JP2003117599A - Sludge treating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sludge treating equipment which flocculates sludge by using a flocculating agent and dewaters the sludge. SOLUTION: (1) In this sludge treating equipment for dewatering the sludge stored in a sludge storing vessel by sending the sludge to a flocculation agitating vessel, adding the flocculating agent to the sludge in the flocculation agitating vessel and sending the sludge mixed with the flocculating agent in the flocculation agitating vessel to a sludge dewatering machine, a batch operated treatment of sending the sludge by as much as the specific capacity of the flocculation agitating vessel to the flocculation agitating vessel, mixing the sludge with the flocculating agent in the flocculation agitating vessel to send all of the corresponding capacities to the sludge dewatering machine after the flocculation reaction attains a prescribed state is adopted to complete the flocculation reaction in the one flocculation agitating vessel. (2) The number of revolutions of the agitating vessel is fluctuated so as to attain the optimum agitating conditions by effectively utilizing the batch treatment process. (3) A corrosion system flocculating agent to permit the direct charging of the flocculating agent each by a fixed amount to the flocculation agitating vessel is used as the flocculating agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge treatment device, and more particularly to a sludge treatment device for aggregating sludge with a coagulant and dewatering the sludge.

[0002]

2. Description of the Related Art Regarding the process of supplying sludge from a sludge supply device to a coagulation and sludge dewatering device in a conventional sludge treatment device, a similar technique is described in Patent Publication Nos. 169891 and 169892 of 1999. It demonstrates using. First, the supply of the coagulation aid composed of the polymer coagulant will be described. The flocculation aid stored in the flocculation aid storage tank 110 is supplied to the flocculation aid mixing tank 112 through the flocculation aid injection pump 111. The coagulation aid mixing tank 112 has a stirrer 112a inside the tank, and a coagulation aid injection pipe 113 and a sludge transfer pipe 122 at the upper part of the tank. In this coagulation auxiliary agent mixing tank 112, the coagulation auxiliary agent injection pipe 113 is connected to the coagulation auxiliary agent injection pump 111, and the coagulation auxiliary agent supplied from the coagulation auxiliary agent injection pipe 113 is added to the sludge supplied from the sludge supply pump 120. The sludge is mixed at a ratio selected according to the concentration and properties of the sludge and stirred by the stirrer 112a.

Next, the supply of the coagulant made of polyiron chloride will be described. The stock solution coagulant tank 101 stirs and stores the coagulant stock solution with a stirrer 101a. A stock solution coagulant pump 102 for discharging the stock solution coagulant solution is provided in the stock solution coagulant tank 101, and a discharge port of the stock solution coagulant pump 102 is connected to a coagulant automatic dissolution tank 104. The coagulant automatic dissolution tank 104 includes a clean water transfer pipe 130 and a clean water solenoid valve 131.
Has an inlet communicating with the stock solution coagulant pump 102 and an outlet communicating with the stock solution coagulant pump 106, and discharges the clean water supplied from the clean water transfer pipe 130 and the stock solution coagulant pump 102. Undiluted solution and flocculant automatic dissolution tank 104
In the agitator 104a inside, the mixture is mixed and the coagulant storage tank 106
Send to.

Next, the operation of the flocculant mixing tank 109 will be described. The coagulant mixing tank 109 is the coagulant storage tank 106.
The coagulant sent from the pipe through the pipe is mixed. A coagulant injection pump 1 for discharging the coagulant is provided in the coagulant storage tank 106.
No. 07 is provided, and the discharge port of the coagulant injection pump 107 communicates with the coagulant mixing tank 109 by piping. As the coagulant injection pump 107, a fixed-quantity discharge pump is used, and the coagulant mixing tank 1 is controlled by a controller.
The coagulant in an amount corresponding to the sludge supply amount to 09 is supplied to the coagulant mixing tank 109. The sludge mixed with this coagulant is sent from the outflow pipe 150 to the dehydrator 160.

