JPS59180091A - Sludge supplying device for sludge dehydrating device - Google Patents

Abstract

PURPOSE:To simplify the structure to reduce cost and improve the dehydrating efficiency of the device by a method wherein supply of accumulated sludge from an accumulating tank to respective sludge dehydrating devices is effected by a volume type screw pump. CONSTITUTION:The accumulated sludge is supplied from the accumulating tank 1 to respective dehydrating devices I , II,...n directly and respective sludge supplying tubes 4 are provided with the volume type screw pump 5. The pump 5 is formed between the hollow part of twin-threaded screw of a stator 7 and a single-threaded type rotor 8, penetrated through the hollow part and rotated eccentrically under following the inner configuration of the hollow part. The sludge is transferred by the clearance 6' of a constant volume, which is moving spirally toward the delivery port 9' by the rotation of the rotor 8. According to this method, the transfer may be effected without pulsations and the sludge may be supplied to respective dehydrating devices without collapsing flocculated blocks in the sludge even when the flocculated sludge is transferred since no impact is applied to the substance to be transferred. Medical agent, such as flocculating agent or the like, effects secondary flocculation by aging the sludge under the transfer and reduces the degree of moisture of the sludge. In this device, a sludge supplying pump, a chemical agent pouring pump or the like is not necessitated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sludge supply device that supplies sludge to a plurality of sludge dewatering devices.

To dewater sludge in a sludge dewatering device, a flocculant is added to the sludge using a chemical injection device using a pump, etc., and the flocculated sludge is stirred rapidly or slowly in a flocculating tank depending on the properties of the flocculant. It is necessary to adjust and feed it to the dehydration equipment.

Therefore, even when dewatering is performed by operating multiple sludge dewatering devices, each dewatering device is equipped with a sludge supply pump, -2 = chemical injection device, and flocculation tank, and the flocculated sludge is adjusted for each dewatering device. Therefore, wiring, piping, etc. are complicated, equipment costs and maintenance costs are high, and operation management is also complicated. Of course, such problems can be solved by using only one chemical feeding device and flocculating tank for multiple sludge dewatering devices, but the conventional method of supplying sludge to dewatering devices is to use a flocculating tank for dewatering. The equipment is also installed in a high position, and the height difference is used to supply sludge from the coagulation tank to the dewatering equipment, so if you supply sludge from one coagulation tank to multiple dewatering equipment, the sludge will be placed near the coagulation tank. It is necessary to supply short piping to the dewatering equipment and long piping to supply the dehydrating equipment located far away, and the large sludge flocs formed in the flocculation tank are difficult to reach due to the steep slope of the short piping. If the pipe is long, it will collapse before it reaches the dehydrator, and it is difficult to make the dewatering efficiency of each dehydrator the same. Furthermore, since the sludge is supplied by overflowing from the coagulation tank, it is difficult to distribute it evenly to each dewatering device.

Unfortunately, with conventional sludge supply methods, it is difficult to distribute and supply sludge from one flocculation tank to multiple dewatering devices, and even if the same sludge is dehydrated, the distance between the flocculation tank and Because the dewatering efficiency of each dewatering device is not uniform due to differences in Although there were some problems, the main focus was on equalizing the dehydration efficiency of each dehydration device.

The present inventors researched a method for forcibly transferring sludge without collapsing the flocs instead of the conventional gravity flow method using a head, and found that when a positive displacement screw pump (commonly known as a snake pump) is used, the pipe line is long and the Even if there are many bends along the way, the flocs of sludge discharged from the outlet of the piping do not disintegrate, and conveniently, the water content of the sludge is maintained by using pipes of the same length. It was found that when the material was transported using the gravity flow method, the cost was also lower.

Based on the above knowledge, the present invention is designed to supply chemically injected flocculated sludge from one flocculation tank to multiple sludge dewatering devices, and to supply flocculated sludge from the flocculation tank to each sludge dewatering device using a positive displacement screw pump. In addition to solving the drawbacks of conventional sludge dewatering equipment that included a sludge feed pump, chemical dosing device, and flocculation tank, we also improved the dewatering efficiency of each sludge dewatering equipment. This will be explained with reference to examples.

1 indicates 6 collection tanks, and 11 .

The capacity of the flocculation tank is set to be larger than the conventional one depending on the number of dewatering devices so that sludge can be supplied to all the sludge dewatering devices. Although the dewatering apparatuses may be of different types, such as per-dove type, filter press type, or screw press type, it is preferable that all dewatering apparatuses that receive sludge supplied from one agglomeration tank be of the same type.

