JPH07265900A - Sludge treating device - Google Patents

Abstract

PURPOSE:To further enhance cost effectiveness and to eliminate the possibility of generation of secondary pollution by improving the efficiency of treating a large amt. of sludge and effectively utilizing the separated water discharged from a dehydrating stage. CONSTITUTION:A sludge press feeding pump 2, a reflux water feed-in pipe 4 for regulating a moisture content to >=30wt.%, a first stirrer 8, more preferably a pipeline stirrer, a flocculating agent supply pipeline 9, a second stirrer 11, more preferably a pipeline stirrer and an expanding pipe for pressure reduction are successively disposed at a sludge transporting pipe 3 from its inlet side. This sludge transporting piping is provided, on its outlet side, with a centrifugal-dehydrated solid separating means consisting of a dehydrated solid separating means, more preferably a centrifugal dehydrating machine loaded with freely attachable and detachable bag-shaped filter cloth and a transfer means for taking out this bag-shaped filter cloth and is provided with a waste water circulating system for returning the separated water discharged by this dehydrating means to the reflux water inflow pipe and a sludge generator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended for the purification and maintenance of the environment by rapidly treating a large amount of sludge such as accumulated sludge, industrial sludge sludge, slime discharged from construction sites, high water content sludge or bentonite drainage. The present invention relates to a processing device for contributing.

[0002]

2. Description of the Related Art As a technique for separating solids from the water content of various sludges containing industrial wastewater and domestic wastewater and disposing them as sparse bodies, that is, dehydrated solids, many proposals have been made and put to practical use. Has been done. Most of them consist of large fixed facilities such as large settling tanks, aeration tanks, digestion tanks, sludge separation tanks, etc.The separated water is discharged into rivers and sewers, and the separated solids are incinerated, composted, and landfilled. Since such equipment is disposed of as soil, etc., it is difficult to dismantle and relocate such equipment, so that it is not mobile enough to move from place to place depending on the sludge discharge place, and it takes a long time for treatment. It is common practice to transport dredged or trapped sludge to a treatment facility by a vacuum vehicle in order to adapt it widely to the treatment purpose and location, but it is enormous to transport the sludge containing a large amount of water by vehicle. Required, resulting in soaring processing costs.

As a measure for improving the above, for example, a jet grout method, an underground continuous wall method, and a Uragomer method, which have been widely used recently, a large amount of slime discharged from a construction site using water as a propellant, and a high water content sludge. Alternatively, for the purpose of economically treating bentonite wastewater and the like, an attempt has been made to continuously perform from the suction of slime to the dehydration treatment using a relatively small pipe. For example, in FIG.
In the conventional method as shown in Fig. 1, the slime 101 is pumped up by the pump 102 through the pipe 103, the hydrophobizing agent is pressure-inserted through the supply pipe 109, stirred by the on-line mixer 111, and then the bag-like filter cloth is stored in a net or the like. The double bags 118 are filled, and the bags 118, 118 ′, 118 ″, ... Which are filled one after another, are transported to a plaza having an appropriate space, suspended, and stored for a long time. Gravity gradually squeezes the free water, and the solid content is dehydrated to a state suitable for disposal in about one day and becomes a sparse body.However, even with such a process, the process up to disposal is still not completed. Not only does it require a long time, but also a large space for storing sludge-filled bags is required in the dehydration process, which is not always efficient and economical. From the dehydration process Since the discharged acidic or alkaline free water is discharged as it is out of the work place, there is a risk of secondary pollution, and it is not considered safe enough for environmental protection.

[0004]

Therefore, the problem to be solved by the present invention is that the treatment of a large amount of sludge is made efficient, and the drainage water from the dehydration process is effectively reused without being discharged to the outside of the work site. By doing so, the economic efficiency will be further increased and the concern about the occurrence of secondary pollution will be eliminated.

