GB2593186A - A process water treatment unit - Google Patents

Abstract

A process water treatment unit 10, forming part of a process water treatment system, comprises a container 11 internally divided by a sealed partition 65 into a process room 66 and a control room 67, at least one electrocoagulation cell 68, 69, 70, 71 and electrical and fluid services therefor located within the process room, such that, in use, the treatment unit is assembled off-site, within the container, and is transportable to a site ready for operation. A rectifier panel (73, Fig. 6) may be located in the control room and electric cabling 74 can connect the electrocoagulation cell(s) to the rectifier panel. A water inlet 51 may be mounted in an external wall of the container, wherein the fluid services can include water piping connecting the water inlet to the electrocoagulation cell(s), and a treated water collection container (114, Fig. 4), which receives treated coagulant rich water from the electrocoagulation cell(s). Adjustable valves (124, 125, Fig. 5), for controlling water flow to the electrocoagulation cell(s), and an inline water pump 78 can be located in the water piping. Suitably, the container is a modified 6.06m shipping container, wherein an extraction fan 35 may be externally mounted on the container.

Description

A process water treatment unit This invention relates to a process water treatment unit and, in particular, to a unit for treating process water using electrocoagulation.

Electrocoagulation is an electrolytic treatment process for separating and removing a broad range of contaminants including metals, solids, pathogens and other undesirable substances from process water, by running the process water though an electrocoagulation cell. Typically, an electrocoagulation cell contains electrodes and an electrolyte that is to be treated. The treatment process brings about the coagulation of suspended and dissolved particles in the process water by applying an electric field, which binds these particles together forming larger particles which will settle out of the process water.

European Patent No. 2 150 500 describes an electrocoagulation cell manufactured by Enva Ireland Ltd. The electrocoagulation cell, as described, may be set up as a process water treatment unit forming part of a process water treatment system, either as a single cell, or as number of cells connected together in hydraulic parallel. In either case the electrocoagulation cell(s) have to be set up on site, which can take a considerable amount of time and effort to accomplish, depending on the particular application.

It is an object of the present invention to overcome the disadvantages of the process water treatment units hereinbefore described.

Thus, the invention provides a process water treatment unit forming part of a process water treatment system, which process water treatment unit comprises a container, the container being internally divided by a sealed partition into a process room and a control room, within which process room are disposed at least one electrocoagulation cell, and electrical and fluid services therefor, such that, in use, the process water treatment unit is assembled off-site, within the container, and is transportable to a site ready for operation.

An advantage of the process water treatment unit in accordance with the invention is that once the specification for a particular application has been established, the unit may be assembled off-site in accordance with the specification and delivered to the site in a ready-togo state. All that is required is that the process water supply and electrical supply be connected to the unit. This reduces any disruption on-site caused by the addition of the unit to an existing process water treatment system.

Preferably, a rectifier panel is located in the control room and wherein the electrical services include electric cabling connecting the and each electrocoagulati on cell to the rectifier panel.

An advantage of this aspect of the invention is that the rectifier, being separated from the process room by the sealed partition, is located in the more suitable environment of the control room.

Further, preferably, a control unit is located in the control room, which control unit controls and monitors the operation of the process water treatment unit.

An advantage of this aspect of the invention is that once the process water treatment unit is in operation, the functioning of the and each electrocoagulation cell can be controlled and monitored without personnel having to enter the process room.

Suitably, a process water inlet is mounted in an external wall of the container, and wherein the fluid services include process water piping connecting the process water inlet to the and each electrocoagulation unit, and a treated water collection container, which receives treated coagulant rich water from the and each electrocoagulation cell, and which treated water collection container is connected to an external holding tank.

An advantage of this aspect of the invention is that the one source of process water, connected to the process water inlet, is distributed to the and each electrocoagulation cell, with the output therefrom being collected in the collection container for transfer to the external holding tank.

Preferably, an inline process water pump is located in the process water piping.

An advantage of this aspect of the invention is that the pump ensures efficient delivery of the process water to the and each electrocoagulation cell.

Further, preferably, adjustable valves are located in process water 5 piping for controlling the flow of process water to the and each electrocoagulati on cell.

