JP4015882B2 - Biological sludge treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a treatment apparatus that solubilizes sludge by destroying cell walls of microorganisms contained in the sludge.
[0002]
[Prior art]
In the activated sludge method, which is widely used as a biological treatment method for organic wastewater, a large amount of surplus sludge is generated, and the surplus sludge is landfilled after intermediate treatment such as dehydration and incineration. Therefore, various techniques for reducing sludge volume have been proposed. For example, there are ultrasonic methods, oxidation-reduction reaction methods, hydrothermal methods, mill grinding methods, high-speed rotating disk methods, etc. In these methods, the cell walls of microorganisms contained in sludge are destroyed by chemical or physical processes. Organic matter in cells is released, and sludge modified by solubilization of this sludge is sent back to the biological treatment process to reduce the amount of sludge that is ultimately incinerated or landfilled. be able to.
[0003]
[Problems to be solved by the invention]
However, it is difficult to say that such sludge solubilization treatment is efficient, and the initial cost and the equipment configuration are complicated due to the need for large-scale equipment to increase the treatment capacity and complicated equipment configuration. A biological sludge treatment apparatus that has the disadvantage of increasing running costs and that can improve the efficiency of sludge solubilization treatment with a simple configuration is desired.
[0004]
In addition, a heating device for heating a liquid material is used in various fields. For example, when a process of injecting a gas such as air is performed together, the liquid material boils at a relatively low temperature due to the influence of the injected gas. There is a limitation that a stable operation cannot be performed at a high temperature. Furthermore, even when a liquid substance is simply heated, the vapor generated by vaporization of a part of the liquid substance may stagnate in the pipeline, resulting in a gas pool, which may cause a decrease in efficiency and overheating. Therefore, it is necessary to consider it at the design stage, which is a limitation in reducing the size and efficiency of the device. From such a viewpoint, there is a demand for a liquid material heating apparatus in which the heating temperature is not limited to a low level by the injected gas and the smooth flow is not hindered by the generated steam.
[0005]
[Means for Solving the Problems]
Therefore, in the present invention, as shown in claim 1, the configuration of the biological sludge treatment apparatus that destroys the cell walls of microorganisms contained in the sludge and solubilizes the sludge has a plurality of resistances in the pipeline through which the sludge flows. A stirrer in which the body is disposed and stirs the sludge and the gas for stirring to physically damage the cell wall of the microorganism, and a heating unit that heats the sludge flowing in the pipe to promote the destruction of the cell wall of the microorganism The stirring means includes a plurality of resistors disposed in a flow path inside a cylindrical casing, and the plurality of resistors are both plate-shaped from the inner peripheral surface toward the center. The protrusions are provided so as not to contact each other while being inclined toward the downstream side, with a predetermined interval in the axial direction and sequentially shifted by a predetermined angle in the circumferential direction . In particular, the stirring gas is preferably air.
[0006]
According to this, the cell wall of the microorganism is physically damaged by the impact action of the stirring means, and the destruction of the cell wall of the microorganism is promoted by the heat of the heating means, thereby dramatically improving the efficiency of the solubilization treatment with a simple configuration. Can be increased. In this case, it is necessary to ensure a required flow rate and pressure so that an appropriate stirring process is performed in the static mixer, which may be configured to be pumped.
[0007]
In particular, when an oxygen-containing gas such as air is used as the stirring gas, the sludge is kept in an aerobic state, and the growth of anaerobic bacteria that can inhabit even at high temperatures can be suppressed and malodor can be prevented. In addition, as the gas for stirring in the present invention, an oxidizing gas having a cell-destroying action such as ozone gas can be used.
[0009]
Furthermore, according to this biological sludge treatment apparatus , by introducing the sludge and the agitation gas into the agitation means (static mixer) at the required pressure and flow rate, a strong turbulent flow is generated in the mixture of the sludge and the agitation gas. The phenomenon of physically damaging the cell walls of microorganisms due to the impact caused by the pressure fluctuation caused by this phenomenon occurs remarkably. In this case, it is preferable that the agitation gas is injected into the sludge and stirred on the upstream side of the agitation means while the sludge is circulated between the agitation means and the tank.
[0010]
Particularly in the agitation means, the pair of resistors protrudes in a tongue shape from the mutually opposing inner peripheral surfaces of the cylindrical body so as to form a generally C shape, and one of the resistors is the center of the cylindrical body. A resistor element is formed so as to be longer than the other so as to intersect the line. A plurality of resistor elements are arranged in the axial direction while being sequentially shifted by a predetermined angle in the circumferential direction. It is good to have the structure made.