[0005]

According to the present invention, a sludge press-fitting pump, a water content adjusting means, a first stirrer, a coagulant adding means, and a second stirrer are arranged in this order from the inlet side of a sludge transfer path to the downstream side. The dehydration / sparse body separating means is provided on the outlet side of the transfer path, and the water separated from the dehydration / sparse body separating means is used as a water content adjusting means and a sludge generation source. It is a sludge treatment device characterized by having a drainage circulation system for recirculating the sludge.

The sludge transfer path is composed of a transportation pipe, and the water content adjusting means preferably supplies the reflux water so that the water content is at least 30% based on the total weight of the sludge according to the water content of the sludge to be press-fitted. It comprises a liquid feeding mechanism for feeding into the transportation piping.

Further, the water content adjusting means is preferably
An automatic control valve, which detects the water content of the sludge to be press-fitted and operates according to the detection signal, is provided in the reflux water inlet pipe.

The first and second stirrers are preferably
It is a static mixer installed in the middle of transportation piping.

The coagulant adding means preferably comprises a press-fitting mechanism for press-fitting the coagulant together with the fluid into the transportation pipe.

The apparatus of the present invention preferably further comprises, following the second stirrer, a solid content aggregating hydrophobic means comprising a mechanism for reducing the liquid pressure in the transportation pipe.

The dehydration / phosporus separation means is preferably
An upright type perforated basket drive type centrifugal dehydrator, a bag-like filter cloth having a size to be attached to the inner wall of the basket and having an upper opening, and a transport mechanism for taking out and transferring the bag-like filter cloth. .

[0012] The drainage circulation system is preferably the dehydration /
It comprises a reflux pipe and a liquid feed pump for collecting the separated water discharged from the lyophobic body separating means and returning it to the water content adjusting means and the sludge generating source.

When the sludge is slime, high water content sludge or bentonite drainage discharged from a civil engineering construction site that uses a large amount of water as a propellant, such as the jet grout method, underground continuous wall method, and Uragomer method, it is separated. The sludge generation source that recirculates water is a construction water tank.

Since the device of the present invention having the above-mentioned structure has a relatively simple structure and is easy to dismantle and relocate, it is possible to efficiently and economically process a large amount of sludge everywhere. In a preferred embodiment, the cake-like dewatered sludge suitable for disposal can be obtained, for example, within 10 minutes or less, and the separated water is recycled to the sludge moisture content adjusting step and reused for coagulation. A significant reduction in the amount of chemicals used is achieved, and separated water is used as a propellant for sludge generation sources, such as construction water tanks or jet grout construction methods, underground continuous wall construction methods, and Uragomer construction methods. Recycling back into the tank allows for a significant savings in the water consumed by such methods. Further, since the sludge treatment system is not used as a closed cycle to discharge the separated water to the outside of the work site, there is no possibility of secondary pollution.

[0015]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a flow sheet of the most preferred embodiment of the device of the present invention. The sludge 1 is pumped up by a sludge injection pump 2 from a lake, a river, a sewage or the like, which is a source of the sludge, and is sent to a transportation pipe 3 which is a sludge transfer route. When the water content of the sludge fed is less than about 30% based on the total weight of the sludge, the coagulation effect in the next step is low and it is difficult to hydrophobize, so that the water content is first increased through the water content adjusting means. The water content adjusting means is composed of a nozzle provided in the middle of the transportation pipe 3 and a reflux water inlet pipe 4 into which the reflux water from the final step is pressed by a pump. In this case, raw sludge is sampled and measured, and when the water content is less than about 30%, it is about
An appropriate amount of water is continuously injected from the reflux water inlet pipe 4 in accordance with the amount of sludge fed so that the amount becomes 30% or more, preferably about 40% or more.

Further, a water content detecting means 5 for detecting the water content of the sludge near the entrance of the transportation pipe 3, and an arithmetic circuit 6 for comparing and operating the detected concentration and the standard concentration to calculate an appropriate water supply amount. It is extremely preferable to provide an automatic water supply amount control system, which is provided in the middle of the return water inlet pipe 4 and is composed of an automatic control valve 7 that operates by receiving a signal from the arithmetic circuit.