The addition of adjustable valves has the advantage of balancing the flow of process water to the and each electrocoagulation cell.

Suitably, a coagulant rich water pump is located in the process room, which coagulant rich water pump is connected to the holding tank, and which coagulant rich water pump, in use, pumps coagulant rich water from the holding tank back to the process water treatment system.

The positioning of the coagulant rich water pump in the process room has the advantage that its operation can be monitored and controlled by the control unit in the control room.

Preferably, the process water pump and the coagulant rich water pump are connected into the fluid services by camlock couplers and flexible piping, with the pumps being mounted on a removable frame An advantage of this aspect of the invention is that if one of the 20 pumps malfunctions it can be conveniently replaced by a spare pump with little downtime of the unit resulting.

Further, preferably, ducting connects the and each electrocoagulation cell to an extraction fan externally mounted on the container.

One of the side products of the electrocoagulation process is he generation of gases at the cathode. By extracting any gases produced from the and each electrocoagulation cell, a build-up of these gases in the process room is avoided with attendant improvements in health and safety standards.

Suitably, the container is a modified 6.06m shipping container.

An advantage of this aspect of the invention is that shipping containers are readily available and are designed for ease of transport. Thus, the process water treatment unit, housed in a modified shipping container, can be delivered to the required location by a truck with an on-board crane by which the system can be offloaded.

The invention will be further illustrated by the following description of an embodiment thereof, given by way of example only with reference to the accompanying drawings in which: Fig. 1 is a perspective view from the front and one side of a process water treatment unit in accordance with the invention; Fig. 2 is a view from the rear of the process water treatment unit of Fig. 1; Fig. 3 is a view of the process water treatment unit of Fig. 1 with some panels removed; Fig. 4 is a view from the rear of the process water treatment unit of Fig. lwith a rear panel removed; Fig. 5 is an end view of the process water treatment unit of Fig. 1 with the end doors removed; Fig. 6 is a view from above of the process water treatment unit of Fig. lwith the top panel removed; Fig. 7 is a further end view of the process water treatment unit of Fig. 1 with the end doors removed; Fig. 8 is a further end view of the process water treatment unit of Fig. 1 with the end doors removed; Fig. 9 is a further end view of the process water treatment unit of Fig. 1 with the end doors removed; and Fig. 10 is a further view from above of the process water treatment unit of Fig. lwith the top panel removed.

Referring to Fig. 1, there is illustrated generally at 10, a process water treatment unit forming part of a process water treatment system (not shown). The process water treatment unit 10 is a container 11, which container 11 is a modified 6.06m shipping container, and which container 11 is divided internally into a process room and a control room (not shown). The container 11 has a front wall 12 in which is located a window 13, a process room access door 14 and a service room access door 15. The container 11 is mounted on blocks 16, 17, 18, 19 and an access platform 20 is located against the container 11 to provide access to the process room and the service room. The access platform 20 includes a set of steps 21, attached at one end 22 thereof The set of steps has a pair of adjustable, ground-engaging feet 23, 24, mounted on side frames 25, 26, respectively, and the access platform has four adjustable, ground-engaging feet 27, 28, 29, 30, mounted at corners 31, 32, 33, 34, respectively, thereof.

An extractor fall 35 is mounted in an extractor fan housing 36, which is mounted on the roof 37 of the container 11 at position 38. An external holding tank 39 is located to the rear wall 40 of container 11.

Referring to Fig. 2, the extractor fan housing 36 is connected to an 15 extracted air outlet 41 located on the rear wall 40 at position 42 and an external duct 43 connects the extracted air outlet 41 to the extractor fan housing 36.

A connector 44 for an external electrical supply is located at corner 45 of the rear wall 40. A pair of cooling fan vents 46,47 are 20 located at corner 48 of the rear wall 40.

A fluid pipe bulkhead 49 is mounted in the rear wall 40 at position 50. The fluid pipe bulkhead 49 has a process water inlet 51, a coagulated water inlet 52 and a coagulated water outlet 53. A coagulated water exit pipe 54 exits the process water treatment unit 10 through the rear wall 40 at position 55 and enters the external holding tank 39 at position 56. A coagulated water pipe 57 connects, at one end 58 thereof to the external holding tank 39 at position 59 and at the other end 60 to the coagulated water inlet 52. Standard container doors 61, 62 are in a closed position during normal operation but may be opened for maintenance purposes.

