JPS613699A - Dehydration device - Google Patents

Abstract

PURPOSE:To give sufficiently good dehydration function even for a cake having hardenable dehydration by arranging closely numerous rolls wrapped by a pair of endless filter cloths and by bringing into contact a water permeable turning belt pressing a cake between only with the filter cloth of the lower side. CONSTITUTION:Numerous rolls 12a, 12b are arranged closely in a high pressure dehydration zone. A water permeable turning belt 14 pressing a cake 13 positioned between No.2 and No.3 turning filter cloths 6, 7 with the co-work of with the roll 12b, is arranged so as to bring into contact with only No.3 turning filter cloth 7 of the lower side almost over the full width. And yet the turning belt 14 thereof is wound on all rolls 12a, 12b and wound from the outside of both 3 cloths 6, 7 against numerous rolls 12. When filter cloths 6, 7 and the belt 14 are forced to run at the same speed, a stabilized dehydration can be performed without loosing of filter cloths 6, 7. The cake is pressed between for long time strongly as well and the dehydration upto low hydration rate is enabled.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to driving and rotating a pair of endless belt-shaped filter cloths in a diseased state in which a cake is sandwiched between the filter cloths and in a state where the filter cloths are wound into a roll. The present invention relates to a dewatering device provided with a water-permeable rotary belt which is freely provided and which presses the cake between the two filter cloths in cooperation with the rolls.

[Conventional technology]

Conventionally, as shown in Fig. 8, the rotating bell) + 14] was
Both filter cloth +61, +6) for large diameter roll H cough,
(7) was wound from the outside, and the cake L9 was dehydrated to 5 ki by both the squeezing force due to the tension of the filter cloth (7) and the squeezing force due to the rotating belt (+4) ( (Unable to provide references).

[Problem that the invention seeks to solve]

However, in order to sufficiently dehydrate the cake 04, it is necessary to apply a strong squeezing force over a long period of time, and the above-mentioned conventional apparatus has the disadvantage that it cannot meet such requirements. In other words, there is an upper limit to the tension that can be applied to the filter cloth (7) and the rotating belt θ from the viewpoint of strength, and in order to apply a strong clamping force, it is necessary to reduce the diameter of the roll (I2). The pressing time becomes shorter, and conversely, in order to lengthen the clamping time, it is necessary to increase the diameter of the roll (12), and the clamping force becomes smaller.

An object of the present invention is to enable dehydration using a rotating belt that can apply a stronger clamping force than a filter cloth for a sufficiently long period of time with a sufficiently strong clamping force, and to provide a structure for this purpose. The point is to make it simple and waste-free.

[Means to solve the problem]

The characteristic configuration of the present invention is to arrange five or more rolls wound with a pair of endless band-shaped filter cloths close to each other so that the filter cloths follow a meandering path, and to pinch the cake between the two filter cloths. The water-permeable rotary belt is arranged so as to contact only the lower one of the filter cloths almost throughout the process, and is wound around three or more of the rolls from the outside of both filter cloths. , and its effects are as follows.

[For production]

In other words, since a rotary belt is wound around three or more rolls in such a way that they can pinch the cake, the rolls are made small in diameter and the cake clamping pressure is strong. can be applied to the cake for a sufficiently long period of time.

Furthermore, by appropriately selecting the diameter and number of rolls to be installed, it is possible to set an appropriate clamping force and clamping time commensurate with the dehydration properties of the cake.

On the other hand, it is also conceivable to make one rotary belt and bring it into contact with the belts on both sides, and apply a strong clamping force to the cake by the rotary belt on all the rolls arranged close to each other.
Experimentally confirmed that when the rotating belt is located above the filter cloth, water from the cake remains attached to the rotating belt, preventing effective dewatering and complicating the device. However, the dehydration performance does not improve.

In the present invention, since the rotary belt is brought into contact only with the lower filter cloth, it has a sufficiently good dewatering function, and
To make a rotating bezel and its auxiliary equipment simple and efficient.