Then, following the water content adjusting means, the first
A stirrer 8 is provided. The sludge whose water content has been adjusted may be once dropped into a tank and stirred with a normal rotary blade type agitator, or may be subjected to a turbulent agitation action through a spiral pump or the like in a transportation pipe. Most preferably,
As shown in the figure, it is a line mixer 8 known as a so-called online mixer or static mixer, that is, a static mixer in which a large number of flow path inverting elements are arranged in series in the pipe.

A nozzle for adding a coagulant to sludge homogenized at an appropriate concentration with a water content of 30% or more is provided in the transportation pipe on the downstream side of the first stirrer 8, and to this nozzle. And a coagulant supply line 9 for press-fitting the coagulant together with the fluid medium.
When the fluid medium is a liquid such as water, and the flocculating agent is dissolved or dispersed and supplied to the liquid medium, press-fitting is performed by the pump 10, and when the powder flocculating agent is conveyed by a gas fluid such as air, an air compressor. Press in with compressed air with the help of (not shown). Further, in the case of a powder flocculant,
It may be fed by pressure with a screw feeder.

Examples of the coagulant having a high cohesive force include inorganic acidic coagulants such as aluminum sulfate and aluminum chloride, inorganic basic coagulants such as sodium aluminate, polyaluminum chloride and low basicity aluminum, and aluminum sulfate and poly There are inorganic amphoteric flocculants combined with aluminum chloride and polyacrylic acid aminoesters, diaminediamide, organic polymer flocculants such as sodium alginate, etc., but the organic polymer flocculants are sparse cakes finally obtained. Since it remains inside and shows tackiness and tends to prevent the cake from separating and collapsing, it is not preferable depending on the purpose of the subsequent disposal of the cake, and the inorganic flocculant is preferably applied. Most preferably, the present inventor
Used in the coagulation separation method of water suspension proposed in No.
Autoset aluminum coagulant "Mukiflock
^TM "is applied. In addition, this flocculant is a cement-based solidifying material, or a solidifying material in which an appropriate amount of gypsum is mixed,
For example, as a representative example, "Autoset (registered trademark) solidifying material" manufactured by Autoset Co., Ltd. is used, and the weight ratio of the solidifying material to the coagulant is 1/1 to 1/5, preferably 1/2 to 1 /.
Applying at a ratio of 4 gives very satisfactory results,
The sparse substance cake from which the free water is separated retains water moderately, loses its adhesive and cohesive properties, and can be easily handled as general residual soil.

The sludge to which the flocculant has been added is then added to the second sludge.
The mixture is stirred by the stirrer 11 and homogenized. At this time, the sludge may be once dropped into a tank and agitated by an ordinary rotary blade type agitator, or may be agitated by a spiral pump or the like in the transportation pipe. Most preferably, like the first stirrer, a line stirrer 11 known as a so-called online mixer or static mixer is applied.

The mixture of sludge and flocculant is homogenized in the second stirrer and immediately reacted, and the suspended solids in the sludge rapidly form flocs of solids in the transport pipe and further grow into coarse particles. Begins to settle. Next dehydration /
Although it may be transferred to the sparse body separating means, it is preferable to go through the solid content aggregating hydrophobic means prior to the transfer. Such a solid content aggregating hydrophobic means has a pipe diameter of the transport pipe, for example, a different diameter joint 12
It is embodied by interposing a reducer 13 enlarged and formed in the pipe. The liquid pressure of the sludge is reduced by the reducer 13 to reduce the flow velocity,
The flocculation and sedimentation are promoted, facilitating the dehydration separation in the next step.

The precipitate and the free water discharged from the transportation pipe are transferred to the dehydration / sparse substance separating means arranged at the pipe outlet. A conventionally known continuous type or batch type centrifugal filter or centrifugal dehydrator can be applied to the dehydrating / sloppy substance separating means. Moreover, you may suspend and dehydrate using the filter cloth accommodated in the well-known net. However, the most efficient, versatile, convenient and suitable means suitable for carrying out at a construction site, a limited work area, or a remote mountain area is an upright perforated basket-driven centrifugal dehydrator. And a bag-shaped filter cloth having a size capable of being attached to the inner wall of the basket and having an opening at the upper side, and a transport mechanism for lifting the bag-shaped filter cloth together with the dehydrated cake, taking it out of the basket, and transferring it in the lateral direction. .