Referring to Fig 3, the process water treatment unit 10 is illustrated with the roof of the container 11, the standard container doors 61,62 and part of the front wall 12 removed for clarity. The container 11 is internally divided by a sealed partition 65 into a process room 66 and a control room 67.

Four electrocoagulation cells 68, 69, 70, 71, as described in European Patent No. 2 150 500, are positioned in line on a floor 72 of the process room 66. A rectifier panel 73 (see Fig 6) is located in the control room 67, which rectifier panel 73 is connected to each electrocoagulation cell 68, 69, 70, 71 by electric cabling 74.

A process water inlet pipe 75 is connected at one end thereof to the process water inlet 51 on the fluid pipe bulkhead 49, and at the other end 76 thereof to a pump inlet 77 of an inline process water pump 78. A process water delivery pipe 79 is connected at one end 80 thereof to a pump outlet 81 on the process water pump 78, and at the other end 82 thereof to a process water distribution pipe 83. Two feeder pipes 84, 85 are connected to the distribution pipe 83 at positions 86, 87, respectively.

The feeder pipes 84, 85 extend above the electrocoagulation cells 68, 69, 70, 71 and split into two pairs of electrocoagulation feeder pipes 88, 89, and 90, 91, respectively, with electrocoagulation feeder pipe 88 being connected to electrocoagulation cell 68, electrocoagulation feeder pipe 89 being connected to electrocoagulation cell 69, electrocoagulation feeder pipe 90 being connected to electrocoagulation cell 70, and electrocoagulation feeder pipe 91 being connected to electrocoagulation cell 71.

A coagulated water inlet pipe 92 connects at one end 93 thereof to the coagulated water inlet 52 on the fluid pipe bulkhead 49, and at the other end 94 thereof to a coagulated water pump inlet 95 of an inline coagulated water pump 96. A coagulated water pump outlet pipe 97 is connected at one end 98 thereof to a coagulated water pump outlet 99 and at the other end 100 thereof to the coagulated water outlet 53 on the fluid pipe bulkhead 49.

Four extractor pipes 101, 102, 103, 104, are respectively connected to the electrocoagulation cells 68, 69, 70, 71 and feed into an extractor duct 105, which in turn is connected to the external duct 43 and thence to the extractor fan 35. Thus, any gases that are produced as part of the electrocoagulation process within the electrocoagulation cells 68, 69, 70, 71 will be extracted by the extractor fan 35.

Referring to Fig. 4, the process water treatment unit 10 is illustrated with part of the rear wall 40 removed for clarity. The electrocoagulation cells 68, 69, 70, and 71 each have an exit chute 110, 111, 112, and 113, respectively from which coagulant rich water spills, in use, and collects in a treated water container 114, to which the coagulated water exit pipe 54 is attached at position 115.

Referring to Fig. 5, an end view of the water treatment unit 10 is 5 illustrated, with the standard container doors 61, 62 and some of the internal piping being removed for purposes of clarity. The inline process water pump 78 and the inline coagulated water pump 96 are both mounted on a removable frame 120, and are connected by camlock couplers 121 and flexible piping 122. A camlock coupler 123 is also 10 used for connecting the coagulated water pipe 57 between the external holding tank 39 and the coagulated water inlet 52.

A first adjustable valve 124 is located in feeder pipe 84 and a second adjustable valve 125 is located in electrocoagulation feeder pipe 88. Similar adjustable valves are located in the second feeder pipe 85 (see Fig. 3)) and in the remaining electrocoagulation feeder pipes 89, 90, and 91 (see Fig. 3). These adjustable valves 124 and 125 can be used to control the rate of delivery of process water to electrocoagulation cell 68 and when valve 125 is fully closed electrocoagulation cell 68 can be taken out of the process for maintenance purposes or when the volume of process water is reduced. The same principle can be applied to the remaining electrocoagulation cells 69, 70, 71.

The flow of water through the process water treatment unit is described with reference to Figs. 5 to 8.

