JP2002248493A - Sludge treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently solubilize sludge by simple and inexpensive constitution. SOLUTION: A rotor 2 is housed in a case 1 in a rotationally drivable manner. The case 1 has an almost cylindrical shape and has a sludge inflow port 11 and a sludge outflow port 9. The rotor 2 forms an annular space 18 between the outer peripheral surface thereof and the inner peripheral surface of the case 1. At least, a plurality of projected parts 17a, 17b and 17c or recessed parts 17d are formed to at least either one of the inner peripheral surface of the case 1 and the outer peripheral surface of the rotor 2. By this constitution, when the gap of the annular space is changed by rotating the rotor 2, cavitation is generated and cell membranes of microorganisms contained in sludge are crushed and solubilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge treatment apparatus for solubilizing sludge by crushing cell membranes of microorganisms contained in the sludge.

[0002]

2. Description of the Related Art Organic wastewater, such as sewage, domestic wastewater, and industrial wastewater, is treated by biological treatment equipment in sewage treatment facilities, septic tanks, industrial wastewater treatment facilities, and the like. In biological treatment equipment, surplus sludge such as sedimentation sludge generated in a final sedimentation tank and concentrated sludge generated in a concentrated sludge device is generated.

Conventionally, such excess sludge is solubilized by crushing cell membranes of microorganisms in the sludge by shearing, crushing, impact of a jet, ultrasonic irradiation, etc., and can be treated by the biological treatment equipment. And For example, Japanese Patent Application Laid-Open No. H11-128975 discloses a configuration in which sludge is solubilized using ultrasonic waves. Also, JP-A-11-147100
Japanese Patent Application Laid-Open Publication No. H11-176,086 discloses a configuration in which an alkali treatment is performed before an ultrasonic treatment to make it easier to solubilize sludge.

[0004]

However, in the above-mentioned conventional configuration, there is a problem that the apparatus becomes large and the cost is increased. In particular, in ultrasonic processing equipment,
The electric capacity of the ultrasonic vibration element alone is small (up to 1k
Since special material characteristics are required, a plurality of materials are required for sludge treatment, and the configuration is complicated. Also,
It requires advanced technology for operation, control, and maintenance, and operation management is not easy, resulting in increased costs.

Accordingly, an object of the present invention is to provide a sludge treatment apparatus capable of efficiently solubilizing sludge with a simple and inexpensive configuration.

[0006]

According to the present invention, as a means for solving the above-mentioned problems, a sludge treatment device is provided in a substantially cylindrical case having an inlet and an outlet for sludge. And a rotor rotatably housed in the case so as to form an annular space between the case and an inner peripheral surface thereof, and at least one of the inner peripheral surface of the case and the outer peripheral surface of the rotor. On either side, a plurality of at least one of the convex portion and the concave portion is formed,
Cavitation is generated by rotating the rotor to change the gap in the annular space.

[0007] According to this configuration, only by rotating the rotor in the case, the gap in the annular space changes due to the convex or concave portion, and cavitation can be easily generated. As a result, an excessive force acts on the microorganisms contained in the sludge flowing into the case and the cell membrane of the microorganisms is crushed, so that the sludge is easily solubilized.

[0008] Various structures can be employed for the projection, such as a ridge having a square cross section, a trapezoid, or a semi-elliptical cross section in the axial direction. Also, various structures such as grooves formed along the axial direction at equal pitches in the circumferential direction of the rotor can be adopted for the concave portions.

The case has an inlet formed at one end thereof, and the rotor has an impeller at one end located near the inlet of the case, without requiring any special device. Just by rotating the rotor,
This is preferable in that sludge can easily flow into the case.

When a guide vane is provided on the inner surface on one end side of the case on the outer peripheral portion of the impeller, the flow rate of sludge in the case can be efficiently converted to pressure, and the same pump shaft driving consumption can be achieved. This is preferable in that the pumping or pumping capacity can be increased.

[0011] It is preferable that the case is provided with a water-cooled jacket, because it is possible to reliably prevent the sludge from boiling and stopping its function before cavitation occurs.

[0012] If the projection or the recess is formed so that the position where cavitation occurs, that is, the standing position, does not reach the inner peripheral surface of the case including the convex or the concave portion and the outer peripheral surface of the rotor, vibration, noise, and the like are generated. While suppressing the occurrence of
This is preferable in that damage to components due to cavitation crushing can be prevented.

