JPH07148404A - Vacuum filtration apparatus - Google Patents

Abstract

PURPOSE:To continuously carry out dehydration and filtration of substances difficult to be filtered at high dehydration efficiency by once dehydrating the object substances for treatment on filtration cloth to form cakes and then breaking the cakes in a pulping part in a non-vacuum region and then adding water, etc. CONSTITUTION:Along the proceeding direction of filtration cloth 3, dehydration regions A in which vacuum suction is carried out for the object substance 5 for treatment and non-vacuum regions B in which no vacuum suction is done are successively and reciprocally formed. A water supplying apparatus to add water, a solvent, etc., to the object substance 5 for treatment and a repulping part 9 are installed in a non- vacuum region B, wherein the repulping part 9 is provided with a stirring apparatus to scratch and stir the substances and a pressing part to supply compressed air C. At first the object substances 5 for treatment on the filtration cloth 3 is vacuum dehydrated in a dehydration region A to form a cake and then vacuum condition is released in a non-vacuum region B and the cake is directly stirred by the repulping part 9 to break the cake and then water, etc., is added. Consequently, water is supplied even to the included water in the cake and when dehydration is carried out again after that, the included water 6 can be taken out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum for solid-liquid separation of a substance having a thixotropic property and hardly filtered, such as iron oxide, silicate and salt, which exhibits a liquefaction phenomenon. The present invention relates to a filtering device.

[0002]

2. Description of the Related Art Conventionally, when filtering and dehydrating a liquid-containing material that is difficult to filter, it is necessary to wash an object to be dehydrated once,
That is, it is known that when the material to be treated is dehydrated and filtered again after the repulping operation, the final water content is further lowered and a good effect is obtained. And the reason is that the rate-controlling layer formed in the object to be treated in the process of dehydration increases the filtration resistance and hinders the discharge of the filtrate by adding water to swell the rate-controlling layer. This is because the material to be treated is easily destroyed by dehydration. By the way, a pressure filtration device is generally used for dehydration / filtration involving the above repulping operation. That is, a filter press is used as a filter, and after being squeezed and dehydrated, water is added to carry out a repulping operation, and the filter is pressed again to obtain a final dehydrated cake.

[0003]

However, in the above-mentioned conventional pressure filtration involving repulping operation, the treatment is batch type, and after dehydration once, the cake produced is once carried out of the filter. However, after the repulping operation, a process of press-filtering by another press-filtering means is required, and there is a problem that the operation is troublesome, time-consuming, and workability is poor. Further, although it is considered that the above repulping operation is performed by a conventional horizontal vacuum filtration device, in this case, the dehydration effect may not be improved. That is,
When the object to be treated has a porous structure, by adding water, even if this water reaches the surface of the substance having a porous structure of the object to be treated, it is difficult to act on the water contained in the porous structure, The water contained therein is not drained to the outside during the dehydration, and therefore the dehydration effect cannot be improved.

The present invention has been made in view of the above circumstances. An object of the present invention is to continuously dehydrate and filter a difficult-to-filter substance in dehydration filtration.
It is to provide a vacuum filtration device having an extremely high dehydration effect.

[0005]

In order to achieve the above object, the first aspect of the present invention is a vacuum filtration apparatus for forming a cake on a filter cloth by vacuum suction for dehydration and filtration, which runs in one direction. In order along the advancing direction of the filter cloth, a first dehydration area in which vacuum suction is performed on the object to be processed on the filter cloth, a non-vacuum area in which vacuum suction is not performed, and again to the object to be processed. A second dehydration area for performing vacuum suction by means of a water supply device for adding water, solvent, etc. to the object to be treated in the non-vacuum area, and a scraping tool attached to the rotary shaft. It is characterized in that a repulp section provided with a stirrer capable of scraping up and stirring the object to be treated is provided, and the second and third inventions, in the repulp section, respectively, instead of the stirrer, Or with this stirrer, the bottom of the filter cloth From provided the pressure chamber via the filtrate cloth is characterized in that the allowed comprising a pressure portion for stirring the 該被 treated by supplying compressed air to the object to be processed.

[0006]

In the vacuum filtration device of the present invention, the object to be treated on the filter cloth is once vacuum-dehydrated in the first dehydration zone to form a cake, and then the vacuum state is released in the non-vacuum zone,
In the repulp part provided in this non-vacuum region, while stirring and destroying the formed cake directly, by adding water and a solvent by the water supply device, the moisture contained in the substance in the cake is also included, Return the combined water of to the free state. Then, by vacuum suctioning again the article to be treated in the second dehydration zone to dehydrate, even if the article to be treated has a porous structure, the water contained in the porous structure can be taken out to the outside. it can.

