KR101185126B1 - Complex dehydration apparatus - Google Patents

Abstract

PURPOSE: A complex dehydrating apparatus is provided to improve the treating efficiency of sludge by maximizing the separating effect of water and sludge cake and lowering the moisture content rate of the sludge cake. CONSTITUTION: A complex dehydrating apparatus includes a dehydrating unit ad a sludge pre-treating unit. The dehydrating unit includes a centrifugal dehydrator and a controller. The sludge pre-treating unit includes at least one of a lime water feeder and a crusher. The centrifugal dehydrator includes a cylindrical bowl(31), a conical scroll(33), a driving motor, and an auxiliary motor. The inclined angle of the conical scroll is 5 to 10 degrees to the bowl. A flight for discharging sludge cake is arranged at the outer circumference of the scroll. The controller operates the centrifugal dehydrator at the constant speed if the introducing concentration of the sludge is highly changed. The controller operates the centrifugal dehydrator such that the pre-determined amounts of sludge and polymer are supplied unless the introducing concentration of the sludge is highly changed.

Description

Complex Dehydration Apparatus

The present invention relates to a complex dehydration apparatus, and more particularly, to a complex dehydration apparatus for efficiently dewatering the sludge accumulated on the floor of a waste water purification facility.

In general, sludge builds up over time at the bottom of facilities that contain water, such as dams, wastewater treatment plants, and water purification plants. The sludge is periodically removed to prevent contamination of fresh water.

The dehydration apparatus used in the prior art includes a sludge storage tank for injecting and storing raw water to settle the sludge, a chemical supply device for supplying chemicals to the sludge, a belt type dehydrator for dewatering the medicine and agitated sludge, and a cake treatment after dehydration. Device.

The belt type dehydrator winds the dehydration belt on the outer surface of the pressure roller disposed in a multi-stage inside the predetermined chamber, compresses the sludge introduced into the dewatering belt rotated by the pressure roller, dehydrates the water contained in the sludge, and then And to remove by cake.

By the way, the above conventional dehydration apparatus has the following problems.

First, since the conventional dehydration apparatus does not have a process for pretreating sludge introduced into the belt type dehydrator, for example, when the sludge has many organic substances, there is a problem in that the moisture content of the cake increases and odor occurs.

Second, the conventional dehydration device does not filter out contaminants contained in the sludge, thus supplying raw water into the device. Frequently occurred.

Third, the conventional belt type dehydrator has a large installation area because of the washing water pump, the air compressor, the coagulation tank, the dehydrator, and the like, and has a poor working environment such as odor or dust.

Fourth, since the conventional dehydration apparatus cannot cope with the change in the sludge concentration, problems such as overloading of the dehydrator, decrease in moisture content, and the use of excess chemicals occur according to the concentration of sludge introduced.

Fifth, the cake having a high moisture content generated due to the problems described above caused odor and leakage due to excessive moisture when stored in the cake processing apparatus.

In this regard, the present applicant has filed and registered the Korean Patent Application No. 10-2009-0106406 'Compound Dehydration Device' as a technology for solving the above problems. The present invention can be operated in accordance with the concentration or torque of the sludge flowing into the centrifugal dehydrator by variable operation of the internal dehydrator to the pump PID or torque PID, it is possible to put the optimum amount of chemicals, significantly lower the moisture content and central It is possible to control from 24 hours of continuous automatic operation is characterized in that.

However, the following problems occurred as a result of operating the technology applied to the actual water treatment plant wastewater facility. For example, in order to improve the water content of the centrifugal dehydrator, the condensation and cake of sludge in Paul should be discharged while reducing the vehicle speed.However, if the vehicle speed is reduced, a portion of the sludge introduced after a certain time is included in the desorbed filtrate. There was a problem that the degree of pollution continued to deteriorate.

The present invention has been made in view of the above-described prior art, and an object of the present invention is to provide a complex dewatering device with high sludge treatment efficiency.

