JPS5927279B2 - Sludge dewatering equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to a device for dewatering sludge.

Increasing awareness of current pollution problems and the increasing amount of waste in industrialized society has created a demand for new wastewater treatment plants and an increasing demand for improvements to existing ones.

Applicant's U.S. Patent No. 3,743,100 (Patent: 197
No. 3, July 3, 1975, Title: Filter Press for Sludge Dewatering in Sewage Treatment Plants), and similarly titled U.S. Pat. A filter press is disclosed.

US Pat. No. 3,896,030 discloses a dewatering system that dewaters sludge by gravity.

In that patent, various known filter presses have a pre-dewatering section which is essentially a squeezing system, while in other cases the material on the filter belt is squeezed by rollers prior to a rotating drum system. It has been pointed out that

The filter press dewatering device described as prior art in this patent has the disadvantages of relatively low filtration efficiency, complex structure, and large space requirements.

The patent states that before the sludge reaches the rotating belt,
A novel dewatering device is shown with a pretreatment system of the type pressed between two filter belts acting as a squeezing device.

Since gravity dewaters most of the water, the amount of water contained in the sludge is reduced before entering the rotating drum system.

Other U.S. patent applications filed by the applicant entitled: Pre-Dewatering Method Based on a Continuous System of Filter Pockets include:
The advantages of partially dewatering the sludge prior to its treatment in a conventional filter press are discussed.

This system is effective in retrofitting existing sludge treatment systems and can be used in conjunction with the method and apparatus of the present invention.

The sludge can also be dewatered by a tower press used in this filtration process with two vertical filter belts pressed against each other.

This improvement to the filter press method described as prior art also does not give satisfactory results.

Regarding the development of drum filter press technology, efforts have been made in this area, but since only one filter belt is used throughout the entire dewatering process, the mesh size of the belt is determined by the maximum pressure used in the process. must be met, otherwise the filtered water resulting from the process will be extremely dirty.

It is true that the condition of sludge changes depending on the amount of water removed.

It is desirable to optimize filter size, pressure and pressurization time, and other conditions across all sludge conditions at each point in the entire process.

Such control is desirable because in a normal drum filter press, water is pushed out for a while, but when the pressure stops being applied, it returns to the sludge, and as a result, the final solid product cannot be obtained. be.

Failure to adjust factors such as time and pressure at each stage will result in less than optimal results.

The present invention provides a plurality of successive dewatering stages (dewatering section) which are independent of each other and have different sludge transport speeds, that is, the sludge is transported at different speeds, and the pressure decreases in each stage. ) provides a sludge dewatering method and apparatus.

Therefore, at each stage, the pressure increases sequentially and the sludge conveying speed decreases sequentially.

In the preferred embodiment of the invention, three processing sections (stages) are used.

The first processing section is a non-pressure dehydration section in which dehydration is performed by gravity, the second processing section is a medium pressure dehydration section, and the third processing section is a high pressure dehydration section.

In another embodiment, the sludge is treated in two dewatering sections, a first medium pressure dewatering section and a second high pressure dewatering section.

In another embodiment, the sludge is treated in two dewatering sections, a first medium pressure dewatering section and a second high pressure dewatering section.

In another embodiment, the sludge is treated with three dewatering sections where the pressure is constantly increasing and the treatment time is constantly decreasing.

The present invention relates to a new combination of continuous applications of dewatering sections, but also includes individual elements and subcombinations within its scope.

For example, when trying to use a drum filter press to treat sludge, it was necessary to use a drum filter press with a relatively complicated structure, but now it is possible to use a drum filter press that is inexpensive and has a simple structure. is possible.

It is also an object of the present invention to provide a high-pressure dewatering section that includes at least two endlessly rotating platen belts pressed against each other and two endlessly rotating filter belts extending into the platen belts.

Another important feature of the present invention is that a chamber for mixing sludge and flocculant is provided in the drum of the drum filter press.
It is one.

A feature of the present invention is that the dewatering sections at each stage are independent of each other and can be independently controlled and operated according to the condition of the fludge.

For example, the mesh size of the filter in the non-pressure dehydration section is made large, the mesh size of the filter in the medium pressure dehydration section is medium, and the mesh size of the filter in the high pressure dehydration section is made fine. I can do it.

