WO2019167023A1

WO2019167023A1 - Siphon bypass system for flotation cell maintenance

Info

Publication number: WO2019167023A1
Application number: PCT/IB2019/051681
Authority: WO
Inventors: Ociel MORALES
Original assignee: Flsmidth A/S
Priority date: 2018-03-01
Filing date: 2019-03-01
Publication date: 2019-09-06

Abstract

A siphon bypass system (100) for a flotation cell bank (1) comprises conduit (106, 107, 108, 111, 113, 122, 123, 124) extending from a first flotation cell tank (10) to a third flotation cell tank (10). The conduit circumvents a second flotation cell tank (10) positioned between the first flotation cell tank (10) and the third flotation cell tank (10). An upstream portion of the conduit may comprise an inlet bend conduit (106) configured to be received within the first flotation tank cell, a guillotine valve (104), and a pump (105). A downstream portion of the conduit may comprise a pinch valve (114) and an outlet bend conduit (111) configured to be received within the third flotation tank cell.

Description

SIPHON BYPASS SYSTEM FOR FLOTATION CELL MAINTENANCE

CROSS-REFERENCE TO RELATED APPLICATIONS

None.

FIELD OF THE INVENTION

This invention relates to flotation cells, and more particularly to apparatus which may be used to transfer slurry or pulp from one flotation cell tank to another flotation cell tank in a controlled fashion. Particularly disclosed, is an apparatus which enables maintenance to be performed on a flotation cell, whilst permitting continuous operation of remaining flotation cells in the flotation cell bank.

BACKGROUND OF THE INVENTION

The number of flotation cells in a flotation cell bank may vary from site to site.

Traditionally, when maintenance is needed on a particular flotation cell within a flotation cell bank, the entire flotation cell bank must be stopped, drained, and locked out/tagged out. This is problematic to production and can increase overall operating expenditures (OPEX) of a flotation process. Accordingly, a novel siphon-based bypass system (which, in some embodiments, may be configured to be retrofitted to an existing flotation cell bank) is proposed. The novel bypass system may overcome problems associated with prior art methods of performing routine maintenance on flotation cells. In particular, with embodiments of the novel bypass system, it is possible to perform maintenance work in cells without the need to stop production. It is envisaged that embodiments may be especially useful with low-yield reduction cell banks.

OBJECTS OF THE INVENTION

It is, therefore, an object of some embodiments of the invention to provide a bypass system apparatus for flotation cells which overcomes problems seen with conventional apparatus and conventional methods of performing maintenance on a flotation cell within a flotation cell bank.

It is also an object of some embodiments of the invention to reduce or eliminate the need to completely stop all operations of a flotation cell bank when flotation cell maintenance is required.

It is further an object of some embodiments of the invention to provide a bypass system which can easily be retrofitted to flotation cell banks.

It is further an object of some embodiments of the invention to provide a bypass system which can easily be attached to one or more flotation cells.

It is further an object of some embodiments of the invention to provide a bypass system which can easily be transported to a flotation cell bank site. It is further an object of some embodiments of the invention to provide a bypass system which can easily be installed on a flotation cell bank.

It is further an object of some embodiments of the invention to provide a bypass system which can easily be removed from a flotation cell bank.

It is further an object of some embodiments of the invention to provide a bypass system which is easy to connect to an existing control system.

It is further an object of some embodiments of the invention to provide a bypass system which is easy to operate.

It is further an object of some embodiments of the invention to provide a bypass system which can easily be operated to allow continuous operation of one or more flotation cells within a flotation cell bank, while maintenance is performed on at least one flotation cell within the flotation cell bank.

It is further an object of some embodiments of the invention to provide a bypass system which is inexpensive, convenient, and configured to be provided with new flotation cell bank installations (e.g.,“greenfield” installations) as well as flotation cell banks already operating or in existence (e.g.,“brownfield” applications), without limitation.

It is further an object of some embodiments of the invention to provide a bypass system which works under principle of siphons so as to adequately regulate the level (e.g., mud height) of the flotation cells without depending on operational reliability of commercial slurry pumps and/or without unnecessary risk of an operational collapse.

These and other objects of the invention will be apparent from the drawings and description herein. Although every object of the invention is believed to be attained by at least one embodiment of the invention, there is not necessarily any one embodiment of the invention that achieves all of the objects of the invention.

