JP2001000808A - Filtering and dehydrating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily scrape off the filter cake adorbed on a filter medium laid over the periphery of a rotary drum. SOLUTION: A filter medium 4 of a metallic-fiber nonwoven fabric, etc., is laid over the periphery of a rotary drum 2. The knife edge 12a of a cutter 12 is pressed on the rotary drum 2. A processing soln. hopper 6 is formed by the drum ring 8 on both ends of the drum 2, the side wall 10 on both sides pressed on the ring 8 and the upper face of the cutter 12. A vacuum suction pipe 20 is provided within the drum 2 to exert a negative pressure on the inside of the drum 2. A compressed air injection nozzle 26 is provided and directed close to the abutment between the drum 2 and the knife edge 12a of the cutter 12. When the drum 2 is rotated and vacuum-sucked from the inside, the liq. component in the processing soln. is permeated through the filter medium 4 and introduced into the drum 2, and the solid component is stuck to the outer face of the medium 4 and dehydrated. Air is blown against the dehydrated cake from the nozzle 26 when the cake is scraped off by the cutter 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration and dehydration apparatus, and more particularly to a filtration and dehydration apparatus for separating and discharging solids in a processing solution via a rotary drum having a filter material attached to an outer peripheral surface. .

[0002]

2. Description of the Related Art As a filtration and dehydration apparatus, a cylindrical rotating body rotatably supported about a horizontal axis, a filtering material attached to an outer peripheral surface of the rotating body, and a suction member from the inside of the rotating body. There is conventionally known a vacuum suction means provided with a vacuum suction means for applying a negative pressure, and a cutter or the like arranged so as to be in contact with the outer surface of the rotating body. In this filtration and dehydration apparatus, while a part of the rotating body is immersed in the processing liquid in the processing liquid hopper and the rotating body is continuously rotated and vacuum-sucked from the inside thereof, the liquid content in the processing liquid is reduced. Passes through the filter medium and flows into the inside of the rotating body, and solids mixed in the liquid are separated from the liquid and adhere to the surface of the filter medium. The solid matter (dehydrated cake) attached to the surface of the filter is scraped off by the cutter and discharged.

[0003]

In the conventional filter dewatering apparatus, the dewatered cake adhered to the filter medium is scraped off by a cutter. However, the dewatered cake is completely removed only by pressing the cutter against the surface of the filter medium. There is a problem in that it cannot be scraped off, remains on the surface of the filter medium, and causes clogging.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a filtration and dewatering apparatus which makes it easy to scrape off a dewatered cake by injecting air into a portion where a cutter comes into contact with a rotating body. It is assumed that.

[0005]

According to a first aspect of the present invention, there is provided a filtration and dewatering apparatus including a processing liquid hopper to which a processing liquid is supplied, a filter medium attached to an outer peripheral surface, and a part of the processing liquid in the processing liquid hopper. , A negative pressure means for applying a negative pressure to the inner side of the rotary drum, and a cutter for contacting the outer surface of the rotary drum and scraping the filtered solids. A nozzle for injecting gas toward the vicinity of the tip of the cutter is provided on the outer side of the cutter.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 is a side view showing an entire filtration and dewatering apparatus according to one embodiment of the present invention, in which a cylindrical drum 2 is supported rotatably about a horizontal axis O1. The rotating drum 2 is rotated by receiving the drive of the motor 3. A filtering material 4 such as a metal fiber nonwoven fabric is attached to an outer peripheral surface of the rotating drum 2. In addition, as this filter material 4, a filter cloth, a synthetic resin porous body, etc. other than a metal fiber nonwoven fabric can be used.

A hopper (generally indicated by reference numeral 6) for a processing liquid is provided on the upper side (upper right part in FIG. 1) of the rotary drum 2. The processing liquid hopper 6 is mounted on a drum ring 8 which is attached to the outer peripheral side of both ends (front side and back side of the paper) of the rotary drum 2 in a flange shape, and is pressed against the drum rings 8 on both sides. Side walls 10
And a cutter 12 described later.

The cutter 12 is disposed obliquely from above the rotary drum 2 toward the rotary drum 2 and is supported so as to be able to move forward and backward. The material of the cutter 12 is preferably stainless steel or the like when a metal fiber nonwoven fabric is used as the filter medium 4, and is preferably made of rubber when the filter medium 4 is a filter cloth or a synthetic resin. A pressing force is applied to the cutter 12 toward the rotary drum 2. The pressing force against the rotating drum 2 may be applied by the weight of the cutter 12, or may be applied by attaching a weight or biasing with a spring. It is preferable that the pressing force of the cutter 12 against the rotating drum 2 be adjustable.