The standing position of cavitation is determined by the peripheral speed of the rotor (outer diameter and rotation speed of the rotor), the projected cross-sectional shape of the convex or concave portion, the surface roughness of the convex portion, the peripheral surface of the convex or concave portion. Directional pitch, axial length of rotor, length and arrangement of protrusions or recesses, radial gap of annular space, surface roughness of inner circumferential surface of case, convex portion on inner circumferential surface of case or The presence or absence of recesses, physical properties of treated sludge (type, viscosity, mass per unit volume, solids concentration, saturated vapor pressure, type of dissolved gas (air, methane, etc.) and components, etc.), temperature of sludge at the inlet, It is determined by pressure, flow rate, rotation speed, temperature and pressure of sludge at the outlet.

[0014] The convex portion is a plurality of ridges formed along the axial direction on the inner peripheral surface of the case and the outer peripheral surface of the rotor, and the ridges do not approach in synchronization with the case and the rotor. This arrangement is preferable in that vibration, noise, pulsation, and the like due to synchronous cavitation can be avoided.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 shows a sludge treatment apparatus according to a first embodiment. This sludge treatment apparatus is generally used in a configuration in which a rotor 2 is rotatably driven in a case 1 and is installed horizontally.

The case 1 includes a case body 3 and a case cover 4. The case body 3 has a bottomed cylindrical shape,
A shaft 6 penetrates through the center of the bottom surface via a mechanical seal 5 (may be another shaft sealing device such as a gland packing). The shaft 6 is rotatably supported by bearings 8a, 8b, 8c in a bearing case 7 provided in the case body 3, and rotational torque is transmitted from driving means (not shown) such as a motor via a coupling or the like. You. As the driving means, one having an easily adjustable number of revolutions, such as an induction motor with a thyristor inverter, is used. This is because sludge is a by-product of biological treatment, and its physical properties fluctuate due to fluctuations in the load of inflow sewage and sewage and fluctuations in the operating state of biological treatment.
This is to enable an operation that appropriately follows the fluctuation of the sludge fluid. An outlet 9 is formed on the bottom side wall of the case body 3 on the upper side of the case 1 installed horizontally. Legs 10a and 10b are provided below the case body 3 and the bearing case 7, and can be installed at desired locations. On the other hand, the case cover 4 has a central portion whose outer surface bulges in a cylindrical shape, and an inflow port 11 whose passage cross-sectional area gradually increases toward the inside is formed therein. Further, a drain plug 12 is provided on the case cover 4. The outlet 9 of the case body 3 and the inlet 11 of the case cover 4 may be formed in a plurality.

The rotor 2 comprises a rotor body 13 and a rotor cover 14. Rotor is ring 1
The rotation torque is transmitted from the shaft 6 to the shaft 6 by the key 16. As shown in FIG. 2, more specifically, FIG. 3, ridges 17 having a triangular cross section in the axial direction are formed on the outer peripheral surface of the rotor 2 at a constant pitch in the circumferential direction. The ridge 17 is an example of a projection according to the present invention.
An annular space 18 is formed between the outer peripheral surface of the rotor 2 and the inner peripheral surface of the case 1. The ridges 17 are finished with high precision so as to have the same shape in order to uniformly generate cavitation by rotation of the rotor 2. The pitch of the ridge 17 and the gap size of the annular space 18 are as follows:
It is determined that cavitation is generated by rotating the rotor 2 within a range that does not adversely affect the inner peripheral surface of the case 1, the outer peripheral surface of the rotor 2, and other ridges 17. In addition, the ridge 17 has a square shape indicated by 17a in FIG. 4A, a trapezoid shape indicated by 17b in FIG.
Various cross-sectional shapes such as a semi-elliptical shape shown by 17c in FIG. 4C can be adopted. Further, instead of the ridge 17, a concave portion according to the present invention, for example, a groove indicated by 17d in FIG. 4D may be formed.

Next, the operation of the sludge crushing apparatus having the above-described configuration will be described.