SUMMARY OF THE INVENTION

A bypass system (100) for a flotation cell bank (1) is disclosed. The bypass system (100) may comprise conduit (106, 107, 108, 111, 113, 122, 123, 124) extending from a first flotation cell tank (10) to a third flotation cell tank (10). The conduit (106, 107, 108, 111, 113, 122, 123, 124) may circumvent a second flotation cell tank (10) positioned between the first flotation cell tank (10) and the third flotation cell tank (10). An upstream portion of the conduit may comprise an inlet bend conduit (106) which is configured to be received within the first flotation tank cell (10). The upstream portion of the conduit may be operatively configured with and/or comprise a guillotine valve (104) and a pump (105). A downstream portion of the conduit may be operatively configured with and/or comprise a pinch valve (114). An outlet bend conduit (111) configured to be received within the third flotation tank cell (10) may further be provided as part of the bypass system (100).

In some embodiments, the bypass system (100) may comprise an accumulator (102), without limitation. In some embodiments, the conduit (106, 107, 108) of the bypass system (100) may comprise one or more sections of flexible conduit (107), one or more sections of rigid conduit (108), one or more downstream adapters (113), one or more upstream adapters (124), one or more inlet conduits (122), one or more outlet conduits (123), or a combination thereof, without limitation. In some embodiments, the conduit (106, 107, 108, 124) of the bypass system (100) may comprise one or more air outlets (109), without limitation. In some embodiments, the air outlets (109) of the bypass system (100) may be operatively connected to air bleed pipe (116), without limitation. In some embodiments, the air bleed pipe (116) may be operatively connected to an air bleed manifold (110), without limitation. In some embodiments, the bypass system (100) may comprise a bleeding pipe (119) extending from the accumulator (102), without limitation.

In some embodiments, the bypass system (100) may comprise one or more clamps (112) configured to join one or more sections of conduit, without limitation. In some embodiments, the bypass system (100) may comprise one or more guides (117) configured for securing the conduit (106, 107, 108), without limitation.

In some embodiments, the bypass system (100) may comprise parallel conduit (106, 107, 108, 111, 113, 122, 123, 124) extending from the first flotation cell (10) to the third flotation cell (10), without limitation. The parallel conduit (106, 107, 108) may circumvent the second flotation cell (10) therebetween, without limitation. It should be understood that in some embodiments, more than one second flotation cell (10) may be circumvented/bypassed, without limitation. In some embodiments, the bypass system (100) may comprise one or more support members (115), without limtiation. The one or more support members (115) may be configured to support the bypass system (100) on flotation cell tanks (10) of a flotation cell bank (1), without limitation. In some embodiments, the one or more support members (115) may be adequately configured to serve as a service platform for access (e.g., to enable walking on by one or more persons, to provide for ingress/egress, to facilitate operation, to install/repair/inspect equipment, etc.), without limitation. In some embodiments, the bypass system (100) may comprise safety railing (118), without limitation. In some embodiments, the bypass system (100) may comprise a bleeding pipe (119) extending from the accumulator (102), without limitation. In some embodiments, the bypass system (100) may comprise a slurry/pulp return (120) extending from the accumulator (102), without limitation. In some embodiments, the bypass system (100) may comprise an air bleed valve (121) regulating air into the accumulator (102), without limitation. In some embodiments, the bypass system (100) may comprise a transport vehicle (140) suitable for transporting components of the bypass system (100) to a flotation cell bank (1) for installation, without limitation.

A method of performing maintenance on a flotation cell is further disclosed. The method may comprise the step of providing a bypass system (100) as described above. In some embodiments, the method may comprise the step of installing the bypass system (100) on a flotation cell bank (1). In some embodiments, the method may comprise the step of using the pump (105), guillotine valve (104), and pinch valve (114) to fill the conduit (106, 107, 108) with slurry from the first flotation cell tank (10). In some embodiments, the method may comprise the step of delivering slurry from the first flotation cell tank (10) to the third flotation cell tank (10) via the conduit (106, 107, 108). It should be understood that one or more second flotation cell tanks (10) between the first flotation cell tank (10) and third flotation cell tank (10) may be circumvented/bypassed, using the bypass system (100), without limitation. The step of delivering slurry from the first flotation cell tank (10) to the third flotation cell tank (10) via the conduit (106, 107, 108) may occur by virtue of siphoning. In some embodiments, the method may comprise the step of performing maintenance on the second flotation cell tank (10), while the slurry is being delivered from the first flotation cell tank (10) to the third flotation cell tank (10) via the conduit (106, 107, 108) by virtue of siphoning.