In the first aspect of the invention, the object to be treated is scraped up directly by the scraping tool attached to the rotary shaft of the stirrer provided in the repulp section. Further, in the second and third inventions, a compressed air portion is provided in the repulp portion instead of or together with the agitator, and compressed air is supplied to the object to be processed in the non-vacuum region. Depending on the stirring by this compressed air, or in combination with the stirring by the above-mentioned stirrer, the separation action of the lumps or granules of the object to be treated is promoted, and the filtration resistance at the time of filtration in the second vacuum region is increased. Reduce.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 5 is a diagram showing the overall configuration of the horizontal vacuum filtration apparatus of this embodiment. This horizontal vacuum filtration apparatus is supported by a large number of intermediate rolls 1 and travels in one direction by a filter cloth drive drum 2. Endless filter cloth 3
On top of the above, an object to be treated (slurry) 5 from the slurry injection port 4
And is provided below the horizontal portion 3a of the filter cloth,
First and second dehydration zones A and A that perform dehydration filtration by suction
And the plate-like body 8 in the non-vacuum region B provided between the dehydration regions A
By reciprocally moving and along the rail 7 by the tray drive cylinder 6, and operating the repulp portion 9 of the non-vacuum region B provided on the upper portion of the horizontal portion 3a, dehydration cake is formed, and the cake is It is scraped off from the filter cloth 3 by the scraper 10. Note that reference numeral 1
1 is a spray for cleaning the filter cloth 3.

In the dehydration area A, as shown in FIGS. 1 and 5, a vacuum tray 12 for vacuum-suctioning the upper surface of the filter cloth 3 is provided below the horizontal portion 3a so as to be movable left and right. . The vacuum trays 12 are connected to the vacuum system 13 by a flexible vacuum hose 13a, and release the vacuum from the vacuum valves 13b and the shutoff valves 13b that shut off between the vacuum system 13 and the vacuum trays 12. A release valve 13c is provided.

Further, as shown in FIG. 2, the repulp portion 9 is arranged within the moving range of the plate-like body 8 and is substantially in the form of the plate-like body 8.
It is set to half the length. And the repulp section 9
Is provided with partition plates 14 on the upstream side and the downstream side with respect to the traveling direction of the filter cloth 3, and between the both partition plates 14, a stirrer 15 scrapes up the workpiece 5 on the filter cloth 3, The height is adjusted so that it can be stirred. This agitator 15
A scraping tool 15c made of a flexible plate is detachably attached to the tips of a plurality of support plates 15b protruding from the rotary shaft 15a. Furthermore, in the repulp section 9,
A water supply device for water injection (not shown) is appropriately provided on the upper portion of the filter cloth 3 so that the object to be treated on the filter cloth 3 can be supplied with water.

The dehydration zone A and the non-vacuum zone B are alternately arranged, and as shown in FIG. 3, the dehydration zone A is divided into a vacuum filtration section A ₁ and a cleaning section A ₂ . That is, in FIG. 3, the vacuum filtration unit A ₁ , the cleaning unit A ₂ , the non-vacuum region B, the cleaning unit A ₂ , and the vacuum filtration unit (dehydration unit) A ₁ are arranged. In addition, FIG. 4 shows a structure in which the vacuum filtration unit A
₁ , cleaning unit A ₂ , non-vacuum region B, cleaning unit A ₂ , non-vacuum region B,
The cleaning unit A ₂ and the vacuum filtration unit A ₁ are arranged. In addition, what is shown by the code | symbol 16 in FIG. 1 is a compressed air part mentioned later.

In the horizontal vacuum filtration device constructed as described above, first, the object to be treated 5 supplied onto the horizontal portion 3a of the filter cloth 3 is placed in the vacuum tray 12 below the filter cloth 3.
It is vacuum sucked and dehydrated. Then, when the water content is dehydrated to a certain extent, the object 5 to be treated on the filter cloth 3 is in a stationary state and gels. At this time, the filter cloth 3 is moved to the right in FIG. 5 by the filter cloth driving drum 2,
Since the vacuum tray 12 and the plate-like body 8 are moved to the right in synchronization with the filter cloth 3 by the tray drive cylinder 6,
Adhesion between each vacuum tray 12 and the filter cloth 3 is maintained well, and efficient vacuum suction is performed. Next, when the stroke of the tray drive cylinder 6 becomes full (see FIG. 4), the vacuum of the vacuum tray 12 is released, the vacuum tray 12 and the filter cloth 3 are no longer in close contact, and the tray drive cylinder 6 causes the vacuum tray 12 to move. Returns to the original position together with the plate-like body 8 (see FIG. 3). Then, when returning to the original position, vacuum suction by the vacuum tray 12 is performed again.