The rotor 2 is driven to rotate so that sludge flows from the inlet 11 of the case 1. When the inflowed sludge reaches the annular space 18, the flow direction is changed in the circumferential direction by the rotation of the rotor 2. In the annular space 18, the movement of the ridges 17 locally increases the flow velocity in the circumferential direction. Then, as the flow velocity increases, the local pressure decreases, and cavitation occurs over a wide range from the tip of the ridge 17. Therefore, the cell membrane of the microorganisms contained in the sludge is crushed by the impact crushing action due to the crushing of cavitation. Therefore, the sludge is solubilized and flows out from the outlet 9. Further, since the outflow port 9 is formed above, the annular space 1 is formed.
The gas component generated in 8 is discharged without staying. Thus, it is possible to prevent the impact crushing effect due to the air cushion effect from being suppressed.

In the above-described embodiment, the camera is installed horizontally, but the camera can be installed vertically.
The case 1 and the rotor 2 are preferably made of stainless cast steel which has corrosion resistance, is hardly corroded by cavitation, and is relatively easy to process. However, it may be formed of an appropriate material according to the type of sludge. In addition, the rotor 2 is not limited to the assembled structure, and may be formed of an integrally cast product, an integrally forged product, or a steel plate welded structure.

In the following embodiments, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

(Second Embodiment) FIG. 5 shows a sludge treatment apparatus according to a second embodiment. This sludge treatment apparatus is different from the first embodiment in detail, as shown in FIG. 6, in that an impeller in which a plurality of two-dimensional open type blades 19 are arranged at a constant pitch in a circumferential direction on a tip end surface of a rotor 2. 20. Guide vanes 2 are provided on the outer periphery of the impeller 20.
1 is provided. The guide vane 21 efficiently converts the velocity head into a pressure head and directs the sludge to the annular space 18. The gap between the blade 19 and the inner surface of the case cover 4 is formed to be 0.3 to 1 mm. The impeller rotates together with the rotor, causing sludge to flow into the case 1. For this reason, a separate pump is not required to flow the sludge into and out of the case 1.
Therefore, a very compact configuration can be achieved.

(Third Embodiment) FIG. 7 shows a sludge treatment apparatus according to a third embodiment. This sludge treatment apparatus is different from the first embodiment in that a water-cooled jacket 2
2 and the shaft 6 is connected to the supporting portions 100a, 10a.
The difference is that both ends are supported by 0b. That is, the annular flow paths 23a,
23b and 23c are respectively formed, and the respective flow paths 23a and 2c are formed.
3b and 23c, the cooling water flows, and by adjusting the flow rate, the sludge can be treated in an appropriate treatment temperature range (about 50% in water).
° C). Thereby, it is possible to prevent the sludge temperature from decreasing and the gas solubility from increasing, or from increasing the sludge temperature and increasing the saturated vapor pressure. Therefore, during cavitation crushing, the cushioning effect does not occur and the impact destructive force does not decrease due to the melted gas or the increased vapor pressure. It becomes possible. In addition, by supporting the shaft 6 at both ends, the supporting state of the rotor 2 can be stabilized.
The rotor 2 can be rotated at a high speed, and the effects of increasing the processing capacity (processing flow rate) of the apparatus, reducing the fluid and mechanical vibration and noise of the apparatus, improving the reliability, and reducing the maintenance cost can be obtained. Becomes possible.

(Fourth Embodiment) FIG. 8 shows a sludge treatment apparatus according to a fourth embodiment. This sludge treatment apparatus differs from the second embodiment in that a motor 24 as a drive source is housed in a sealed state in a motor case 25 attached to the bearing case 7, and can be installed vertically in water. Different.
For this reason, the legs 10 a and 10 b are provided on the end surface of the case 1. Further, a nozzle 26 is provided at the outlet 9,
The solubilized sludge can be scattered in water. If a discharge pipe or a liquid feed pipe (both not shown) is attached in place of the nozzle 26, it is possible to make the liquid flow further. If a suction pipe (not shown) is attached to the inflow port 11, it is possible to suck distant sludge. According to this, since the entire apparatus can be installed in water, there is an advantage that noise and vibration during driving can be reduced.

(Fifth Embodiment) FIG. 9 shows a part of an annular space 18 of a sludge treatment apparatus according to a fifth embodiment. This sludge treatment apparatus is different from the first embodiment in that a ridge (a groove or the like may be formed) on the inner peripheral surface of the case 1. That is, the ridges 17 are arranged at the same pitch in the circumferential direction, but are one less than the ridges 17 of the rotor 2. Thereby, the rotor 2 and the case 1
As a result, the ridges 17 do not approach each other in synchronization with each other, so that the occurrence of cavitation in all the ridges 17 can be suppressed and vibration, noise, and pulsation can be prevented from increasing.

