GB2326634A - Apparatus for unloading particulate solids - Google Patents

Description

Vessel Unloading Apparatus The present invention is relates to vessel unloading apparatus, and more particularly to vessel unloading apparatus for use in unloading particulate material from a vessel.

Particulate solids are conventionally conveyed pneumatically using high velocity air or gas under negative pressure (vacuum) Such pneumatic conveying systems are used extensively in the oil, gas, chemical and petrochemical industries to discharge catalyst pellets from reactor vessels into containers (such as drums) either to allow the catalyst to be changed or to permit internal inspection or repairs to be carried out within the reactor.

When discharging catalyst pellets, it is important to avoid dust evolution, because the catalytic material often contains volatile and inflammable hydrocarbons, toxic elements, or residual precious metals. Some catalytic material may be pyrophoric, and extruded catalyst pellets (which are now widely used) are relatively fragile and can be easily damaged during pneumatic conveying, rendering them unfit for further use.

An example of a pneumatic conveying system for use in discharging particulate catalyst from a reactor is disclosed in US-A-4312388.

In this system catalyst is discharged from catalytic reaction vessel into a drum or series of drums either via the top port of the vessel or the lower port provided toward the bottom of the vessel.

When unloading through the lower port or manway using the system disclosed in US-A-4892123, the material is conveyed pneumatically from a drain zone of the reactor vessel via a first vacuum line and a gas/solids separator to a sealed receiving drum. A gastight line and an inlet port provided on a cover member sealingly engages with the top of the drum. Gas is recirculated from the drum to the main vacuum return line via an outlet port provided on the cover member towards and away from the drum so that successive drums can be covered by the cover member and filled with separated solids.

When unloading from the lower port in this way, the particulate solids are first discharged into a hopper container bolted to the reactor vessel wall about the lower port such that the hopper container defines a substantially enclosed, sealed zone about the lower port. The container is provided with a vacuum outlet port through which particulate material is pneumatically conveyed into the first vacuum line. The container is further provided with a vacuum inlet port for recirculating conveying gas.

A disadvantage of unloading apparatus such as the container hopper disclosed in US-A-4892123, is that mechanical fixing to the catalyst vessel by means of bolts is required.

Improved apparatus has now been devised.

According to the present invention there is provided apparatus for use in unloading particulate solids from a vessel via a port accessing the vessel, which apparatus comprises: (a) a plurality of closure elements arranged, in an engaged position, to engage another respective closure element in order to define a substantially enclosed zone adjacent the port, each closure element comprising a respective collar portion arranged to engage with respective collar portion of the port; and (b) clamping means arranged to secure the closure elements in the engaged position and releasable to permit disengagement and separation of the respective closure elements.

Advantageously at least one closure element is arranged to be supported such that the collar portion of the respective closure element is held in a disengaged position relative to the collar portion of the port. Movement means is preferably provided to facilitate movement of the respective closure element from the disengaged position,such that the collar portion engages the respective collar portion of the port.

Preferably, the supported closure element is raised from the disengaged position to the position in which the respective collar portions of the supported closure element and the port engage. Desirably one or more further closure elements being lowered into position to define the enclosed zone.

It is believed that unloading apparatus comprising closure elements, one of which is raised into engagement with a port of a vessel from a disengaged supported position, is novel and inventive per se; accordingly this provides a further aspect of the invention.

The apparatus typically comprises support means for supporting thereon the supported closure element. The support means may be a frame such as a scaffolding frame or the like.

The support means is preferably movable from a remote position spaced from the vessel to an operational position adjacent the vessel. The support means maybe provided with wheels, castors or endless belt tracks or the like, such that the support means may be transported from the remote position to the operational position adjacent the port for use.

The movement of the supported closure element into engagement with the port is typically by raising and lowering relative to the support means preferably by one or more jacking arrangements, preferably acting adjacent the collar portion of the supported closure element. A jacking arrangement may comprise a rotatable screw threaded member and threaded bush arrangement, one being carried by the support means and the other by the closure element. Alternatively an arrangement of one or more pneumatic or hydraulic jacks may be used.

