JPS58212A - Dehydrating method for sludged matter - Google Patents

Abstract

PURPOSE:To improve a dehydrating effect of sludge, by press-dehydrating sludge after forming plural band-shaped rows of the sludge separated approximately parallelly by gaps. CONSTITUTION:Two endless filter-cloth belts 1 and 2 are arranged to a sludge feeding step A, a gravity filtration step B, a press-dehydration step C, and a stripping step D so as to run the belts in overlapped contact with each other and in a state of clamping the sludge between a group of pressing rolls 5 which forms the step C. Further, dividing jigs 13 to form rows of the sludge is provided to a part between from the step A to the step B. The jig 13 are made to form the sludge of breadth (b), built-up on the filter-cloth belt 2 of belt breadth (a), into a state of small divided rows of the sludge, that is; plural rows of sludge, divided small to the breadth (c) and separated parallelly by a gap (d), are formed. In such a way, improvements of the effect of dehydration and the effect of cake stripping condition, etc. are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides sludge generated from human waste, sewage, various industrial waste liquids,
The present invention relates to an improvement in a mud dewatering method for dewatering sludge and other difficult-to-filter muds generated from the water purification process of a water purification plant by pressurized dehydration using an r-cloth conveyance type such as a roll press.

Conventionally, in the cloth conveying type dewatering machine, from the sludge supply to the gravity passing process, the slurry is formed into a concentrated cake with a uniform thickness over the entire surface of the cloth.

Pressure dehydration is common. however.

With this conventional method, when it comes to models with large P cloths.

This model has the disadvantages of uneven moisture content in the middle direction, where the moisture content of the dehydrated cake is higher in the center of the P cloth, and a phenomenon where the average moisture content is higher than that of a small model. Ta.

The present invention attempts to solve these conventional drawbacks,
To provide a simple and useful method for eliminating non-uniformity of moisture content of a dehydrated cake in one direction of the cloth, and for obtaining a dewatering ability equal to or higher than that of a small one even in a model with a large F cloth.

The present invention is a method in which mud is conveyed with a single cloth belt and dehydrated under pressure, in which the mud is formed into a plurality of approximately parallel sludge bands separated by one interval, and then the mud is dewatered under pressure. This is a sludge dewatering method characterized by:

Next, to explain the present invention in terms of embodiments, Fig. 1 shows a roll press, which is a type of cloth conveying pressure dewatering machine, and two endless cloth belts 1 and 2 are passed through the sludge supply step A1 and the gravity e-passing step. B. A pressurized dewatering process C and a peeling process DK were arranged, and the sludge was sandwiched between the five groups of pressurizing rolls forming the pressurizing dewatering process C, and the sludge was run while being in polymeric contact with each other. It is something. In addition, a dividing jig 13 for forming a sludge row is provided in a part from the sludge supply process A to the gravity f passing process B, and this dividing jig 15 has a belt width a as shown in FIG. The sludge accumulated on the P cloth belt 2 with a width b i is divided into small sludge rows, that is, a plurality of small sludge rows with a width C are arranged in parallel with an interval d apart. be.

As the r-fabric belt 1, a water-absorbing or water-permeable belt such as a sponge belt is mounted endlessly on the roll 5 and the pressure roll 5 so as to be able to run.

In addition, roll a water-permeable to water-absorbent belt or a water-impermeable belt into a roll 4. Mounted on the pressure roll 5 so that it can run,
Each belt is tensioned with tension rolls 6.7 and is used as a roll press for contact polymerization between pressure rolls, and each belt is equipped with a cake peeling device 9.10 such as a knife or a doctor, and a cleaning device 11.1 for cleaning the belt. 12 is installed to serve as a trap to perform the filtration process well.

8 in the figure is a sludge supply box. In the specific example shown in Figure 3, the cloth belt 1 is reversed in the 1-gravity passing step B, and a dividing jig 13 is provided at the reversed portion, and the falling sludge is divided, so that the division resists resistance. This method effectively eliminates gravity dehydration. It is preferable that the cloth belt 2 has water absorbency or water permeability.

Thus, the sludge is first supplied to the sludge supply step A, and then subjected to gravity dewatering in the wind ripple step B.

Here, the sludge is divided into two parts using a dividing jig 13 installed between them.
As shown in the figure, the sludge is divided and formed into a plurality of parallel sludge rows spaced apart. After that, the sludge column is conveyed to the pressurized dewatering process C formed by pressurizing rolls 5, where it is pressurized and dehydrated with appropriate efficiency, and the resulting cake is peeled off and collected in the peeling process, thereby significantly improving the dewatering work efficiency. It is something that can be improved upon.

As mentioned above, in the present invention, the sludge is dehydrated not as one large plate-shaped sludge as in the conventional method, but as a plurality of rows of sludge divided into small pieces. The liquid can be effectively removed and an effective dehydration effect can be obtained.In other words, unevenness in the moisture content in the direction of the P cloth is eliminated, and a cake with a uniform moisture content can be obtained.

6- The moisture content can also be reduced by 3-7% on average.

In particular, models with a large F-dish cloth are effective, and the F-dish cloth is 2 m long.
The above is remarkable. This is because the difference between a model with a large dish towel and a model with a small dish towel becomes large, and if you dehydrate it by dividing it into 4 smaller dish towels, even a model with a large dish towel will have the same dehydration effect as a model with a small dish towel. It's for a reason. In addition, the peeling of the cake is improved, especially in the central part, which was previously bad, and the recovery rate is improved.Furthermore, the cake produced is thin plate-like, so it does not form large lumps and is extremely easy to handle.