The composite dehydration apparatus according to the present invention for achieving the above object includes a dewatering unit including a centrifugal dehydrator and a control unit for centrifuging sludge into cake and filtrate, and a sludge pretreatment unit for pretreatment before supplying sludge to the dewatering unit. In the complex dewatering device, the sludge pretreatment unit includes at least one of a lime water feeder and a crusher, the centrifugal dehydrator is a cylindrical scroll and a conical scroll that rotates relative to each other within the Paul and the drive motor for rotating the scroll With auxiliary motor, the inclination angle of the conical scroll has 5 to 10 degrees with respect to Paul.

In addition, the scroll of the composite dewatering device according to the present invention includes a flight for discharging the sludge cake on the outer peripheral surface, the pitch of the flight is between 20 to 30% of the cylindrical pole diameter.

In addition, the dewatering unit of the complex dehydration apparatus according to the present invention further includes a sludge supply pump, a sludge feeder having a flow meter and a concentration meter, and a polymer input device having a flow meter, wherein the control unit has a large change in inflow concentration of the sludge While operating the centrifugal dehydrator at constant speed, the densitometer and flow meter are sensed to meet the specified total solids throughput, and the sludge feed pump is controlled by controlling the sludge feed pump based on the detected data. While driving to supply a certain amount, the drive motor torque of the Paul and the auxiliary motor torque of the scroll is sensed and the torque of the auxiliary motor in the centrifugal dehydrator in accordance with the torque change to drive control.

In the composite dehydration device according to the present invention, the inclination angle of the scroll is about 5 to 10 degrees and the pitch of the flight is limited to 20 to 30% of the diameter of the cylindrical pole to facilitate the transport of the inorganic sludge and to separate the water and the sludge separation effect. Sludge treatment efficiency can be improved by maximizing and significantly lowering the water content of the cake.

1 is a view schematically showing a complex dehydration apparatus according to an embodiment of the present invention.
2 is a view schematically showing a centrifugal dehydrator of the complex dehydration apparatus according to an embodiment of the present invention.
Figure 3 is a cross-sectional side view of the centrifugal dehydrator of the complex dehydration apparatus according to an embodiment of the present invention.
4 is a flow chart showing the dehydration operation of the complex dehydration apparatus according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view schematically showing a complex dehydration apparatus according to an embodiment of the present invention.

Referring to the drawings, the complex dewatering apparatus of this embodiment includes a sludge pretreatment unit 10, a dewatering unit 20, and a post-treatment unit 40.

The sludge pretreatment unit 10 detects the amount of the sludge contained in the raw water supplied to the dewatering unit 20 and the degree of contaminants in advance, so that the lime water feeder 11 can supply the sludge of a certain property to the dewatering unit 20. And a crusher 15.

The lime water feeder 11 adds lime water to the storage tank 1 when the sludge flowing into the sludge storage tank 1 contains a large amount of organic matter, thereby improving the organic matter in the sludge to improve dewatering ability. If lime water is added, since the reactivity and sedimentation with the flocculant supplied from the dehydration unit 20 is improved later, the amount of organic chemicals can be reduced and the specific gravity of the sludge can be increased. The lime water feeder 11 includes a lime water storage tank 12 for dissolving and stirring calcined lime at a predetermined ratio with industrial water, and a supply pump 13 for supplying quantitative lime water. The sludge storage tank 1 may further include a stirrer 2 for storing wastewater sludge introduced into the dehydration apparatus of the present invention to equalize the concentration, and mixing the lime water with lime water as necessary.

The crusher 15 crushes contaminants such as vinyl, waste wood, fish and shellfish in the inlet sludge, and prevents device failure in a later process. Since the crusher 15 may use a conventional crusher or crusher, detailed description thereof will be omitted.