On the other hand, the object 5 to be treated on the filter cloth 3 that has reached below the repulp portion 9 is washed and then subjected to a stirring operation by the stirrer 15, and water is supplied from the water supply device as needed in the next step. By being supplied, it destroys the rate-controlling layer in the article to be treated 5 formed and fixed by the above dehydration operation, and acts on the contained water taken in the porous structure of the article to be treated 5, The contained water is taken out by washing. At this time, for example, the total amount of cleaning water is controlled by dividing the supply from the first stage to the second stage in the order of 3, 4, and 3. Therefore, the dehydration effect in the second dehydration zone A of the next step arranged in the alternation is further enhanced.

To show the above effect by an example in which a concrete experiment was conducted, the object (slurry) 5 used as a sample is shown in Table 1.
In this case, I: this example (vacuum filtration) + (washing) + (stirring) + (washing) + (dehydration) II: Comparative proportion (vacuum filtration) + (washing) + (dehydration) Under the conditions, the results shown in Table 2 were obtained.

[0015]

[0016]

Of course, the substances recovered as impurities may be useful substances. Although the process shown in FIG. 3 was used as the present embodiment, the removal rate of impurities is further improved by using the process shown in FIG. 4 depending on the case.

An embodiment of the third invention will be described with reference to FIGS. 1 and 6. In this embodiment, the plate-like member 8 in the above embodiment is provided with the compressed air portion 16. That is, the compressed air portion 16 applies the compressed air C to the plate-shaped body 8 via the pressure regulating valve 17.
Is supplied into the pressure chamber 18 formed in the upper part of the
Air is ejected from the lower surface of the filter cloth 3 through the through hole plate 19 installed on the upper part of the filter cloth 8. Further, instead of the agitator 15, a spiral wire or elastic body 2 is attached to the tip of a support 20b provided on the rotary shaft 20a at appropriate intervals.
The stirrer 20 which arrange | positions 0C is installed. Then, by operating the compressed air portion 16 to eject air from the lower side of the filter cloth 3, the individual molecules of the object to be treated 5 are omnidirectionally worked together with the stirring or water injection action. Due to the drying capacity of the compressed air, the surface tension of the water adhering to the molecules is weakened.
In addition to the effect of improving athletic performance in, the pretreatment operation before the dehydration step is more effective when water is not injected.

In the non-vacuum region B, the following second dehydration region A is obtained by appropriately combining the stirring operation by the stirrers 15 and 20, the water injection operation (not shown), and the compressed air operation by the compressed air section 16. It is intended to improve the dehydration effect in. Further, in each of the above-mentioned embodiments, the above-mentioned stirrers 15 and 20 are used for description, but the present invention is not limited to this. For example, as shown in FIG. 7, a rotary shaft 30a that is rotatably provided in parallel with the width direction of the filter cloth 3 and that is rotated by a drive device 31, and a rotary shaft 30a that is attached to the rotary shaft 30a and has spiral directions relative to each other. A stirrer 30 composed of a pair of left and right screw blades (raising tools) 30b formed in reverse
May be used.

As a scraping tool, as shown in FIG. 8, a rotary shaft 30a is provided with a plurality of scraping rods 30c radially along the axial length thereof, or as shown in FIG. A plurality of protrusions 30d provided on the peripheral surface of the scraping rod 30c in a dot shape, an annular shape, or a spiral shape,
Alternatively, as shown in FIG. 10, a scraping rod 30e may be attached to the tip of the scraping rod 30c, or a scraping plate 30f may be attached as shown in FIG. Further, as shown in FIG. 12, along the length direction of the rotating shaft 30a,
A spiral screw rod 30 continuous through a support rod 30g
As shown in FIG. 13, a plurality of scooping rods (plates) 30i held by the supporting rod 30g are attached to the rotary shaft 30a.
14 may be attached parallel to the axis of the support rod, or obliquely and superposed on each other. As shown in FIG.
A plurality of screw-shaped screw rods 30j held at 0 g may be overlapped with each other and appropriately provided so as to rotate in the same direction or different directions.