Another feature of the invention is that the speed of the filter belt in each processing section can be different.

That is, the speed of the belt in each dewatering section can be adapted to the flow rate of the sludge in each dewatering section.

Furthermore, each dewatering section is equipped with pressure means such as rollers, plates or platens, which can be adapted to the condition of the sludge in each dewatering section to obtain the best form of pressurization.

Another feature of the present invention is that in each dewatering section, the sludge can be formed into a layer of arbitrary thickness according to its condition by adjusting the speed of the belt.

Furthermore, in the case of a type having three dewatering sections, the three dewatering sections can be combined depending on the state of the sludge and requirements.

For example, sludge with a large amount of solids and easy to dewater requires only a medium-pressure dewatering section using a drum filter press. It will be done.

The sludge, which is low in solids and easy to dewater, can be dewatered by a pressureless preliminary dewatering section combined with a drum dewatering section.

Sludge that contains a lot of solids and is difficult to dewater is treated using a combination of a drum dewatering section and a high-pressure dewatering section.

Sludge with a low solid content and which needs to be highly dehydrated is 3.
Dehydration is performed by a combination of two dehydration sections.

High-pressure dewatering sections may be added, depending on the possible expense, if the sludge needs to be discharged in the final dewatering section as containing very large amounts of solids.

Such an increase in the number of dewatering sections increases the same pressurization time in the final dewatering section, and the dewatering conditions correspond accordingly.

Dewatering with high-pressure dewatering plates or platens has the same effect as with the known discontinuous chained filter presses, which are very expensive and of complicated construction.

In view of the solid material obtained, the high-pressure dewatering section according to the present invention can be called a continuously operated chained filter press.

A disadvantage of known Chendo filter presses is their discontinuous mode of operation.

Of course, the Chendo filter press must convey the sludge containing few solids straight through the first processing section.
It is an expensive device simply because each dewatering treatment must be applied to the sludge afterwards.

However, if the sludge were to enter such a press with a solids content of, for example, 30% to 35%, multiple sealing means in the high pressure area would be unnecessary.

According to the present invention, the problem of sealing means is solved because the sludge is brought into such a state by the first two dewatering sections, namely the pressureless pocket filter and the medium pressure drum dewatering section, before entering the high pressure dewatering section. ing.

Another feature of the invention is that filtered water is produced independently in each dewatering section.

Obviously, the dry matter of the filtrate varies with the filtrate in each dewatering section, with the filtrate in the no-pressure dewatering section being virtually free of solids, and the filtrate in the medium-pressure dewatering section containing considerable solids. The filtrate in the high-pressure dehydration section contains a large amount of solid matter.

To give an example, the flow rate of filtrate in the pocket dewatering section is 7.35 m/h and in the drum dewatering section 1.35 m/h.
m', which is 0.3 m/hour in the high-pressure dewatering section.

Since these filtrate waters are generated independently, it is extremely effective to recirculate defective filtrate water from the high-pressure dehydration section and furthermore from the medium-pressure dehydration section from the viewpoint of saving coagulant.

The features of the invention are described in more detail in the following description of the examples.

In the example, it is assumed that the raw material is a sludge containing about 4% solids and the flow rate is 10 m'/hour.

In a preferred embodiment, the pressureless pocket dewatering section is the first
A flow rate of 10 m@3 per hour of sludge forming the dewatering section and containing 4% solids is converted here into a sludge containing 15% solids from which water has been removed at a rate of 7.35 rrl per hour.

The flow rate of the sludge at the discharge from the pocket dewatering section, i.e. at the inlet to the medium pressure dewatering section, is 2.65 m/hr.

Therefore, the medium pressure dehydration section has a relatively low speed and approximately 3
It is dehydrated to contain 0% to 40% solids.

In the case of 30%, the flow rate of sludge at the outlet of the medium pressure dewatering section is 1.3 m3 per hour.

Therefore, the filtered water here is approximately 1.35 m/hour.

If a sludge containing 50% solids is expected at the outlet of the high-pressure dewatering section, the sludge flow rate is approximately 0.80 per hour.
m' and that of the filtered water is approximately 0.5 m' per hour.

The reduction in total volume evident from the above makes it clear that, despite high flow rates, the time during which the pressurizing means acts on the sludge can be varied over a wide range.