The centrifugal dehydrator in the dehydration / sparse substance separating means has a built-in upright type perforated basket 14 and a motor-driven rotating shaft 15 for rotating the basket 14 at a speed of at least several thousands of revolutions per minute. And a drainage port 17 at the bottom of the casing 16. The basket 14 has a size which is inscribed on the inner wall surface thereof, and is formed by a filter cloth and has an opening at the top, that is, a bag-shaped filter cloth 18 is attached to the inner peripheral surface and accommodated therein. The bag-like filter cloth 18 is formed of a cloth that is water-permeable but impervious to fine particles of sparse material, for example, a filter cloth made of a woven fabric or a non-woven fabric having a dense structure made of natural or synthetic fibers, and includes a hook 19 on the upper side. Mechanism, for example,
It can be lifted by a hoist, crane, etc., and further moved in parallel. As a material for the cloth, cellulosic fibers such as cotton, hemp, and viscose staple are easily decomposed by corrosion and incinerated after use, and non-woven fabric is preferable in terms of filtration performance and cost. It goes without saying that this filter cloth should be designed to be water-permeable but have a fabric weight that does not allow permeation of sparse particles, and to have sufficient strength to withstand the load of the treated sludge contained therein.

When the inhibition valve 20 at the end of the outlet of the transportation pipe is opened and a proper amount of sludge is injected into the centrifugal dehydrator and the rotary shaft 15 is driven, the sludge is separated into separated water and a sparse body layer in advance, Water is rapidly discharged from the bottom drainage port 17 of the casing 16, and by continuing the operation for several minutes, substantially all of the particle external liquid, that is, the liquid adhering to the particle surface, the wedge liquid, and the capillary rising liquid are separated, and the bag body In 18, the sparse material cake, which retains the liquid in the particles but whose volume is remarkably reduced, remains. When the state is reached, the centrifugal dehydrator is stopped, and at the same time, the bag-like filter cloth 18 and the sparse material cake are lifted by the hook 19 and further transferred to an appropriate storage place or a transportation means. The centrifugal dehydrator is loaded with a new bag to prepare for the next operation.

In a conventional centrifugal filter equipped with a filtering means such as a filter cloth, the filter cloth equipped in the centrifugal dehydrator has a significant decrease in filtration efficiency due to clogging caused by repeated use, and the cake produced is discharged. Although various efforts on the device and considerable labor are required for removing and removing the bag-like filter cloth, the bag-like filter cloth is disposable because the dehydrating / sparse body separating means of the present invention shows no reduction in filtration efficiency. Without this, the operation is completed in a short time, and it is easy to take out and convey from the centrifugal dehydrator. Furthermore, if the aggregating agent is an inorganic type such as "Mukifloc ^™ " or if it is used in combination with "Autoset (registered trademark) solidifying material", the sparse substance cake separated in this step will be cohesive nodule at all. It has the advantage that it can be treated as normal soil because it easily collapses without any treatment. Furthermore, compared to the conventional double bag suspension type self-weight-based squeezing method,
A sparse cake that can be disposed of in a short period of time can be obtained, and a large space for suspending and storing in a bag is not required.

One of the most important points of the present invention is that a drainage circulation system is formed by providing separated water recirculation means. That is, the separated water discharged from the bottom drainage port 17 of the centrifugal dehydrator is collected and temporarily stored in a storage tank 21 such as a tank or a pit, and is fed by a liquid feed pump 22 through a reflux pipe 23 to feed reflux water. The water is returned from the inlet pipe 4 to the water content adjusting means and also to the sludge generating source 24. In this case, the liquid feed pump 22 is
It functions as a reflux water injection pump to the transportation pipe in the water content adjusting means or as an infusion pump to the sludge generation source.