〔Effect of the invention〕

As a result, even cakes that are difficult to dehydrate, such as water treatment sludge, can be dehydrated to a sufficiently low moisture content by applying sufficiently strong and long-term cake compression, and post-processing such as incineration or melting can be done. In addition, the equipment related to the rotating belt can be made inexpensive and easy to maintain, and overall, it has become possible to provide a dewatering device that is excellent in all aspects of dewatering performance, economy, and management. Example] Next, an example will be shown.

As shown in Fig. 1, a rotary mixer (3) is installed to mix the material to be treated supplied from the first storage tank il+ and the flocculant supplied from the second storage tank (2). Machine (3
A first rotary filter cloth (4) in the form of an endless belt forming a first gravity dewatering section (A1) for the processed material from the first rotary filter cloth (4) is rotatably provided. A second rotary filter cloth (6) in the form of an endless belt is provided to form a second gravity dewatering section (A2) for the object to be treated, and the cake is gradually compressed by cooperation with the second rotary filter cloth (6). A forced dewatering section (B), (C) has an axial pressure dewatering zone (B), a shear dewatering zone (C) consisting of a meandering path, and a high pressure dewatering zone (9).
The eighth rotary filter cloth (7) in the form of an endless belt is provided so as to be freely rotatable. The objects to be processed such as
) to forced dehydration sections CB), (C), and (D) for continuous dehydration treatment, and the dehydrated cake is sent to the scraper (
8) constitutes a dewatering device for collecting waste on the conveyor (9).

Note that (10a), (10b), and (10c) are containers for collecting wastewater obtained in the dehydration process.

In the high-pressure dehydration zone (D), a large number of rolls (12a), (12b), for example 72 rolls, are arranged close to each other, and as shown in FIG.
, (7) The water-permeable rotary belt (14) that squeezes the cake (13) between them in cooperation with the roll (12b) is almost completely covered only with the lower 8th rotary filter cloth (7). and all rolls (12a).

(12b) Both filter cloths (611(6), (
7), that is, the water from the cake (13) is wound so that it is easy to flow down from the rotary belt θ(1).

Rolls (15a) and (15b) that separately drive the second and third rotating filter cloths +6)+ (7), and rotating belts (I
The roll (15c) that drives the roll (15c) is connected to seven winding transmission devices (
17) is interlocked and connected to the motor (M, ), and the rolls (15a) or 15c) are arranged near the lower side of ) of the high-pressure dehydration zone, and the lower side of the rolls (12a), etc. The cake clamping pressure by the second rotating filter cloth (6) increases, and the lower the roll (12b), the more the eighth rotating filter cloth (7) and the rotating belt (I
4) is configured to increase cake clamping pressure to improve cake dewatering efficiency. A dedicated motor (M2) is operatively connected to the roll (15d) that drives the first rotary filter cloth (4), and - tension rolls (lea) are connected to the second rotary filter cloth (6).

(16b), two tension rolls (16c) and (16d) on the eighth rotating filter cloth (7), and rotating belt θ4I.
K tension rolls (16e) are attached.

20〇〇〇〇〇〇〇〇〇 At the end of the first gravity dewatering section (A), there is a cake thickness adjustment roll (
Ila), a cake thickness adjusting roll (llb) is provided at the end of the second gravity dehydration zone (A2), and the roll (lla)
= (llb), filter cloth (4) or (
By rotating at a speed 1.2 to 2.5 times the running speed in step 6), forced dehydration and thickness adjustment are facilitated.

In the shear dewatering zone (C), the number of rolls is at least J
[1 or more, and the outer diameter ratio of the rolls is set so that the outer diameter ratio of the rolls at the end is about % to 100% compared to the roll at the front end. Also, in the high-pressure dewatering zone Φ), the outer diameter ratio may be changed at the entrance and end of the high-pressure dewatering zone Φ), and the front end roll of the shear dewatering sheet (C) is twice as large as the roll rough at the entrance of the high-pressure dewatering zone (Φ), and It is preferable to reduce the diameter of the exit roll to about y%. By arranging many rolls like this,
In addition, by changing the outer diameter ratio, it is possible to operate without stains coming out from the filter cloth.

