JP2006016253A - Granulation water-circulation type slag granulation method and slag granulation facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent various troubles at granulation water-circulation type granulation equipment due to slag suspension from occurring, and to reduce running costs charged on granulation of slag. <P>SOLUTION: The method for granulating slag comprises granulating molten slag X1 with granulation water W, and after taking out granulated slag X2 outside the granulation water W, the granulation water W is circulated and utilized again for granulation of the molten slag X1. In a slag granulation facility equipped with a plate type heat exchanger having a heat transfer plate, flow velocity of the granulation water W is controlled to be one which can prevent the suspending slag from being sedimented in the plate type heat exchanger 6. Alternatively, a liquid cyclone is installed in the circulation system to separate a part of suspension slag from the circulation water and discharge it outside the system. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a granulated water circulation type slag granulation method and a slag granulation facility.

  The slag discharged in the dry smelting process of copper is solubilized and cooled by dropping the molten slag into the slag water granulated water stream, so-called “water granulation”. It is common to be done. This granulated slag is recovered from the slag granulated water from the granulated slag pit where the granulated slag stays once by a bucket elevator for granulated slag discharge, and sold as a product such as cement raw material, sandblasting material, concrete fine aggregate Is done. Conventionally, in water granulation, slag granulated water that has been used for cooling at the factory as slag granulated water and recovered granulated slag is fine slag that floats in filters and sedimentation pits In general, the suspended slag was separated and removed before being discharged into nearby waters.

  However, in such a general water granulation method, it is difficult to completely separate and remove suspended slag even with a filter or a sedimentation pit, and heavy metal components such as Pb and As are contained in the slag. Due to the fact that more heavy metals dissolve in slag granulated water compared to the case where normal temperature slag and slag granulated water contact when high temperature molten slag and slag granulated water contact And the problem that the heavy metal density | concentration of slag granulated water discharged increases increases.

In recent years, with the improvement of environmental awareness, there has been proposed a method of granulating slag that does not release slag crushed water containing heavy metals in the nearby water area by circulating slag crushed water. There are an increasing number of factories adopting the.
Specifically, in this circulating granulation method, slag granulated water heated by granulating molten slag is cooled in a heat exchanger and used again for molten granulation of molten slag.
JP-A-8-301635

By the way, in the above-mentioned granulated water circulation method, the suspended slag, which is fine slag floating in the slag granulated water, is not discharged into the sea area, while the amount of suspended slag generated during the granulation and the circulation system As long as the amount of suspended slag discharged from the inside is not balanced, the concentration of suspended slag in the circulating water only rises. Therefore, it is indispensable to provide such a slag granulating facility with some function for discharging suspended slag from the circulation system. Needless to say, it is advantageous that the concentration of suspended slag allowed for each device to exhibit its normal ability is high.
From this point of view, regarding heat exchangers, in general, plate-type heat exchangers have advantages such as excellent heat exchange efficiency, small installation area, good maintainability, and no loss of water. The current mainstream is to adopt a cooling tower exclusively without using a heat exchanger and a tube heat exchanger. This is because the flow path of the plate heat exchanger and tube heat exchanger is narrow, so that suspended slag accumulates inside the heat exchanger flow path, reducing heat exchange efficiency and reducing the amount of water due to increased pressure loss. This is because the problem arises.

 However, since the cooling tower is based on the cooling principle that most of the heat removal is caused by latent heat of vaporization, when the cooling tower is used as a heat exchanger, a large amount of new water that meets the evaporation loss is circulated. Therefore, it is necessary to replenish constantly, and the running cost for slag granulation increases as a water bill. Also, depending on the location of the factory, it is often difficult to procure water itself. Furthermore, even when a cooling tower is used as a heat exchanger, suspended slag accumulates in the cooling tower due to long-term use, resulting in reduced heat exchange efficiency or inability to withstand the weight of the slag accumulated inside. However, troubles such as collapse of the cooling tower have been reported, and it cannot be said that it is an optimal and established technology as a heat exchanger to be introduced into a slag granulation facility with a granulated water circulation type.

  In addition, as a function of discharging suspended slag and reducing the concentration of suspended slag in the circulating water, it is generally performed to send a part of the circulating water containing the suspended slag to a drainage factory. However, if the suspended slag concentration in the circulating water is maintained at a low level, naturally the amount of water sent to the drainage plant will increase, and it will be necessary to replenish the system with water that is commensurate with the amount of water delivered. The running cost for slag granulation increases as water cost, and it is necessary to secure new water itself.

