Filter aid adding device

Abstract

The utility model discloses a filter aid adding device which comprises a lime milk tank, a crude liquid tank and a leaf filter, and the crude liquid tank is connected with the leaf filter through a first delivery pump; a second conveying pump is arranged on a discharging pipe of the lime milk groove, a discharging port of the second conveying pump is directly communicated with a feeding port of the first conveying pump, and a first control valve is arranged on a communicating pipeline. The utility model solves the technical problem of high consumption of lime milk.

Description

Technical Field

[0001] The utility model belongs to the technical field of alumina production, and in particular relates to a filter aid adding device. Background Art

[0002] During the alumina production process, filter aids must be added to the leaf filter. The filter aid is made of lime milk and sodium aluminate solution in a certain proportion. The principle is that calcium hydroxide in the lime milk reacts with sodium aluminate solution to form a filter aid, tricalcium aluminate, which can make the filter cake in the mud hanging stage of the leaf filter loose and porous, and easy to unload, thereby improving the filtering effect of the leaf filter. The amount of lime milk added is generally 4‰ of the sodium aluminate solution.

[0003] At present, the traditional alumina enterprises add filter aids in the following ways: Figure 1 As shown, the semen in the high-level tank enters the lime milk tank through the pipeline to react and generate filter aids. The filter aids enter the coarse liquid tank through the lime milk pump. The filter aids and coarse liquid in the coarse liquid tank are pumped to the leaf filter for treatment through the coarse liquid pump. The discharge port of the leaf filter is connected to the coarse liquid tank through the pipeline to realize material circulation. The traditional method of adding filter aids is to pump the filter aids directly to the top of the coarse liquid tank through the lime milk pump. Since the lime milk contains a large amount of coarse sand particles, it is easy to cause the pressure of the leaf filter to rise and the filtering effect is poor. The lime milk is added to the coarse liquid tank from the top of the coarse liquid tank. The coarse sand is unevenly distributed in the tank. The feed port position of the coarse liquid pump is different, and the feed solid content of the leaf filter is quite different. When the feed port position of the leaf filter is low, the leaf filter is prone to cause the pneumatic valve to be stuck, the barrel to accumulate mud and production to be interrupted due to excessive coarse sand. At the same time, since the top position of the coarse liquid tank is high, the lime milk pump needs to maintain a high speed to ensure smooth addition of lime milk, resulting in a large consumption of lime milk. In addition, the leaf filter only needs to use filter aids in the mud hanging stage of fine filtration, while lime milk is continuously added to the fine filtration process, which will also increase the consumption of lime milk.

[0004] In summary, the current process of adding filter aids to alumina leaf filters is that the filter aids are transported to the top of the coarse liquid tank through a lime milk pump, resulting in fluctuating addition amounts and large consumption of lime milk. At the same time, the feed solid content varies greatly due to the different feed positions of the coarse liquid pump, resulting in large fluctuations in the operating pressure of the leaf filter. Utility Model Content

[0005] In view of the current technical problems, the utility model aims to provide a filter aid adding device, which can solve the technical problem of large consumption of lime milk.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A filter aid adding device comprises an ash emulsion tank, a coarse liquid tank and a leaf filter, wherein the coarse liquid tank and the leaf filter are connected via a first delivery pump; the structural feature is that a second delivery pump is arranged on the discharge pipe of the ash emulsion tank, the discharge port of the second delivery pump is directly connected to the feed port of the first delivery pump, and a first control valve is arranged on the connecting pipeline.

[0008] During operation, the semen in the high-level tank enters the lime milk tank through the pipeline to react and generate filter aids. When the leaf filter is in the mud hanging stage, the first control valve is opened, and the filter aid is pumped into the leaf filter through the second delivery pump and the first delivery pump, and forms a pre-coating on the filter cloth surface of the leaf filter, acting as a filter medium, so that the filter cake of the leaf filter in the mud hanging stage is loose and porous, easy to unload, and improves the filtering effect of the leaf filter. When the mud hanging stage is over, the first control valve is closed. The filter aid adding device of the utility model only introduces filter aids into the leaf filter when the leaf filter is in the mud hanging stage, which can realize the quantitative and timed addition of filter aids, thereby reducing the consumption of lime milk, and at the same time reducing the chemical loss of alumina.