In addition, in the present invention, the width c of each sludge row to be divided is 10
~15 octIL is desirable. If the width of the sludge row exceeds 2 m, the effect of school-up will be significant;
If it is less than that, it is not practical and should be avoided. In addition, if the interval d between strip-shaped sludge rows is too small, the sludge will disappear after pressurized dewatering, making the effect less effective, and if it is too large, unused space will increase, making it impractical. After pressure dewatering, there remains a gap = 7-2 for free water to be removed, for example, 1 to 20.

However, the size of the interval d varies depending on the extent to which the sludge spreads in the pressurized dewatering step C, so it goes without saying that it varies depending on the sludge and the dewatering conditions.

As a pressurized dehydration method for sludge, any F cloth conveyance type pressurized dehydrator may be used, but specific models include a roll press, a belt press, and the like. As the pressurizing means in the pressurized dehydration step C, a press plate of a press roll that can be moved above ground or below is used, and the press rolls may be disposed facing each other.

They may be arranged in a zigzag pattern. Further, the R cloth to be conveyed may be felt having a capillary action or may be a mesh R cloth. When using two or more r cloths, the same ones or different ones may be combined.

As the dividing jig 15, a tip having a semicircular, triangular or similar shape and widths matched to the interval dK is used, but division can be easily performed if the one dividing jig 13 is provided to the supply process person. However, it is better to lengthen the dividing jig 13 until it reaches the point at which the gravity dehydration is completed (when the dividing jig 13 is installed after the gravity dehydration is completed, it can be shortened, but if the dividing jig 13 is already semi-solid) Because of this, the resistance is large, so it is desirable to have a tip shape that reduces the resistance.

As described above, in the present invention, the sludge is divided into a plurality of small sludge rows and then dehydrated under pressure, which has the effects of improving the dehydration effect, improving the cake peeling state, and improving the handling of the cake. , and <KF It is possible to eliminate uneven moisture content in the direction of the cloth and prevent an increase in moisture content due to scale-up.
The large R cloth model has the advantage of producing a cake with the same moisture content as the small P cloth model.

Next, examples of the present invention will be shown.

Example 1 In a belt press type dehydrator of 310 countries, 0.5 g of cationic polymer was added per solid to sewage sludge with a solid concentration of 50 f/l, and the sludge was mixed in a mixing device. Supply amount 15 → 9- The sludge is supplied to the sludge supply process A with a supply amount of 2.7 m.

The sludge is spread over 2.7 m on the r cloth, and free water is removed in the 1 gravity r pass step B, resulting in 21 shrinkage sludge, which is spaced 10 times apart using this time-sharing jig. Five strip-shaped sludge rows each having 44 scratches are formed.

The sludge formed in this way is conveyed by F cloth, and is dehydrated under pressure in a pressurized dehydration step C to form a dehydrated cake, which is peeled off by a peeling plate. The cake produced here still had gaps of about two scratches.

This cake had an average moisture content of 69 inches, and there was almost no non-uniformity in the moisture content in the direction of the P cloth. Moreover, the cake peeling was also good, and the recovery rate was 99%.

On the other hand, in a conventionally known method, thickened sludge that has been gravity-dehydrated with the same supply amount using the same belt press is processed without dividing it.
When the sludge was dehydrated as a large plate of 2.7 m, the average water content of the resulting cake was 74%, and there was non-uniformity in the water content in the direction of the F cloth. The difference in moisture content was as much as 4% between the maximum and the 10-minimum, and the highest moisture content was found in the center of the fabric.

In addition, peeling at the center of the fabric F was poor and the recovery rate of 9 was 97%.

Also, for reference, using the same type of belt press with a P cloth 60 cm, the amount of solids fed to the f cloth teeth was the same (14
5≠88/m, h) K L ”C, sludge supply amount 44
When dehydrated in Step 3, the moisture content of the resulting cake was 70%.
Therefore, there was almost no non-uniformity in the moisture content in the width direction. The recovery rate was 99.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and Figure 1 is a vertical cross-sectional view 1, 1.
Figure '-2 is an enlarged sectional view taken along the line II in Figure 1, and Figure 3 is a longitudinal sectional view of a portion of another embodiment. 1.2...F cloth bell), 3.4...roll, 5...
・Pressure four-wheel, 6,7... tension roll, 8... sludge supply box, 9.10... cake peeling device, 11.
12...r cloth cleaning device, 13... division jig. A...Sludge supply process, B-Heavy filtration process, C...Addition-11-pressure dewatering process, D...Peeling process, a...Melt width, b
...In total sludge, C...In sludge row, d...Sludge row interval. Patent Applicant Ebara Infilco Co., Ltd. Agent Patent Attorney Go Hatayama 1) Minoru Japanese Patent Publication No. 58-212 (4) Figure 1 Figure 2 Figure 3 Figure 72

Claims (4)

[Claims] (1) In a method of transporting muddy material with a P cloth belt and dewatering under pressure, the muddy material is formed into a plurality of substantially parallel strip-shaped sludge rows with one gap spaced apart on the F cloth belt. A sludge dewatering method characterized by subsequent pressurized dewatering. (2) The dewatering method according to claim 1, wherein the gap is such that the sludge cake rows produced after pressurized dewatering do not come into contact with each other. (3) The r cloth belt is along its traveling direction. Sludge supply process 1 Gravity filtration process, pressure dewatering process. A stripping process is formed, and a plurality of strip-shaped sludge rows are formed and processed between the sludge supply process and the start of the gravity passing process or in the gravity passing process, or Dehydration method described in Section 2. 2- (4) The P cloth belt runs endlessly and includes at least a gravity filtration step. This gravity r passing process is reversed, and at this reversal part,
A dewatering method according to claim 1, 2, or 3, wherein the sludge is processed by forming a plurality of strip-shaped sludge rows.