The coagulant automatic dissolution tank 104, the coagulant aid mixing tank 112 and the coagulant mixing tank 109 are provided with water level gauges for detecting the storage amount, and the stock solution coagulant pump 102 is provided with the float switch 103 and the coagulant. The injection pump is provided with a float switch 108, and the sludge supply pump 120 is provided with a float switch 121, which are controlled by the controller based on their detection outputs and the like.

For dewatering, a 160 multi-plate outer shell type screw dewatering machine, a screw press type dewatering machine or the like is used as the dewatering machine, and the sludge mixed with the coagulant is dewatered to obtain a water content of 8
Make a dehydrated cake of 5% or less.

[0007]

As described in the section of the prior art, a polymer flocculant is generally used in the flocculation step of sludge treatment. Had to be mixed and supplied in the coagulation stirring tank immediately before the coagulation reaction occurred. Therefore, at the stage of supplying the coagulant, the apparatus is complicated and the operation mode is also complicated. Further, in order to mix the sludge with the coagulation auxiliary agent and further mix the coagulant, only a method of providing two coagulation stirring tanks and continuously flowing it was possible. Therefore, it is necessary to control the agitator by providing two agitation stirring tanks, which complicates the apparatus. But,
Regarding the sludge treatment device, install it in a small scale,
It was often driven, and it caused many problems in terms of maintenance and maintenance personnel and cost.

[0008]

In order to solve the above problems, the inventor of the present invention has found means for simplifying the apparatus.

As described in claim 1, sludge stored in the sludge storage tank is sent to a coagulation stirring tank, a coagulant is added to the sludge in the coagulation stirring tank, and the sludge mixed with the coagulant in the coagulation stirring tank is sludge dehydrated. In the sludge treatment device that sends the sludge to the machine and feeds it in the specified volume of the flocculation stirring tank, mix it with the flocculant in the flocculation stirring tank, and after the flocculation reaction reaches a predetermined state, sludge dehydration of the entire volume The flocculation reaction is completed in one flocculation and agitation tank by performing a batch-type process of sending the flocculation to the machine.

Further, as described in claim 2, a coagulant capable of directly adding the coagulant to the coagulation stirring tank is used. According to the third aspect of the present invention, in the present invention, rapid stirring is performed at the stage of supplying the sludge to the coagulation stirring tank by performing batch processing.
When the flocculation progresses, it is slowly stirred, then left standing for a while, and at the stage of supplying it to the sludge dehydrator, the rotation speed of the stirrer is changed so that it becomes the optimal stirring condition at the stage of the slow speed stirring and the batch treatment process. I am trying. As described in claim 4, a humus-based coagulant is used as the coagulant capable of directly adding the coagulant to the coagulation stirring tank in a fixed amount. As a particularly preferable humus-based flocculant, in the present invention, a trade name “Papyrus No. 525” manufactured by MC Kinsan Co., Ltd. was used.

[0011]

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described below with reference to the drawings and tables. FIG. 1 shows a schematic diagram of the sludge treatment device of the present invention. The sludge treatment device 1 includes a surplus sludge dewatering unit 2, a raw garbage input unit 3, and a fermentation unit 4. The excess sludge dewatering unit 2 is composed of a sludge storage tank 10, a coagulation stirring tank 13, and a sludge dewatering machine 16, and the sludge cake taken out from the sludge dewatering machine 16 was sent from the crusher 5 of the garbage disposal section 3. Along with the crushed raw garbage, it is sent to the fermentation device of the fermentation section 4 through the screw conveyor 6 and processed. Further, it may be directly delivered as compost without using the fermentation section 4.

The present invention relates to the excess sludge dewatering section 2. Therefore, the range will be described in detail. The sludge is temporarily stored in the sludge storage tank 10. The sludge is sent from the sludge storage tank 10 to the sludge supply / transfer pump 12 through the sludge supply / transfer switching valve 11. Sludge supply / transfer pump 1
2 supplies sludge to the coagulation stirring tank 13. When the water level gauge 14 detects that the sludge is full, a fixed amount of the coagulant is fed from the fixed amount feeder 15 and is stirred by the stirrer 13 a attached to the coagulation stirring tank 13. The agitation is controlled such that rapid agitation is performed during sludge supply and coagulant addition, and slow agitation operation agitation is stopped and agitation is allowed to stand during a flocculation reaction. By adopting a humus-based flocculant, which is a natural agent, as the flocculant, it is possible to ensure the safety of the produced compost.