As shown in the figure, between the coagulation tank/and each dewatering device, connect the discharge pipe 2 of the coagulation tank to the header, and connect the slurry supply pipes 1 to each dewatering device to the header 3 in a branched manner. Alternatively, individual sludge supply pipes are connected to the coagulation tank l so that flocculated sludge is directly supplied from the coagulation tank to each dewatering device, and in either case, a positive displacement screw pump S? is connected to each slurry supply pipe l. establish.

Figure 2.3 shows an example of a positive displacement screw pump, which includes a stator 7 made of synthetic rubber and having a double-threaded hollow part 6 with an oval or oval cross section, and a stator 7 that passes through the hollow part of the stator and rotates eccentrically. The stator has a single threaded rotor gf with a circular cross section, and a gap 6' with a constant volume is formed in the hollow part of the stator between it and the rotor. It moves along the line and performs a pumping action,
It is discharged from the discharge port 9' of the tip pipe connected to the front end of the stator.

A rear cylinder 10 is connected to the rear end of the stator, and sludge is supplied to a supply port io' in the rear cylinder. In addition, the drive shaft // driven by the motor to rotate the rotor g is supported by a bearing in the rear bearing phase of the rear cylinder and protrudes into the rear cylinder, and the universal joint //a, / Connected to the rear end of the rotor via /bf.

6- Note that the stator 7 is vulcanized and molded on the inner circumference of a metal outer tube 7', and is integrated with the outer tube 7'.

In this way, a positive displacement screw pump is formed between a double threaded hollow part of the stator and a single threaded rotor that passes through the hollow part and rotates eccentrically according to the inner shape of the hollow part. Since the transfer is carried out in a gap 6' having a constant volume that moves in a spiral direction, there is no pulsation in the transfer and no impact is applied to the transferred object. Therefore, even if the flocculated sludge is transferred, the flocs in the sludge can be supplied to each dewatering device with almost no disintegration, and the flocculant and other chemicals added in advance by the chemical feeding device will mature during the transfer. Secondary flocculation is performed to lower the water content of sludge.

If there is an air reservoir between the discharge port of the screw pump and the outlet end of the mud supply pipe that opens to the mud supply section of each dewatering device,
Since the flocs will collapse there, it is preferable to make the space from the discharge port of the pump to the outlet end of the slurry supply pipe horizontal or slope upward to prevent air pockets from forming.

-7- Thus, according to the present invention, large-capacity coagulation tanks are used according to the number of sludge dewatering devices, and one sludge supply pump/,
At step 2, sludge is supplied to the coagulation tank L, and at the same time, the number of chemical injection ports corresponding to the number of types of flocculants to be added is supplied/g/3, L! The flocculated sludge can be fed to each dewatering device without disintegrating the flocculated sludge.

Therefore, if the sludge dewatering equipment is a combination type, for example, a positive displacement screw pump will be required, but only one sludge supply pump and flocculation tank will be needed compared to the conventional four, and the flocculation tank can be of two types, for example. When two types of flocculants were added using two chemical dosing pumps, the conventional method required g-level chemical dosing pumps and five agitators, but now only two dosing pumps and agitators are needed. .

Although the maximum length of flocculated sludge that can be transported under natural flow without floc collapse is 10 m at most, pipes of the same diameter (100A) are used, and elbows are installed in the middle.
Even when the bent portion was formed using a number of flocs, when the flocs were transported using an eccentric displacement screw pump, almost no collapse of the flocs occurred even when the transport distance was 21 Im.

In addition, the water content of the dehydrated cake was 11% when the flocculated sludge was transferred by gravity, but it was as low as go% when it was transferred using an eccentric displacement screw pump.

Although it is necessary to install a positive displacement screw pump for one of the sludge supply pipes leading from the sludge and flocculation tank to each dewatering device, only one flocculation tank is required, and the sludge supply pump, chemical feeder pump, and agitator It has the extremely advantageous feature that equipment costs and maintenance costs can be significantly reduced due to a significant reduction in the number of equipment required, and that the equipment is simple and operation management is also extremely easy.

[Brief explanation of the drawing]

Figure 1 is a flow sheet of an embodiment of the present invention, and Figure 2 is an example of an eccentric displacement screw pump. The vertical cross-sectional view shown in FIG. 3 is a cross-sectional view taken along the lll-1 line in FIG.
...n indicates a sludge dewatering device, l indicates a coagulation tank, t indicates a sludge feed pipe, and y indicates a positive displacement screw pump. −to

Claims (1)

[Claims] A sludge supply device that supplies flocculated sludge from one coagulation tank to a plurality of sludge dewatering devices, the sludge dewatering device being characterized in that the flocculated sludge from the coagulation tank is supplied to each sludge dewatering device using a positive displacement screw pump. sludge supply equipment to.