IE50346B1 - Duct apparatus for treating bulk material - Google Patents

Description

Price 90p S©34© -2This invention relates to apparatus for the treatment with gaseous fluid of a granular, fibrous or other material which is oermeable to such fluid when stored in bulk, which apparatus is of the kind comprising a main duct into which the treatment fluid can be introduced under pressure and a plurality of lateral ducts each communicating with and extending from the main duct so as in use to lie across the storage floor on which the said material is to he heaped so as to cover the lateral ducts and each of which lateral ducts has one . or more apertures extending over or distributed along its length through which the treatment fluid passing into the lateral duct from the main duct can emerge at or near floor level for permeating said material.

In some cases the main duct might be designed to be within the storage enclosure for the material so as to provide one or more of the walls bounding the floor area on to which the material is to be heaped. In other cases the main duct might be designed to lie outside the storage enclosure and the lateral ducts pass to it through apertures in the enclosure walls.

The treatment fluid may be a gas, vapour or gaseous suspension according to the nature of the material and the type of treatment to be carried out.

The invention is especially, although not exclusively, concerned with such apparatus for treating agricultural material such as seeds (for example grain) or plants (for example herbage) or roots (for example potatoes) and especially for drying or ventilating such 3o material with air, which may be conditioned (for example heated) before supply to the lateral ducts.

The invention will be further described and explained with particular reference to its use for the drying of grain stored in bulk. 5034β -5The drying of grain is frequently carried out in large grain sheds which may typically be 40 metres long by 20 metres wide. When grain is in such a Btore it is normally piled on the floor to a depth of about three to four metres.

If damp grain is stored, it will rapidly become unfit for consumption if steps are not taken to dry it thoroughly.

A conventional grain store therefore is usually fitted with a main duct extending along its entire length, positioned either along one wall or down the centre of the grain store. The main duct is fitted with large air blowers.

At one or both sides of the main duct, there are provided a plurality of lateral ducts. These are usually formed of expanded metal, perforated plate or the like and are in communication with the interior of the main duct so that the air supplied by the blowers is conducted along the main duct and distributed through the lateral ducts from which it can pass into the bulk of the grain heaped over the lateral ducts.

Clearly, it would be advantageous to be able to use mechanical handling means to put the grain in and to remove the subsequently dried grain from the bulk store but this has hitherto not proved easy to achieve because of the construction of the drying apparatus. Although, the floor of the grain store is usually of flat concrete or the like, the lateral ducts impede the progress of any mechanical handling means and also prevent grain lorries from being brought into the store as it is being emptied.

Hitherto, the usual solution to this difficulty has been to make the lateral ducts in sections which have had to be manually dismantled and removed as the grain is being taken out of the store. This dismantling has to S03 ο continue as the grain is being renewed, to enable mechanical handling gear and lorries to be used in the grain store.

Clearly, this is wasteful of effort and tends to disrupt the ranoval of the grain, particularly as it is necessary to ranove the upper layers of grain before the sections of the lateral ducts beoane accessible for renoval.

An alternative which has been proposed is to form the lateral ducts as recesses in the concrete floor of the grain store and to cover than by means of flat metal grids of expanded metal or the like which are laid flush with the floor surface. Ihis enables mechanical shovels and similar means to be used to ranove the grain without cbstructicn but difficulties are encountered with grain falling through the mesh which subsequently needs to be ranoved for cleaning purposes. Furthermore the weight of the mechanical handling gear and in particular of grain lorries moving into the store tends to distort the mesh covers of the lateral ducts, making frequent replacansnt necessary. The presence of the mesh covered ducts in the floor tends to make it unsuitable for general storage purposes during the period when grain is not in store.

It is an object of the present invention to provide drying or treating apparatus which is capable of avoiding or reducing these disadvantages associated with the known grain drying apparatus.