[0011]
According to this, since the resistor has a tongue shape, the flow that collided with the resistor is distributed in multiple directions around the resistor, and a vortex (wake) due to entrainment occurs on the back side of the resistor, and this resistance By repeating the collision, dispersion and entrainment of the circulating fluid by the body one after another, a strong turbulent flow is generated and the circulating fluid is vigorously stirred. Furthermore, by arranging the resistor elements while shifting by a predetermined angle in the circumferential direction along the flow direction, the resistor formed in a long shape so as to intersect the center line of the cylindrical body is arranged in a spiral shape as a whole As a result, a swirling flow around the center line of the cylindrical body is generated in the circulating fluid, and stirring is continuously performed in the downstream portion.
[0012]
In addition, since the resistor has a simple configuration in which the resistor is inclined from the inner peripheral surface of the cylindrical body while being inclined to the downstream side so as not to oppose the flow, fibrous or particulate solid matter is caught or accumulated. In addition, even sludge containing a large amount of solid matter can be stably stirred without causing clogging.
[0017]
The heating means in the present invention is a simple electric heater, but in addition to this, a configuration using steam may be used. For example, a jacket into which steam is introduced may be provided on the outer peripheral side of the cylindrical body. . A heating means using induction heating is also possible. In this case, an induction coil is provided on the outer peripheral side of the cylindrical body, and the cylindrical body made of a conductive material may be configured to generate heat by an induced current. .
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
[0019]
FIG. 1 is a schematic diagram showing a schematic configuration of a biological sludge treatment apparatus according to the present invention. The treatment apparatus is provided with a solubilization treatment unit 1 that heats while stirring sludge and agitation gas to destroy the cell walls of microorganisms contained in the sludge and solubilizes the sludge. In the solubilization processing unit 1, air is used as a stirring gas.
[0020]
The solubilization processing unit 1 includes a tank 2 into which the sludge to be treated is sent, a static mixer 3 that stirs the sludge and air, and a pump 4 that extracts the sludge from the tank 2 and sends it to the static mixer 3. The sludge sent out from the static mixer 3 is returned to the tank 2, and the sludge is circulated between the tank 2 and the static mixer 3, while the static mixer 3 circulates for a required time. Sludge and air are continuously stirred. Thereby, it is possible to physically damage the cell walls of microorganisms in the sludge. Here, pressurized air is injected into the sludge upstream of the static mixer 3.
[0021]
The static mixer 3 of the solubilization processing unit 1 is provided with a heater, and heats sludge flowing through the interior to promote cell wall destruction of microorganisms. A thermostat 5 is provided on the upstream side of the static mixer 3, and power supply to the heater of the static mixer 3 is stopped when the sludge exceeds a set temperature (for example, 60 ° C.). Thus, the sludge is kept in a predetermined temperature range.
[0022]
Furthermore, in this processing apparatus, the tank 7 into which the sludge extracted from the tank 2 of the solubilization processing unit 1 is introduced after the solubilization processing unit 1, the static mixer 8 for stirring the sludge and air, and the tank 7 and a pump 9 that draws sludge out of 7 and feeds it into the static mixer 8. In the tank 7, sludge stays for a required time, and the modified sludge containing organic matter released by microbial cell destruction is withdrawn and returned to the raw water tank or the adjustment tank, where it is biologically treated again. On the other hand, sedimenting solids such as cell walls separated by cell destruction of microorganisms settle to the bottom of the tank 7, and this sediment is returned to the solubilization processing unit 1 or sent to a dehydrator and dehydrated. After that, it is incinerated. The agitation treatment with air in the static mixer 8 increases the efficiency of reprocessing after returning to the pretreatment unit 2 and increases the efficiency of dehydration when sent to the dehydrator, and keeps it in an aerobic state. It is effective in suppressing malodors.
[0023]
FIG. 2 is a cross-sectional view showing the heating-type static mixer shown in FIG. The static mixer 3 has a large number of resistor elements 21 inserted in a cylindrical casing 20. This resistor element 21 is formed by a first and second pair of resistors 23 and 24 projecting in a tongue shape from the inner peripheral surfaces of a cylindrical body 22 having a circular cross section facing each other toward the center. The cylindrical body 22 continuously forms a flow path.
[0024]
An electric heater 26 is disposed on the outer peripheral surface of the casing 20. The electric heater 26 is a sheathed heater in which a heating wire (nichrome wire) is accommodated in a sheath tube (sheath pipe) filled with an insulating material (magnesia powder) so as to draw a spiral according to the outer diameter of the casing 20. And is externally wrapped around the casing 20. The electric heater 26 heats the casing 20 and the resistor element 21 from the outer peripheral side, and the sludge (liquid substance) that circulates inside is heated by heat transfer from the casing 20 and the resistor element 21. A lagging jacket 27 is provided around the casing 20 to surround the electric heater 26 and suppress heat radiation to the atmosphere.