Desirably, the supported closure element is pivotally mounted to the support means such that the supported closure element pivots when moving from the collars disengaged position to the collars engaged position.

It is preferred that the collars comprise an arcuate engagement surface arranged to engage radially with a peripheral arcuate collar surface of the port. U-shaped inserts can be positioned in the collar portion of one or more of the closure elements such that the size of the collar portion may bwe varied. This is particularly advantageous if the size of the port which is to be engaged is not standard. In such an arrangement an engagement surface of the insert will engage with the collar portion of the port.

Typically, the clamping means comprises one or more quick release clamps or catches, or other clamps or catches that are easy to use.

The apparatus preferably further comprises sealing means sandwiched between the respective mutually engaging closure elements.

The closure elements are preferably provided with respective engagement flanges for engagement with respective flanges of another respective closure element in the engaged position. It is preferred that the clamping means is arranged to act upon engaging flanges of respective adjacent closure elements.

The apparatus preferably comprises a first and a second closure elements arranged to define the enclosed zone.

In a particularly preferred embodiment the first element is arranged as a lower receptacle element and the second element as an upper lid element.

The upper-lid element typically comprises a vision panel arranged to allow observation of the interior of the enclosed zone.

The respective closure elements are preferably walled or shell elements The apparatus preferably further comprises an inlet port permitting entry into the enclosed zone of pneumatic conveying gas, and an outlet port permitting conveying gas and conveyed material to be removed from the enclosed zone. It is preferred that the inlet and outlet ports are arranged through walls in one or more closure elements and preferably substantially in line with one another.

The invention may be more clearly understood from the following description given by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a diagrammatic perspective view of exemplary apparatus according to the invention prior to engagement with the port; Figure 2 is a diagrammatic perspective view of an exemplary hopper according to the invention during engagement with the port; Figure 3 is a perspective detail view of a preferred arrangement of clamping and lowering/raising comprising the apparatus of Figures 1 and 2.

Referring to Figures 1 and 2, catalyst material is removed from a catalytic convertor reactor vessel through a bottom manway port 1. Unloading apparatus (generally shown by the reference numeral 2) comprises a lower receptacle 3, and an upper lid 4.

The lower receptacle 3 comprises an arcuate outer wall 16 and a semi-circular endwall 17, both of which have their upper limits defined by a flange 18 running around the periphery of the receptacle. Arcuate wall 16 is provided with a conveying gas inlet port 19 and outlet port 20 which are arranged in line with one another as this has been found to give the most efficient vacuum performance. Lower receptacle 3 is provided with an arcuate collar 10 opposite endwall 17 collar 10 being configured to have a curvature corresponding to the curvature of the peripheral collar surface 21 of port 1.

The upper lid 4 comprises a walled shell having placement handles 24 and a lowermost peripheral flange 25 configured to lie in register with the peripheral flange 18 of the lower receptacle 3. A seal is preferably interposed between flanges 18 and 25.

The upper lid 4 is also provided with a collar 26, shaped arcuately similarly to collar 10 so as to cooperatively engage with the upper arcuate collar surface of the port 1.

The lower receptacle 3 is supported on a frame 5 which is mounted on wheels 6a, 6b and 6c (a fourth is not shown), which are arranged to run on tracks 7a and 7b. Raising and lowering jacking bolts 8 are threaded through respective threaded bushes 12 carried by the lower receptacle element 3. The lower ends of jacking bolts 8 engage with respective engagement plates 12 comprising the support frame 5, such that when bolts 8 are rotated axially, the lower receptacle 3 is jacked up or lowered relative to the frame enabling the collar 10 of lower receptacle 3 to be moved into an engaged or disengaged position with the collar surface 21 of port 1 as required. The lower receptacle 3 is additionally pivotally mounted to frame 5 by pivot 9 (a second is not shown) such that the raising and lowering jacking bolts 8 cause the receptacle 3 to pivot about pivots 9 as the collar 10 of the receptacle 3 moves into or out of engagement with the collar 21 of port 1.

In operation the lower base element 3 is transported along tacks 7a and 7b from a remote or stored position to an operational position adjacent the bottom manway 1.

