RU2619695C2 - Jet mixer-settler - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: method of functioning of mixer-settler comprises the steps of: mixing - mixing in each block provide turbulent eddies created by the secured pressure source high flow rate of the fluid entering the feed end of mixing, and simultaneously high flow rate of fluid passing from block to block in the direction of the delivery end to move, so that displacement is provided a dense and light fluids from block to block in a direction from the feed end to feed end to mix for moving; sedimentation - defending dense fluid to provide each block when fluid flow stopped to the mixer-settler and out; movement - movement of the light fluid is performed by introducing into a mixer-settler at its feed end to move with a suitable fluid flow from the low to moderate ensuring fluid flow in the direction of the feed end for easy mixing and fluid movement in a mixer-settler only from block to block.

EFFECT: mixing efficiency during fluid movement.

2 cl, 5 dwg

Description

The present invention relates to a jet mixer-settler system. Various devices for settling mixers are known in the art.

US patent 3126258 describes the simultaneous use of separate compartments for mixing and settling in each of the many areas of implementation of the stages in a complex system. Jet mixing of fluids occurs after the removal of liquids from the mixing chamber and their discharge back into the mixing chamber with several jets. Despite the absence of moving parts inside the jet mixing device, it is slightly different in functionality from the device with mechanical mixing. The sedimentation tank operates continuously with a flow rate determined in accordance with the requirements for sedimentation in each area of the stage implementation, at a total flow rate corresponding to each countercurrent flow. Therefore, the flow rate is not controlled over a wide range, and a state known as “flooding” can be achieved, while settling is incomplete and mixed fluids are moved instead of separated fluids. The movement of fluids occurs simultaneously through connecting tubes or channels and depends on gravity in combination with differences in the density of the fluid and the relative lift height of successive regions of the stages. Since this height is constant, the ability to create threads at different speeds is limited.

US Pat. Nos. 2,646,346, 2,754,179, 2,980,514, 3,089,756 and 3,20688 describe systems that have separate chambers for mixing and settling with mechanical stirring and which typically have characteristics similar to those described in relation to US Pat. No. 3,126,258. US Pat. No. 3,549,332 discloses three exploded the time of the sub-operation of mixing and moving light and heavy fluids in opposite directions. Channels for connecting the stages of the implementation of the stages connect the bottom of one area of the implementation of the stage with the top of another area of the implementation of the stage in order to provide different movements forward and backward. Channels are not intended for mixing. This patent does not suggest the possibility of using several physical areas of the implementation of the stages for each working stage. The movement of fluid always occurs with the flow of one fluid to another. Thus, moving the volume of the fluid larger than the normal working volume of this fluid to the stage of implementation requires settling of the fluid or rapid lifting through another fluid. This can lead to poor mixing and suction. This factor is very important in large-scale systems, where poor-quality mixing can create big problems, since the cross-sectional area of the flow in the areas where the stages are implemented increases in proportion to the flow rate to a power of 2/3 for a similar flow time. In the cited document, stirring is carried out using mechanical stirring, and there are no proposals to eliminate mechanical stirring means by moving flows instead. The technique described in this source is not applicable to operations with liquids / solids, because moving any fluid involves moving from below from the densified layer, where blockages can easily occur.

As used herein, the word "light" is used for convenience to mean a fluid having a lower density than another fluid, which in turn is referred to as a "dense fluid".

In FIG. 1 of the accompanying drawings, a device 10 is shown, named in the description of South African Patent Application 2012/03142, as a column of a settling mixer and for cyclic mixing, settling and countercurrent movement of a fluid in many separate modes. These operations are carried out at different time periods in the same physical areas instead of using different physical areas for different operations. The device contains a vertically oriented column. A single column with standard plates can be used for any of a number of processes in a wide range of operating conditions. Modes of use include liquid-liquid contacting, countercurrent decantation, countercurrent ion exchange, countercurrent leaching, and thickening.

An object of the present invention is to provide a device for multi-block countercurrent mixing and settling operations with horizontal arrangement of blocks. Such operations also include liquid-liquid contacting, countercurrent decantation, countercurrent ion exchange, countercurrent leaching, and thickening.

The horizontal arrangement of the blocks can provide several advantages depending on practical needs and limitations. In some cases, the upper part of the support structure with a horizontal arrangement of a set of blocks (or in a horizontally oriented device) is usually less complex and expensive than in the case of a vertical column. A set of horizontally located blocks is often more convenient to maintain when working at ground level, while draining, cleaning and repairing individual blocks. In cases where the process requires many blocks, the use of high or long sequences of blocks can be avoided by using a vertical column consisting of vertically composed layers, each of which contains a certain number of horizontal blocks.

