JPS6150079B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum press roll filter.

Conventionally, horizontal continuous filtration machines have been widely used for over-cleaning of highly reactive substances with relatively coarse particles and large specific gravity. The features of this filter are that the horizontal surface of the filter allows a large amount of washing water to be applied uniformly, and that the liquid and washing liquid can be strictly separated, allowing multi-stage countercurrent washing. However, this type of permeator has the drawback of extremely low permeability for slurries with low permeability.

On the other hand, with recent advances in flocculants, slurry from industrial wastewater or sewage treatment equipment, which was previously thought to be separable, can now be made into aqua pellets by adding a flocculant, and then filtered. ing. Slurry flocculated with a polymer flocculant can be dehydrated using a horizontal vacuum filtration machine, but the dehydration rate of the cake is generally poor. In conventional horizontal filtration machines, the cloth is placed on a rubber drainage belt, and both are simultaneously moved over a fixed vacuum box. In this method, the drainage belt is moved under a vacuum, so a very large tension is applied to the drainage belt, and a high-strength rubber belt is required, making it expensive. There is also a method in which only the cloth is moved onto a vacuum box without using a drainage belt, but in this case the degree of vacuum that can be applied is low, at most a few tens of millimeters to a few hundred millimeters of water column, and dehydration is insufficient. There were flaws. Furthermore, depending on the slurry, it is desired to reduce the amount of components contained therein.

The present invention overcomes the above-mentioned drawbacks of the prior art, and therefore, the object of the present invention is to obtain a dehydrated cake that is highly dehydrated and has a reduced amount of components in the slurry, while making it possible to obtain a slurry that is difficult to pass through. To provide a press roll filter.

A feature of the present invention is that it combines a horizontal belt filter that does not have a drainage belt and can perform filtration and cake cleaning under high vacuum, and a press roll-type press mechanism, thereby rationally performing filtration, cake cleaning, and dewatering. It is.

Next, a vacuum press roll filter according to the present invention will be explained with reference to the drawings. As shown, this filter includes a movable vacuum box 1,
The vacuum box 1 is divided into an appropriate number of chambers 1' by partition walls 2. Each chamber is equipped with a fabric support bed 3 and connected to a vacuum source by a freely flexible conduit 4. Further, the conduit 4 is provided with a vacuum valve 5 for cutting off communication to a vacuum source, and an air valve 6 for releasing the vacuum in each chamber to atmospheric pressure. The vacuum box 1 is supported on rails 8 by means of a plurality of wheels 7 and is adapted to be reciprocated by a suitable drive, preferably an air cylinder arrangement 9. The reciprocating movement of the vacuum box 1 is performed by a control device, which preferably comprises a limit switch 10 for detecting the moving distance of the vacuum box, and can be controlled by a simple mechanism. Note that 11 is a lever for operating a limit switch attached to the vacuum box. In this case, the opening and closing operations of the vacuum valve 5 and the air valve 6 are also performed by the limit switch 10.

A belt-shaped endless cloth 12 is provided which passes over the vacuum box 1 and is stretched almost horizontally on the upper part. , a guide roll 14 and a tension roll 15 that applies tension to the fabric.
It is being passed around. As shown in FIG. 1, the pressing rolls are arranged alternately above and below the cloth, preferably a plurality of rolls, for example three rolls 16, 17, 18.
are arranged in an S-shape. A cloth 19 is provided on top of the cloth 12 and is driven at the same speed in the opposite direction. 13', a guide roll 14' and a tension roll 15'. These drive rolls are controlled by a variable speed reduction motor 2 using a chain.
Driven by 0.

In the embodiment shown in FIG. 1, a series of pressing rolls are provided along the upper running portion of the fabric 12, but these pressing rolls are arranged as shown in FIG.
It can also be provided along the lower running portion of the fabric 12, if space below the support frame of the filter is available.

The device further includes a plurality of nozzles 21 for spraying wash water onto the wet cake on the fabric 12, each nozzle being connected to a wash water tube. In the figure, 22 is a slurry feeder that supplies slurry to a predetermined position on the cloth 12, and 23 is a scraper.

During operation, a pair of cloths 12,1 arranged one above the other
9 travels at the same constant speed and supplies slurry to a predetermined position of the lower cloth 12 by a slurry feeder 22. First, the vacuum valve 5 is opened, the air valve 6 is closed, and the vacuum box 1 is moved in the same direction and at the same speed as the cloth 12 by the air cylinder device 9, and the slurry on the cloth 12 is suctioned by the vacuum force. Cloth 12
Form a wet cake on top. At that time, cloth 12
is supported on the supporting floor 3 of the vacuum box 1, and due to the reciprocating operation of the vacuum box, there is no need for a strong drainage belt, and combined with the fact that the drainage belt is not used, it has excellent elasticity and can generate a high degree of vacuum force. can be loaded. Next, washing water is sprayed onto the wet cake through the nozzle 21 and sucked into the wet cake, thereby replacing the mother liquor in the cake with the washing water. Incidentally, the partition wall 2 of the vacuum box serves as a separation wall for separately extracting the filtered liquid and the washing water through the conduit 4.