In the above embodiment, the shaft 6 is supported by a cantilever structure, but may be supported by both ends.

Further, in the above-described embodiment, the ridge 17 has been described as an example of the projection, but it may be formed by a plurality of projections.
On the other hand, although the groove 17d has been described as an example of the concave portion, it may be formed by a plurality of dents or the like. These may be formed on at least one of the inner peripheral surface of the case 1 and the outer peripheral surface of the rotor 2. In this case, a convex portion and a concave portion may be mixed on one side. In short, it is sufficient that cavitation can be generated in a wide range in the annular space 18 by the convex portion or the concave portion, and in particular, cloud cavitation may be generated. Preferably, And
Optimally, it can be formed in a range that does not contact the case 1 and the rotor 2.

Further, the sludge treatment apparatus, particularly the sludge treatment apparatus according to the fourth embodiment, improves water pollution by eutrophication of lakes, marshes, ponds, closed sea areas, etc., and particularly, algae (such as blue-green algae) which overgrows abnormally. It can also be used for those that disrupt microbial cells. For example, in the case of a submersible motor type sludge treatment apparatus, it can be hung underwater by a rope or a chain arranged from the hull or land, and can perform a sweeping operation to provide water quality improvement. In addition, chemical manufacturing equipment, petrochemical manufacturing equipment, food manufacturing equipment, waste treatment equipment, water treatment equipment,
The present invention can also be used as a reaction device or a reaction promotion device in a unit chemical operation such as emulsification, dispersion, stirring, diffusion, dissolution, separation, cell fusion, extraction, aggregation, and heating in a microorganism treatment device or the like.

[0030]

As is apparent from the above description, according to the present invention, a cell membrane of microorganisms contained in sludge is crushed by a simple and inexpensive structure in which only a convex portion or a concave portion is provided in a case and a rotor. And solubilized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a sludge treatment device according to a first embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is a partially enlarged view showing another embodiment of the protrusion shown in FIG. 3;

FIG. 5 is a sectional view of a sludge treatment apparatus according to a second embodiment.

6 is a sectional view of the BB ship shown in FIG. 5;

FIG. 7 is a sectional view of a sludge treatment device according to a third embodiment.

FIG. 8 is a sectional view of a sludge treatment device according to a fourth embodiment.

FIG. 9 is a partially enlarged view showing a projection of a sludge treatment apparatus according to a fifth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Case 2 ... Rotor 6 ... Shaft 9 ... Outflow port 11 ... Inflow port 17 ... Ridge 18 ... Annular space 20 ... Impeller 21 ... Guide vane 22 ... Water-cooled jacket

Claims (6)

[Claims] 1. A case having a substantially cylindrical shape having an inflow port and an outflow port through which sludge flows in, and a rotary drive to form an annular space between the case and an inner peripheral surface of the case. And a rotor that is accommodated as possible. Of the inner peripheral surface of the case or the outer peripheral surface of the rotor,
Cavitation is generated by forming at least one of a plurality of protrusions or recesses on at least one of them and changing the gap of the annular space by rotating the rotor. Sludge treatment equipment. 2. The case according to claim 1, wherein the case has an inlet formed on one end surface thereof, and the rotor has an impeller on one end surface located near the inlet of the case. Sludge treatment equipment. 3. The sludge treatment apparatus according to claim 2, wherein a guide vane is provided on an inner surface on one end side of the case on an outer peripheral portion of the impeller. 4. The sludge treatment apparatus according to claim 1, wherein the case includes a water-cooled jacket. 5. The sludge treatment according to claim 1, wherein the protrusions or the recesses are arranged in the circumferential direction of the rotor at intervals at which at least generated cavitation disappears. apparatus. 6. The projecting portion includes a plurality of ridges formed along an axial direction on an inner peripheral surface of the case and an outer peripheral surface of the rotor, and the ridges are synchronized between the case and the rotor. The sludge treatment device according to any one of claims 1 to 5, wherein the sludge treatment device is arranged so as not to approach.