SETTLER ARRANGEMENT FOR LIQUID-LIQUID EXTRACTION, EQUIPMENT TO BE PLACED IN THE SETTLER OF LIQUID-LIQUID EXTRACTION AND METHOD FOR INSTALLING THE EQUIPMENT

FIELD OF THE INVENTION

The invention relates to a settler arrangement for liquid-liquid extraction, defined in the preamble of claim 1. The invention also relates to equipment to be placed in the settler of liquid-liquid extraction, defined in the preamble of claim 10. Moreover, the invention relates to a method for installing the equipment, defined in the preamble of claim 18.

BACKGROUND OF THE INVENTION From the prior art, there is known a settler arrangement for ^' liquid-liquid extraction from the publication US ^' 6,267,900 Bl, by which a first solution and a second solution that is heavier than the first solution, can be, separated from a dispersion of said solutions. The ^" known settler arrangement comprises side walls and a bottom that define the settler. The settler has a feed end, through which the dispersion is fed into the settler, and a discharge end, through which the first and second solutions are arranged to be discharged as mutually separated. In between the feed and discharge ends of the settler, there are provided separating elements, such as picket fences, between which there are established successive separating steps, where the first solution is separated in an upper phase, and the second solution is separated in a lower phase underneath the upper phase. The settler discharge end is provided with an overflow chute that is positioned transversally with respect to the flowing direction and receives the first solution separated in the upper phase as an overflow from the settler. On a lower level with

respect to the overflow chute, there is a first outlet box that receives the first solution from the overflow chute. In succession to the overflow chute in the flowing direction, and adjacently thereto, there is arranged a collecting chute for receiving the second solution as an underflow from the settler. From the collecting chute to the settler, there are extended rising pipes, through which the second solution can rise to the collecting chute. In the rising pipes, there are arranged level control valves, by which the level of the second solution and thereby also the overflow height of the first solution can be adjusted. On a level that is positioned lower than the collecting chute, there is arranged a second outlet box to receive the second solution from the collecting chute .

Typically current arrangements are assembled of single elements at the site of usage in the settler, which is cumbersome, expensive and time-consuming. A further problem is that in known arrangements, the outlet boxes are placed outside the settler, wherefore they take up space and can cause leaks.

OBJECT OF THE INVENTION

The object of the invention is to eliminate the above mentioned drawbacks.

A particular object of the invention is to introduce a settler arrangement for liquid-liquid extraction, which settler arrangement can be assembled easily and rapidly with low expenses, and is compact in structure and takes up as little space as possible.

SUMMARY OF THE INVENTION

The settler arrangement for liquid-liquid extraction according to the invention is characterized by what is set forth in the appended claim 1. Further, the equipment according to the invention is characterized by what is set forth in claim 10. Moreover, the installing method according to the invention is characterized by what is set forth in claim 18.

According to the invention, an overflow chute, a first outlet box, a collecting chute, a set of rising pipes, level control valves and a second outlet box are interconnected in order to together form an essentially rigid self-supporting subassembly that can, as one uniform entity, be transferred and installed on the bottom of a settler.

In the method according to the invention, in a place of manufacture, such as an engineering workshop, the overflow chute, the first outlet box, the collecting chute, the rising pipes, the level control valves and the second outlet box are interconnected in order to together form an essentially rigid and self-supporting subassembly. The created subassembly is transferred, as one uniform entity, to the site of installation. At the site of installation, the subassembly is installed to be supported by the settler bottom.

An advantage of the invention is that the subassembly can be manufactured in a factory and transferred as a ready-made entity to the site of usage, which makes the installation at the site of usage both easier and more rapid. The settler arrangement can be assembled easily and rapidly with low expenses, and it is compact and takes up as little space as possible.

In an embodiment of the settler arrangement and equipment, the subassembly includes an essentially vertical front wall that is parallel with the overflow chute, the upper edge of the front wall being attached to the outer side of the overflow chute, and the lower edge of said front wall extending to the vicinity of the settler bottom, so that in between the lower edge and the bottom, there is left an aperture that allows the second solution to flow through the aperture to the rising pipes.

In an embodiment of the settler arrangement and equipment, the subassembly includes support plates that are arranged transversally with respect to the lengthwise direction of the overflow and collecting chutes, spaced apart from each other underneath the overflow and collecting chutes, to which support plates the overflow chute, the collecting chute and the front wall are attached.

In an embodiment of the settler arrangement and equipment, in the support plates there are integrated legs for supporting the subassembly against the settler bottom.

In an embodiment of the settler arrangement and equipment, the overflow chute is semi-circular in cross-section.

In an embodiment of the settler arrangement and equipment, the collecting chute is semi-circular in cross-section.

In an embodiment of the settler arrangement and equipment, the first outlet box is attached underneath the overflow chute.

In an embodiment of the settler arrangement and equipment, the second outlet box is attached underneath the collecting chute.

In an embodiment of the settler arrangement and equipment, the subassembly includes a support frame that is attached rigidly with respect to the collecting chute in order to support the level control valve.

