Digestion system and piping installation method

Abstract

To provide a digestion system and a piping installation method capable of suppressing deterioration of an anticorrosive coating within a tank.SOLUTION: A system comprises: a tank that performs digestion of sludge; a first pipe that circulates digested sludge between the inside and the outside of the tank; a second pipe that supplies surplus sludge to the first pipe; a heater that heats the surplus sludge in the second pipe; and a control device that, based on at least one of a temperature of the surplus sludge in the first pipe and a temperature of the surplus sludge in the second pipe, controls supply of the digested sludge from the tank to the first pipe.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to fire extinguishing systems and piping installation methods. [Background technology]

[0002] In a digestion system having a tank (hereinafter also referred to as a digestion tank) for digesting the material to be treated (for example, organic matter contained in primary sludge and excess sludge), a technology has been proposed that achieves efficient digestion of the material to be treated by maintaining the temperature inside the tank at an appropriate temperature (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special table 2011-516246 publication Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described fire extinguishing system, for example, heated materials to be treated are sometimes supplied to the tank so that the temperature inside the tank is at an appropriate level. Therefore, in the above-described fire extinguishing system, it is desirable to prevent deterioration (damage) of the anticorrosive coating applied to the inner wall of the tank due to contact with the heated materials (high-temperature materials). [Means for solving the problem]

[0005] The digestion system of the present disclosure comprises a tank for digesting sludge, a first pipe for circulating the digested sludge in the tank between the tank and the outside, a second pipe for supplying excess sludge to the first pipe, a heater for heating the excess sludge in the second pipe, and a control device for controlling the supply of the digested sludge from the tank to the first pipe based on at least one of the temperature of the excess sludge in the first pipe and the temperature of the excess sludge in the second pipe. [Effects of the Invention]

[0006] The fire extinguishing system and piping installation method disclosed herein make it possible to suppress deterioration of the anticorrosive coating inside the tank. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating the configuration of a processing system 1000 according to the first embodiment. [Figure 2] FIG. 2 is a diagram illustrating the configuration of the temperature adjustment system 100 according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating the hardware configuration of the control device 200 in the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating the function of the control device 200 in the first embodiment. [Figure 5] FIG. 5 is a flowchart illustrating the temperature control process in the first embodiment. [Figure 6] FIG. 6 is a diagram illustrating the configuration of a processing system 2000 according to the second embodiment. [Figure 7] FIG. 7 is a diagram illustrating the configuration of a processing system 2000 according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, such descriptions should not be interpreted in a limiting sense, and do not limit the subject matter described in the claims. Furthermore, various changes, substitutions, and modifications can be made without departing from the spirit and scope of the present disclosure. Furthermore, different embodiments can be combined as appropriate.

[0009] [Processing system 1000 according to the first embodiment] First, a processing system 1000 according to the first embodiment will be described. Fig. 1 is a diagram illustrating the configuration of the processing system 1000 according to the first embodiment.

[0010] The treatment system 1000 in this embodiment is, for example, a water treatment system that treats liquid such as sewage (hereinafter also referred to as water to be treated).

[0011] 1, the treatment system 1000 includes, for example, a primary sedimentation tank 10, a tank 20 (hereinafter also referred to as a reaction tank 20), a final sedimentation tank 30, a thickening device 40, a thickening device 50, a tank 60 (hereinafter also referred to as a digestion tank 60), a temperature adjustment system 100, and a control device 200. Note that, hereinafter, the treatment system 1000 will also be referred to as a digestion system 1000.

[0012] The primary sedimentation tank 10 separates, for example, organic and other contaminants (e.g., solid organic matter) contained in the water to be treated. The separated contaminants (hereinafter also referred to as primary sludge) are then discharged to a concentration device 40 by, for example, a pump (not shown). The water to be treated after the separation of contaminants by sedimentation is then discharged to a digestion tank 60 by, for example, a pump (not shown).