It will be appreciated from this disclosure, and the drawings, that various

features/components and method steps described herein may be altered without significantly departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

To complement the description which is being made, and for the purpose of aiding to better understand the features of the invention, a set of drawings illustrating preferred valve apparatus and methods of using the same is attached to the present specification as an integral part thereof, in which the following has been depicted with an illustrative and non-limiting character. It should be understood that like reference numbers used in the drawings may identify like components. In the figures:

FIGS. 1-9 describe or illustrate various images of an exemplary and non-limiting first embodiment of a bypass system installed on a flotation cell bank comprising three flotation cells. The number of flotation cells in a flotation cell bank may vary between sites and therefore be different from what is illustrated. Depending on the tank size(s) of a flotation cell(s) and/or slurry flow volumes to be transferred between two flotation cells, a“single” or“double” conduit arrangement may be required. Both types are shown on the images provided

FIGS. 10-14 show exemplary and non-limiting steps of transporting a bypass system to a flotation cell bank, and installing structural support members onto the flotation cell bank, according to some embodiments. FIGS. 15-17 describe or illustrate various images of an exemplary and non-limiting second embodiment of a bypass system installed on a flotation cell bank comprising four flotation cells.

FIGS. 18 and 19 suggest various components of a bypass system according to some preferred embodiments.

FIG. 20 shows a PNID schematic of a flotation cell bank employing a bypass system according to some embodiments, wherein a middle flotation cell tank can be shut down for maintenance operations without disrupting a flotation process, by virtue of siphoning slurry from an upstream flotation cell tank and sending the slurry to a downstream flotation cell tank.

In the following, the invention will be described in more detail with reference to drawings in conjunction with exemplary embodiments.

DETAILED DESCRIPTION OF THE INVENTION

A bypass system (100) for a flotation cell bank (1) may be provided. Components of the bypass system (100) may be loaded onto a transport vehicle (140), delivered to the flotation cell bank (1), and offloaded from the transport vehicle (140) as suggested in FIGS. 10 and 11. The transport vehicle may comprise a truck, a ship, or freight train, without limitation. The components of the bypass system (100) may be delivered to the flotation cell bank (1) at once, or in piecemeal, without limitation. Components of the bypass system (100) may be stored in one or more shipping containers, without limitation.

As suggested in FIGS. 12-14, one or more support members (115) may be set up on one or more flotation cell tanks (10) in the flotation cell bank (1). The support members (115) may serve as a foundation for components of the bypass system (100). As shown, support members (115) may comprise one or more floors, one or more trusses, one or more load-bearing beams, one or more frame portions, etc. The support members (115) may be bolted or welded, or otherwise fastened to portions of the flotation cell bank (1), without limitation.

According to some embodiments, flexible conduit (107) and/or rigid conduit (108) sections may be provided to form a channel which links an upstream flotation cell (10) in the flotation cell bank (1) with a downstream flotation cell (10) in the flotation cell bank (1), such that a flotation cell therebetween is bypassed or short-circuited. In some embodiments, conduit sections may comprise one or more air outlets (109) which are operably connected to one or more air bleed pipes (116).

The one or more air outlets (109) may be located at upper portions conduit sections as shown in the figures. The one or more air bleed pipes (116) may converge at an air bleed manifold (110) before leading to an accumulator (102). Air contained within conduit sections of the channel bridging the upstream and downstream flotation cells may travel to the accumulator, regulated by an air bleed valve (121).

Condensed slurry (having air removed therefrom) may settle at the bottom of accumulator (102). Accordingly, in some embodiments, a slurry/pulp return (120) may be provided to the bypass system (100) in order to re-supply the conduit with the de-aerated slurry.

In order to start moving slurry from the upstream to the downstream flotation cell, and prime the channel formed by conduit sections with slurry, a pump (105) may be temporarily initiated. Using an upstream guillotine valve (104) and a downstream pinch valve (114), the conduit sections can be primed with slurry, and siphoning effect commenced.

According to some embodiments, the channel may be comprised of various types of conduit sections, including, but not limited to, flexible conduit (107) and/or rigid conduit (108) sections, bent sections (e.g., one or more inlet bend conduits (106), one or more outlet bend conduits (111)), one or more inlet conduits (122), one or more outlet conduits (123), one or more upstream adapters (124), one or more downstream adapters (113), a combination thereof, or the like, without limitation. In some instances, one or more clamps (112) may be employed within the bypass system (100) to connect conduit sections together, without limitation. In some cases, traditional bolted flanges with seals may be employed, without limitation.