Embodiments of the present invention will be described in detail below based on the drawings.

In the embodiment shown in FIG. 1, three independent dehydration processing sections are shown as a no-pressure pocket dehydration section A, a medium-pressure drum dehydration section B, and a high-pressure plate or platen dehydration section C. They are distinguished by dashed lines.

Reference numeral 1 is a mixing hopper for mixing sludge and flocculant therein.

After flocculation, the mixture of sludge and flocculant is sent along the line 2 to a rotating pocket filter 3 to a pressureless dewatering section.

The pre-dewatered sludge is delivered from the filter 3 to the outer filter belt 4 of the drum filter press.

The filter belt 4 first runs approximately horizontally across the water on the rollers 5.51.

At this time, a vibrator may be used to apply vibration to the belt 4.

After passing the roller 5', the filter belt 4 and the second filter belt 6 form a wedge-shaped entrance.

The belt 6 is wound around a spring-loaded roller 8 in the cleaning section γ.

The outer belt 4 and the inner belt 6 are mesh-like, and the mesh becomes thinner as the pressure in the drum dewatering section increases.

The drum dewatering section has a back belt that can withstand high pressure.
This belt consists, for example, of iron wire woven vertically into a horizontal steel bar.

Tensioners 9, 10 are used for the belt 6 and tensioners 11, 1
2 are provided for the belts 4, respectively.

The wedge-shaped entrance ends at the point where the belts 4, 6 begin to turn around the drum 13.

The drum 13 has a smooth outer peripheral surface and is driven by a motor 15 via a drive shaft 15 and a gear box.

Around the drum, there is a spring 1 in 15 directions inside the drum.
A pair of pressure rolls 16 biased at γ extend approximately half the circumference of the drum from the end of the wedge-shaped inlet.

Only two of these roll pairs are shown in complete form in the figure.

The sludge sandwiched between the filter belts 4 and 6 is therefore pressed by the pair of rolls 16 and the outer peripheral surface of the drum 13.

Following the roll pair 16, a roll group 18 consisting of three rolls is similarly arranged along the outer periphery of the drum 3.

Roll group 18 is biased toward the center of drum 13 by spring 19 and functions similarly to roll pair 16.

The additional roller 20 is arranged to form an equilateral triangle with other roller pairs, and has an independently adjustable spring 2.
1, it is biased towards the center of the drum 13.

After the belts 4 and 6 pass between the outer circumferential surface of the drum 13 and the roll pair 16 and roll group 18, their direction is changed by the roll 22, and they head in the opposite direction to the rotational direction of the drum 13, and then pass through the additional roll. 20 and another pair of rolls.

This further compresses the sludge.

After the belt 6 leaves its last contact with the roll 20,
It passes through the reversing roll 24, over the top of the additional roll 20, and returns to the wedge-shaped inlet.

A doctor or scraper 23 is provided on the roll 24 to prevent the belt 6 from carrying sludge.

The belt 4 is guided to a redirection roller 26.

This roll 26 is provided at a position to transfer the sludge from the medium-pressure dewatering section to the high-pressure dewatering section, and has a doctor or scraper 25.

The belt 4 is further connected to another direction changing roller 27 and roll pair 1.
6 and returns to the roll 5 via the cleaning section 28.

Before entering into the explanation of the high-pressure dehydration treatment section C, a more detailed explanation of the pressureless dehydration section A shown in FIG. 1 will be provided.

As can be understood from FIG. 1, the pressureless dewatering section is configured as a rotating belt type pocket filter.

Inside the casing 29 of the filter 3 is a rotating conveyor belt 30.
is provided, and this belt 30 is provided with a filter material 32
Or a tin rocket wheel 3 having a filter pocket 31 made of porous material and driven by a motor 35 via a sprocket wheel 33 and a drive belt 34.
3a.

As detailed later, the sludge should be placed in each pocket by arrow 3.
6, through the inlet 3γ of the casing 29,
sent.

The pocket belt moves from left to right in FIG.

At the lowest point of the wheel 33a, the dehydrating agent sludge moves onto the belt 4.

The wheel 33 need not be a hooked wheel like wheel 33a, but may be a cage whose bars engage between each pocket as the belt passes through the wheel 33.