  Further, as a function of discharging the suspended slag and reducing the suspended slag concentration of the circulating water, it is generally performed to install a large settling pit in the circulation path. This is based on the idea of sinking and separating suspended slag by reducing the flow rate of circulating water in the settling pit. However, it is impossible if the installation area of the pit cannot be secured, and slag sedimentation and deposition on the sedimentation pit is fast, and it is necessary to always keep the pit capacity in a normal state in order to secure the residence time required for sedimentation. is there. Therefore, the sedimentation slag scraping work by the excavator is performed at a pace of twice a week from the current day in the current factory, and it cannot be said that it is an effective means in terms of cost and labor.

  The present invention has been made in view of the above-described problems, and suppresses various troubles of the water granulated water granulation equipment caused by the suspended slag and reduces the running cost required for the water granulation of the slag. Objective.

In order to achieve the above object, the slag granulation method of the present invention is such that the molten slag is granulated with slag granulated water, the granulated slag is taken out of the slag granulated water, and then the slag granulated water is extracted. Is a slag granulation method that is used again for the granulation of the molten slag, in a plate-type heat exchanger having a heat transfer plate, or in a slag granulation facility having a tubular heat exchanger, heat exchange The flow rate of the slag crushed water in the vessel flow path is controlled to a flow rate at which accumulation of suspended slag in the plate heat exchanger or the tube heat exchanger is suppressed.
In addition, the definition of the flow velocity in the plate type heat exchanger referred to here will be described with reference to FIG. The total cross-sectional area of the flow path of the plate heat exchanger is “total cross-sectional area of the flow path = (L−X * δ) * W / 2” based on the assembly dimensions of the plate heat exchanger, the number of plates, and the plate thickness. . The value obtained by dividing the flow rate by the total cross-sectional area of the plate cooler is the flow velocity.

  Further, the slag granulation facility of the present invention, after pulverizing molten slag with slag granulated water, taking out the granulated slag outside the slag granulated water, circulating the slag granulated water again and In a slag granulating facility used for granulating molten slag, the flow rate of the slag granulated water in the plate heat exchanger with a heat transfer plate or the tube heat exchanger and the heat exchanger flow path is controlled. By this, it is provided with the flow-rate control means which suppresses accumulation of suspension slag in the said plate type heat exchanger or the said pipe | tube type heat exchanger.

According to the slag granulation method and the slag granulation facility of the present invention having such characteristics, the flow rate of the slag granulated water in the plate heat exchanger or the tube heat exchanger is included in the slag granulated water. It is controlled to a flow rate at which accumulation of turbid slag in a plate heat exchanger or a tube heat exchanger is suppressed. For this reason, the fall of the heat exchange efficiency of the heat exchanger resulting from accumulation of suspension slag is suppressed, and it becomes possible to employ a plate heat exchanger or a tube heat exchanger that has not been introduced conventionally.
In the present invention, since a plate heat exchanger or a tube heat exchanger is used as the heat exchanger, the new water supplied to the granulating equipment is compared with the case where a cooling tower is used as the heat exchanger. The amount of can be greatly reduced. Therefore, according to the slag granulation method and the slag granulation facility of the present invention, it is not necessary to secure a new source of a large amount of water, and it is possible to reduce the running cost for slag granulation as a water bill. It becomes.

 Specifically, the accumulation of suspended slag is suppressed by controlling the flow rate of the slag crushed water in the flow path of the plate heat exchanger or the tube heat exchanger to 0.1 to 2 m / s. It becomes possible.

Further, in the slag granulation equipment of the present invention, when a plate heat exchanger is adopted, a configuration in which a plurality of plate heat exchangers are arranged in series is adopted, thereby unnecessarily increasing the pump capacity. It is possible to control the flow rate to suppress the accumulation of the above-mentioned suspended slag without doing so. When the flow rate of circulating water is the same as the desired amount of exchange heat, the plate type heat exchanger 1 is more when a plurality of plate type heat exchangers are installed in series than when a single plate type heat exchanger is installed. Since the total cross-sectional area per channel becomes small, that is, the flow rate of slag granulated water in the plate heat exchanger can be increased. According to this, since it is not necessary to increase the pump capacity and increase the flow rate of the slag crushed water in order to obtain a flow rate that suppresses the accumulation of suspended slag in the plate heat exchanger, the introduction cost of the pump, It is advantageous in terms of running cost as a power bill.
In general, when heat exchange is performed between the water to be cooled and the cooling water via a heat transfer plate, the heat transfer coefficient is improved as the flow rate is increased. In terms of heat transfer engineering, this is because the temperature boundary layer near the surface of the heat transfer plate becomes small. That is, when a plurality of plate heat exchangers are arranged in series, the heat transfer efficiency is improved by both the above-described suspension slag accumulation suppression and the effect of reducing the temperature boundary layer, and a single plate heat exchanger is obtained. The total number of plates is reduced compared to the case of installing the plate, and the introduction cost can be reduced, the installation area is small, and the labor for opening and cleaning the plate can be reduced.
In addition, when installing a plurality of plate type heat exchangers in series, the larger the number, the greater the effect said in the present invention. However, if it is avoided that the piping connection is complicated, two units are connected in series. It is preferable to install.