[0013] The reaction tank 20 is a tank that treats the water to be treated by biological treatment such as the standard activated sludge method. Specifically, the reaction tank 20 decomposes organic matter (e.g., soluble organic matter) contained in the water to be treated, for example, by microorganisms (hereinafter also referred to as activated sludge) propagated in the reaction tank 20. Then, after the organic matter has been decomposed by the activated sludge, the water to be treated is discharged from the reaction tank 20 to the final sedimentation tank 30 by, for example, overflow.

[0014] The final settling tank 30, for example, separates and discharges activated sludge contained in the water to be treated discharged from the reaction tank 20. Then, a part of the settled and separated activated sludge (hereinafter also referred to as excess sludge) is discharged to the thickening device 50, for example, by a pump (not shown). Another part of the settled and separated activated sludge (hereinafter also referred to as returned sludge) is returned to the reaction tank 20, for example, by a pump (not shown). Furthermore, the water to be treated after the activated sludge separation is discharged to a downstream sterilization treatment device (not shown) by, for example, overflow. Thereafter, the sterilization treatment device sterilizes the water to be treated discharged from the final settling tank 30, for example, and releases the sterilized treated water into a river or the like.

[0015] The thickening device 40 thickens, for example, the primary sludge discharged from the primary sedimentation tank 10. The thickened primary sludge is then discharged into the digestion tank 60 by, for example, a pump (not shown). The liquid separated from the primary sludge by thickening is returned to the primary sedimentation tank 10 by, for example, a pump (not shown).

[0016] The thickening device 50 thickens excess sludge discharged from, for example, the final settling tank 30. The thickened excess sludge is then discharged to the digestion tank 60 by, for example, a pump (not shown). Note that the liquid separated from the excess sludge by the thickening is returned to the final settling tank 30 by, for example, a pump (not shown).

[0017] In the digestion tank 60, for example, anaerobic bacteria in the digestion tank 60 anaerobically digest (decompose) organic matter contained in the primary sludge supplied from the thickener 40 and the excess sludge supplied from the thickener 50 through a biological reaction, thereby producing digested sludge. Specifically, the anaerobic bacteria in the digestion tank 60 produce digestion gases such as methane gas (hereinafter simply referred to as digestion gas) during the digestion process. Note that the temperature of the digested sludge (digestion liquid) in the digestion tank 60 is preferably maintained between 35°C and 39°C (hereinafter, this temperature range is also referred to as the optimum temperature) in order to efficiently promote biological reactions and improve the digestion rate.

[0018] The temperature adjustment system 100 adjusts the temperature of excess sludge, for example, before it is supplied to the digestion tank 60. Specifically, the temperature adjustment system 100 heats the excess sludge, for example, before it is supplied to the digestion tank 60. The temperature adjustment system 100 will be described below.

[0019] [Temperature Adjustment System 100 in the First Embodiment] FIG. 2 is a diagram illustrating the configuration of the temperature adjustment system 100 according to the first embodiment.

[0020] As shown in FIG. 2, the temperature adjustment system 100 in this embodiment includes, for example, a heater 110, a pump P1, and a pump P2.

[0021] Pump P1 is provided, for example, in line L1, and supplies excess sludge supplied from the thickening device 50 to the heater 110, and supplies the excess sludge whose temperature has been adjusted by the heater 110 to line L3. Line L1 is, for example, a pipe connecting the thickening device 50 to a position on line L3 between pump P2 and the digestion tank 60. Line L3 is, for example, a circulation pipe that circulates the digested sludge inside the digestion tank 60 between the outside of the digestion tank 60. Hereinafter, line L3 will also be referred to as the first pipe. Hereinafter, line L1 will also be referred to as the second pipe.

[0022] Pump P2 is provided, for example, in line L2, and circulates the digested sludge in digestion tank 60 between the inside and outside of digestion tank 60.