The tension of the filter cloth (611 (yl) is the roll (16d), (16
In c), the tension of the rotating belt θ4) is the same as that of the roll (16e).
is applied using an air cylinder, etc., and the surface pressure generated accordingly (= 2 x belt or filter cloth tension ÷ roll outer diameter - ~ 0 at the end roll of the shear dewatering zone (C)
．． If the roller (12b) is set to 2 to 1.0, and the roll (12b) is set to about 1 to 5 times that value depending on the sludge properties, dehydration to a low moisture content can be achieved while preventing cake oozing and staining.

By setting the running speed of the filter cloth (4) lower than the filter cloth (611 (7+) and allowing sufficient dehydration time, the moisture content of the cake at the end point can be reduced, allowing stable pressurized dehydration. The running speed of filter cloth +611 (7) is 0
．． Make it about 8 to 2 pieces. Note that this running speed may be reversed depending on the sludge properties, and the cake supply thickness may be changed between the first and second gravity dewatering sections (As) r
(It also differs depending on the difference in AJ. Also, filter cloth (611+6), (7), bell, etc.) (14) is
By setting the drive unit so that it can run forcibly at the same running speed, stable dewatering can be achieved without filter cloth +6+ 1 +6) and walnuts (7).

The typical property ranges of sewage and raw sludge to be dewatered are as follows.

Since sludge properties vary widely, operating conditions for dewatering vary widely depending on the target sludge, and the resulting dewatering performance also varies greatly.゛It is practical for the sludge supply width in the second gravity dewatering section (A2) to be approximately 0.5 to 4 grooves, and accordingly, the pressurizing force at the inlet of the high-pressure dewatering zone (D), which can be designed and manufactured in terms of equipment, is , maximum 1
Similarly, the pressurization time in the high pressure dehydration zone (D) is approximately 15 minutes at maximum.

Within this range of conditions, sludge that is easy to dewater to sludge that is difficult to dewater can be dewatered with sufficient time and pressure. In addition, the pressure on the outlet side is the filter cloth tol? +6), (
7) The tension and dewatering resistance caused by the drive of the rotating bell (14) is sufficiently larger than that at the inlet.

[Another example]

Next, another example will be described.

The form of dehydration in the forced dehydration section (B) l (C) l (D) can be changed as appropriate, such as by combining 7 types or a suitable plurality of types. In short, a pair of filter cloths (8 )
It is sufficient if there is a configuration in which the cake 03) is dehydrated by driving and rotating the l +7+ along a stuttering path by five or more closely arranged rolls (12g) and (t2b). In addition, the first and second gravity dehydration sections (AI),
Omit (A2) and rotate the bell so that the cake θ barrel, which has been pre-dehydrated using a separate device, is fed to the filter cloth +611 (7)? When (14) is wound into a roll, roll (12b)
Both filter cloth tel + +6), (7) for 3 or more of
It is sufficient if it is wound from the outside of the rotating belt (
I4) may be driven by the filter cloth (7), and the rotating bell (+4) may be in the form of a net, a film with small holes, or any other water-permeable structure.

The object of dehydration treatment and the purpose of treatment may be any.

[Brief Description of the Drawings] Fig. 1 is a schematic diagram showing an embodiment of the present invention, and Fig. 2 is a schematic diagram showing an embodiment of the present invention.
It is an enlarged view of the main part of the figure. FIG. 3 is a schematic diagram of the main parts of a conventional example. +61 # (7) --- Filter cloth, (12a), (
12b) -... Roll, +131... Cake, α4)... Rotating belt. Agent Patent Attorney Kitamura Shukan

Claims (1)

[Claims] A pair of endless belt-shaped filter cloths (6) and (7) are attached to the filter cloths (6) and (7).
), (7) with the cake (13) sandwiched between them, and
It is provided so as to be freely driven and rotatable while being wound around the rolls (12a) and (12b), and in cooperation with the rolls (12b), it pinches and presses the cake (13) between the two filter cloths (6) and (7). The dewatering device is equipped with a water-permeable rotating belt (14), in which five or more of the rolls (12a) and (12b) are moved so that the filter cloths (6) and (7) follow a meandering path. The rotating belt (14) is arranged so as to contact only the lower one (7) of the filter cloths over almost the entire width thereof, and A dewatering device in which the filter cloths (6) and (7) are wound from the outside around at least one of the filter cloths (6) and (7).