AU674229B2 - Flowable material discharge system - Google Patents

Description

WO 94/22746 PCT/EP94/01088 1 FLOWABLE MATERIAL DISCHARGE SYSTEM The invention relates to a flowable material discharge system for controlling the discharge of flowable material such as pellets, viscous materials such as slurries, solids, powder or particles and the like from a store such as a bunker, hopper, reactor, impregnation vessel and the like. Material such as powder or particulate material and the like is often housed in bulk in a store such as a bunker and the like, from which it is to be discharged periodically.

Known bunkers or hoppers for discharging free flowing materials such as particulate or powdered materials are provided with vertically liftable cones at their outlet.

Such liftable cones open by vertically lifting the cone against the pressure of the flowable material to be discharged on the cone.

However, such known arrangements have several disadvantages.

For example, opening is not always possible in case of large vessels or completely filled vessels.

Further, such arrangements are suitable for discharging free flowing materials, but are subject to serious problems with respect to discharging cohesive or sintering materials due to bridging, sintering and clogging of the particles. In that case lifting and vibration of the cone can cause further densification and sintering of the solids and so making flow activation even worse.

It is therefore an object of the invention to provide a simple bunker discharge system, particularly suitable for discharging cohesive, sintering, bridging or free flowing solid materials with all kirA of particle sizes.

It is another object of the invention to provide a simple bunker discharge system which is suitable for discharge in case of large vessel: or completely filled vessels.

The invention therefore provides a flowable material discharge system for a bunker which is provided at its outlet with an outlet WO 94/22746 PCT/EP94/01088 2 member and a seat located underneath the said member, characterized in that the said seat is movable from a first (closed) position wherein no discharge gap between the seat and the said member exists, to a second (open) position thus making a discharge gap between the seat and the said member without lifting the member, and vice versa; and further comprising means for moving the said seat in the desired direction.

Advantageously, the outlet member is (vertically) liftable and has e.g. a conical or pyramidal shape.

The invention will now be described in more detail by way of example by reference to the accompanying drawings, in which: fig. 1 represents schematically a longitudinal section of an advantageous embodiment of the invention; and fig. 2 represents schematically a longitudinal section of another advantageous embodiment of the invention; fig. 3a represents schematically a longitudinal section of still another advantageous embodiment of the invention; and fig. 3b represents a top view of the embodiment of fig. 3a.

The term "bunker" should not be understood in a restrictive manner, but also indicates e.g. hoppers, silos, containers, bins or solids process vessels like reactors, impregnation or washing vessels and the like.

Such bunkers etc. can e.g. have a conical, cylindrical, pyramidal, prismatic or spherical shape.

Referring to fig. 1 a flowable material discharge system with a(n) (inverted) cone type seat has been represented. The lower part of a bunker wall 1 with a cone type seat is represented. In the bottom of the bunker an outlet member e.g. in the form of a cone or pyramidal shaped body is provided in any suitable manner. In fig. 1 a liftable cone 2 is applied as outlet member.

The cone 2 can be moved up and down from a first (lower) position 2a to a second (lifted) position 2b and vice versa by allny suitable cone actuating means 3 e.g. a pneumatic cylinder with a double pi3ton rod and can be vibrated at any suitable frequency by any suitable cone vibrator 5. The bunker 1 is provided with a WO 94/22746 PCT/EP94/01088 3 movable seat 4 located underneath the cone. The seat can be moved up and down by any suitable seat actuating nmeans 6 from a first (upper) position (4a) to a second (lower) position (4b) and vice versa.

The shape of the bottom edge of the cone 2 needs to be such, that in its lower position (2a) it matches the shape of the seat 4 in upper position (4a) in such a way that no gap exists. Thus, in the lower position (2a) of the cone and the upper position (4a) of the seat the cone is pressed with its lower edge on the seat. In this situation there is no gap between seat and cone. Reference numeral 7 represents a support frame for supporting the cone actuating means and reference numeral 8 represents the discharge cone of the bunker.

The seat may be of any suitable shape, e.g. pyramidal, conical, spherical, flat or tore shape. The seat may consist of a single part as well as of more than one individual or collective moving parts e.g. moving flaps as will be described in connection with figs. 3a, 3b below in more detail.

In practice, there is a mechanism to prevent rotation of the liftable cone 2 and movable seat 4 (not shown for reasons of clarity).

Control mechanisms to position the cone 2 at positions between upper (2b) and lower (2a) position are useful (not shown for reasons of clarity) Control mechanisms to position the seat 4 at positions between upper (4a) and lower (4b) position are useful (not shown for reasons of clarity).