The lower base element 3 is raised by use of jacking bolts 8 to cause collar 10 of the receptacle 3 move into engagement with the collar 21 of port 1.

When collar 10 is in position the upper lid element 4 is positioned on top of the lower base element 3 and secured in place by over-centre quick release clamps 11 (further clamps are provided but not shown) operated by respective levers 27.

The zone enclosed by receptacle 3 and lid 4 (when engaged and clamped) may be viewed through vision panel 12.

The present invention provides unloading apparatus which is substantially more convenient to make ready for use than apparatus known in the art, and which does not require bolting into position, thus requiring less time and effort to attach them to the bottom manway.

Claims (23)

claims:

1. Apparatus for use in unloading particulate solids from a vessel via a port accessing the vessel, which apparatus comprises: (a) a plurality of closure elements arranged, in an engaged position, to engage another respective closure element in order to define a substantially enclosed zone adjacent the port, each closure element comprising a respective collar portion arranged to engage with respective collar portion of the port; and (b) clamping means arranged to secure the closure elements in the engaged position and releasable to permit disengagement and separation of the respective closure elements.

2. Apparatus according to claim 1, wherein at least one closure element is arranged to be supported by support means such that the collar portion of the respective closure element is held in a disengaged position relative to the collar portion of the port.

3. Apparatus according to claim 2 further comprising movement means facilitating movement of the supported closure element from the disengaged position, such that the collar portion engages the respective collar portion of the port.

4. Apparatus according to claim 3, wherein the movement means is operable such that the supported closure element is raised from the disengaged position to the position in which the respective collar portions of the supported closure element and the port engage.

5. Apparatus according to claim 4, wherein one or more further closure elements are configured to be lowered into position to define the enclosed zone.

6. Apparatus according to any of claims 2 to 5, wherein the support means comprises a support frame such as a scaffolding frame or the like.

7. Apparatus according to any of claims 2 to 6, wherein the support means supports the supported closure element to be movable from a remote position spaced from the vessel to an operational position adjacent the vessel.

8. Apparatus according to any of claims 2 to 7, wherein movement of the supported closure element into engagement with the port is by raising and lowering relative to the support means by one or more jacking arrangements.

9. Apparatus according to any of claims 2 to 8, wherein the supported closure element is pivotally mounted to the support means such that the supported closure element pivots when moving from the collars disengaged position to the collars engaged position.

10. Apparatus according to any preceding claim, wherein the respective collar portions of respective closure elements comprise an arcuate engagement surface arranged to engage radially with a peripheral arcuate collar surface of the port.

11. Apparatus according to any preceding claim, wherein the clamping means comprises one or more quick release clamps or catches.

12. Apparatus according to any preceding claim, further comprising sealing means sandwiched between the respective mutually engaging closure elements.

13. Apparatus according to any preceding claim, wherein two closure elements define the enclosed zone.

14. Apparatus according to any preceding claim, wherein respective closure elements are provided with respective engagement flanges for engagement with respective flanges of a respective adjacent closure element in the engaged position.

15. Apparatus according to claim 14, wherein the clamping means is arranged to act upon engaging flanges of respective adjacent closure elements.

16. Apparatus according to any preceding claim, wherein a first closure element is arranged as a lower receptacle element and a second closure element provides an upper lid element.

17. Apparatus according to claim 16, wherein the upper-lid element comprises a vision panel arranged to allow observation of the interior of the enclosed zone.

18. Apparatus according to any preceding claim, wherein the respective closure elements are walled or shell elements.

19. Apparatus according to any preceding claim, further comprising an inlet port permitting entry into the enclosed zone of pneumatic conveying gas, and an outlet port permitting conveying gas and conveyed material to be removed from the enclosed zone.

20. Apparatus according to claim 19, wherein the inlet and outlet ports are arranged to communicate with the enclosed zone through walls in one or more closure elements.

21. Apparatus according to claim 20, wherein the inlet and outlet ports are arranged substantially in line with one another.

22. Apparatus according to claim 21, wherein the inlet and outlet ports are arranged substantially in line with one another and transversely to the axis of the port accessing the vessel.

23. Apparatus substantially as herein described with reference to the accompanying drawings.