[0023] The heater 110 heats the excess sludge supplied from the concentrator 50 via a line L1, for example. Specifically, the heater 110 is a heat exchanger that conditions the excess sludge using a fluid (e.g., a fluid such as hot water) circulating through a line L2. The line L2 is a circulation pipe that connects the heater 110 to a heat source (not shown), for example.

[0024] The heat source for heating the fluid supplied to the heater 110 may be, for example, a heat exchanger that heats the fluid using waste heat from exhaust gas generated in an incinerator (not shown) that incinerates the digested sludge discharged from the digester tank 60. The heat source for heating the fluid supplied to the heater 110 may be, for example, a heat exchanger that heats the fluid using waste heat generated in conjunction with power generation using the digester gas discharged from the digester tank 60. The heat source for heating the fluid supplied to the heater 110 may be, for example, a water heater that heats the fluid using the digester gas discharged from the digester tank 60.

[0025] That is, in the treatment system 1000 of this embodiment, for example, excess sludge (high-temperature excess sludge) supplied via line L1 is merged with digested sludge (low-temperature digested sludge) in line L3 before being supplied to the digestion tank 60. In other words, in the treatment system 1000 of this embodiment, the temperature of the excess sludge supplied via line L1 is lowered by the digested sludge before being supplied to the digestion tank 60.

[0026] As a result, the treatment system 1000 of this embodiment can, for example, prevent high-temperature excess sludge from being directly supplied to the digestion tank 60. Therefore, the treatment system 1000 of this embodiment can, for example, prevent high-temperature excess sludge from adhering to the inner wall of the digestion tank 60. Therefore, the treatment system 1000 of this embodiment can, for example, control the temperature of the digested sludge in the digestion tank 60 to maintain an appropriate temperature, while preventing deterioration (damage) of the anticorrosive coating (not shown) applied to the inner wall of the digestion tank 60 due to contact with heated excess sludge (high-temperature excess sludge).

[0027] [Control device 200 in the first embodiment] Next, the control device 200 in the first embodiment will be described. Fig. 3 is a diagram illustrating the hardware configuration of the control device 200 in the first embodiment. Fig. 4 is a diagram illustrating the function of the control device 200 in the first embodiment.

[0028] The control device 200 performs, for example, control of the temperature of the excess sludge supplied to the digestion tank 60 (hereinafter also referred to as temperature adjustment control).

[0029] Specifically, the control device 200 is, for example, an electronic device having an electronic circuit, as shown in Fig. 3. More specifically, the control device 200 is, for example, a computer device having a CPU 201 which is a processor, a memory 202, a communication device 203, and a storage medium 204. Each unit is connected to each other, for example, via a bus 205.

[0030] The storage medium 204 has, for example, a program storage area (not shown) that stores a program 210 for performing temperature adjustment control. The storage medium 204 also has, for example, an information storage area 230 that stores information used when performing temperature adjustment control. The storage medium 204 may be, for example, a hard disk drive (HDD) or a solid state drive (SSD).

[0031] The CPU 201 performs temperature adjustment control by executing a program 210 loaded into the memory 202 from the storage medium 204, for example.

[0032] The communication device 203 accesses an operation terminal (not shown) through which an operator inputs necessary information, for example, via a network (not shown) such as the Internet.

[0033] Then, the control device 200 acquires the temperature (i.e., the temperature of the excess sludge in the line L3) measured by, for example, a thermometer T provided in the line L3, as shown in Fig. 4. Thereafter, the control device 200 performs temperature adjustment control by using, for example, the acquired temperature.

[0034] The electronic circuitry of the control device 200 may be, for example, a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). The temperature adjustment control may be performed by, for example, the FPGA or the ASIC.

[0035] [Temperature Control Process in the First Embodiment] Next, the temperature control process in the first embodiment will be described. Fig. 5 is a flowchart illustrating the temperature control process in the first embodiment. Note that the following description will be given assuming that the temperature adjustment control is performed automatically by the control device 200, but is not limited to this. Specifically, the temperature adjustment control may be performed manually by an operator, for example.

