 1 to 5, wherein said chute has a spiral path for the flow of said particulate material.

7. A method of transferring loose particulate material between a fist level and a lower level, such method being substantially as hereinbefore described with reference to Figures 1 to 17 or Figures 18 to 30 of the accompanying drawings.

8. A cargo chute for use in transferring loose particulate material between a fist level and a lower level, comprising: a pair of laterally positioned side wall members; a bottom wall member interconnecting said side wall members; and means for decelerating the flow of loose particulate material down said chute, said decelerating means comprising a plurality of flow control plates extending between the laterally positioned side walls and at spaced locations down the chute, each said flow control plate defining with said bottom wall a gap at that particular location, and having an upper edge above which said laterally positioned side wall members project at that location, the upper edges being lower for each successive flow control plate down the chute, whereby an initial charge portion of said loose particulate material can be trans ferred to a downstream end portion of said cargo chute through the gaps formed between said obstruction plates and bottom wall at said locations and the material can then build up as an inclined layer of particulate material on the said bottom wall between every two successive flow control plates.

9. A chute according to claim 8, wherein said flow control plates are vertical.

10. A chute according to claim 9, wherein said bottom wall is stepped by the existence of vertical bottom wall portions which are adjacent each flow control plate on the up stream side of the plane of said flow control plate.

1.1. A chute according to claim 8, 9 or 10, wherein said flow control plates have their upper edges inclined to the horizontal with the inclination of successive plates altemating in opposite directions for successive plates down the chute.

12. A chute according to claim 8, 9, 10 or 1'1, wherein there are two sets of identical said flow control plates with the plates of one set shorter in height than the plates of the other set and with the plates of one set altemating with the plates of the other set along the chute.

13. A chute for loose particulate material substantially as hereinbefore described with reference to and as illustrated in Figures 18 to 30 of the accompanying drawings.