[0009] Preferably, the discharge port of the second delivery pump is connected to the feed port of the ash emulsion tank, and a third control valve is provided on the connecting pipeline. After the mud hanging stage of the leaf filter is completed, the third control valve is opened, and the filter aid circulates along the pipeline between the outlet and the inlet of the ash emulsion tank under the action of the second delivery pump. Since the filter aid contains more calcium hydroxide, the precipitation generation is reduced by circulating flow, thereby preventing pipeline blockage.

[0010] Preferably, the first control valve comprises an electric valve and a manual valve arranged in series, and the amount of filter aid added is controlled by controlling the pipeline switch through the electric valve and the opening degree through the manual valve.

[0011] Preferably, the discharge port of the leaf filter is connected to the coarse liquid tank through a first connecting pipeline, and a second control valve is provided on the first connecting pipeline, and the second control valve, the electric valve and the third control valve are all electrically connected to the control system. The second control valve, the electric valve and the third control valve are automatically controlled by the control system to achieve automatic interlocking operation. When the leaf filter is in the mud hanging stage, material circulation is carried out at this time, the control system controls the second control valve and the electric valve to open, and the third control valve to close, and the material at the discharge port of the leaf filter enters the coarse liquid tank through the second control valve for circulation, and the filter aid is pumped into the leaf filter. After the mud hanging stage is over, the control system controls the second control valve and the electric valve to close, and the third control valve to open, and the filter aid is self-circulated through the pipeline to avoid clogging the pipeline.

[0012] Specifically, the manual valve is arranged on a side close to the first delivery pump.

[0013] Preferably, a flow meter is provided on the pipeline connecting the discharge port of the second delivery pump and the feed port of the first delivery pump. By providing the flow meter, pipeline blockage can be discovered in time so as to be handled in time.

[0014] Preferably, the leaf filters are provided in plurality, the crude liquid tank and the plurality of leaf filters are respectively connected in parallel via the first delivery pump, and the discharge port of the second delivery pump is connected to the feed ports of the plurality of first delivery pumps. By arranging the plurality of leaf filters to work simultaneously, the concentration of the filter aid added by each leaf filter is balanced and stable, and the amount and time of adding the filter aid by the leaf filter are consistent, thereby promoting continuous and stable production.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. The filter aid adding device of the utility model has reasonable design, simple process, and easy chain control operation. The filter aid is added only in the mud hanging stage of the leaf filter, which reduces the consumption of lime milk and the chemical loss of alumina, while ensuring the production capacity and filtering effect of the leaf filter.

[0017] 2. With the filter aid adding device of the utility model, the concentration of ash milk added to each leaf filter is balanced and stable, and the amount and time of adding filter aid to the leaf filter are consistent, thereby promoting continuous and stable production.

[0018] 3. The filter aid adding device of the utility model eliminates the fluctuation of the feed solid content of the leaf filter caused by process differences, avoids the scarring and mud accumulation of the leaf filter barrel that affects the production and the withdrawal for maintenance and cleaning, reduces the maintenance workload, avoids the pollution of the on-site environment by cleaning the scarring and mud accumulation, greatly reduces the cost of the alumina production process, reduces the production ash consumption, has strong versatility, and has certain reference and application value for the lean technology improvement of the leaf filter process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a conventional filter aid adding device;

[0020] Figure 2 It is a schematic diagram of the structure of the filter aid adding device of the utility model.

[0021] In the figure:

[0022] 1-ash emulsion tank; 2-coarse liquid tank; 3-leaf filter; 4-first delivery pump; 5-second delivery pump; 6-first control valve; 61-electric valve; 62-manual valve; 7-second control valve; 8-flow meter; 9-first connecting pipeline; 10-third control valve; 11-high-level tank. DETAILED DESCRIPTION