[0036] The control device 200 waits, for example, until it is time to execute temperature adjustment control (hereinafter also referred to as control execution time). The control execution time may be a regular time such as every minute.

[0037] Then, for example, when the control execution time arrives, the control device 200 acquires the temperature measured by the thermometer T (the temperature of the excess sludge in the line L3) (step S1 in FIG. 5). That is, in step S1, the control device 200 acquires, for example, the temperature of the excess sludge after it has merged with the digested sludge.

[0038] Next, the control device 200 determines whether or not the temperature acquired in step S1 satisfies a predetermined condition (hereinafter also simply referred to as the predetermined condition) (step S2 in FIG. 5).

[0039] Note that, although the following description will be given of a case where the control device 200 performs control from step S2 onwards by using the temperature measured by the thermometer T, the present invention is not limited to this. Specifically, the control device 200 may perform control from step S2 onwards by using, for example, a temperature measured by another thermometer. Specifically, the control device 200 may perform control from step S2 onwards by using, for example, a temperature (the temperature of the excess sludge in line L1) measured by a thermometer (not shown) provided downstream of the heater 110 in line L1 (upstream of the junction with line L3).

[0040] As a result, for example, if it is determined that the temperature acquired in step S1 satisfies a predetermined condition (YES in step S2 in Figure 5), the control device 200 adjusts the temperature of the excess sludge supplied to the digestion tank 60 (step S3 in Figure 5).

[0041] On the other hand, for example, if it is determined that the temperature acquired in step S1 does not satisfy the predetermined condition (NO in step S2 in FIG. 5), the control device 200 does not perform step S3.

[0042] Specifically, for example, if it is determined that the temperature acquired in step S1 exceeds a predetermined threshold value (hereinafter simply referred to as the threshold value), the control device 200 determines that a predetermined condition is satisfied and controls the pump P2 (controls the rotation speed of the pump P2) to increase the amount of digested sludge circulating through the line L3 (the amount of digested sludge circulating through the line L3 per unit time). The threshold value is, for example, a temperature lower than the temperature of excess sludge that can be determined to have the potential to deteriorate (damage) the anticorrosive coating applied to the inner wall of the digestion tank 60.

[0043] For example, if the amount of digested sludge circulating through line L3 (the amount of digested sludge circulating through line L3 per unit time) is increased and then it is determined that the temperature measured by thermometer T has fallen below the threshold value, the control device 200 performs control to reduce the amount of digested sludge circulating through line L3 (the amount of digested sludge circulating through line L3 per unit time).

[0044] As such, the treatment system 1000 in this embodiment includes, for example, a digestion tank 60 (hereinafter also referred to as the first tank) for digesting sludge, a line L3 for circulating the digested sludge in the digestion tank 60 between the inside and outside of the digestion tank 60, a line L1 for supplying excess sludge to line L3, a heater 110 for heating the excess sludge in line L1, and a control device 200 for controlling the supply of digested sludge from the digestion tank 60 to line L3 based on at least one of the temperature of the excess sludge in line L3 and the temperature of the excess sludge in line L1.

[0045] Specifically, the treatment system 1000 in this embodiment includes, for example, a thermometer T (hereinafter also referred to as a measuring device) installed between the junction of line L3 with line L1 and the digestion tank 60. In the treatment system 1000 in this embodiment, the control device 200 controls the supply of digested sludge from the digestion tank 60 to line L3, for example, based on the measurement results from the thermometer T.

[0046] Furthermore, in the treatment system 1000 of this embodiment, the control device 200 increases the amount of digested sludge supplied from the digestion tank 60 to the line L3 when the temperature measured by the thermometer T is equal to or higher than a threshold value, for example.

[0047] That is, in the treatment system 1000 of this embodiment, for example, excess sludge (high-temperature excess sludge) supplied via line L1 is merged with digested sludge (low-temperature digested sludge) in line L3 and then supplied to the digestion tank 60.