Since the separated water discharged from the dehydration / phobic substance separation means contains a considerable amount of unreacted coagulant, it is refluxed to the water content adjusting means and supplied to the sludge to adjust the water content. In this case, the amount of the coagulant added in the coagulant addition step may be a small amount for replenishing the consumed amount, and a significant saving of the coagulant is achieved.

A huge amount of slime discharged from a construction site that uses a large amount of water as a propellant, such as a so-called jet grout construction method, an underground continuous wall construction method, and a Uragomer construction method, and a high water content sludge. Alternatively, when the apparatus of the present invention is applied to the treatment of bentonite wastewater and the like, the separated water is recirculated to the construction water storage tank 24 and reused, so that a significant saving of construction water, which conventionally used tap water, can be achieved. Further, when sludge is discharged from the construction site as described above, the separated water is often biased to be alkaline. If the alkalinity is released beyond a certain level, it may cause secondary pollution in life or industry, but in the device of the present invention, the separated water is recycled and reused as construction water. Therefore, the separated water is not discharged at all and there is no danger of secondary pollution. In addition, in the case of sludge treatment of lakes, rivers, sewers, etc., the clear separated water is returned to the original sludge source, and in this case also, environmental pollution caused by being discharged to a place other than the sludge source. There is no fear of.

To summarize the preferred embodiment of the sludge treatment apparatus of the present invention, the sludge transport pipe 3 is provided with an inlet side of the sludge press-fitting pump 2 and a reflux water inlet pipe for adjusting the water content to 30% by weight or more. 4, a first stirrer 8, preferably a line stirrer, a flocculant supply line 9, a second stirrer 11,
Pipe line stirrer, large diameter reducer for decompression
13 are sequentially arranged, and on the outlet side thereof, dehydrated solid content separation means,
It is preferable to provide a dehydrating / loose substance separating means including a centrifugal dehydrator in which the filter cloth bag body 18 is detachably loaded and a transport mechanism for taking out and transferring the filter cloth, and the separated water discharged from the dehydrating / loose body separating means. Is a sludge treatment device comprising a reflux water inlet pipe 4 and a sludge generation source, for example, a drainage circulation system including a reflux pipe 23 for returning the sludge to a construction water storage tank 24 for construction using propellant water.

[0030]

As described above, the sludge treatment apparatus of the present invention is provided with the separated water recirculation means, and the separated water discharged from the dewatering / mesophobic body separation means is recirculated to the water content adjusting means and supplied to the sludge. Since it is reused for adjusting the water content, a significant reduction of the coagulant in the coagulant addition step is achieved. Further, the present invention is applied to the treatment of a huge amount of slime, high water content sludge, bentonite drainage, etc. discharged from a construction site that uses a large amount of water as a propellant such as the so-called jet grout method, underground continuous wall method, and Uragomer method. When the device is applied, not only can the huge transportation cost for transportation by the conventional vacuum vehicle be saved, but also the separated water can be reused as construction water by the drainage circulation system of the device of the present invention, Significant savings can be achieved on construction water, which previously cost tap water. Furthermore, since the apparatus of the present invention uses water as a closed cycle in this way, there is a great advantage that the separated water is not discharged to the outside of the work site at all and there is no risk of secondary pollution due to the discharge. In the most preferred embodiment of the device of the present invention, all of the sludge transfer and treatment from pumping of sludge to transfer to the dehydration / sparse body separation step are continuously carried out in the transport piping system, and in the dehydration / sparse body separation means. No decrease in filtration efficiency due to clogging of the filter cloth was observed, the operation was completed within a short time of less than 10 minutes, and the dehydrated sparsely-dispersed cake was in a state where the bulk and weight were significantly reduced. Therefore, it is easy to take out and convey from the centrifugal dehydrator. Further, since the sparse substance cake separated by appropriately selecting the flocculant is easily collapsed without causing cohesive agglomeration, there is an advantage that it can be handled as normal soil and is easily disposed. in this way,
Despite being smaller and lighter than conventional large-scale fixed sludge treatment equipment, it is possible to efficiently and economically treat large amounts of sludge everywhere, so-called small turning It is highly versatile, does not require a large processing space, and is suitable for use in construction sites, limited work areas, or in remote mountain areas.