Near the wheel 33, a sprayer 38 is supported by a plate 36a for cleaning the walls of the pocket 31.

The washing space is separated from the transfer area from the non-pressure dewatering section 3 to the filter belt 4 by a partition wall 39.

The filter holes in the wall of the pocket 31 are larger than the holes in the belt 4.6.

Further, the conveying speed of the pressureless dewatering section 3 can be independently and steplessly changed by the variable speed motor 35 so as to achieve the highest efficiency.

High pressure dewatering section C is shown in FIG. 1 as a device 40 called a plate or platen belt press.

In order to obtain maximum final dryness, the press 40 is required to apply high and reliable pressure to the sludge as quickly as possible.

From medium pressure dehydration section to high pressure dehydration section C doctor or scraper 2
The sludge transferred by 5 falls between the outer filter belt 41 and the inner filter belt 420 of the press 40.

Belt) 41 and 420 meshes are smaller than belt 4°6 meshes to suit the condition of the sludge.

The outer belt 41 includes three platen belts 44°45.
46 into the pinching part between two of them through the direction change roller 43, and reach the direction change roller 41 below,
From there it goes to the nip between the upper belts 45 and 46.

At the top of the belt 46 the belt 41 reaches a deflection roller 48 which has a doctor or scraper 49 and is finally in the position of discharging the dewatered sludge.

It is desirable to have the discharge location elevated, ie close to the top of the device, so that it can be loaded directly into a container or truck.

If a relatively high degree of solidification is required, the high-pressure dewatering section 40 can be increased as much as required, but in order to maintain the advantage of the high discharge position, two plates or platen belts may be used. It is desirable to add.

Another method is to extend the discharge location of FIG. 1 to serve as a transfer point to another high pressure plate press.

The belt 41 goes downward from the roll 48 to a redirection roll 50 having a tensioner 51, passes through a cleaning chamber 52 having therein a redirection roll 53 equipped with a tensioner 54, and then returns to the roll 43.

The inner filter belt 42 descends within the first clamping pressure section between the bells 44 and 45, and rises within the second clamping pressure section between the belts 45 and 46 by the roll 4γ.

At the discharge point the roll 55 is moved by a doctor or scraper 56
There is.

The belt 42 reaches the cleaning section 5γ from the roll 55.

The cleaning section 57 has rolls 5 each equipped with tensioners 60 and 61.
8,59 is located.

The outlet of the cleaning section 57 is located above the first clamping pressure section.

Details of this high-pressure dewatering section are shown in FIGS. 1, 2, and 8.

The device for applying high and positive pressure to the filter belts 4L42 receiving the sludge is constructed as rotating plates or platen belts 44, 45346, these belts being substantially identical, one of which It is shown in detail in the figure.

The plate or platen belt is attached to the spindle 63.64
It includes a plate 62 that rotates around zero.

For structural reasons, the plate is divided in the circumferential direction, and the overall width is as shown in Figure 8.
Determined by the number of each rotating plate belt.

A number of sprockets 65 meshing with the chain 66 and corresponding to the separation belt 62 are mounted on the spindle 63,64.

The plate 67 of the plate belt 62 is attached to the ring of the chain 66 and is formed of a metal plate with holes.

On one or both sides, each chain link is provided with a roll 68 running along a suppression plate 69 on the pressing side of the plate belt, i.e. on the side closer to the nip between the two plate belts.
has.

Plate 69 has separate guides or rails 10 for rolls 68 of each chino 66.

In addition, the press plate 69 supports the pedestals 1 arranged at appropriate intervals.
1 toward the associated clamping part.

This suppression can be achieved by a hydraulic or pneumatic cushion or by a reciprocating hydraulic actuator.

However, in order to simplify the construction, in the illustrated embodiment this is done by means of a strain-adjustable pressure spring IJ 72.

In the embodiment in FIG. 1, the two outer bells) 4
4 and 46 are pressed toward the belt 45 which is substantially fixedly arranged in the center by the suppression spring 12 mounted on a bolt 73 passing through the pedestal 71.

As is clear from FIG. 2, the plate belts 44-46 are commonly driven by the drive motor 14 and its gearbox 75, which motor can vary its speed steplessly.

The drive shaft 16 directly drives the central plate belt 45,
The two outer bells) 44, 46 are connected to the chain γ7. which engages the sprocket 79 of the drive shaft γ6. Driven by γ8.