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following text, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0024] like Figure 2 As shown, a filter aid adding device provided in this embodiment includes an ash emulsion tank 1, a coarse liquid tank 2, a leaf filter 3, a high-level tank 11 and a control system, and the coarse liquid tank 2 is connected to the leaf filter 3 through a first delivery pump 4. The leaf filter 3 is connected to the high-level tank 11, and the high-level tank 11 is connected to the ash emulsion tank 1 through a pipeline, and a valve is provided on the connecting pipeline. When the filter aid needs to be prepared, the valve is opened, and the semen enters the ash emulsion tank to react and generate the filter aid. The discharge port of the leaf filter 3 is connected to the coarse liquid tank 2 through a first connecting pipeline 9, and a second control valve 7 is provided on the first connecting pipeline 9. A second delivery pump 5 is provided on the discharge pipe at the bottom of the ash emulsion tank 1, and the discharge port of the second delivery pump 5 is directly connected to the feed port of the first delivery pump 4, and a flow meter 8 and a first control valve 6 are provided on the connecting pipeline. The first control valve 6 includes an electric valve 61 and a manual valve 62 arranged in series, and the manual valve 62 is arranged on a side close to the first delivery pump 4. The discharge port of the second delivery pump 5 is connected to the feed port at the top of the ash emulsion tank 1, and a third control valve 11 is provided on the connecting pipeline. The second control valve 7, the electric valve 61 and the third control valve 11 are all electrically connected to the control system.

[0025] When the leaf filter 3 is in the mud hanging stage, the control system controls the electric valve 61 and the second control valve 7 to be opened and the third control valve 11 to be closed, the semen at the discharge port of the leaf filter 3 enters the coarse liquid tank 1 through the first connecting pipeline 9 for circulation, and the filter aid is pumped into the leaf filter 3 through the second delivery pump 5 and the first delivery pump 4, and forms a pre-coat on the filter cloth surface of the leaf filter 3, acting as a filter medium, so that the filter cake of the leaf filter 3 in the mud hanging stage is loose and porous, easy to unload, and improves the filtering effect of the leaf filter 3. When the mud hanging stage is over, the control system controls the electric valve 61 and the second control valve 7 to be closed and the third control valve 11 to be opened, and the filter aid circulates between the outlet and the inlet of the lime milk tank 1 along the pipeline under the action of the second delivery pump 5. The filter aid adding device of the utility model only introduces the filter aid into the leaf filter 3 when the leaf filter 3 is in the mud hanging stage, which can realize the quantitative and timed addition of the filter aid, thereby reducing the consumption of lime milk, and also reducing the chemical loss of alumina.

[0026] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A filter aid adding device, comprising an ash emulsion tank (1), a coarse liquid tank (2) and a leaf filter (3), wherein the coarse liquid tank (2) and the leaf filter (3) are connected via a first delivery pump (4); characterized in that: A second delivery pump (5) is provided on the discharge pipe of the ash emulsion tank (1); the discharge port of the second delivery pump (5) is directly connected to the feed port of the first delivery pump (4) via a connecting pipeline, and a first control valve (6) is provided on the connecting pipeline.

2. The filter aid adding device according to claim 1, characterized in that: The discharge port of the second delivery pump (5) is connected to the feed port of the ash emulsion tank (1), and a third control valve (10) is provided on the connecting pipeline.

3. The filter aid adding device according to claim 2, characterized in that: The first control valve (6) comprises an electric valve (61) and a manual valve (62) which are arranged in series.

4. The filter aid adding device according to claim 3, characterized in that: The discharge port of the leaf filter (3) is connected to the coarse liquid tank (2) via a first connecting pipeline (9), a second control valve (7) is provided on the first connecting pipeline (9), and the second control valve (7), the electric valve (61) and the third control valve (10) are all electrically connected to a control system.

5. The filter aid adding device according to claim 3, characterized in that: The manual valve (62) is arranged on a side close to the first delivery pump (4).

6. The filter aid adding device according to claim 1, characterized in that: A flow meter (8) is provided on a pipeline connecting the discharge port of the second delivery pump (5) and the inlet port of the first delivery pump (4).

7. The filter aid adding device according to any one of claims 1 to 6, characterized in that: A plurality of leaf filters (3) are provided, and the coarse liquid tank (2) and the plurality of leaf filters (3) are respectively connected in parallel via first delivery pumps (4), and the discharge port of the second delivery pump (5) is connected to the feed ports of the plurality of first delivery pumps (4).

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