Moreover, in the slag granulation equipment of the present invention, a configuration is adopted in which the suspension slag is concentrated to a part of the slag granulation water and a hydrocyclone is provided that separates the suspension slag in the form of concentrated water. Can do.
The hydrocyclone can separate suspended slag of 20 μm or more with a high yield by setting an appropriate model. For this reason, a hydrocyclone is provided in the granulated water circulation system, and the slag granulated water from which part of the suspended slag has been separated by the hydrocyclone is sent to a plate heat exchanger or a tube heat exchanger, thereby generating heat. Suspension slag load on the exchanger can be reduced. Therefore, in addition to the effect of the flow rate control, it is possible to further suppress the accumulation of suspended slag in the plate heat exchanger or the tube heat exchanger. In addition, it is not necessary to install a large sedimentation pit, the amount of water sent to the drainage factory can be greatly reduced, and problems caused by suspended slag can be further reduced.

In preparing the hydrocyclone, the hydrocyclone is installed in two stages. First, the suspended slag discharged by the first-stage hydrocyclone is separated, and the recovered suspended slag concentrated water is further sent to the second-stage hydrocyclone. Further, it is possible to employ a configuration in which the suspended slag is further concentrated and the amount of water is reduced and then recovered outside the circulation system.
In general, the concentrated water of the suspended slag discharged from the hydrocyclone is 10 to 20% of the total processing flow rate in a single stage. For example, when 1000 m ³ / hr is circulated as circulating water for slag crushed water, the amount of concentrated water discharged from the hydrocyclone is as large as 100 to 200 m ³ / hr, so use solid-liquid separation means such as filtration. Finally, it is troublesome to collect only the suspended slag because there is too much water. On the other hand, when the hydrocyclone is installed in two stages, the amount of concentrated water in the first stage can be reduced to 100 to 200 m ³ / hr, and the amount of concentrated water in the second stage can be reduced to 10 to 20 m ³ / hr. When only suspended slag is collected, the handling becomes easy.

Moreover, the structure which supplies the said concentrated water containing the said suspended slag to the bucket elevator for granulated slag discharge | emission can be employ | adopted as a separation and collection | recovery method of final suspension slag from concentrated water. In general, a plurality of holes are formed in the bottom of each bucket of a granulated slag discharge bucket elevator for draining water. When concentrated water reduced in volume due to the two-stage hydrocyclone is continuously supplied onto each bucket of the granulated slag discharge bucket elevator, the concentrated water is filtered by the granulated slag layer being discharged, and only suspended slag Is reliably recovered, and the filtered water is returned to the circulation system without loss. According to this, it is not necessary to newly install a mechanism for collecting the suspended slag, and the suspended slag can be easily collected.
Even if only suspended slag is separated and recovered from the concentrated water by another method, only fine slag is currently used and cannot be shipped as a product. On the other hand, when recovered in a bucket elevator for granulated slag discharge, the final product slag that rises due to suspended slag is less than 0.5% of fine particles and is continuously supplied to the bucket. Therefore, the dispersion of the particle size distribution does not occur, and the quality (particle size) of the product slag is not particularly affected.
In addition, the method of supplying concentrated water to a granulated slag storage hopper is also considered as another method of collect | recovering suspended slag from the concentrated water which reduced the amount of water by the liquid cyclone two-stage installation. Even in this method, the same effect as described above can be obtained because the filtration and separation can be performed by the granulated slag layer stored in the hopper.