A back belt can be added to all filter bells) 4, 6j, 41.42.

FIG. 2 also shows a motor 80 for driving the drum 13 of the drum filter press of the medium pressure dewatering section B.

As is clear from FIGS. 1 and 8, the liquid produced in the high-pressure dehydration section C is collected in the casing 81.

A water collecting gutter 82 is provided between the roll 41 and the belt 45, and since both ends of this gutter 82 are lowered, water generated in this area is combined with water from other areas.

The water collection gutter 82 is for preventing the squeezed water from flowing back into the sludge from the roller 47.

The anhydrous dewatering section is shown in FIGS. 1 and 4, and another embodiment is shown in FIG. 10.

As is clear from FIG. 4, the filter pockets with walls made of filter material or perforated sheet material are preferably provided in the form of conveyor belts or plate belts with an endless chain 83 mounted on sprockets 33, 33a. ,8
4 is supported.

The filter pocket 31 is fixed to the chain by a bar 85 so that it is substantially triangular in cross section.

The structure of this filter pocket belt can be quite simple - preferably chains 83, 84
The chain ring has rolls 86 on both sides thereof, which run along guides 87 at the top and along guides 88 at the bottom between the sprockets 33 and 33a.

Water collection play) 36a collects water generated from sludge in the horizontal direction (
(Fig. 4).

In the embodiment in Figure 10, the filter pocket dewatering section is simplified and can be used for sludges containing relatively near-solid objects, or where the requirements for the final solid material are less stringent. can.

In this embodiment, used in combination with a drum filter press, a packet wheel or drum 91 is housed within a casing 90 and rotated counterclockwise by a shaft 92.

The filter pocket 94 is arranged in a wedge-shaped space formed by the wall portion 93 and is formed of a filter belt or a metal sheet with holes, and both end faces are closed with a similar filter material.

The mesh of the filter is coarser than that of the filter belts 4 and 6.

The filter is designated at 95 in FIG.

The length of the drum 91 is equal to the width of the filter belts 4 and 6, and the drum 91 is driven by a motor (not shown).

It is desirable that the speed can be varied steplessly.

The drum 91 is completely contained within the casing 90 and its discharge point 96 is located above the filter belt 4.

The belt 4 is sloped slightly upwards in order to facilitate the drainage of the water resulting from the pre-drying between the rolls 5.5'.

Figures 3 and 5 to T show examples of drum filter presses constituting the medium-pressure dewatering section, and the features of each of these examples are that the inside of the drum 13 is used for sludge and coagulant. It is divided into additional reaction chambers.

There are two types of flocculants, and the difference between them lies in the reaction time with the sludge.

That is, there are flocculants that react quickly and flocculants that react slowly, and the interior of the drum is configured as an additional reaction chamber so that either flocculant can be used in the present invention.

Since the drum rotates in any case, the inside of the drum can be used without any expense.

The drum 13 thus has a reaction chamber 99 closed by side walls 97, 98, which has a partition 100 which is inclined in the direction of rotation of the drum and forms a transport pocket 101.

The drum 13 has a heavy membrane structure, with an inner shell 102 forming a reaction chamber 99 and an outer shell 103 made of a metal sheet with holes to receive water generated during the medium pressure dehydration stage. I'll put it in.

In order to remove water between the inner shell 102 and the outer shell 103 in one direction, the cylindrical space between the two membranes is divided at equal intervals by partition walls 104, and the partition walls 104 are provided diagonally in the circumferential direction. (See Figure 7).

The embodiments shown in FIGS. 3, 6, and 1 are illustrated in FIG.
However, in the embodiment shown in FIG.
A roll row 105 is provided above the filter belt 4.
, 6 runs on this.

This allows the drum to rotate in the opposite direction relative to the belts 4, 6, so that the sludge is subjected to wave-like movements and a very strong squeezing effect is exerted.

As is clear from FIG. 3, the sludge supplied from a sludge feed pump (not shown) is sent to the conical mixer 1 as indicated by the arrow 106, and the mixer 1 has a hollow shaft 108.
A stirrer 101 driven by a stirrer 101 is provided.

The flocculant is sent to the mixer 1 and mixed with the sludge, and the mixture rises and is sent to the reaction chamber 109 provided above the mixer 1.