Further, there can be a suitable mechanism to lock the seat 4 in its closed position to prevent opening due to gravity when the energy for lifting the seat might be broken down (not shown for reasons of clarity).

Further, a level sensor e.g. a capacitive level sensor underneath the seat to prevent overfilling of the space underneath the seat is useful (not shown for reasons of clarity).

In fig. 2 a flowable material discharge system with a tore seat having a first (upper) position and a second (lower) WO 94/22746 PCTIEP94/01088 4 position has been shown. The same reference numbers as in fig. 1 have been used for representing the same members of the system.

In fig. 3a a flowable material discharge system with a flap type seat 4" is shown, wherein also the same reference numerals as in figs. 1 and 2 are used for representing the same members of the system. In this advantageous embodiment the seat is multi-sided and in particular 4-sided and comprises collective moving parts.

Further, the seat flaps 4" are connected in any suitable manner to a hinge line 9. A bar mechanism with over centering provided with a drive shaft 10 has been shown and the said mechanism and flap are represented in open and closed position respectively It will be appreciated that any suitable mechanism for moving the seat flaps can be applied In fig. 3b a top view of the flap type seat of fig. 3a is shown.

Hinge lines 9 and drive shafts 10 have been shown.

Reference numeral 6a represents a seat flaps actuating means and reference numeral 11 represents any suitable coupling mechanism such as e.g. (angular) gear boxes coupling the drive shafts Each of the sides hangs on a hinge line and is moved by bar mechanisms with over centering locking.

Advantageously, there is one common drive with a pneumatic actuator. More advantageously, the opening of the seat is adjusted with an adjustable stop in the actuator.

The operation of the system of the invention is as follows: Upon request of flowable material the movable seat will be opened and solids can flow downwards via the gap between the outlet member and lowered seat. When required, the outlet member can be vibrated to activate and smoothen the flow. When due to bridging or sintering no flow takes place, the outlet member can be lifted and/or be vibrated to break the bridge. Vibration can be carried out at high frequencies or at a low frequency by repeatedly up and down movement of the outlet member. A very constant material flow during discharge can be achieved by vibration at high frequencies.

WO 94/22746 PCTIEP94/01088 5 The flow will then be very much independent on the particle size and the internal friction. Material flow at very low throughput can be achieved by intermittently vibration of the outlet member. By selecting short successive pause vibration periods, a rather continuous flow can be achieved. During vibration periods relatively high flows outside the unstable flow no flow region can be adjusted. In this way lifting forces do not need to be very high and flow of de-agglomerated solids is always possible.

As soon as the flowable material is activated the outlet member i0 10 may be lowered again and normal discharge can take place.

When the level sensor underneath the seat is activated the seat may be closed or lifted in order to stop or reduce the flow to prevent overfilling below the seat.

Various modifications of the present invention will become apparent to those skilled in the art from the foregoing description.

Such modifications are intended to fall within the scope of the appended claims.

Claims (23)

1. A flowable material discharge system for a bunker which is provided at its discharge opening with a separate outlet member and a seat located underneath the said member, said outlet member and seat being mounted internally of the said discharge opening, characterised in that the said seat is movable from a first closed position wherein no discharge gap between the seat and the said member exists, to a second open position thus making a discharge gap between the seat and the said member without lifting the member, and vice versa; and further comprising means for moving the said seat in the desired direction.

2. The system as claimed in claim i, characterised by means for vibrating the outlet member.

3. The system as claimed in claim 1 or 2, characterised in that the outlet member is (vertically) liftable.

4. The system as claimed in any one of claims 1-3, characterised in that the seat consists of a single movable part.

5. The system as claimed in any one of claims 1-3, characterised in that the seat consists of more than one movable part.

6. The system as claimed in any one of claims 1-5, characterised in that the seat has a pyramidal or conical or spherical or flat or tore shape. 20

7. The system as claimed in claim 5, characterised in that the seat is multi- sided..

8. The system as claimed in claim 7, characterised in that the seat is 4- sided.

9. The system as claimed in any one of claims 3-8, characterised by means for preventing rotation of the liftable member and seat.

The system as claimed in any one of claims 3-9, characterised by means for moving the liftable member in the desired direction.

11. The system as claimed in claim 10, characterised by control means to position the liftable member at positions between a first and second position.

12. The system as claimed in any one of claims 1-11, characterised by control means to position the seat at positions between the first closed and the second open position.

13. The system as claimed in any one of claims 1-12, characterised by means for locking the seat in its closed position.

14. The system as claimed in any one of claims 1-13, characterised by a level sensor underneath the seat.

The system as claimed in claim 5, 7 or 8, characterised in that each of the movable parts hangs on a hinge line.