[Brief description of drawings]

FIG. 1 is a flow sheet of a sludge treatment device of the present invention.

FIG. 2 is a flow sheet of a conventionally known sludge treatment device.

[Explanation of symbols] 1 sludge 2 sludge press-fitting pump 3 transportation piping 4 reflux water feeding pipe 5 water content detection means 6 arithmetic circuit 7 automatic control valve 8 first stirrer 9 coagulant supply pipeline 10 pump 11 second stirrer 12 Different diameter joint 13 Reducer 14 Upright type perforated basket 15 Rotating shaft 16 Casing 17 Drainage port 18 Bag-like filter cloth 19 Hook 20 Suppression valve 21 Storage tank 22 Liquid feed pump 23 Reflux pipe 24 Construction water tank

Claims (10)

[Claims] 1. A sludge injection pump, a water content adjusting means, a first stirrer, a coagulant adding means, and a second stirrer are connected in this order from the inlet side of the sludge transfer path toward the downstream side. A drainage circulation system is provided on the outlet side of the transfer path, wherein dewatering / mesophobic material separating means is disposed, and water separated from the dewatering / mesophilic material separating means is circulated to the water content adjusting means and the sludge generation source. A sludge treatment device characterized in that 2. The sludge transfer path is constituted by a transportation pipe, and the reflux water is transported by a piping so that the water content adjusting means has a water content of at least 30% based on the total weight of the sludge according to the water content of the sludge to be press-fitted. The sludge treatment device according to claim 1, further comprising a liquid feeding mechanism for feeding into the sludge. 3. The sludge treatment device according to claim 2, wherein the water content adjusting means detects the water content of the sludge to be press-fitted, and an automatic control valve which operates according to a detection signal is provided in the reflux water inlet pipe. 4. The static mixer in which the first and second agitators are incorporated in the middle of the transportation pipe.
Or 3 sludge treatment device. 5. The sludge treatment device according to claim 2, wherein the coagulant addition means includes a press-fitting mechanism for press-fitting the coagulant together with the fluid into the transportation pipe. 6. The sludge treatment device according to claim 2, further comprising a solid content aggregating hydrophobic means comprising a mechanism for reducing the liquid pressure in the transportation pipe, following the second stirrer. . 7. The dehydration / mesophilic material separating means comprises an upright basket driving centrifugal dehydrator having a hole, a bag-like filter cloth having a size to be attached to the inner wall of the basket and having an upper opening. The sludge treatment device according to claim 1, comprising a carrying mechanism for taking out and transferring the bag-shaped filter cloth. 8. A recirculation pipe and a liquid feed pump for collecting the separated water discharged from the dehydration / lysate separation means by the drainage circulation system and returning it to the water content adjusting means and the sludge generation source. Claims 1, 2, 3, 4, 5, comprising
6 or 7 sludge treatment device. 9. The sludge is a slime, a high water content sludge or a bentonite drainage discharged from a civil engineering construction site using a large amount of water as a propellant, and the sludge generation source for refluxing the separated water is a construction water tank. Item 8
Sludge treatment equipment. 10. A sludge transport pipe, a sludge press-fitting pump, a reflux water inlet pipe for adjusting the water content to 30% by weight or more, a first pipe agitator, a flocculant supply pipe, from the inlet side thereof. A second pipe line stirrer and a large-diameter reducer are sequentially arranged, and at the outlet side thereof, a centrifugal dehydrator in which a filter cloth bag is detachably loaded and a transport mechanism for taking out and carrying the filter cloth bag are carried out. A sparse substance separating means is provided, and a drainage circulation system is provided which includes the reflux water inlet pipe and the return pipe for returning the separated water discharged from the dehydrating / sparse substance separating means to the sludge generation source. Sludge treatment equipment that does.