[0048] As a result, the treatment system 1000 of this embodiment can, for example, prevent high-temperature excess sludge from being supplied to the digestion tank 60. Therefore, the treatment system 1000 of this embodiment can, for example, prevent high-temperature excess sludge from adhering to the inner wall of the digestion tank 60. Therefore, the treatment system 1000 of this embodiment can, for example, control the temperature of the digested sludge in the digestion tank 60 to maintain it at an appropriate temperature, while preventing the corrosion-resistant coating applied to the inner wall of the digestion tank 60 from being deteriorated (damaged) due to contact with heated excess sludge (high-temperature excess sludge).

[0049] The ceiling of the digestion tank 60 may be provided with, for example, agitating blades (not shown) for agitating the excess sludge supplied to the digestion tank 60.

[0050] As a result, the treatment system 1000 of this embodiment can, for example, more uniformly maintain the temperature of the excess sludge supplied to the digestion tank 60. Therefore, the treatment system 1000 of this embodiment can, for example, further suppress deterioration (damage) of the anticorrosive coating applied to the inner wall of the digestion tank 60.

[0051] [Processing system 2000 according to the second embodiment] Next, a treatment system 2000 according to the second embodiment will be described. Figures 6 and 7 are diagrams illustrating the configuration of the treatment system 2000 according to the second embodiment. Specifically, Figures 6 and 7 are diagrams illustrating the configuration of the digestion tank 60 according to the second embodiment. Note that, hereinafter, the treatment system 2000 will also be referred to as the digestion system 2000.

[0052] As shown in Figure 6, a supply member 61 is attached to the ceiling 60a of the digestion tank 60 in the second embodiment, which can supply (introduce) at least either excess sludge or digested sludge from outside the digestion tank 60 into the digestion tank 60. The supply member 61 is, for example, a hollow cylindrical member, and is attached to the ceiling 60a so that one end (tip) extends from the ceiling 60a in the Z2 direction.

[0053] Specifically, the supply member 61 is attached to the ceiling 60a, for example, so that the inner wall of the supply member 61 functions as a through-hole that penetrates the ceiling 60a. Then, at least one of the excess sludge and the digested sludge is supplied (introduced) into the digestion tank 60 from outside the digestion tank 60 through the through-hole.

[0054] A flange 61a extending toward the XY plane is provided on the other end (the end on the Z1 direction side) of the supply member 61. That is, the flange 61a is provided on the end located outside the digestion tank 60, of both ends of the supply member 61 in the Z axis direction.

[0055] Then, for example, an insertion pipe 62 is inserted into the supply member 61 (through hole) provided in the ceiling portion 60a. That is, the insertion pipe 62 is, for example, a pipe whose outer diameter is smaller than the inner diameter of the supply member 61. Specifically, the insertion pipe 62 is attached, for example, so that its end on the Z2 direction extends to a position (position on the Z2 direction side) lower than the Z2 direction end of the supply member 61. More specifically, as shown in FIG. 6, the insertion pipe 62 is attached, for example, so that the height of its end on the Z2 direction is lower than the height of the liquid level WL of the digested sludge stored in the digestion tank 60. Hereinafter, the insertion pipe will also be referred to as a third pipe.

[0056] A flange portion 62a extending toward the XY plane is provided at the other end (the end on the Z1 direction side) of the insertion pipe 62. That is, the flange portion 62a is provided at the end located outside the digestion tank 60, of both ends of the insertion pipe 62 in the Z axis direction.

[0057] 6, the supply member 61, the insertion pipe 62, and the supply pipe 63 are fixed to each other, for example, on the outside of the digestion tank 60 (the Z1 direction side of the ceiling 60a). The supply pipe 63 is, for example, a pipe that supplies at least either excess sludge or digested sludge to the digestion tank 60. In other words, the supply pipe 63 is, for example, the line L3 described in FIG.