The cutter 12 has a rectangular through hole (opening) 12b slightly above the cutting edge 12a at the tip. The opening 12b allows the rotating drum 2
The excess of the processing liquid supplied into the processing liquid hopper 6 constituted by the drum rings 8 on both sides, the side walls 10 on both sides, and the upper surface of the cutter 12 overflows. On the upper surface of the cutter 12, a plate 14 for adjusting the depth of the processing liquid hopper 6 according to the type of the processing liquid or the like is movably attached. It can be adjusted.

A supply pipe 16 for supplying a processing liquid into the hopper 6 is provided above the processing liquid hopper 6.
In this embodiment, the liquid supply port 16a is open to the side so that the processing liquid supplied from the supply pipe 16 does not flow out of the opening 12b of the cutter 12 as it is. A circulation pipe 18 is attached to the lower surface side of the opening 12b of the cutter 12, and the untreated processing liquid flowing out of the opening 12b is circulated to the supply pipe 16 by a pump (not shown). I have.

A vacuum suction pipe 20 is provided at the center of the rotary drum 2. By suctioning the vacuum drum 20 while rotating the rotary drum 2,
A negative pressure is applied to the inside of the rotating drum 2. Due to this negative pressure, the processing liquid in the processing liquid hopper 6 permeates the filter medium 4 and the turbid substances (solids) in the processing liquid adhere to the surface of the filter medium 4 and are filtered and dehydrated.

Below the cutting edge 12a of the cutter 12, a chute 22 for discharging the dewatered cake scraped off by the cutter 12 is provided. Further, a discharge conveyor 24 for receiving and discharging these dehydrated cakes is disposed below the chute 22.

Also, the tip 12 of the cutter 12
A compressed air injection nozzle (an injection nozzle on the outer side of the rotary drum 2) 26 is provided below the edge a of the rotary blade 2 so as to face the vicinity of a position where the cutting edge portion 12a and the filter medium 4 of the rotary drum 2 come into contact with each other. A plurality of compressed air injection nozzles 26 are arranged in the width direction of the rotary drum 2 and the cutter 12, and a compressed air supply source (not shown) such as a compressor or a blower is provided.
And compressed air can be blown to the entire area where the cutter 12 and the filter medium 4 come into contact with each other.

On the other hand, on the inner side of the rotary drum 2, a second compressed air injection nozzle 28 is provided near or slightly below the position where the cutting edge 12a of the cutter 12 contacts the filter medium 4. Have been. The second compressed air injection nozzle 28 is also connected to the external compressed air injection nozzle 2.
As in the case of 6, a plurality of the rotary drums 2 are arranged in the width direction, and are connected via a valve to the same compressed air supply source as the compressed air jet nozzle 26 on the outside described above. The air jet nozzle 28 on the inner side of the rotary drum 2 does not always jet air, but jets when clogging of the filter medium 4 becomes severe, and may be omitted.

Further, nozzles 30 and 32 for spraying a cleaning liquid are provided outside the rotary drum 2 on the left side and the upper right side of the figure, respectively.
Are arranged facing the direction of the rotating drum 2. A plurality of these cleaning liquid spray nozzles 30 and 32 are also provided in the width direction of the rotary drum 2, and are used when cleaning the filtering material 4.

Next, the operation of the filtration and dewatering apparatus having the above configuration will be described. A processing liquid hopper 6 configured by the cutter 12, the drum ring 8 of the rotary drum 2, and the side walls 10 on both sides in a state where the tip blade tip 12 a of the cutter 12 is in contact with the filter medium 4 attached to the rotary drum 2. Within
The processing liquid is supplied from the supply pipe 16. When the supplied processing liquid exceeds a certain amount, it overflows from an opening 12 b formed in the cutter 12. Therefore, depending on the position of the depth adjusting plate 14, the processing liquid hopper 6
The height of the liquid level of the processing liquid supplied into the inside can be changed.

The processing liquid is supplied into the processing liquid hopper 6, and the rotary drum 2 is rotated by the motor 3, while the vacuum suction pipe 20 provided at the center of the rotary drum 2 supplies the processing liquid. Aspirate the processing solution. The liquid component of the processing liquid in the processing liquid hopper 6 passes through the filter material 4 and is sucked into the rotating drum 2, and the underwater contaminants (solid content) in the processing liquid are removed from the filter material 4. Filtration and dehydration are performed on the surface.