16. The system as claimed in claim 15, characterised in that each of the 'Q movable parts is moved by a bar mechanism with over centring locking. f 1 '4 o N. C', ILibMI\23330:JOC 6S 2

17. The system as claimed in claim 16, characterised in that the bars are driven by drive shafts.

18. The system as claimed in claim 17, characterised in that the drive shafts are coupled with each other via gear boxes.

19. The system as claimed in any one of claims 15-18, characterised by one common drive with a pneumatic actuator.

The system as claimed in claim 19. characterised in that the opening of the seat is adjusted with an adjustable stop in the actuator.

21. The system as claimed in any one of claims 1-20, characterised in that the outlet member has a conical or pyramidal shape.

22. A flowable material discharge system for a bunker which is provided at its discharge opening with a separate outlet member and a seat located underneath the said member, substantially as hereinbefore described with reference to the accompanying drawings. Dated

23 October, 1995 Shell Internationale Research Maatschappij B. V. o Patent Attorneys for the Applicant/Nominated Person S" SPRUSON FERGUSON 0.At LE S 7 of 2 [LibM\23330:JOC 7 of 2 WO 94/22746 WO 9422746PCT/EP94/01088 F IG.1o'f WO 94122746 2/3 PCTIEP94/O1O88 4 1 b Af FIG.2 WO 94/22746 WO 9422746PCT/EP94/01088 FIG.3b 11~ 1- I4~I- II a FIG.3a INTERNATIONAL SEARCH REPORT Wne onal Application No PCT/EP 94/01088 A. CLASSIFIlCAION OF tlll~ MAiTlTR IIPC 5 865090/62 According to International P'atent (lassification (111C) or to both national classiication and ll'C Minimum documentation searced (classification systcmn followed by classification symbols) IPC 5 865D 861D B60P B67G lDocumenitaton scarchcd other than minimum documentation to the extent that such dlocuments arc included in the field.,; searched lIectronic data base consulted durng the international search (name of data base anid, where practical, search terms used) C. l)OCttM IINTS (:ONSlIIRIII) TO HEl RLEIVA NT Category Citation of documeot, with indication, where appropriate, of the rrlcvant passages Relevant to claim No. A EP,A,0 380 255 (MATCON) 1 August 1990 1-3 see the whole document A EP,A,0 049 992 (SEMENENKO) 21 April 1982 1-3 see the whole document A DE,A,23 33 086 (WAESCHLE) 16 January 1975 1 see page 4, line 13 page 4, line 19; figures [I lurthcr document,; are listed in the continuation of box C. ElPatent faily members are listed !n annex. *Special categories of cited documenLa: "I later document published after the intemazonal riling date A doumet dfinng he eneal tat oftheartwhih ~notor pniority date and not in conflict with the application hut ocuentdcriingthegenral tat oftheart hic isnotcited to understand the principle or theory underlying the considered to he of partii-4ilar relevance invention irearlier document but published on or after the international W document (if particular relevance; the claimed invention filing date cannot be considered novel or cannot he considered to L' document which may throw doubts on proity claim(s) or involve an tnventive step when the document is taken alone which is cited to establish the publication date of another .Y document of particular relevance; the claimed invention citation or other special reason (as specified) cannot he ctmnsidered to involve an inventive step when the document refernog to an oral disclosure, use, exhibitiion or document is combined with one or mtor- other such docu- other means menis, such combination heinit otivimis to a person skilled document published poior tot the international filing date hut in the art. later than the prority date claimed W document member of the same patent family lDate of the actual completion of the international search D~ate of mailing of the intcmnati'inal search report 27 July 1994 05 08, 94 Name and mailing address of the ISA Authorized officer iumopean Patent Office, 1P.11. 58118 Patcntlaan 2 INI. 22810 1IIV Rij~svolk Tel. (31-70) 340-2040, Tx. 31 651 epo nl, ty ,T Fax: (i31.70) 340.3016 O tn rorm PCT ISA'211 (scond sheet) ([July 1992) IN'TRN ITr),NA I. SIPARCI M-RIJORT Intc onal Application No .nformau, oi patent family members PCT/EP 94/01088 Patent document I Publicatio Patent Family 1 Publication Cited in search report date member(s) Idate EP-A-0380255 01-08-90 AU-B- 631838 10-12-92 AU-A- 4863690 26-07-90 JP-A- 2233390 14-09-90 US-A- 5036894 06-08-91 EP-A-0049992 21-04-82 AU-B- 544720 13-06-85 AU-A- 7575281 22-04-82 GB-A,B 2084969 21-04-82 US-A- 4470524 11-09-84 DE-A-2333086 16-01-75 NONE Form PCT ISA 210 (patent family annex) (July 1992)