According to the invention apparatus for staring and treating, with gaseous fluid, a granular, fibrous or other material which is permeable to such fluid when stored in bulk, comprising a storage enclosure; a main duct into which the treatment fluid can be introduced under pressure; and a plurality of lateral ducts each communicating with, and extending frem, the main duct so as in use to lie across the floor of the storage enclosure on which the material is to be heap®! so as to cover the lateral ducts, the lateral ducts having one or more apertures extending over or distributed along its length through which the treatment fluid passing into the lateral duct frem the main duct, can emerge, at or near floor level fear permeating the material, at least one lateral duct being formed of a number of telescopically interfitting sections so as to be telescopies 11y con35 tracti hl p in length tewards the end designs! to cannunioate with the main duct during use and in which means are provided to effect the telescopic contraction in length whilst the lateral duct is covered with the material -5Ihe lateral duct may in same cases be arranged to telescope canpletely into the main duct but in other cases may be arranged to telescope into a relatively small region immediately adjacent to the ’ main duct.

Preferably each of the lateral ducts is a telescopically contractible duct, but in sane cases it might suffice if only sane of the lateral ducts nearer the entrance to the storage enclosure are telescopically contractible, since this might suffice for clearing a sufficient floor area to permit the entry of mechanical handling apparatus or lorries.

The invention will be further described by way of example with reference to the accompanying drawings, which are purely schematic and in which Figure 1^ shows a plan view of an appratus in accordance with the invention, for the treatment with gaseous fluid of the stored material, Figure 2 shows a perspective view of part of an apparatus in accordance with the invention, and, Figure 2 shows a part of an apparatus in accordance with the invention.

Referring first to Figure 1, the store or storage enclosure of the apparatus consists of a rectangular building having side walls 1 and end walls 1', cne of T.-hich end walls incorporates double doors 2 giving access to the store.

Within the store, along one of the side walls 1, is fitted the main duct 2 of the grain drying apparatus and a number of lateral ducts 4 extend from the main duct 3 on and across the floor of the store. Only four lateral ducts are shown for convenience of illustration, but the number used will usually be greater than this. Likewise each lateral duct will usually contain more than four sections.

The main duct 3 Is provided with an access door 2 Θ 3 4 Q -6and incorporates a blower 6 for introducing 'air at pressure into the duct, which air escapes into the store through apertures distributed along the walls of the lateral ducts.

Each of the lateral ducts 4 is formed in a 5 number of sections which are arranged to telescope into each other towards the wall of the main duct. > For effecting this telescoping each, lateral duct is provided internally with a cable 7 which passes from a bar 8 fixed across that end of the lateral duct which is further from the main duct to a-winch 9 mounted within the main duct® By operating the winch the telescopic sections can be successively drawn into each other so as to lie wholly within the section nearest the main duct, the lateral ducts nearest the doors 2 being shown fully contracted in this way. Referring now to Figure 2, this illustrates the nature of the main duct and lateral ducts of a grain drying apparatus in accordance with the invention fitted into a grain store.

The apparatus comprises a main duct 10 designed to be fitted against and along one wall of the grain store, and which is formed from heavy metal sections provided with reinforcing ribs as shown. It will be appreciated that the force exerted on the main duct by the grain will be considerable since the grain, a portion of which is indicated at 11, will be stacked to a depth of three to four metres high and the duct 10 will be more or less completely buried in the grain in use, so that it should be strong enough to withstand this.

The main duct 10 is provided with an access door 12 through which access can be had to the ventilating equipment and to the winches to be described hereinafter.

In the example shown, lateral ducts -7qenerally indicated at 13 are provided along the side of the main duct within the grain store enclosure. Each lateral duct can be telescopically extended from the main duct 10 to the opposite side wall of the grain store enclosure but, for purposes of illustrating the construction used in the present invention, the overall length and number of sections of the lateral ducts have been reduced for clarity It will he seen that each lateral duct 15 is in a plurality of sections, four of which are shown at 14, 15, lo 16 and 17· Each section has a sheet metal top 18 which is capable of withstanding the load of the grain 11 and each lateral duct further has side walls 19 of expanded metal, metal mesh or the like. The cross-section of each of the sections 14 to 17 shown in the drawing is rectangu15 lar hut it will he appreciated that say suitable form of lateral can he used and in particular the cross-section may he inwardly tapered towards the top, may he triangular or even circular if desired.