[0025]
The resistors 23 and 24 are both arranged in a C shape in a state of being inclined toward the downstream side, and are offset in the axial direction so as to ensure a required interval between the resistors 23 and 24. ing. The upstream first resistor 23 is short so as not to cross the center line of the cylindrical body 22, and the downstream second resistor 24 is long so as to cross the center line of the cylindrical body 22. Is formed.
[0026]
As shown in FIG. 3 and FIG. 4, the cylindrical body 22 is formed with unevenness as shown in FIG. 3 and FIG. Moreover, it can divide | segment into the two division bodies 22a * 22b in which a pair of resistor 23 * 24 was each formed by the dividing line along an axial direction. As a result, manufacturing can be facilitated and obstacles attached to the surface can be easily removed.
[0027]
When the resistor element 21 thus formed is inserted into the casing 20, the resistor element 21 is disposed by being shifted by 45 degrees in the circumferential direction with respect to the resistor element 21 immediately before indicated by an imaginary line in FIG. In the following, the subsequent resistor elements 21 are also shifted in the same direction by 45 degrees with respect to the immediately preceding one, and the first resistor element 21 is 45 degrees, 90 degrees, 135 in the circumferential direction, respectively. The angular position is such as 180 degrees or 180 degrees. Therefore, when viewed as a whole, the resistors 23 and 24 paired in a C shape are arranged so as to draw a spiral with a lead angle corresponding to the shift angle of the resistor element 21.
[0028]
For this reason, when the fluid is introduced into the inside, the flow of the first resistor element 21 facing the resistors 23 and 24 collides with the resistors 23 and 24 and is distributed to the surroundings. A flow that does not face 24 collides with any of the resistors 23 and 24 of the downstream resistor element 21 without causing a short path and is dispersed in multiple directions, and a strong turbulent flow is generated inside.
[0029]
In this way, by introducing sludge and agitation gas (air, etc.) into the static mixer at the required pressure and flow rate, a vigorous turbulent flow is generated in the mixture of sludge and agitation gas. The phenomenon of physical and mechanical damage to the cell walls of microorganisms due to the impact caused by pressure fluctuations is accompanied.
[0030]
Further, in the static mixer, fine bubbles of air are generated at a high density by the stirring action by strong turbulent flow, and the contact efficiency is greatly increased. In addition, since the fine bubbles persist without becoming coarse, oxygen is continuously dissolved in the sludge liquid layer after being sent out from the static mixer, and the gas-liquid contact reaction is promoted. The
[0031]
FIG. 6 is a schematic diagram showing a schematic configuration of an oil removing device to which the liquid substance heating device according to the present invention is applied. This oil removing device removes fats and oils in the processing of fish meat, and stirs and heats the tank 31 into which the object to be processed (liquid substance) is fed, and the object to be processed and air, as shown in FIG. The heating-type stationary mixer 32 is the same as the above, and the pump 33 that pulls out the object to be processed from the tank 31 and feeds it into the stationary mixer 32, and the object to be processed sent out from the stationary mixer 32. Is returned to the tank 31, and the object to be processed and air are continuously stirred in the static mixer 32 over a required time while the object to be processed is circulated between the tank 31 and the static mixer 32. While being heated. As a result, the oil component dispersed in the object to be processed is collected and removed by the action of the fine air bubbles. In such a process of injecting air into the object to be treated mainly containing water to separate the oil component, conventionally, 80 ° C. is the limit, but according to this configuration, the diameter of the generated bubbles is small. Heating up to 94 ° C. is possible, and boiling occurs at 94.5 ° C., making stable operation difficult. The tank 31 is provided with a lagging jacket 34 for heat insulation.
[0032]
FIG. 7 is a schematic diagram showing a schematic configuration of a water tube boiler to which a liquid material heating apparatus according to the present invention is applied. Here, a resistor element 42 similar to that shown in FIG. 3 is inserted in the water pipe 41. Water is fed into the water pipe 41 from the pump 43, and the water flowing through the water pipe 41 is heated by the flame generated by the burner (heating means) 44 and the heat transfer from the outside by the combustion gas to obtain water vapor. In this case, water is agitated by the turbulent flow generated by the resistor of the resistor element 42 and the bubbles of the generated steam are suppressed from being coarsened, and at the same time, the bubbles are finely crushed. it can. The resistor elements 42 do not need to be disposed over the entire length of the water pipe 41, and a required number of resistor elements 42 may be provided at a portion where there is a possibility of gas accumulation or upstream thereof.