SUMMARY OF THE INVENTION

The present invention relates to settling mixers and includes at least a first and a second unit arranged horizontally relative to each other, each unit having a corresponding closed chamber and a channel for movement, the first end of which extends to the upper region of the first unit and the second end extends to the upper region of the second block, which connects the upper region of the first block with the upper region of the second block and which has such a shape that an increase in flow rate flowing from the first block to the second block of fluid.

The mixer settler may be connected through fluid openings to an external pressure source applying pressure to the fluids in the blocks.

The corresponding chamber in each block may have a cylindrical shape. Blocks can be located along a common horizontal axis. Blocks can adjoin each other, between them there can be vertical partitions. Thus, adjacent blocks may have common or closely spaced walls. Alternatively, the blocks may be spaced horizontally.

Each block has a volume with a fluid located below the level of the channel for movement and providing the capture of dense fluid with the prevention of its flow into the neighboring block.

The channel for movement can be narrowed, that is, its cross-sectional area may decrease in the direction from the first block to the second block.

When the fluid flows at a relatively high flow rate from the first end of the channel to the second end, the second end can serve as a nozzle for ejecting fluid into the second block, preferably in the direction of the region in the inner part of the second block that is located at the maximum distance from the nozzle (second end channel). In this case, the jet of ejected fluid causes turbulent mixing of the fluid in the second block.

When the fluid flows at a low to moderate flow rate from the second end of the channel to the first end, the first end can realize the function of ejecting the fluid into the first block at a relatively low speed so as not to disturb the dense fluid contained within the first block. In this case, the light fluid located above the dense fluid in the second block moves with mixing with the light fluid located above the dense fluid in the first block, or with its movement.

The channel for movement can be located outside the first and second blocks. Alternatively, it may be located inside the first and second blocks. In both cases, the channel may enter some distance into one or both blocks.

In accordance with the requirements, the third block can be connected to the second block in the same way as the second block is connected to the first, and the fourth block can be similarly connected to the third block and so on.

Other designs are possible. For example, the blocks can be arranged in the form of a column, which includes a number of layers of blocks, and the layers are vertically arranged one above the other.

Individual blocks can be of various lengths and shapes, but their volumes and cross-sections of the channels, as a rule, are the same in size. As required, each unit may include an outlet or valve for inspection and maintenance if necessary.

The term “mixing inlet end” is used to denote such an end to a sequence of device blocks that, if fluid is introduced at this end, it flows in adjacent channels of the device from the first ends to the second ends of the respective channels. Conversely, the term "feed end for movement" is used to denote the end of a sequence of blocks such that if a fluid is introduced at this end, it flows in adjacent channels of the device from the second ends to the first ends of the corresponding channels.

Mixing can be accomplished over a predetermined duty cycle (“mixing sub-cycle”) by introducing a suitable high flow rate fluid into or near the mixing device at the mixing end, causing the fluid to flow to the feeding end for transfer and causing dense mixing and light fluids in each unit of the device. The volume of the dense fluid moved over such a period may be the volume of the dense fluid that needs to be processed with the device in a full cycle.

The sedimentation can be performed during a given period of the working cycle after mixing. In this period, the flow of fluid from the ends and to the ends of the device is stopped.

The movement of light fluid can be carried out for a predetermined period of the working cycle after settling by introducing a fluid with a suitable flow rate of low to moderate in the device at the supply end for movement or near it, as a result of which the flow of fluid moves to the supply end for mixing, and light fluid moves only from block to block inside the device. The volume of fluid transferred during such a period may include a volume sufficient to return a similar volume of light fluid displaced during the previous mixing sub-cycle and an additional volume of light fluid to obtain the total volume of light fluid displaced that may need to be processed by the device for a full working cycle.

The countercurrent flow of light and dense fluid requires a device at the feed end to move the device for separating dense and light fluid in the corresponding unit. This separation can be done outside of the device blocks or at the end block of the device. In the latter case, the channel for moving the end block at the supply end for movement should preferably not taper into the nozzle, and there may be two openings for the fluid at this end: an upper two-sided opening for light fluid located at a level similar to the level of the channels for moving, and a lower outlet for dense fluid at a level below the upper part of the filled block volume.