The main feature of the lateral ducts is that each 2o section is capable of being slidably received within the next. Thus, the section 17 has a larger cross-section than the section 16 and so on. Each section can he provided with any suitable form of slide means to allow for smooth sliding movement of one section into another.

Longitudinal guiding means for reducing the possibility of sideways displacement of the sections relative to each other will usually also he desirable.

In general, since the typical width occupied hy a lateral duct in a grain etore is about eight metres, it will he possible to subdivide each lateral into eight interfitting sections of about one metre each, the laterals furthest from the main tunnel being about 0.12 metres in depth and those adjacent the main tunnel being about 0.55 metres in depth. Each section is provided with a suitable -8end formation to receive the next adjacent Smaller section without allowing ingress of large quantities of grain® Each lateral duct is provided with a cable 20 which extends throughout its length and is secured to a suitable bar or similar anchor 21 at the end of the lateral duct remote from the main duct 10. The cable 20 passes through the centre of the lateral duct to a winch 22 mounted within the main duct. The winch 22 may be hand or mechanically operable.

In use, the lateral ducts are extended across the floor of the grain store enclosure to their full lengths and, since the grain store is empty at this time, extension can be readily carried out by hand. Alternatively, a winch and cable arrangement may be attached externally to the anchor bar 21 to extend the lateral ducts.

Grain can then be loaded into the store hy any suitable means. It will be appreciated that the lateral ducts may need only he extended as and when they are required and this enables the grain to be brought into store using mechanical means.

When the grain is in position, air blowers (not shown) provided in or in communication with the main duct can be started up and the drying process will proceed conventionally with air passing along the lateral ducts and out through the mesh side walls 19. The fact that the lateral ducts are of smaller cross-section at positions remote from the main ducts need not cause any problems with the distribution of air since the air volume along the lateral duct will in any case tend to drop towards the end remote from the main duct 10 due to dissipation of the air into the grain taking place along the lateral duct.

When it is desired to remove the grain from store, the blowers are stopped and it is then possible to enter 90346 -9the main duct hy the access door 12 to operate the winches 22 and draw in telescopically the sections of each of the lateral ducts 15. The sections may in some cases be arranged to be withdrawn wholly into the main duct 10 or in other cases may simply telescope into the final section 17 immediately adjacent the main duct. In the latter case, the floor of the grain store enclosure will not be completely- unobstructed but the obstruction will be relatively small compared with the obstruction provided by an entire fully extended lateral duct.

The lateral ducts are arranged to be contracted in length while the grain is still in the store and before any steps have been taken to remove it. When the lateral ducts have been telescoped, unloading can take place using mechanical handling apparatus with maximum efficiency since the floor area is unobstructed or substantially unobstructed. Access is also possible for lorries without substantial risk of damage to the grain store structure and grain drying apparatus.

Referring now to Figure 5 this shows a preferred form of lateral duct designed to reduce the winching force required to produce the telescopic-contraction under the weight of the superposed grain in use.

The duct is shown as formed in eight sections 50 each of which is perforated, as indicated in part at 51« to permit air to escape from its interior in use· Each section consists of a metal sheet bent to Gothic arc shape, i.e. to form two convex arcuate sides 52, 53 meeting at a centrallongitudinal ridge 54, and welded along their lower sides to a bottom sheet in the for» of a tray 55 having upturned edges 56.

For each section except the last (i.e. the section designed to telescope into it), the tray 55 extends as at 57 towards the next section for somewhat less than half the length of that section, so as to provide a base -10on which that section can slide and so that the upturned edges of the tray provide longitudinal guidance means preventing excessive bending (i.e. sideways displacement in the manner of jack-knifing) of the two sections relative to each other. Such excessive bending would, of course, greatly increase the telescoping force required if it did occur. Preferably zinc-coated steel is used for the sections for reducing the sliding friction.