When the vacuum box 1 travels a predetermined distance, for example 500 mm, the lever 11 contacts the limit switch 10 and activates its control system, closing the vacuum valve 5 and opening the air valve 6, sucking air into the vacuum box 1. to lower the vacuum to atmospheric pressure, then quickly return the vacuum box. Once the vacuum box returns to its original position, repeat the above operations. This reciprocating operation of the vacuum box prevents excessive vacuum force from being applied to the cloth, making it possible to perform over-cleaning using a high vacuum.

Next, the washed wet cake is covered with an upper cloth 19, the cake is sandwiched between the two cloths 12, 19, and the cake is passed through the three press rolls 16, 1.
7 and 18, pressure with shearing force is applied to the cake by the tension of the roll and cloth, and the cake is compressed and dehydrated. The tension of the cloth is preferably 1
The tension is adjusted to 3 to 15 kg/cm ² by an adjustment mechanism provided on each tension roll 15, 15', for example, by adjusting the air pressure of an air spring. The compressed and dehydrated cake is discharged by a scraper 23. After the cake is discharged, each cloth is cleaned by a cloth cleaning device (not shown).

Therefore, the filter according to the present invention can use a high vacuum and has excellent permeability, and furthermore, since the wet cake is washed and then dehydrated by pressing with a pressing roll, the water content of the final cake is reduced. The rate is low and contains significantly less slurry mother liquor components.

Next, an example of use of the filter of the present invention will be described.
This equipment with a 500 mm cloth vacuum box and a 1.4 m ² excess area was used for cane mat processing in a factory with a cane processing capacity of 500 T/b. The solid humidity of Cane Matsudo extracted from Clarifair is 60g/,
In addition, as a super-aid, bagashiro, which has been separated from coarse particles through an 8-mesh sieve, is added at a rate of 20 to 30% based on the solid matter.
Added and processed. As a result of operation at a cake washing water rate of 500/hr, an operating vacuum level of -300 mmHg, and a cloth speed of 2.2 m/min, the cake moisture content was 68 to 70%, the residual sugar content in the cake was 0.8 to 1.0%, and the overspeed was is about 28
A value of Kg/m ² ·hr (dry cake amount) was obtained. Compared to the general results of the drum-type vacuum filtration machine conventionally used to process cane mats, the moisture content of the cake is 5 to 8% lower, and the sugar content in the cake is 2 to 8% lower.
3% less. It can be seen from the above examples that the filter constructed according to the present invention has a significantly superior cake moisture content and cake cleaning effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a vacuum press roll filter according to an example of the present invention, FIG. 2 is a schematic cross-sectional view taken along line A-A in FIG. 1, and FIG.
The figure is a schematic side view showing another embodiment. In the figure, 1...vacuum box, 1'...overchamber, 2...
Partition wall, 3... fabric support floor, 12... first fabric,
16, 17, 18...press roll, 19...second
cloth, 21...Washing water nozzle, 22...Slurry feeder, 23...Scraper, 9...Air cylinder device, 10...Limit switch.

Claims (1)

[Claims] 1. A first endless cloth that is driven in one direction and whose upper part is stretched substantially horizontally; The vacuum box includes a reciprocating vacuum box that moves at the same speed and a slurry feeder that supplies slurry to a predetermined position on the fabric, and the vacuum box has an overchamber partitioned by a partition wall, and the top surface becomes a fabric support floor. and a nozzle for dispersing cleaning water onto the wet cake on the cloth that has been dehydrated by the vacuum chamber; A second endless cloth sandwiching the wet cake thus washed together with the cloth, and a second endless cloth placed alternately above and below the stacked first and second cloths to guide the cloths and sandwiching the wet cake therebetween. A vacuum-type press roll filter includes a plurality of press rolls for pressing and dewatering a cake that has been pressed and dehydrated, and a scraper that removes the cake that has been pressed and dehydrated. 2. The vacuum press roll filter according to claim 1, wherein the reciprocating movement of the vacuum box is performed by an air cylinder device. 3. In the vacuum press roll filter according to claim 1, the squeeze roll is S
Consists of multiple compression rolls arranged in a letter shape.
Vacuum press roll filter. 4. The vacuum press roll filter according to claim 1, wherein the vacuum box is moved back and forth by a control device including a limit switch.