In some embodiments, one or more guides (117) may be employed to secure and/or stabilize conduit to the support members (115), without limitation. In doing so, stabilization of the bypass system and increased safety may be achieved. Moreover, one or more safety railings (118) may be provided as part of a bypass system (100) kit to reduce the possibility of accidents.

When the accumulator (102) has excessive air that might potentially compromise the siphon in conduit (106, 107, 108, 111, 113, 122, 123, 124), the pump (105) is activated to refill the accumulator (102) with slurry, thereby displacing the excessive air out through the bleeding pipe (119). A slurry suction conduit (125) may be provided to the bypass system (100) for the pump (105). The pump may be used to surge the main conduit (106, 107, 108, 111, 113, 122, 123, 124) with slurry, and to pump slurry into the accumulator (102) to displace air out of the bypass system (100) when/if required.

In use, accumulator (102) may typically filled with slurry. Over time, slurry in the accumulator (102) may become replaced or partially-displaced with air as air is collected from the air bleed pipe (116). If/when the amount of air received in the accumulator (102) becomes excessive, the pump (105) may activate to fill the accumulator (102) with slurry again, thereby replacing or partially-displacing the excess air from the accumulator (102) out through air relief valve (128) and bleeding pipe (119), without limitation. An air bleed valve (121) may be activated to isolate the accumulator (102) from the air bleed manifold (110) and/or bypass conduit (106, 107, 108, 111, 113, 122, 123, 124). For example, the air bleed valve (121) may be activated if/when air accumulated in the accumulator (102) should be replaced with slurry from flotation cell tank (10) using pump (105).

While not expressly shown, it should be understood that the bypass system (100) and/or components thereof may be provided in duplicates. For example, multiple flotation cell banks (1) may be provided in series and/or in parallel - and each of said multiple flotation cell banks (1) may incorporate a novel bypass system and/or components thereof, without limitation.

In short, proposed embodiments may comprise a channel extending from the tank of a first flotation cell (10) in a flotation cell bank (1), to a tank of a second flotation cell (10) within the flotation cell bank (1), wherein at least one flotation cell (10) is provided between the first and the second flotation cell (10). The channel extends far enough into the tanks of the first and second flotation cells so that an adequate siphon can be achieved via the channel. The channel may comprise piping (e.g.,“conduit”) configured with a series of air bleeds (109) that allow entrained air in slurry to escape from the channel without compromising the siphon in the channel.

A contractor or other entity may provide a bypass system or operate a bypass system in whole, or in part, as shown and described. For instance, a contractor may receive a bid request for a project related to designing or operating a bypass system (e.g., as part of a service or maintenance contract for a flotation cell or flotation cell bank, without limitation). Or, a contractor may offer to design any number of bypass systems or components thereof. A

contractor may offer to design a process for a client involving one or more of the features and/or method steps shown and described herein. The contractor may then provide, for example, any one or more of the features and/or method steps thereof shown and/or described in the embodiments herein.

A contractor may provide one or more of the devices shown and described herein by selling those devices or by offering to sell those devices, without limitation. A contractor may provide various embodiments of a bypass system that are sized, shaped, and/or otherwise configured to meet the design criteria of a particular client or customer (e.g., a specific flotation cell bank which may be comprised of different types or brands of flotation cells), without limitation.

A contractor may subcontract the fabrication, delivery, sale, installation, commissioning, decommissioning, and/or removal of the bypass system disclosed - or, of a component of the bypass system disclosed, without limitation. The contractor may also survey a site (e.g., a flotation cell bank installation) and design a bypass system, designate one or more storage areas for storing the material used to manufacture the bypass system or for storing one or more components of a bypass system, without limitation.

The contractor may also maintain, modify, replace, or upgrade any of the disclosed devices making up embodiments of a bypass system. The contractor may provide such services by subcontracting such services or by directly providing those services. In some cases, a contractor may modify a preexisting flotation cell bank with a“retrofit kit” to arrive at a modified flotation cell bank which has functionally provided by the disclosed bypass system. The“retrofit kit” may comprise one or more of the features, devices, components, or method steps associated with the bypass system and processes thereof discussed herein.

Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

REFERENCE NUMERAL IDENTIFIERS

1 Flotation cell bank

10 Flotation cell tank

100 Bypass system

102 Accumulator

104 Guillotine valve

105 Pump (e.g., surge pump)

106 Inlet bend conduit

107 Flexible conduit

108 Rigid conduit

109 Air outlet

110 Air bleed manifold

111 Outlet bend conduit

112 Clamp

113 Downstream Adapter

114 Pinch valve

115 Support member

116 Air bleed pipe

117 Guide

118 Safety Railing

119 Bleeding Pipe

120 Slurry/pulp return

121 Air bleed valve

122 Inlet conduit

123 Outlet conduit

124 Upstream adapter

125 Pipe (e.g., to suck slurry from flotation cell tank 10 to the pump 105)

126 Guillotine valve (e.g., to shut the main conduit slurry surge process at start)

127 Guillotine valve (e.g., for slurry suction for pump 105)

128 Air relief valve (e.g., for when slurry is pump in the accumulator to displace excessive air inside)

140 Transport vehicle

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A bypass system (100) for a flotation cell bank (1) comprising:

conduit (106, 107, 108, 111, 113, 122, 123, 124) extending from a first flotation cell tank (10) to a third flotation cell tank (10); the conduit circumventing a second flotation cell tank (10) positioned between the first flotation cell tank (10) and the third flotation cell tank (10); an upstream portion of the conduit comprising an inlet bend conduit (106) configured to be received within the first flotation tank cell, a guillotine valve (104), and a pump (105); and a downstream portion of the conduit comprising a pinch valve (114) and an outlet bend conduit (111) configured to be received within the third flotation tank cell.

2. The bypass system (100) according to any one of the preceding claims, further comprising an accumulator (102).

3. The bypass system (100) according to any one of the preceding claims, wherein the conduit of the bypass system (100) comprises one or more sections of flexible conduit (107), one or more sections of rigid conduit (108), one or more downstream adapters (113), one or more upstream adapters (124), one or more inlet conduits (122), one or more outlet conduits (123), or a combination thereof.

4. The bypass system (100) according to any one of the preceding claims, wherein the conduit of the bypass system (100) comprises one or more air outlets (109).

5. The bypass system (100) according to any one of the preceding claims, wherein the air outlets (109) of the bypass system (100) are operatively connected to air bleed pipe (116).

6. The bypass system (100) according to any one of the preceding claims, wherein the air bleed pipe (116) is operatively connected to an air bleed manifold (110).

7. The bypass system (100) according to any one of the preceding claims, further comprising a bleeding pipe (119) extending from the accumulator (102).

8. The bypass system (100) according to any one of the preceding claims, further comprising one or more clamps (112) configured to join one or more sections of conduit.

9. The bypass system (100) according to any one of the preceding claims, further comprising one or more guides (117) configured for securing the conduit.

10. The bypass system (100) according to any one of the preceding claims, further comprising

parallel conduit extending from the first flotation cell (10) to the third flotation cell (10) and circumventing the second flotation cell (10) therebetween.

11. The bypass system (100) according to any one of the preceding claims, further comprising one or more support members (115) which are configured to support the bypass system (100) on flotation cell tanks (10) of a flotation cell bank (1).

12. The bypass system (100) according to any one of the preceding claims, further comprising safety railing (118).

13. The bypass system (100) according to any one of the preceding claims, further comprising a bleeding pipe (119) extending from the accumulator (102).

14. The bypass system (100) according to any one of the preceding claims, further comprising a slurry/pulp return (120) extending from the accumulator (102).

15. The bypass system (100) according to any one of the preceding claims, further comprising an air bleed valve (121) regulating air into the accumulator (102).

16. The bypass system (100) according to any one of the preceding claims, further comprising a transport vehicle (140) suitable for transporting components of the bypass system (100) to a flotation cell bank (1) for installation.

17. A method of performing maintenance on a flotation cell comprising: providing a bypass system (100) according to any one of the preceding claims; installing the bypass system (100) on a flotation cell bank (1); using the pump (105), guillotine valve (104), and pinch valve (114), filling the conduit (106, 107, 108, 111, 113, 122, 123, 124) with slurry from the first flotation cell tank (10); delivering slurry from the first flotation cell tank (10) to the third flotation cell tank (10) via the conduit by virtue of siphoning; and, performing maintenance on the second flotation cell tank (10) while the slurry is delivered from the first flotation cell tank (10) to the third flotation cell tank (10) via the conduit (106, 107, 108) by virtue of siphoning.