At the supply end for mixing, only light fluids exit the mixing supply opening during the moving period, and the dense fluid and some backward flowing light fluids are supplied externally through the same opening during the mixing period.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described by way of example with reference to the accompanying drawings, in which:

in FIG. 1 schematically shows a side view of a jet mixer-settler, which includes a number of horizontally arranged blocks with external interblock channels;

in FIG. 2 shows a system similar to that illustrated in FIG. 1, but with internal interblock channels;

in FIG. 3 shows essentially the same structure as the system in FIG. 2, but with a terminal block at the supply end for movement, having two fluid openings, and with an interblock channel not tapering into the nozzle;

FIG. 4 is a side view of a device that includes layered horizontally arranged blocks; and

FIG. 5 is a sectional view of the mixer settler of FIG. four.

DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 1 shows a sectional view and a side view of a mixer-settler 10 in accordance with the invention. The device comprises a set of horizontally arranged blocks 12, 14 and 16. Three blocks are shown. This number is not limiting, and the number of blocks in the set can be changed. Each block contains a corresponding closed chamber. The cameras are located along a common horizontal axis 20. In this example, the cameras are located close to each other, essentially adjacent to each other, or are made in one piece, and between adjacent cameras there are vertical partitions 22.

Each chamber has a corresponding exhaust valve 26. If necessary, openings not shown in the drawings may be made in the upper part of each block for inspection and maintenance.

The first block 12 has at least one fluid hole 30, and the last block in the kit has at least one fluid hole 32. Between adjacent chambers are corresponding channels 40 and 42 for movement. Channel 40 has an inlet 40A, which is located in the upper region 12A of block 12. The channel has a tapering shape, and its cross-sectional area decreases in the direction of the outlet 12B in the upper region 14A of block 14. The exhaust channel is directed not vertically downward, but at an angle so that the fluid exiting the channel flows the maximum distance inside the block 14 - this is indicated by a dashed line 44, which runs from the outlet 12B in the direction of the diagonally placed lower end 14B of the block. All this is aimed at causing maximum turbulence of the fluid inside the chamber. Channel 42 is oriented the same way. The device 10 comprises a feed end 46 for mixing and a feed end 48 for movement. The fluid hole 32 in the last block 16 is double-sided, i.e. a hole for light fluid and an outlet for dense fluid.

Channels 40 and 42 for transmission are located outside the units.

A pressure source 50 is connected to the hole 30.

In FIG. 2 shows a mixer-settler system 10A in accordance with the invention, which is essentially the same as that shown in FIG. 1, with a set of horizontally arranged blocks 52, 54 and 56. However, channels 60 and 62 for moving between adjacent blocks are located inside the respective blocks. Similarly, a fluid hole 64 is located inside the block 52, and a two-way hole 66 is located inside the block 56.

In both drawings, adjacent blocks are made with common or closely spaced walls. Thus, the blocks can be made in one piece or consist of separate chambers. Also, the blocks can be spaced and can be connected using channels of the desired tapering shape. Blocks do not have to be placed on one straight line, and instead can be located, viewed from above, along a curve or a combination of connected straight and curved lines.

In FIG. 3 shows a substantially the same structure as that of FIG. 2, and for this reason, the structure shown in FIG. 3 is not described in detail. Similar components have the same item numbers. The main difference between the structures shown in FIG. 2 and 3, consists in the fact that in the latter case, the channel 62A between adjacent blocks 54 and 56 does not taper into the nozzle and that there is a dense fluid outlet 78 which is located near the bottom of the block 56. Instead of using external means for separation light and dense fluids, design in accordance with FIG. 3 allows separation of light and dense fluids within the block at the supply end for movement due to the lack of turbulent mixing provided by the nozzle in the end block.

In FIG. 4 and 5 show a side view and a top view of the mixer-settler 80 having a cylindrical body 82. Six layers 84, 86, 88, 90, 92, 94 blocks are placed inside the body, and four respective blocks 84A, 84B are horizontally located in each layer, 84C and 84D, etc.

Individual blocks have different lengths and shapes, but their volume and cross-section of channels, as a rule, are of the same order of magnitude. The end blocks of each horizontal layer are connected to blocks located higher or lower using the corresponding channels P, Q, R, etc., moreover, part of the wall of such a channel may be part of the wall of the device.

Channels P, Q, R, etc. are internal. Similarly, the channels for moving between adjacent blocks, marked only as an example as X, Y, Z for layer 90, are internal and have the form described previously in relation to FIG. 1 and 2.

The mixer-settler 80 has a fluid hole 100 connected to the block 94A in the uppermost layer 94, and a fluid hole 102 connected to the block 84A in the lowermost layer 84.

In the mixer-settler according to the invention, each unit, as already noted, may contain a sealed chamber. Thus, the movement of the fluid between adjacent blocks can be carried out only when external pressure is applied and does not depend on the action of gravity.