The dewatering unit 20 is a polymer for supplying a polymer such as a sludge feeder 20A for supplying the sludge introduced through the dehydrator 30, the crusher 15 to the dehydrator 30, and a flocculant for mixing with the sludge. Feeder 24.

The sludge feeder 20A is for sending the sludge deposited in the sludge storage tank 1 to the dehydrator 30 by a predetermined amount. The sludge feeder 20A includes a pump 21 for supplying sludge, a variable device 22, a densitometer 23, and a flow meter 24.

The polymer feeder 20B serves to aggregate and crosslink by supplying an organic chemical (polymer) to the sludge. The polymer feeder 20B includes a dissolution tank 25 including a stirrer for storing a polymer, a pump 26, a variable device 27, a flow meter 28, and the like.

The dehydrator 30 is for separating the sludge mixed with the polymer and separating the sludge into the dehydration cake and the filtrate. In this embodiment, a centrifugal dehydrator using a simple equipment, a small installation area, and easy automatic control is used.

The centrifugal dehydrator 30 is provided with an outer cylinder Paul 31 and a scroll 33 installed inside the Paul 31 as shown in an enlarged view in FIG. 2. Paul (31) receives a rotational driving force through the drive motor 32, one side is provided with a sludge inlet 34, the bottom surface is provided with a cake outlet 35 and the filtrate discharge (36). Paul 31 is rotatably installed on the base platform, the bearing (not shown) and the vibration preventing member is installed.

The scroll 33 is installed on the opposite side of the sludge inlet 34 so as to be relatively rotatable with the Paul 31. The cone-shaped scroll 33 receives rotational force from the auxiliary motor 38 including the gearbox 37. The spiral flight 39 is provided in the outer periphery of the scroll 33, and the cake liquid-separated by this flight 39 is conveyed to the cake discharge port 35, and is discharged | emitted. The solid-liquid separated filtrate overflows the side wall of the paul 31, and is collected and discharged to the filtrate discharge port 36. In addition, the centrifugal dehydrator 30 includes a bearing temperature sensor, a vibration sensor, and the like as a safety device.

The inclination angle of the conical scroll 33 has an angle of about 5 to 10 degrees. If the inclination angle of the scroll 33 is less than 5 degrees, the length of the scroll becomes relatively longer than the length of the cylindrical portion of the paul 31, and the processing capacity becomes smaller, resulting in economic efficiency. In addition, if the inclination angle of the scroll 33 exceeds 10 degrees, incompressible water purification plant sludge (inorganic sludge) is difficult to discharge the sludge smoothly continuously along the inclined surface, causing the congestion between the cylindrical portion and the cone portion is blocked. Becomes Therefore, it is desirable that the inclination angle of the scroll 33 be as small as possible to facilitate the transport of sludge and maximize the separation effect of water and sludge.

Table 1 below shows the dehydration performance test results according to the inclination angle of the scroll.

Tilt angle and dehydration performance test result (water treatment plant) Tilt angle Moisture content (%) Tally filtrate concentration (mg / l) Capacity (m3 / hr) Remarks  Less than 5 degrees 69-74 30 to 60 12  5 to 10 degrees 69-74 30 to 60 20  Greater than 10 degrees 78-83 250-500 20 Cake discharge blockage

As shown in Table 1, when the inclination angle of the scroll 33 is less than 5 degrees, the water content and the concentration of the desorption filtrate are excellent, but the treatment capacity is relatively small. When the inclination angle exceeds 10 degrees, the treatment capacity Although excellent in water content and the concentration of the desorption filtrate, it can be seen that the cake discharge blockage occurs.