Referring to Fig. 5, process wate is drawn into the process water treatment unit 10 by the inline process water pump 78, via the process water inlet pipe 75 and is delivered to the process water distribution pipe 83 via the process water delivery pipe 79.

Referring to Fig. 6, the process water passes from the process water delivery pipe 83 through the feeder pipes 84, 85 and the two pairs of electrocoagulation feeder pipes 88, 89 and 90, 91 to the electrocoagulation cells 68, 69, 70, 71. Coagulant rich water exits each electrocoagulation cell 68, 69, 70, 71 from exit chutes 110, 111, 112, 113, respectively and thence to the treated water container 114.

Referring to Fig. 7, coagulant rich water exits the treated water container 1 I 4 through the coagulated water exit pipe 54 and enters the external holding tank 39 under gravity.

Referring to Fig. 8, coagulant rich water is drawn from the external holding tank 39 via the coagulated water pipe 57 and the coagulated water inlet pipe 92 by the action of the inline coagulated water pump 96 and thence, via the coagulated water outlet pipe 97, to the coagulated water outlet 53 (see Fig. 2). The purpose of the external holding tank 39 is to protect the inline coagulated water pump 96 from running dry if the flow of process water to the process water treatment unit 10 is interrupted.

The extraction of gases from the electrocoagulation cells 68, 69, 70,71 is described with reference to Figs. 9 and 10.

Referring to Fig. 9, gases from the electrocoagulation cell 68 are vented to the atmosphere via the extractor pipe 101, with the electrocoagulation cell 68 having a hood 130 to which the extractor pipe 101 is attached. The gases from the extractor pipe 101 are fed into the extractor duct 105, which in turn is connected to the external duct 43 and thence to the extractor fan housing 36.

Referring to Fig. 10, the process water treatment unit 10 is illustrated from above and shows the extractor pipes 101, 102, 103, 104 attached between the electrocoagulation cells 68, 69, 70, 71, respectively, and the extractor duct 105.

Claims (11)

1. Claims: -I. A process water treatment unit forming part of a process water treatment system, which process water treatment unit comprises a container, the container being internally divided by a sealed partition into a process room and a control room, within which process room are disposed at least one electrocoagulation cell, and electrical and fluid services therefor, such that, in use, the process water treatment unit is assembled off-site, within the container, and is transportable to a site ready for operation.
2. 2. A process water treatment unit according to Claim 1, wherein a rectifier panel is located in the control room and wherein the electrical services include electric cabling connecting the and each electrocoagulation cell to the rectifier panel.
3. 3. A process water treatment unit according to Claiml or 2, 15 wherein a control unit is located in the control room, which control unit controls and monitors the operation of the process water treatment unit.
4. 4. A process water treatment unit according to any one of Claims 1 to 3, wherein a process water inlet is mounted in an external wall of the container, and wherein the fluid services include process water piping connecting the process water inlet to the and each electrocoagulation unit, and a treated water collection container, which receives treated coagulant rich water from the and each electrocoagulation cell, and which treated water collection container is connected to an external holding tank.
5. 5. A process water treatment unit according to Claim 4, wherein an inline process water pump is located in the process water 5 piping.
6. 6. A process water treatment unit according to Claim 4 or 5, wherein adjustable valves are located in process water piping for controlling the flow of process water to the and each electrocoagulation cell.
7. 7. A process water treatment unit according to any one of Claims 4 to 6, wherein a coagulant rich water pump is located in the process room, which coagulant rich water pump is connected to the holding tank, and which coagulant rich water pump, in use, pumps coagulant rich water from the holding tank back to the process water 1 5 treatment system.
8. 8. A process water treatment unit according to any one of Claims 5 to 7, wherein the process water pump and the coagulant rich water pump are connected into the fluid services by camlock couplers and flexible piping, with the pumps being mounted on a removable frame.
9. 9. A process water treatment unit according to any preceding claim, wherein ducting connects the and each electrocoagulation cell to an extraction fan externally mounted on the container.
10. 10. A process water treatment unit according to any preceding claim, wherein the container is a modified 6.06m shipping container.
11. 11. A process water treatment unit according to Claim 1 forming part of a process water treatment system, substantially as 5 hereinbefore described with particular reference to and as illustrated in the accompanying drawings.