In addition, when the flow rate of suspended slag concentrated water supplied to the bucket elevator for discharging granulated slag is high, the concentrated water supplied into the bucket overflows, and the recovery rate of suspended slag is reduced and the corner separation is performed. There is a concern that the suspended slag may return to the circulation system. For this reason, the slag granulation facility of the present invention is provided with a flow rate buffer means for reducing the flow rate of the slag granulated water including the suspended slag in the concentrated water supply part of the bucket elevator for discharging the granulated slag. Is preferably adopted.
By adopting such a configuration, the flow rate of the slag granulated water supplied to the granulated slag bucket elevator is reduced, so that the slag granulated water can be prevented from overflowing from the bucket and more reliably. It becomes possible to collect suspended slag.
Specifically, a receiving tank that receives the slag crushed water containing the suspended slag and supplies the overflow water to the crushed slag discharge bucket elevator can be used as the flow rate buffering means.

  Hereinafter, an embodiment of a slag granulation method and slag granulation equipment according to the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a flowchart showing a schematic configuration of the slag granulation facility S1 of the first embodiment. In this figure, reference numeral 1 is a granulated slag pit, 2 is a bucket elevator for discharging granulated slag, 3 is a circulation pump pit, 4 is a circulation pump, 5 is a first hydrocyclone (liquid cyclone), and 6 is a plate type heat exchange. , 7 is a head tank, 8 is a suspension slag concentrated water intermediate pit, 9 is a pump for supplying suspended slag concentrated water, 10 is a second liquid cyclone (second liquid cyclone), and 11 is a receiving tank.

 In the first embodiment, the granulated equipment S1 granulates molten slag X1 with slag granulated water W, and granulate slag X2 with slag granulated water W1 (slag granulated water using a bucket elevator 2 for discharging granulated slag). W) is a so-called closed-type slag granulation facility that circulates slag granulated water W1 (slag granulated water W) and uses it again for molten slag X1.

The granulated slag pit 1 is a residence tank in which the granulated slag X2 and the slag granulated water W1 (slag granulated water W) are temporarily retained after the molten slag X1 is granulated with the slag granulated water W.
The granulated slag discharge bucket elevator 2 is a chain conveyor type elevator including a plurality of buckets 21 and takes out the granulated slag X2 from the granulated slag pit 1 and conveys it to the outside. The bucket 21 has a plurality of holes for draining at the bottom.

The circulation pump pit 3 is connected to the granulated slag pit 1 through the open culvert a, and slag granulated water W (hereinafter referred to as suspended slag crushed granule) containing suspended slag supplied through the open culvert a. A circulation pump 4 for circulating water (referred to as water W2) is installed.
The suspended slag referred to here is fine slag floating in the slag crushed water W.
The circulation pump 4 is connected to the circulation pump pit 3 via a pipe b, and sends out suspended slag crushed water W2 via the pipe c. As will be described later, since the flow rate control for suppressing the accumulation of suspended slag in the plate heat exchanger 6 is performed by the installation method of the plate heat exchanger, the pump only supplies the amount necessary for the water granulation. As long as it has a capacity of
The first hydrocyclone 5 is connected to the circulation pump 4 via a pipe c, and is disposed on the upstream side of the plate heat exchanger 6. The first liquid cyclone 5 concentrates and separates the suspended slag into a part of the suspended slag granulated water W2, and the first suspended slag concentrated water W3 (slag granulated slag having an increased suspended slag concentration). Water W) is discharged, and the remaining suspended slag diluted water W4 (slag crushed water W) from which part of the suspended slag has been removed is discharged through the pipe e. In addition, the pipe i is connected to the middle part of the pipe e, and the suspension slag dilute water W4 (slag water) containing finer suspended slag that could not be removed by the first hydrocyclone 5 through the pipe i. A part of the crushed water W) is provided so that it can be sent to a wastewater treatment plant or the like.

The plate-type heat exchanger 6 has a heat transfer plate, and suspends slag diluted water W4 (slag crushed water W) supplied via a pipe e and cooling water R supplied from the outside. By indirectly exchanging heat through the heat transfer plate, the suspended slag diluted water W4 (slag crushed water W) is cooled and discharged through the pipe f.
FIG. 2 is a schematic view schematically showing the flow path of the suspended slag diluted water W4 (slag crushed water W) and the flow path of the cooling water R in the plate heat exchanger 6. As shown in FIG. As shown in this figure, in the plate heat exchanger 6, suspended slag diluted water W4 (slag crushed water W) and cooling water R are provided in each independent flow path partitioned by heat transfer plates. Flow in the directions opposite to each other, the suspended slag diluted water W4 (slag crushed water W) is extracted by the cooling water R and cooled.