[0021]

As described above, according to the present invention,
Since the object to be continuously processed on the filter cloth can be appropriately combined with dehydration operation, water injection, stirring, and air supply operation, in addition to the ordinary hardly filterable object, its structure Even if it contains a porous substance, it is possible to dehydrate continuously and more effectively, and it is possible to improve workability and dehydration ability.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a main part of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a non-vacuum region B according to an embodiment of the present invention.

FIG. 3 is a schematic explanatory view showing a positional relationship between a dehydration area A and a non-vacuum area B.

FIG. 4 is a schematic explanatory view showing a positional relationship between a dehydration zone A and a non-vacuum zone B when they are arranged in two rows.

FIG. 5 is a schematic explanatory view showing a horizontal vacuum filtration device according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a non-vacuum region B according to another embodiment of the present invention.

FIG. 7 is a side view of an example in which a screw blade is provided as a scraping tool of an agitator.

FIG. 8 is a side view of an example in which a raking rod is radially provided on a rotary shaft as a raking tool of a stirrer.

FIG. 9 is an explanatory diagram of an example in which projections are provided on a scraping rod as a scraping tool of a stirrer.

FIG. 10 is an explanatory view of an example in which a scraping rod is attached to a scraping rod as a scraping tool of an agitator.

FIG. 11 is an explanatory diagram of an example in which a raking plate is attached to a raking bar as a raking tool of a stirrer.

FIG. 12 is a side view of an example in which a spiral screw rod is provided on a rotating shaft via a support rod as a scraping tool of an agitator.

FIG. 13 is a side view of an example in which a scraping bar (plate) is provided on a rotating shaft via a supporting bar as a scraping tool of an agitator.

FIG. 14 is a side view of an example in which a plurality of screw rods are provided on a rotating shaft via a supporting rod as a scraping tool of an agitator.

[Explanation of symbols]

 3 Filter cloth 5 Object to be treated (slurry) 9 Repulp part 12 Vacuum tray 15 Stirrer 16 Compressed air part 20,30 Stirrer A Dewatering area B Non-vacuum area C Pressure air

Claims (4)

[Claims] 1. A vacuum filtration device for performing dehydration and filtration by forming a cake on a filter cloth by vacuum suction, and treating the filter cloth in order along the traveling direction of the filter cloth running in one direction. A first dehydration region for performing vacuum suction on the object, a non-vacuum region where vacuum suction is not performed, and a second dehydration region for performing vacuum suction again on the object to be processed are provided. Includes a water supply device for adding water, a solvent and the like to the object to be treated, and a repulping machine equipped with a stirrer capable of agitating the object to be treated by a scraping tool attached to a rotary shaft. A vacuum filtration device, which is provided with a section. 2. A vacuum filtration apparatus for forming a cake on a filter cloth by vacuum suction for dehydration and filtration, wherein the objects to be treated on the filter cloth are sequentially processed along the traveling direction of the filter cloth running in one direction. A first dehydration region for performing vacuum suction on the object, a non-vacuum region where vacuum suction is not performed, and a second dehydration region for performing vacuum suction again on the object to be processed are provided. Is a water supply device for adding water, a solvent, etc. to the object to be treated, and a compressed air is supplied to the object to be treated from the pressure chamber provided in the lower part of the filter cloth through the filter cloth. A repulping section provided with a compressed air section for stirring the object to be treated is provided. 3. A vacuum filtration device for forming a cake on a filter cloth by vacuum suction for dehydration and filtration, wherein the treated objects on the filter cloth are sequentially processed along the traveling direction of the filter cloth running in one direction. A first dehydration region for performing vacuum suction on the object, a non-vacuum region where vacuum suction is not performed, and a second dehydration region for performing vacuum suction again on the object to be processed are provided. Includes a water supply device for adding water, a solvent, etc. to the object to be treated, a stirrer capable of agitating the object to be treated by a scraping tool attached to a rotating shaft, and the filter cloth. A repulping section provided with a compressed air section for agitating the object to be processed by supplying compressed air to the object to be processed from the pressure chamber provided in the lower part of the object through the filter cloth. Vacuum filtration device. 4. The stirrer is characterized in that the scraping tool made of a flexible plate is detachably attached to the tips of a plurality of support plates protruding from the rotary shaft. The vacuum filtration device according to claim 1 or 3.