Further, the form of the aggregating agent is one kind of powder,
The coagulant does not need to be mixed, and the equipment is simplified as compared with the equipment disclosed in the conventional art. Next, after coagulation is completed in the coagulation stirring tank 13, the sludge supply / transfer switching valve 11
And the sludge supply / transfer pump 12 is operated to send the coagulated sludge to the sludge dehydrator 16. Sludge dehydrator 16
Uses a twin-screw screw press system. As a feature, it uses a Teflon-made twin-screw opposed screw, so that it can be conveyed without a large co-rotation of the propulsive force with respect to the slurry-like one. As a measure to prevent clogging, it is devised such as adopting a deformed bar screen on which a well-drained cylinder slides. Excess sludge is contained from the coagulated sludge sent using the sludge dehydrator 16 with a water content of 85%.
Dehydrate to the following: The sludge cake produced by dehydration is sent to the fermentation device of the fermentation section 4 via the screw conveyor 6 and processed. Further, it may be directly delivered as compost without using the fermentation section 4.

Next, the operation of each device of the excess sludge dewatering unit 2 of the present invention will be individually described. The sludge supply / transfer pump 12 has a function capable of operating in both directions of sludge supply operation and transfer operation by rotating the motor in the forward and reverse directions with respect to the coagulation stirring tank 13. At the same time, it also has the function of controlling the motor speed by inverter control and adjusting the sludge supply and movement amount. Manual operation or automatic operation can be switched, but the operation speed can be freely set with the inverter. During automatic operation, it operates based on the operation time chart. Although it is the stirrer 13a of the flocculation stirring tank 13, it is possible to change the operating speed such as rapid, slow, stationary, slow and slow depending on the stage of flocculation. Each speed can be freely set by the inverter. Manual operation or automatic operation can be switched, but during automatic operation, the operation time chart shows rapid stirring when sludge is supplied, slow agitation when coagulant is added, stationary, and slow speed operation when transferring coagulated sludge. Quantitative feeder for supplying flocculant 15
Similarly, the manual operation and the automatic operation can be switched, but during the automatic operation, the operation is performed when sludge is supplied and the timer is stopped when a fixed amount of the coagulant is supplied.

Similarly, the sludge dewatering machine 16 can be switched between manual operation and automatic operation. In manual operation, the sludge dewatering state can be adjusted by arbitrarily setting the motor shaft speed of the sludge dewatering machine 16 with an inverter. At the time of automatic operation, it is an automatic operation based on the operation time chart under the condition set by the inverter at the preselected motor shaft speed, and it is stopped by the timer after the completion of dehydration. The sludge supply / transfer switching valve 11, which switches the sludge supply / transfer, is opened during manual operation, when the sludge is supplied to the coagulation stirring tank 13, the sludge supply side is opened, and during transfer, the transfer side is opened. During automatic operation, it switches according to the operation time chart, and during supply, the supply side opens,
The transfer side is open during transfer. For the operation of each device,
Table 1 is an operation table for the excess sludge dewatering unit.

Table 1

The automatic operation will be described based on the operation time chart (FIG. 2) of the batch type excess sludge dewatering system.

In the standby process, the operation start timer is activated and the supply side of the sludge supply / transfer switching valve 11 is opened. Next, in the sludge supply step, the sludge supply / transfer pump 12 operates to supply the sludge to the coagulation stirring tank 13. At that time, the coagulation stirring tank 13
The agitator 13a of the first agglomerating and agitating tank 13 after starting to supply sludge
When the water level meter 14 reaches a medium level, it senses the water level and starts rapid stirring at the same time when the timer is activated. At the same time, the fixed amount of the flocculant starts to be fed from the fixed amount feeder 15 with the timer. The fixed-quantity feeder 15 is set with a timer, and stops after injecting the coagulant into the fixed-quantity coagulation stirring tank 13.