Here, the flow rate of the suspended slag diluted water W4 (slag crushed water W) in the plate heat exchanger 6 is as described above by arranging a plurality of (two) plate heat exchangers in series. The flow rate is controlled to suppress the accumulation of suspended slag. For this reason, it becomes possible to suppress the fall of the heat exchange efficiency of the plate type heat exchanger 6 resulting from accumulation of suspension slag. Of course, in the plate heat exchanger 6, clogging due to the accumulation of suspended slag can also be suppressed, and the pump flow rate drop due to increased pressure loss does not occur.
Specifically, the suspension in the plate heat exchanger 6 is controlled by setting the flow rate of the suspended slag diluted water W4 (slag crushed water W) in the plate heat exchanger 6 to 0.1 to 2 m / s. Accumulation of cloudy slag can be suppressed. Here, when the flow velocity is less than 0.1 m / s, the heat transfer efficiency is significantly reduced due to the accumulation of the suspended slag. In terms of heat transfer efficiency, the higher the flow rate, the better. However, if the flow rate exceeds 2 m / s, the pressure loss inherent to the plate heat exchanger, which is completely unrelated to the presence or absence of suspended slag accumulation, increases too much, and the pump capacity There is a disadvantage that must be unnecessarily large.
In addition, the plate heat exchanger 6 is originally a heat exchanger that does not involve any loss of water, so a new source of a large amount of water is secured as compared with the case where a cooling tower is used as the heat exchanger. There is no need, and it becomes possible to reduce the running cost for slag granulation as a water bill.

In addition, as the cooling water R, seawater introduced from the neighboring sea area may be used as it is. However, since the plate heat exchanger is a heat exchanger with excellent heat transfer efficiency, the crushed water to be circulated and an appropriate temperature are used. If there is a difference, the water once used for cooling at the factory may be reused. Depending on the amount of slag production, the amount of crushed water in the plate heat exchanger, the amount of cooling seawater, etc., for example, seawater in the neighboring sea area where the seawater temperature changes by 8 to 32 ° C due to annual seasonal fluctuations is once in the factory. Seawater that has been used for cooling and has reached 20 to 44 ° C., that is, seawater that has been once cooled by a temperature difference of 12 ° C., can be used as the cooling water R sufficiently.
Moreover, in the slag granulation equipment S1 of the present embodiment, as described above, the first cyclone 5 separates the suspended slag together with a part of the suspended slag granulated water W2, and a part of the suspended slag is obtained. The remaining suspended slag diluted water W4 (slag water crushed water W) that has been removed is sent to the plate heat exchanger 6 through the pipe e. For this reason, the suspension slag density | concentration of the slag granulated water W in the plate-type heat exchanger 6 can be reduced, and it becomes possible to further suppress accumulation of suspension slag in the plate-type heat exchanger 6.
Moreover, in the slag granulation equipment S1 of this embodiment, although the plate-type heat exchanger 6 is used as a heat exchanger, this invention is not limited to this, A pipe-type heat exchange is used as a heat exchanger. A vessel can also be used. Thus, even when a pipe heat exchanger is used as a heat exchanger, the same effect as that obtained when a plate heat exchanger 6 is used as a heat exchanger can be obtained by performing the same flow rate control. Can do.

  Returning to FIG. 1, the head tank 7 is connected to the plate heat exchanger 6 through the pipe f, and the suspension slag diluted water W4 (slag water granulation) supplied from the heat exchanger 6 through the pipe g is used. Water W) is supplied to the granulated slag pit 1 as granulated slag granulated water W. The head tank 7 is connected to the circulation pump pit 3 via a pipe h, and a small amount of crushed water is always returned from the head tank 7 to the circulation pump pit 3 via the pipe h. 7 is always full. This maintains the level of suspended slag diluted water W4 (slag granulated water W) and stabilizes the flow rate of suspended slag diluted water W4 (slag granulated water W) supplied to the granulated slag pit 1. it can. Further, by arranging the head tank 7, even if an emergency trouble occurs in which the driving of the circulation pump 4 or the like is stopped due to a power failure or the like, the suspended slag diluted water W4 (slag water) for the granulated slag pit 1 It is possible to prevent the supply of the crushed water W) from being stopped instantaneously.