On the other hand, the pitch P of the flight 39 provided on the outer circumference of the scroll 33 is dense so as to maintain the discharge time as long as possible to improve the dryness of the cake. For this purpose, the pitch of the flight is preferably about 20 to 30% of the inner diameter of Paul 31. This pitch has the effect of reducing the moisture content by increasing the depth of the cake layer accommodated between flights (wings) to obtain a blocking effect with water. If the pitch is less than 20% of the Paul's inner diameter, the distance between the plates is narrow, which makes the sludge cake deep but inefficient due to the small amount of sludge cake accommodated. In addition, if it exceeds 30%, the distance between flights is increased, and the depth of sludge cake is lowered, and the water content is not improved and the water content is not improved. In this case, separate baffles should be provided between Paul and the scroll to block the water and the sludge cake.

Table 2 below shows the dehydration performance test results according to the pitch of the flight.

Pitch and Dewatering Performance Test Results (Water Treatment Facility) Flight pitch Moisture content (%) Tally filtrate concentration (mg / l) Capacity (m3 / hr) Remarks  Less than 20% 69-74 30 to 60 15 Cake discharge blockage  20-30% 69-74 30 to 60 20  Greater than 30% 78-83 320 to 600 20

* Pitch is percentage of Paul diameter.

As shown in Table 2, when the pitch of the flight 29 is less than 20% of the diameter of the Paul, the water content and the concentration of the desorption filtrate are excellent, but the treatment capacity is relatively low, and the cake discharge clogging occurs. When the concentration exceeds 30%, the treatment capacity is excellent, but the water content and the concentration of the desorption filtrate are high.

Meanwhile, the aftertreatment unit 40 includes a feeder 41 for transporting the sludge cake discharged from the dehydrator 30, a powder lime feeder 42, and a storage passage 43.

The feeder 41 is for transferring the dehydration cake solid-separated from the centrifugal dehydrator 30 to the storage cell 43, and a conventional screw conveyor can be used.

The powder lime feeder 42 adds powder quicklime to the dehydrated cake to cause a chemical reaction, thereby reducing the moisture content of the cake and stabilizing (eliminating toxicity and solidifying) during the post-treatment. As shown, the powder lime feeder 42 may be introduced in the middle of the feeder 41 so that the powder lime feeder 42 may be efficiently stirred with the dewatering cake while moving the feeder 41.

The storage cell 43 is for storing the dehydrated cake for a certain period of time, which can improve efficiency at the time of external discharge, and can reduce water content, disinfect, solidify, and reduce odor by securing a reaction time between quicklime and dehydrated cake. . The finished sludge cake can be used as a soil improver.

The components of the present embodiment as described above may be interlocked and automatically operated through the controller 50. Details will be described later.

Then, the dehydration operation of the composite dehydration device of the present embodiment having the configuration as described above will be described with reference to FIG.

When the raw water is supplied to the sludge storage tank 1 through the inlet pipe, sludge contained in the raw water is settled in the storage tank 1, the water overflowed in the storage tank 1 is discharged to the outside. When the sludge has a large amount of organic matter, the lime water is supplied to the sludge storage tank 1 through the lime water feeder 15 and mixed with the stirrer 2 (S100). The sludge settled on the bottom of the storage tank 1 is supplied to the crusher 15 through a transfer pipe to remove bulky contaminants (S200).

Subsequently, the lime water and the stirred sludge are supplied to the centrifugal dehydrator 30 through the pump 21 of the sludge supply unit 20A, and at the same time, the polymer such as the coagulant is also centrifugal dehydrator through the pump 26 of the polymer supply unit 20B. S30 is supplied to (S300). The sludge is sensed and controlled in the control panel 50 through the densitometer 23 and the flow meter 24, and likewise, the polymer is also sensed and controlled through the flow meter 28.

When the centrifugal dehydrator 30 first starts a high speed rotation at 2000 to 3000 rpm, the sludge and the polymer are supplied into the Paul 31 through the sludge inlet 33. As the flocs become larger and the sedimentation effect is improved by the reaction, the sludge is solid-liquid separated into the dehydrated cake and the filtrate (S400). Increasing the rotational speed of Paul increases the G value normally felt in the gravitational field to about 2000-3000, and the sludge rapidly solidifies and attaches the dehydration cake to the outer wall. Is discharged to outside. For example, the dewatering cakes are discharged to the outside through the cake outlet 35 by the flight 39 of the scroll 33, and the filtrate overflows the drain hole near the sludge inlet 33 and then through the filtrate outlet 36. Discharged.