LIST OF DRAWINGS

The invention is described in more detail below by way of exemplary preferred embodiments and with reference to the appended drawings, where

Figure 1 is an axonometric illustration of an embodiment of a settler arrangement according to the invention, provided with a subassembly at the discharge end, viewed in a slanted direction from the top,

Figure IA illustrates a detail of Figure 1,

Figure 2 is a side-view illustration of the subassembly placed at the discharge end of the settler arrangement of Figure 1,

Figure 3 is a top-view illustration of the subassembly of Figure 2,

Figure 4 illustrates a cross-section IV-IV of Figure 2,

Figure 5 illustrates a cross-section V-V of Figure 2, and

Figure 6 is an axonometric illustration of the subassembly of Figures 1 - 5, viewed from a slanted downwardly direction.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 illustrates a settler arrangement for liquid- liquid extraction. The settler arrangement has side walls 1, 2, 3, 4 and a horizontal bottom 5, which define a rectangular-shaped settler 6. The settler 6 need not, however, necessarily be rectangular. In another embodiment, it can also be narrowed towards the discharge end, so that either one or both of the side walls are arranged in an inclined position with respect to the front and rear walls, while the bottom is horizontal.

The settler β has a feed end 7, through which the dispersion is fed into the settler 6. The settler also has a discharge end 8, through which the first and second solutions that are separated into layered phases are arranged to be discharged as mutually separated.

Picket fences are arranged as separating elements 9 in the settler, in between the feed end and the discharge end, to establish successive separating steps in the flowing direction, for separating the first solution as an upper phase and for separating the second solution as a lower phase.

The discharge end 8 of the settler 6 is provided with an overflow chute 10 that is arranged transversally with respect to the flowing direction, so that it can receive as an overflow from the settler the first solution forming the topmost phase. Underneath the overflow chute 10, there is arranged a first outlet

box 11, in which the first solution flows from the overflow chute 10. A collecting chute 12 is positioned after the overflow chute 10 in the flowing direction, adjacently with the overflow chute 10. The collecting chute 12 receives the second solution forming the lower phase from the settler 6. At the bottom of the collecting chute 12, there are arranged rising pipes 13, which extend from the collecting chute 12 to the settler 6, so that the second solution can rise along them to the collecting chute through level control valves 14. In the rising pipes 13, the purpose of the level control valves 14 is to adjust the level of the second solution, and in the settler their purpose is to adjust the phase boundary surface. The second outlet box 15 is arranged on a lower level with respect to the collecting chute 12, attached underneath it, and can receive second solution from the collecting chute 12. Being integrated in the subassembly 16, the outlet boxes 11 and 15 do not need a separate foundation, and because they do not extend to outside the extreme measures of the chutes, they do not need separate floor space in a factory. The outlet pipes of the outlet boxes can be positioned freely, which renders versatile possibilities for planning the industrial layout. Because the outlet boxes 11 and 15 are located inside the settler, they cannot cause leaks to outside the settler. In the drawings, the discharge pipe of the second outlet box 15 is arranged in the side wall 3. It can also be arranged in the rear wall 4.

The overflow chute 10, the first outlet box 11, the collecting chute 12, the rising pipes 13, the level control valves 14 and the second outlet box 15 are interconnected in order to together form an essentially rigid self-supporting subassembly 16 that

can be transferred as a uniform entity and installed on the settler bottom.

In addition, the subassembly 16 also includes an essentially vertical front wall 17 that is parallel with the overflow chute. The front wall 17 is at its upper edge 18 attached to the external side of the overflow chute 10. The lower edge 19 of the front wall

17 extends to the vicinity of the bottom 5 of the settler 6, so that in between the lower edge and the bottom, there is left an aperture 20, through which the second solution has access to the rising pipes 13.

Moreover, the subassembly 16 includes support plates 21 that are arranged transversally with respect to the lengthwise direction of the overflow and collecting chutes 10, 12, spaced apart from each other underneath the overflow and collecting chutes, and the overflow chute 10, the collecting chute 12 and the front wall 17 are attached to said support plates 21. This makes the structure of the subassembly extremely rigid. Also legs 22 are integrated in the support plates 21 for supporting the subassembly 16 against the bottom 5 of the settler 6. The integration of the legs 22 in the support plates 21 ensures that the subassembly does not need any other separate support legs.

Both the overflow chute 10 and the collecting chute 12 are semi-circular in cross-section, and hence they can be manufactured by cutting prefabricated pipe into half. In addition, the semi-circular shape is rigid in bending, its walls can be thin, and additional reinforcement is not needed.

In addition, the subassembly 16 includes a support frame 23, which is rigidly attached with respect to the collecting chute 12 in order to support the level

control valve 14. The level control valves 14 can be readily installed at the factory. Moreover, the support frame 23 makes the structure of the subassembly 16 even more rigid.

The measures of the subassembly 16 are advantageously designed so that the subassembly fits into a freight truck trailer, in which it can be transported from the place of manufacture to the place of usage.

The invention is not restricted to the above described embodiments only, but many modifications are possible within the scope of the inventive idea defined in the appended claims.