The solid residue (dehydrated cake) composed of the turbid substance in water adhered to the surface of the filter medium 4 is pressed against the filter medium 4 on the outer peripheral surface of the rotary drum 2 as the rotary drum 2 rotates. It is scraped off by the cutter 12, dropped onto the lower discharge conveyor 24 via the chute 22 and discharged. At this time, since the compressed air is sprayed from the outside of the rotary drum 2 toward the cutting edge 12a of the cutter 12, the dewatered cake is easily peeled off from the filter medium 4, which is more difficult than the conventional filter dewatering device. Also, the dehydrated cake can be scraped off easily and neatly. In addition, the dewatered cake scraped by the cutter 12 can be prevented from sticking to the cutting edge 12a of the cutter 12.

In the above embodiment, the processing liquid is supplied from above the rotary drum 2 (top feed type). However, in the present invention, the lower part of the rotary drum is brought into contact with the processing liquid tank provided below. It is also applicable to a filtration type dewatering device (bottom feed type). FIG. 2 shows an example of a bottom feed type filter dewatering apparatus. A rotating drum 102 rotatably supported about a horizontal axis O2 has a metal fiber nonwoven fabric, a filter cloth or a synthetic resin porous material on the outer peripheral surface. And the like, and a lower portion thereof is brought into contact with the processing liquid stored in the processing liquid tank 106 by a predetermined area. The cutter 112 is disposed obliquely with the cutting edge 112a at the tip facing upward, and the cutting edge 112a is
02 is pressed against the filtering material 104 on the outer surface. As in the first embodiment, stainless steel, rubber, or the like is used for the cutter 112 according to the material of the filter medium 104, as in the first embodiment.

A compressed air injection nozzle 126 is disposed outside the rotary drum 102, and injects compressed air toward a portion where the tip 112a of the cutter 112 and the rotary drum 102 come into contact with each other. I have. The plurality of compressed air injection nozzles 126 are arranged in the width direction of the rotary drum 102 as in the above-described embodiment. Further, a second compressed air injection nozzle 128 is disposed inside the rotary drum 102. A plurality of the second compressed air injection nozzles 128 are also arranged in the width direction of the rotating drum 102.

In the filtration and dewatering apparatus according to the second embodiment, when the inside of the rotary drum 2 is sucked by a vacuum suction pipe (not shown) while rotating the rotary drum 102, the processing liquid in the processing liquid tank 106 is discharged. While being sucked, the liquid component permeates through the filter medium 104 and flows into the rotating drum 102, and the solid content adheres to the surface of the filter medium 104, and then dehydrates while rotating out of the treatment liquid to the outside. It becomes a dewatered cake. This dehydrated cake is supplied to the cutter 11
When it comes to the position 2, the cutting edge 112 of the cutter 112
scraped off by a. When the dewatered cake is scraped off, air is blown by the compressed air jet nozzle 126 arranged on the outside near the cutting edge 112a of the cutter 112. Easily scraped from 104.

[0022]

As described above, according to the present invention, the processing liquid hopper to which the processing liquid is supplied and the filtering material attached to the outer peripheral surface, a part of which is in contact with the processing liquid in the processing liquid hopper. In a filtration and dewatering apparatus including a rotating drum, a negative pressure means for applying a negative pressure to an inner side of the rotating drum, and a cutter for contacting the outer surface of the rotating drum and scraping the filtered solid, On the outside, by disposing a nozzle that injects gas toward the vicinity of the tip of the cutter, the dewatered cake is easily peeled off from the filter medium,
Can be easily scraped. In addition, it is possible to prevent the dewatered cake from sticking to the cutter.

[Brief description of the drawings]

FIG. 1 is a side view showing an entire filtration and dewatering apparatus according to an embodiment of the present invention.

FIG. 2 is a simplified side view showing a filtration and dewatering apparatus according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 2 rotating drum 4 filter material (metal fiber nonwoven fabric) 6 treatment liquid hopper 12 cutter 12a tip of cutter (blade tip) 20 negative pressure means (vacuum suction means) 26 nozzle for injecting gas on the outside 28 gas on the inside Inject nozzle

Claims (2)

[Claims] 1. A processing liquid hopper to which a processing liquid is supplied, a filter medium attached to an outer peripheral surface, a rotating drum part of which is in contact with the processing liquid in the processing liquid hopper, and an inner side of the rotating drum. In a filtration and dewatering apparatus comprising a negative pressure means for applying a negative pressure and a cutter which abuts on the outer surface of the rotary drum and scrapes the filtered solid, the filter dehydrator is provided on the outer side of the rotary drum, near the tip of the cutter. Characterized in that a nozzle for injecting gas toward the nozzle is provided. 2. The filtration and dewatering apparatus according to claim 1, wherein a nozzle for injecting gas toward the vicinity of the tip of the cutter is provided inside the rotary drum.