Here, the centrifugal dehydrator 30 is a pump PID operation (proportional integral derivative control) for controlling the sludge supply pump 21 by using the concentration meter 23 and the flow meter 24 of the sludge feeder 20A and the auxiliary motor of the dehydrator. 38) Variable operation may be performed through torque PID operation using torque (S410, S420).

In the pump PID operation, the control unit 50 detects the densitometer 23 and the flow meter 24 so as to meet the predetermined total solids throughput (Kg.DS / hr), and controls the sludge supply pump 21 based on the detected data. It is to control the sludge feed amount and also to control the polymer feed amount accordingly. This operation method is suitable when the inflow concentration change of the sludge is large, and the centrifugal dehydrator 30 operates at a constant speed.

Torque PID operation, the control unit 50 detects the torque of the driving motor 32 of the Paul 31 and the torque of the auxiliary motor 38 of the scroll 33, the auxiliary motor 38 in the centrifugal dehydrator 30 in accordance with the torque change. ) Is to control the torque of the vehicle. This operation method is suitable when the sludge inflow concentration change is small. During operation, a certain amount of sludge and polymer is supplied, and the rotational speed of the scroll 33 is controlled according to the situation in the dehydrator. For example, if the amount of dehydration cake in the dehydrator 30 is large, the speed of the scroll 33 is increased. If the amount of dehydration cake is small, the speed of the scroll 33 is lowered so that the settling and separation time is long.

The dewatered cake discharged from the centrifugal dehydrator 30 is transferred to the storage cell 43 through the feeder 41, and at this time, by adding powder quicklime to the dehydrated cake through the powder lime feeder 42, a chemical reaction occurs. , Stabilizing the moisture content of the cake and post-treatment (S500).

The dewatering cake of the storage cell 43 is stored for a period of time and reacted with quicklime to reduce moisture content, disinfection, solidification, and odor reduction, and then disposed of through a vehicle (S600).

1 .. sludge storage tank 10 .. sludge pretreatment unit
11..lime water feeder 15.crusher
20. Dewatering unit 20 A. Sludge feeder
20B. Polymer feeder 21. Sludge feed pump
23. Density meter 24. Flow meter
30. Dehydrator 31. Paul
32. Drive motor 33. Scroll
38.Secondary motor 39.Flight
40. Aftertreatment unit 42. Powder lime feeder
43..between storage

Claims (3)

A dehydration unit comprising a centrifugal dehydrator and a control unit for centrifuging sludge into a cake and a filtrate;
The sludge pretreatment unit includes at least one of a lime water feeder and a crusher, and the centrifugal dehydrator is provided with a cylindrical scroll and a conical scroll that rotates relatively within the Paul, a drive motor and an auxiliary motor for rotating the scroll and the scroll, respectively. The inclination angle of the conical scroll has 5 to 10 degrees with respect to Paul,
The scroll includes a flight for discharging the sludge cake on the outer circumferential surface, the pitch of the flight is between 20-30% of the cylindrical pole diameter,
The dewatering unit further includes a sludge feed pump, a sludge feeder having a flow meter and a concentration meter, and a polymer input device having a flow meter. The sludge feed rate is controlled by sensing the densitometer and flow meter according to the throughput, and controlling the sludge feed pump based on the detected data, and when the sludge inflow concentration change is small, the sludge and polymer are operated to supply a certain amount, A composite dewatering device, characterized in that for detecting the drive motor torque and the auxiliary motor torque of the scroll to control the torque of the auxiliary motor in the centrifugal dehydrator according to the torque change. delete delete

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