[0033]
FIG. 8 shows another embodiment of the liquid material heating apparatus according to the present invention. Here, an induction heating device (heating means) 53 is provided around the casing 52 of the static mixer 51 similar to that shown in FIG. 2 instead of the electric heater. In this induction heating device 53, an induction coil 54 is disposed on the outer periphery of a casing 52, and an induction current is generated in the resistor element 55 and the casing 52 similar to those shown in FIG. In this case, the casing 52 and the resistor element 55 are formed of a material having required conductivity and electric resistance characteristics. A configuration in which induction heat generation is generated only in one of the casing 52 and the resistor element 55 is also possible.
[0034]
FIG. 9 shows another embodiment of the apparatus for heating a liquid substance according to the present invention. Here, a steam jacket 63 is provided around a casing 62 of a static mixer 61 similar to that shown in FIG. 2 instead of the electric heater. In the steam jacket 63, an outer cylinder portion 64 into which steam is introduced is disposed on the outer periphery of the casing 62, and the resistor element 65 and the casing 62 are heated by heat transfer from the steam. In this configuration, fins may be provided inside in order to improve heat exchange characteristics, or a heat insulating material may be disposed outside in order to suppress heat radiation to the atmosphere.
[0035]
【The invention's effect】
As described above, according to the present invention, the cell wall of the microorganism is physically damaged by the impact action of the stirring means, and the destruction of the cell wall of the microorganism is promoted by the heat of the heating means, thereby dramatically improving the efficiency of the solubilization treatment. This can greatly increase the initial cost and running cost of sludge volume reduction.
[0036]
Further, since the injected gas is made into fine bubbles by the stirring means, it can be heated without becoming a boiling state even at a high temperature, and a remarkable effect can be obtained in stably performing the high-temperature heat treatment of the liquid substance. Furthermore, since the agitation means suppresses the generation of bubbles in the generated steam and avoids the inconvenience of forming a gas pool, the efficiency and efficiency of the heating device can be improved, and the shape and arrangement of the piping can be used to prevent the gas pool. Is eliminated, and the degree of freedom in designing the device is increased. Further, since there are no restrictions due to gas accumulation, there is an advantage that the operation control becomes easy.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a schematic configuration of a biological sludge treatment apparatus according to the present invention.
FIG. 2 is a cross-sectional view showing the heating type static mixer shown in FIG.
FIG. 3 is a perspective view showing a main part of the static mixer shown in FIG. 1;
4 is a front view of the resistor element shown in FIG. 2 as viewed from the upstream side. FIG.
5 is a front view similar to FIG. 4 for explaining the arrangement state of the resistor elements shown in FIG. 2;
FIG. 6 is a schematic diagram showing a schematic configuration of an oil removing device to which a liquid substance heating device according to the present invention is applied.
FIG. 7 is a schematic diagram showing a schematic configuration of a water tube boiler to which a liquid material heating apparatus according to the present invention is applied.
FIG. 8 is a side view showing another embodiment of the liquid material heating apparatus according to the present invention.
FIG. 9 is a side view showing another embodiment of the liquid material heating apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Solubilization process part 2 * 7 Tank 3 * 8 Heating type static mixer 4 * 9 Pump 5 Thermostat 20 Casing 21 Resistor element 22 Cylindrical body 23 * 24 Resistor 26 Electric heater 31 Tank 32 Static mixer 33 Pump 34 Lagging jacket 41 Water pipe 42 Resistor element 43 Pump 44 Burner 51 Static mixer 52 Casing 53 Induction heating device 54 Inductive coil 55 Resistor element 61 Static mixer 62 Casing 63 Steam jacket 64 Outer cylinder 65 Resistor element

Claims (2)

A biological sludge treatment device that solubilizes sludge by destroying the cell walls of microorganisms contained in the sludge,
A plurality of resistors are arranged in a pipeline through which the sludge flows, and stirring means that stirs the sludge and the stirring gas to physically damage the cell walls of the microorganism,
By heating the sludge flowing through conduit e Bei and heating means for promoting cell wall destruction of microorganisms,
The agitation means includes a plurality of resistors disposed in a flow path inside a cylindrical casing, and the plurality of resistors are projected in a plate shape from the inner peripheral surface side toward the central portion, and are downstream. A biological sludge treatment apparatus, wherein the biological sludge treatment apparatus is provided with predetermined intervals in the axial direction so as not to contact each other while being inclined to the side, and sequentially shifted by a predetermined angle in the circumferential direction . The biological sludge treatment apparatus according to claim 1, wherein the stirring gas is air .

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