  The suspended slag concentrated water intermediate pit 8 is a pit for temporarily receiving the first suspended slag concentrated water W3 discharged from the first hydrocyclone 5. The suspension slag concentrated water feed pump 9 is connected to the suspension slag concentrated water intermediate pit 8 via the pipe j, and the first suspension slag concentrated water W3 staying in the suspension slag concentrated water intermediate pit 8 is supplied. Water is supplied through the pipe k.

  The second hydrocyclone 10 concentrates and separates the suspended slag from the first suspended slag concentrated water W3 into a part of the first suspended slag concentrated water W3, and the suspended slag concentration further increases. The second suspended slag concentrated water W5 is discharged through the pipe l, and the fresh water W6 from which the suspended slag has been removed is discharged through the pipe m and returned to the granulated slag pit 1.

  The receiving tank 11 (flow velocity buffering means) reduces the flow velocity of the second suspension slag concentrated water W5, and is disposed on the upstream side of the bucket elevator 2 for discharging the granulated slag. FIG. 3 is a schematic view schematically showing the receiving tank 11 and the bucket 21 provided in the bucket elevator 2 for discharging the granulated slag. As shown in this figure, the receiving tank 11 receives the 2nd suspension slag concentrated water W5, and supplies the overflow water to the bucket 21 with which the granulated slag discharge bucket elevator 2 is equipped gently. Thus, the flow rate of the second suspension slag concentrate W5 is reduced by supplying the second suspension slag concentrate W5 to the bucket 21 provided in the granulated slag discharge bucket elevator 2 via the receiving tank 11. Therefore, it is possible to prevent the second suspension slag concentrated water from overflowing from the bucket 21 and to collect the suspension slag more reliably.

  FIG. 4 is a perspective view of the receiving tank 11. As shown in this figure, the receiving tank 11 is formed with a notch 11a for reliably overflowing the second suspension slag concentrated water W5 to the bucket 21 side. The area of the notch 11a is set so that the flow rate of the second suspension slag concentrated water W5 is moderately reduced.

The bucket 21 of the granulated slag discharge bucket elevator 2 contains the granulated slag scooped up from the granulated slag pit 1, and the granulated slag is drained by a plurality of holes formed in the lower part of the bucket 21. Slag is being transported. When the second suspended slag concentrated water W5 concentrated and reduced in water volume as described above is gently supplied to the bucket 21 by the flow rate buffering means, the suspended slag is filtered by the granulated slag layer in the bucket 21 and suspended. The turbid slag is reliably collected and transported together with the granulated slag X2, and the filtered fresh water is discharged from the bottom hole of the bucket 21 and returned to the granulated slag pit 1, so that water loss in the system is minimized.
This eliminates the need to newly install a mechanism for collecting the suspended slag. Moreover, even if only the suspended slag is separated and recovered from the second slag concentrated water W5 by another method, there is no use at present with only the fine slag. On the other hand, when recovered in a bucket elevator for granulated slag discharge, the final product slag that rises due to suspended slag is less than 0.5% of fine particles and is continuously supplied to the bucket. Therefore, the dispersion of the particle size distribution does not occur, and the quality (particle size) of the product slag is not particularly affected.

  The granulated slag X2 and the suspended slag collected by the granulated slag discharge bucket elevator 2 are conveyed from the granulated slag discharge bucket elevator 2 by a belt conveyor or the like, and temporarily store the granulated slag X2. After being temporarily stored in a granulated slag storage hopper (not shown), it is carried out by a truck or the like.

In the slag granulation method in the slag granulation facility S1 of the first embodiment having such a configuration, by installing a plurality of plate heat exchangers 6 in series, in the flow path of the plate heat exchanger 6 Since the flow rate of the suspended slag diluted water W4 (slag water crushed water W) is a flow rate at which the accumulation of the suspended slag in the plate heat exchanger 6 is suppressed, the heat exchange efficiency resulting from the accumulated suspended slag It is possible to suppress a decrease in pump flow rate due to a decrease in pressure and an increase in pressure loss. In addition, by installing a liquid cyclone that discharges a portion of the suspended slag from the system in two stages, the concentration of the suspended slag concentrated water is increased and the amount of water is reduced. By supplying the crushed slag discharge bucket elevator 2, the suspended slag can be recovered efficiently and reliably.
This makes it possible to adopt plate heat exchangers that have not been introduced in conventional granulated water circulation slag granulation facilities, and can significantly reduce the amount of water used in slag granulation facilities. The slag granulation equipment which reduced the running cost while overcoming various problems caused by cloudy slag is achieved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In the description of the second embodiment, the description of the same parts as those of the first embodiment will be omitted or simplified.