In the meantime, after the agitation stirring tank 13 is full and the timer for rapid stirring has timed up, the process proceeds to the slow stirring step, and the stirring machine 13a in the agitation stirring tank 13 uses a timer for a certain time as a stable aggregation action. Enter the slow stirring operation. At the same time, the sludge supply / transfer switching valve 11 is switched to an open state on the transfer side in preparation for supplying the sludge, which has completed coagulation, from the coagulation stirring tank 13 to operate the sludge supply / transfer pump 12 to supply it to the sludge dehydrator 16.

In the stationary step, the agitator 13 of the aggregating agitation tank 13 is used.
a is stopped, and the agitation stirring tank 13 is left as it is until the aggregating reaction is completed. In the dehydration step, the agitator 13a of the coagulation stirring tank 13 is switched to a slow speed operation by a timer, and the sludge supply / transfer pump 12 is operated to operate the coagulation stirring tank 1
The sludge is transferred from No. 3, and the stirrer 13a is operated at a very low speed, and at the same time, it is supplied to the sludge dewatering machine 16 which is in operation through the sludge supply / transfer switching valve 11. The stirrer 13a of the aggregating and stirring tank 13 that was being stirred at a low speed is stopped when the water level detected by the water level gauge 14 of the aggregating and stirring tank 13 shows a low level.

The sludge supply / transfer pump 12 is a coagulation stirring tank 1
When the water level gauge 14 of 3 indicates that there is no water level in the coagulation stirring tank 13, the sludge supply / transfer switching valve 11 is switched to open on the supply side, and preparation for the next batch process is started as a cleaning process.
After that, the timer of the sludge dehydrator 16 stops working. Although details will be omitted, after the sludge dewatering machine 16 is stopped, the timer operates and the cleaning device of the sludge dewatering machine 16 operates for a certain time and then stops. After that, the process returns to the standby process as the next batch process.

Next, various conditions of the batch type excess sludge dewatering system of the present invention will be described. First, as the humus-based flocculant used in the present invention, the product name "Papyrus No. 525" manufactured by MC Kinsan Co., Ltd. was used in the present invention. The amount used is about 0. 3 per batch process while the capacity of the coagulation stirring tank 13 is 0.4 cubic meter.
A 28 kilogram weight is used and it is charged in about 1.5 minutes using the quantitative feeder 15. In addition, the flocculation tank agitator 13a set by the inverter is 40
From 60 Hz to 60 Hz as a standard setting value of 45 Hz (45 rpm for agitator rotation speed), 15 to 4 during slow operation
0 Hz and the standard setting value is 25 Hz (the agitator rotation speed is 25 rotations / minute), and the rotation speed is 0 to 15 at low speed operation.
The standard setting value is 10 Hz (the rotation speed of the stirrer is 10 rotations / minute).

Regarding the time in each step, as shown in the operation time chart of FIG. 2, when the capacity of the flocculation stirring tank 13 is 0.4 cubic meters, the sludge supply step has 10 steps.
Minutes, slow stirring 5 minutes, standing time 5 minutes, dehydration step 9
It is 0 minutes, and the operation time of the sludge dehydrator 16 is 1
Including the operation time of 40 minutes after the completion of the sludge transfer of No. 3, it is about 130 minutes in total. Since the operating time of the sludge dewatering machine 16 is longer than the total of sludge supply, slow stirring, and stationary time, the start of transition from the standby process to the sludge supply process is set in anticipation of the sludge dewatering completion time.