The device operates cyclically with periods of mixing, settling and moving in each working cycle.

The mixing inside each block occurs due to turbulent eddies created by the high pressure flow rate provided by the pressure source 50, which flows through the feed end for mixing, and at the same time, the high flow rate of the fluid when it moves from block to block in the direction of the feed end for movement. Each channel directs a stream of fluid down through a corresponding adjacent block located downstream and creates strong turbulence of the fluid in this block. During the mixing phase, dense and light fluids move from block to block in the direction from the feed end for mixing to the feed end for movement. Dense fluid does not move between blocks at any time, with the exception of the mixing phase.

The dense fluid settling in each block occurs during the settling period of the duty cycle, when the flows entering and leaving the device stop.

The movement of the light fluid from block to block in the direction from the supply end to move to the supply end for mixing occurs during the period of movement of the duty cycle, so that the movement of light fluid during mixing is essentially the opposite, and the additional volume of light fluid moves with obtaining a clean stream of light fluid per working cycle in the direction of the feed end for mixing. Thus, the mixer-settler system of the invention has one compartment per area of the stage in which mixing and settling at different times during the operating cycle are provided. Mixing is carried out thanks to the jet supply of fluid and the flow in one direction from one area of the stage to another. Thus, mixing requires only one pressure source, which is supplied externally to one of the ends of the device.

In the system described in the invention, the sedimentation does not occur continuously, but is a constituent process, which is part of the full working cycle. Thus, it is ensured that the working stages include several physical areas for the implementation of the stages (i.e., not necessarily only one area for the implementation of the stages), which allows you to dynamically adjust the area of sedimentation at each working stage, taking into account the number of working stages in the column. In addition, the movement of fluid flows can be carried out by applying pressure from the outside at different periods of time, to provide significant process flexibility, regardless of gravity.

The channels connecting the upper ends of adjacent areas of the implementation of the stages, provide mixing and movement of the fluid. Only light fluids between adjacent regions of the stages are moved through the channels, and the movement can be carried out with relatively high flows and large volumes without mixing. This is important in large-scale systems. Mixing is carried out, as already noted, using a jet feed provided during the process by means of one external pressure source. Thus, the movement of the fluid between at least two adjacent blocks is used to create mixing and thus eliminate the need for a separate mixing method. In addition, the system described in the invention is applicable to operations with liquid / solids and allows you to effectively process compacted layers.

Claims (5)

1. The method of operation of the mixer-sump (10), containing a set of horizontally arranged blocks (12, 14, 16), having a first block (12) and a last block (16), each block containing a corresponding closed chamber containing a corresponding exhaust valve ( 26), and the mixer-settler also contains corresponding channels (40, 42) for movement, which are located between adjacent chambers (12, 14; 14, 16) and each of which contains an inlet (40A) that extends to the upper region (12A ) of the upstream block (12) and having a narrowing a curable shape with a decrease in cross-sectional area in the direction from the inlet (40A) to the outlet (12B) located in the upper region (14A) of the downstream unit (14) at an angle, so that fluid flowing out of channel for movement, the maximum distance in the downstream block (14) with maximum turbulence in the fluid present in the chamber of the downstream block (14), and the mixer-settler also contains a feed end (46) For mixing, comprising a fluid inlet (30) in a first unit (12), a pressure source (50) connected to a fluid inlet (30), and a conveying end (48) for containing, containing a hole (32) for the fluid in the last block (16), containing a hole for light fluid and an outlet for dense fluid, and according to the method, the steps of the mixer-settler (10) are performed cyclically with periods of mixing, settling and moving in each working cycle, and (A) during the mixing period, the mixing in each block is provided by turbulent turbulences created by the high pressure flow rate (50) provided by the pressure source (50) entering the supply end (46) for mixing, and at the same time, the high flow rate of the fluid flowing from the block to the block in the direction the supply end (48) to move, so that the dense and light fluids are transferred from block to block in the direction from the supply end (46) for mixing to the supply end (48) to move; (B) during the settling period, sedimentation of the dense fluid in each block is ensured when the flow of fluid into and out of the mixer-settler (10) is stopped; (C) during the period of movement, the movement of light fluid is carried out by introducing into the mixer-sump (10) at its supply end (46) to move the fluid with a suitable flow rate from low to moderate, providing a flow of fluid in the direction of the supply end (48) for mixing and with the movement of light fluid in the mixer-sump (10) only from block to block. 2. The method of claim 1, wherein, during the moving period, the movement of the light fluid is reversed and the additional volume of the light fluid is moved to produce a clean stream of the light fluid in the direction of the feed end for mixing.

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