  FIG. 5 is a flowchart showing a schematic configuration of the slag granulating equipment S2 of the second embodiment. As shown in this figure, in the slag granulation facility S2 of the second embodiment, a pipe c which is a flow path of the suspended slag granulated water W2 fed from the circulation pump 4 is directly connected to the head tank 7. ing. The circulation pump pit 3 is provided with a cooling system circulation pump 12 that supplies a part of the suspended slag crushed water W2 supplied through the pipe n to the first hydrocyclone 5 through the pipe o. Yes. A pipe f which is a flow path of the suspended slag diluted water W4 (slag crushed water W) cooled by the plate heat exchanger 6 is connected to the circulation pump pit 3. That is, in the slag granulation facility S2 of the second embodiment, the circulation channel of the slag granulated water W and the cooling channel of the slag granulated water W are formed separately.

  According to the slag granulation equipment S2 of the second embodiment having such a configuration, even if an abnormality occurs in the cooling flow path due to, for example, a failure of the first hydrocyclone 5, it circulates instantaneously. It is possible to prevent the use of the flow path from being stopped.

  As mentioned above, although preferred embodiment of the slag granulation equipment and the slag granulation method which concern on this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, the suspended slag is recovered together with the granulated slag X2 by supplying the second suspended slag concentrated water W5 to the bucket 21 of the bucket elevator 2 for granulated slag discharge. However, the present invention is not limited to this, and the second suspended slag concentrated water W5 is supplied to a granulated slag storage hopper (not shown), and the granulated slag layer in the granulated slag storage hopper The suspended slag may be recovered together with the granulated slag X2 by filtering the second suspended slag concentrated water W5.

Slag granulation was carried out using the slag granulation facility S1 of the first embodiment of the present invention. In order to confirm the effect of the present invention, what is described below uses a circulation pump or a plate heat exchanger installed as a spare for switching, and the equipment is intentionally deviated from the normal operation. The result of driving is also included.
FIG. 6 shows the result of comparing the heat transfer coefficients after operating for a certain period of time by varying the flow rate of the granulated water in the flow path of the plate heat exchanger. Although the heat transfer coefficient is improved as the flow rate is increased, the heat transfer coefficient is gradually changed at a flow rate of 0.1 m / s or more, whereas the heat transfer coefficient is rapidly decreased when the flow rate is 0.1 m / s or less. When the plate heat exchanger was disassembled and inspected, suspended slag accumulated significantly in the flow path between the plates.
FIG. 7 shows the particle size distribution of the product granulated slag when the conventional technique of performing water granulation with seawater and discharging the water after granulation to the neighboring sea area and the particle size distribution of the product granulated slag after carrying out the present invention. FIG. In the present invention, suspended slag that has not been collected in the past is collected in the form of being included in the product slag, so the amount of fine particles (0.15 mm or less) increases slightly, but there is a problem in selling granulated slag. Is not to be done. Further, since the suspended slag is continuously collected where the granulated slag is continuously conveyed by the bucket elevator, there is no variation in the particle size distribution.
Table 1 compares the operation status and trouble cases in a factory that employs the conventional cooling tower and sedimentation pit in the same granulated water circulation type water granulation equipment and a factory that employs the water granulation equipment of the present invention. .

  The factory using the conventional technology installs a large sedimentation pit and settles and separates the suspended slag, but the suspension slag accumulates quickly and the slag is scraped out twice a week to secure the pit capacity. We are carrying out. In addition, although a cooling tower is used as a heat exchanger, suspended slag has accumulated in the tower in the past, resulting in a decrease in heat exchange capacity, or the tower collapses because it cannot withstand the weight of the accumulated suspended slag. In order to reduce the concentration of suspended slag in the circulating water, a large amount of circulating water is sent to the drainage factory. The new water that must be replenished to the granulation facility, including the use of a cooling tower, is more than three times that of the present invention.

It is the flowchart which showed schematic structure of slag granulation equipment S1 of 1st Embodiment of this invention. It is the schematic diagram which showed typically the flow path of the suspension slag diluted water W4 (slag crushed water W) and the flow path of the cooling water R when two plate-type heat exchangers 6 are installed in series. It is the schematic diagram which showed typically the receiving tank 11 and the bucket 21 with which the bucket elevator 2 for granulated slag discharge is provided. 2 is a perspective view of a receiving tank 11. FIG. It is the flowchart which showed schematic structure of slag granulation equipment S2 of 2nd Embodiment of this invention. It is the result of having investigated the heat transfer coefficient after a fixed period by changing the flow velocity in the flow path of a plate type heat exchanger variously. The particle size distribution of the product granulated slag was compared between the case where the conventional sea water was crushed and the crushed water was discharged into the neighboring sea area and the slag granulation facility S1 of the first embodiment of the present invention was used. Is. It is a figure explaining the definition of the flow velocity in the flow path of a plate type heat exchanger.