[0024]

As for the excess sludge dewatering in the conventional sludge treatment, since it is a continuous type equipment as disclosed in the prior art, the coagulation reaction process can always be carried out only under constant conditions. . In the present invention, a method of supplying a certain amount of sludge to a flocculation stirring tank and varying the stirring speed rapidly, slowly, statically, and slowly until the flocculation process is completed batchwise, which is suitable for the performance of the flocculant. Thus, it was possible to carry out a steady aggregation reaction. Further, by doing so, the sludge dewatering machine can be kept in good operating condition by repeating the dehydration and washing cycle.

Regarding the coagulant, in the present invention, since a natural humus-based coagulant that can obtain the coagulation reaction by simply mixing and stirring the powder is adopted, the equipment is simplified and, as shown in the prior art, A tank and a stirrer that stir the flocculant found in the polymer flocculant and a pump that sends the flocculant, a tank and a stirrer that stir the flocculation aid, and also a flocculation aid in the mixing tank in the coagulation process with sludge. The problem that two tanks, a mixing tank and a coagulant mixing tank, are required, the process is complicated, the equipment cost is increased, and the operation and maintenance are complicated, is solved.

In comparison with the number of equipment, in the conventional equipment, a sludge supply pump, a coagulant storage, a tank coagulant injection pump, a stock solution coagulant tank and an agitator for a stock solution coagulant tank, a stock solution coagulant pump, a coagulant automatic dissolution tank and Stirrer for coagulant automatic dissolution tank, coagulant aid storage tank, coagulant aid injection pump, coagulant aid admixture tank and coagulant aid talker tank agitator, coagulant admixture tank and coagulant admixture tank agitator, sludge dehydrator While 15 points are required, the number of equipment required to increase the same processing capacity in the present invention is a sludge supply / transfer switching valve, a sludge supply / transfer pump, a coagulation stirring tank, a stirrer, a quantitative feeder, a sludge dewatering machine. 6 points and simplification is possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a sludge treatment device of the present invention.

FIG. 2 is an operation time chart relating to sludge treatment of the present invention.

FIG. 3 is an example of a schematic view of a conventional sludge treatment device.

[Explanation of symbols]

1 Sludge treatment equipment 2 Excess sludge dewatering section 3 Raw garbage input department 4 Fermentation Department 5 crusher 6 Screw Conveyor 7 Fermentation equipment 10 Sludge storage tank 11 Sludge supply / transfer switching valve 12 Sludge supply / transfer pump 13 Aggregation stirring tank 13a Stirrer 14 Water gauge 15 Quantitative feeder 16 Sludge dehydrator 101 Stock Solution Flocculant Tank 101a stirrer 102 Stock solution coagulant pump 103 flow switch 104 Flocculant automatic dissolution tank 106 Flocculant storage tank 107 Flocculant injection pump 108 Flow Switch 109 Flocculant mixing tank 109a stirrer 110 Flocculant storage tank 111 Agglomeration aid injection pump 112 Coagulation auxiliary agent mixing tank 112a stirrer 113 Agglutination aid injection tube 120 Sludge supply pump 121 flow switch 122 Sludge transfer pipe 130 Clean water transfer pipe 131 Water solenoid valve 140 treated water 150 outflow pipe 160 dehydrator

Claims (4)

[Claims] 1. A sludge treatment in which sludge stored in a sludge storage tank is sent to a coagulation stirring tank, a coagulant is added to the sludge in the coagulation stirring tank, and sludge mixed with the coagulant in the coagulation stirring tank is sent to a sludge dehydrator for dehydration. In the apparatus, a batch in which sludge is fed by the specified volume of the flocculation stirring tank, mixed with a flocculant in the flocculation stirring tank, and after the flocculation reaction reaches a predetermined state, the entire volume is fed to a sludge dehydrator A sludge treatment device that is characterized by performing a type treatment. 2. The sludge treatment device according to claim 1, wherein the coagulant is directly charged into the coagulation stirring tank. 3. The sludge treatment device according to claim 1, wherein the number of revolutions of the stirrer is changed for stirring in the coagulation stirring tank. 4. The sludge treatment device according to claim 1, 2 or 3, wherein a humus-type flocculant is used in flocculating the sludge.