Across the free end of the last section is welded a bar 38 of width sufficient to gather up the sections as they are telescoped together.

To the bar 38 is attached the retractor cable 39 which passes within and through all of the sections for engagement hy the retractor winch (not shown).

It will he appreciated that the arrangements described above enable all the grain to be removed without danger of substantial quantities of grain remaining trapped, in crevices since the floor area is unobstructed and can be cleaned out readily. It will also be appre20 ciated that particularly where a power winch 22 is used to telescope the lateral ducts, the telescoping can be carried out by one man in a relatively short time compared with the dismantling of non-telescoping sections as used hitherto.

It will also he appreciated that various modifications can he made to the apparatus as described above.

For example, instead of each lateral duct being provided with its own winch, a single portable winch might be used, to he carried to each lateral duct in turn and attached to its retractor cable when telescoping of that duct is required.

Also the lateral ducts might in some cases be made of a suitably strong plastics material and/or the cable could be in the form of a chain or rope; all 30346 -11such possible replacements for the cable are to be understood as covered by the term cable.

Also in some cases the main duct might be formed integrally with the wall of the storage enclosure.

Claims (11)

CLAIMS:

1. Apparatus for storing and treating, with gaseous fluid, a granular, fibrous or other material which is permeable to such fluid when stored in bulk, comprising a storage 5 enclosure; a main duct into which the treatment fluid can be introduced under pressure: and a plurality of lateral ducts each communicating with, and extending from, the main duct so as in use to lie across the floor of the storage enclosure on which the 10 material is to be heaped so as to cover the lateral ducts, the lateral ducts having one or more apertures extending over or distributed along its length through which the treatment fluid passing into the lateral duct from the main duct, can emerge, at or near floor level for permeating the material, at least 15 one lateral duct being formed at a number of telescopically interfitting sections so as to be telescopically contractible in length towards the end designed to communicate with the main duct during use and in which means are provided to effect the telescopic contraction in length whilst the lateral duct is 20 covered with the material.

2. Apparatus as claimed in Claim 1 wherein the means comprises a cable secured to the end of the or each telescopically contractible lateral duct which end is designed to be remote from the main duct and which cable passes within the lateral 25 duct to its other end so as to be operable from within the main duct. - 13 3. Apparatus as claimed in either Claim 1 or Claim 2 wherein each telescopically contractible duct comprises a number of telescoping sections which are designed to telescope into a relatively small region adjacent the wall of the main duct.

3. 5 4. Apparatus as claimed in Claim 3 in which the relatively small region consists of the section which lies nearest the wall of the main duct in use. 5. Apparatus as claimed in any of the preceding claims wherein each of the lateral ducts connected to the main duct 10 is telescopically contractible.

4. 6. Apparatus as claimed in any of the preceding claims wherein the main duct is housed within the storage enclosure.

5. 7. Apparatus as claimed in Claim 6 wherein the main duct is provided with an access door through which an operator can gain 15 access to the operating means for the telescopic lateral ducts.

6. 8. Apparatus as claimed in any of claims 1-5 wherein the main duct is external of the storage enclosure.

7. 9. Apparatus as claimed in any of the preceding claims including means for introducing gaseous fluid under pressure 20 into the main duct.

8. 10. Apparatus as claimed in any one of the preceding claims - 14 wherein the interfitting sections of the lateral duct members are provided with longitudinally extending guidance means which reduces the extent to which the sections can be displaced sideways relative to each other. 5

9. 11. Apparatus as claimed in Claim 10 wherein .the longitudinally extending guidance means consists of a forward extension of the bottom of one section in the form of a tray over which the next and smaller section in the telescopic sequence can slide and which tray has upturned edges which bound the sides of the said 10 next section.

10. 12. An apparatus as claimed in Claim 1 in which each lateral duct is constructed substantially as hereinbefore described with reference to Fig. 3 of the accompanying drawings.

11. 13. An apparatus for storing and treating substantially as 15 hereinbefore described with reference to either Fig. 1 or 2 of the accompanying drawings.