Explanation of symbols

S1-S2 slag granulating equipment, 2 ... bucket elevator for granulating slag discharge, 4 ... circulation pump, 5 ... 1st liquid cyclone (liquid cyclone), 6 ... plate heat exchanger, 7 ... ... head tank, 8 ... suspended slag concentrated water intermediate pit, 9 ... suspended slag concentrated water feed pump, 10 ... second liquid cyclone (second liquid cyclone), 11 ... receiving tank (flow rate buffering means) ), 12 ... Cooling system circulation pump, X1 ... Molten slag, X2 ... Granulated slag, W ... Slag granulated water, W1 ... Slag granulated water (slag granulated water), W2 ... ... suspended slag crushed water (slag crushed water), W3 ... first suspended slag concentrated water, W4 ... suspended slag diluted water (slag crushed water), W5 ... second suspended slag concentrated water 、 W6 …… Shimizu

Claims (10)

After the molten slag is granulated with slag granulated water, and after the granulated slag is taken out of the slag granulated water, the slag granulated water is circulated and used for the granulation of the molten slag again. The slag granulation method of
In a slag granulation facility having a plate heat exchanger having a heat transfer plate or a tubular heat exchanger, the flow rate of the slag granulated water is determined by the plate heat exchanger or the tubular heat exchanger. A method for granulating slag, characterized by controlling the flow rate so as to suppress the accumulation of suspended slag in the flow path. After the molten slag is granulated with slag granulated water, and after the granulated slag is taken out of the slag granulated water, the slag granulated water is circulated and used for the granulation of the molten slag again. Slag granulation equipment
A plate heat exchanger having a heat transfer plate, or a tube heat exchanger;
A slag comprising flow rate control means for controlling accumulation of suspended slag in a flow path of the plate heat exchanger or the tubular heat exchanger by controlling a flow rate of the slag crushed water. Granulated equipment. The slag granulation facility according to claim 2,
The slag granulation facility, wherein the flow rate control means controls the flow rate of the slag crushed water in the flow path of the plate heat exchanger or the tubular heat exchanger to 0.1 to 2 m / s. . The slag granulation equipment according to claim 2 or 3,
When employing the plate heat exchanger, a plurality of plate heat exchangers are arranged in series as means for controlling the flow velocity in the flow path. It is the slag granulation equipment in any one of Claims 2-4,
As a means for removing a part of the suspended slag, a hydrocyclone for concentrating and separating the suspended slag into a part of the slag granulated water is provided. The slag granulation facility according to claim 5,
The liquid cyclone is installed in two stages, concentrated and separated by the first-stage liquid cyclone, and the slag concentrated water discharged is sent to the second-stage liquid cyclone, further concentrating the slag concentrated water, and reducing the amount of water, Slag granulation equipment that collects suspended slag. The slag granulation facility according to claim 6,
The granulated slag is supplied by supplying concentrated water containing suspended slag discharged from the second stage liquid cyclone to a granulated slag discharge bucket elevator for taking out the granulated slag from the slag granulated water to the outside. A slag granulation facility, wherein the concentrated water is filtered by a granulated slag layer in a bucket in a slag discharge bucket elevator, and the suspended slag is separated and recovered. The slag granulation facility according to claim 7,
When supplying the said concentrated water containing the said suspension slag to the said bucket elevator for granulated slag discharge | emission, the flow rate buffer means which reduces the flow rate of concentrated water is provided, The slag granulation equipment characterized by the above-mentioned. The slag granulation facility according to claim 8,
The slag granulation equipment, wherein the flow rate buffer means is a receiving tank that receives the concentrated water containing the suspended slag and supplies the overflow water to the bucket elevator for discharging the granulated slag. The slag granulation facility according to claim 6,
By supplying concentrated water containing suspended slag discharged from the second-stage hydrocyclone to a granulated slag storage hopper for temporarily storing the granulated slag, A slag granulation facility, wherein the concentrated water is filtered through a granulated slag layer, and the suspended slag is separated and recovered.

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