The mixture passes through the hollow tube 110 of the drum 13 into the reaction chamber 99.
Since the drum 13 is rotating slowly,
The sludge and flocculant are given additional time to react.

A pocket 101 formed by a partition wall 100 brings the sludge to the top of the drum 13 where it is collected by a collection gutter 112 located close to the central axis of the drum.

The mixture of sludge and flocculant collected in gutter 112 is pumped through pipe 113 in the direction indicated by arrow 114.

The delivered sludge is sent to the pressureless pocket dewatering section in the embodiment shown in FIG.

In the embodiment described above, there are three independently operating dewatering sections A.
, B, and C are provided.

It is possible to use filters of optimum size that meet the sludge conditions in each dewatering section.

Also, as already mentioned, since the volume to be treated decreases continuously, even if there is a large amount of sludge at the beginning, the time during which the sludge is under pressure can be increased without a reduction in production. I can do it.

This is because most of the reduction in sludge volume occurs in the pocket dewatering section.

This feature is particularly important for high pressure plate dewatering sections.

Subsequently, the sludge is further dewatered by means of a filter belt at an appropriate speed and pressure taking into account the quantity to be dewatered.

Although not shown for simplicity, another important element of the invention is the recovery of the dirty liquid that is separated and squeezed out in each dewatering section.

Since this liquid contains excess flocculant, recovering it provides significant cost savings.

With pressureless pocket dewatering, the slight increase in the total volume to be dehydrated is virtually negligible.

Another feature not shown is that the clean water produced in the pressureless dewatering section can be used for washing.

Furthermore, since each dewatering section can be operated completely independently, a wide variety of combinations are possible, and similar dewatering sections can be added forward or rearward as required. be.

Figures 9 and 12 show examples of such combinations, and the one shown in Figure 1 is the one shown in Figures 9 and 12, with the dewatering part of the no-pressure pocket in the front and the high-pressure pocket in the rear. It is equipped with a dehydration section.

FIG. 9 shows only the medium-pressure dewatering section B, where the sludge is treated very simply for dewatering and the demands on the final solids are relatively mild, and are similar to those shown in FIG. Similarly, the emitting portion 115 is located at a high position.

Figure 10 shows a small pocket dehydrator.
Most of the water is removed here, and the drum filter press is driven at the appropriate speed and has an appropriately sized mesh filter belt.

In FIG. 11, depending on the sludge and final solids to be treated, a version without high-pressure dewatering section is shown.

FIG. 12 shows a combination of a medium pressure dehydration section and a high pressure dehydration section without a non-pressure dehydration section.

As is clear from the above, first of all, the present invention makes it possible to tolerate all changes in the state of the sludge during the dewatering process.

The combination of a pressureless pocket dewatering section and a high pressure plate dewatering section is of great importance to the present invention, as it allows the prior art, in which the treatment is intermittent, to be replaced by a continuous treatment plant.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal cross-sectional view of an apparatus consisting of three dehydration processing sections, FIG. 1A is a detailed side view of the high-pressure dehydration section shown in FIG. Figure 1 is a side view of the medium pressure dewatering section, Figure 2 is a plan view of the apparatus in Figure 1, and Figure 2A is a side view of the medium pressure dewatering section.
The figure is a rear view of the high-pressure dewatering section in FIG. 2, FIG. 2B is a side view of the first drive section of the high-pressure dewatering section in FIG. 2, FIG. 2C is a plan view of the medium-pressure dewatering section in FIG. The figure is a view taken along arrows ■-■ in FIG. 1, FIG. 3A is a partially cutaway plan view of the device shown in FIG. 3, FIG. Fig. 5 is a vertical side view showing an example of a drum filter press provided as a medium pressure dewatering section, Fig. 6 is a longitudinal side view showing another form of the drum shown in Fig. 5, and Fig. A partially cutaway front view of the drum, FIG. 8 is a view from the ■-X arrow in FIG. 1,
Figure 8A is a detailed view of the drive section of the device shown in Figure 8;
Figure B is a cross-sectional view in another plane corresponding to Figure 8;
The figure is a longitudinal side view showing an example of a drum filter press that constitutes a medium-pressure dewatering section, Fig. 10 is a longitudinal side view of a drum filter press equipped with a no-pressure dewatering section, and Fig. 11 is a side view of another type of no-pressure press. FIG. 12 is a longitudinal side view of a drum filter press with a dewatering section, and FIG. 12 is a longitudinal side view of an expandable device with a medium pressure dewatering section and a high pressure dewatering section. A: Non-pressure dehydration section, B: Medium pressure dehydration section, C: High pressure dehydration section, 1: Mixer,
3...Pocket filter, 4,6...
Filter belt, 13...Drum, 16...
...Pressure roll pair, 18...Pressure 0-ru group,
41, 42... Belt, 44, 45, 46...
...Platen belt.

Claims (1)

[Claims] 1. One or more preliminary dewatering means A are provided upstream of the drum filter press B, one or more high-pressure dewatering means C are provided downstream of the drum filter press B, and the drum filter press , a pre-dewatering means and a high-pressure dewatering means, forming successive dewatering stages, where each dewatering stage is independent, and the pressure applied to the sludge increases in each successive dewatering stage, A sludge dewatering device for sludge or similar materials, in particular for sewage or sewage treatment plants, characterized in that the relative velocity of the sludge passing therethrough is reduced and water is separated and removed in each dewatering stage. 2. The preliminary dewatering means A includes a plurality of pockets 31, 94 made of filter material to achieve pressureless dewatering of the sludge.
2. Apparatus according to claim 1, characterized in that it comprises rotating filter means having: 3. Apparatus according to claim 2, characterized in that the preliminary dewatering means A is a packet drum, the packets being formed by a plurality of pocket-shaped filter chambers 94. 4. The apparatus according to claim 2, wherein the preliminary dewatering means A includes the pocket-shaped filter chamber 31 as part of a rotating belt. 5. The high-pressure dewatering means C has at least two endless rotating platen belts 44 to 46 that are pressurized in the direction of engagement with each other, and two rotating filter bells 41 and 42 extend over the platen belts 44 to 46. It is growing,
5. Apparatus according to any one of claims 1 to 4, characterized in that these filter belts receive sludge from the drum filter press B on the inlet side of the platen belt. 6) three platen bells) 44, 45, 46 are provided forming two parallel constrictions and two outer belts 4
4 and 46 are pressurized in the direction of a stationary platen belt 46 in the middle, and each platen belt 44, 45, 46 has the same drive means, according to claim 5. equipment. 1. Each of the platen bells) 44, 45, 46 is rotated across a sprocket 65, and the tension between the sprockets on the pressure side is supported by a continuous pressure plate or pressure support 69, and the pressure grate 69 is Pressurized by a spring 72 acting on the bolt 13, the sprocket 65 is supported by a shaft 63, 64, a chain 66 is looped around the sprocket 65, and the platen belt 44, 45° 46
A platen (67) is secured to a link of said chain (66), said chain (66) link having a roller (68) rotating on said pressure plate or pressure support (69). The apparatus according to any one of items 6 to 6. 8 One or more preliminary dewatering means A are provided upstream of the drum filter press B, and one or more high pressure dewatering means C are provided downstream of the drum filter press B, and the drum filter press, the preliminary dewatering means and the high pressure The dewatering means forms successive dewatering stages, where each dewatering stage is independent, the pressure applied to the sludge increases in each successive dewatering stage, and the relative velocity of the sludge through each dewatering stage is In addition, the interior of the drum 13 of the drum filter press B forms a sludge and flocculant reaction chamber and a sludge and flocculant mixer 1.
A plurality of transport pockets 101 are provided in the reaction chamber, and the transport pocket 1
01 is formed by a transverse wall 100 inclined in the direction of rotation of the drum, and both upper regions of the reaction chamber are provided with troughs 112, the outlet of which is connected to the preliminary dewatering means A, the sludge is removed from the drum 13. introduced into the reaction chamber through the shaft,
Further, the sludge from the reaction chamber is discharged through the shaft of the drum 13 to the preliminary dehydration means A, and the sludge is discharged from the outer shell 103 of the drum 13.
A sludge dewatering device for sludge or similar materials, in particular for sewage or sewage treatment plants, characterized in that a laterally inclined wall guiding filtered water is provided between the inner wall of the reaction chamber and the internal wall of the reaction chamber.