[0058] Specifically, the supply member 61, the insertion pipe 62, and the supply pipe 63 are fixed to one another by, for example, fastening together a flange portion 61a of the supply member 61, a flange portion 62a of the insertion pipe 62, and a flange portion 63a (flange portion 63a extending toward the XY plane) provided at the end of the supply pipe 63 on the digester tank 60 side. More specifically, the flange portions 61a, 62a, and 63a are fixed, for example, by fastening multiple sets of bolts 64 and nuts 65 (for example, triple fastening), as shown in Figure 6.

[0059] Thus, the treatment system 2000 of this embodiment includes, for example, a digestion tank 60 that digests sludge, and a supply pipe 63 that circulates the digested sludge in the digestion tank 60 between the inside and outside of the digestion tank 60. In the treatment system 2000 of this embodiment, the ceiling 60a of the digestion tank 60 is provided with, for example, a supply member 61 (hereinafter also referred to as a supply unit) whose lower end extends from the ceiling 60a toward the bottom of the digestion tank 60 and which can supply at least one of excess sludge and digested sludge supplied from the supply pipe 63 into the digestion tank 60, and an insertion pipe 62 that is inserted into the supply member 61 and whose lower end extends to a position lower than the lower end of the supply member 61. Furthermore, in the processing system 2000 of this embodiment, the supply pipe 63, the supply member 61, and the insertion pipe 62 are each fixed to each other, for example, at a flange portion 61a provided at the end of the supply member 61 outside the digestion tank 60, a flange portion 62a provided at the end of the insertion pipe 62 outside the digestion tank 60, and a flange portion 63a provided at the end of the supply pipe 63 on the digestion tank 60 side.

[0060] That is, in the digestion tank 60 of this embodiment, for example, the position of the lower end (the end on the Z2 direction side) of the supply member 61 is higher than the liquid level WL of the digested sludge stored in the digestion tank 60, as shown in Fig. 6. Then, for example, when excess sludge is directly supplied (charged) into the digestion tank 60 from the supply member 61, the excess sludge (high-temperature excess sludge) supplied into the digestion tank 60 may bounce off the liquid level WL and adhere to the inner wall of the digestion tank 60. Therefore, in this case, for example, the anticorrosive coating applied to the inner wall of the digestion tank 60 may be deteriorated (damaged) by contact with the heated excess sludge (high-temperature excess sludge).

[0061] Therefore, in the digestion tank 60 of this embodiment, for example, an insertion pipe 62 is used that can be installed so that the height of its lower end is lower than the height of the liquid level WL, thereby supplying excess sludge at a height lower than the liquid level WL (i.e., within the digested sludge stored in the digestion tank 60).

[0062] As a result, in the treatment system 2000 of this embodiment, for example, it is possible to prevent excess sludge (high-temperature excess sludge) supplied into the digestion tank 60 from bouncing off the liquid surface WL, and it is possible to prevent the excess sludge supplied into the digestion tank 60 from adhering to the inner wall of the digestion tank 60. Therefore, in the treatment system 2000 of this embodiment, it is possible to prevent, for example, the corrosion-resistant coating applied to the inner wall of the digestion tank 60 from being deteriorated (damaged) due to contact with the heated excess sludge (high-temperature excess sludge).

[0063] Furthermore, in the treatment system 2000 of this embodiment, for example, by inserting the insertion pipe 62 into the supply member 61, it becomes possible to perform the installation work of the insertion pipe 62 outside the digestion tank 60 (above the digestion tank 60). In other words, in the treatment system 2000 of this embodiment, for example, it is not necessary to perform the installation work of the insertion pipe 62 inside the digestion tank 60. Therefore, in the treatment system 2000 of this embodiment, for example, when installing the insertion pipe 62, it is not necessary to empty the digestion tank 60, and it is not necessary to stop operation of the digestion tank 60.

[0064] After the insertion pipe 62 is attached to the supply member 61, for example, a heat insulating material 66 may be placed between the inner wall of the supply member 61 and the outside of the insertion pipe 62, as shown in FIG. 7.

[0065] As a result, in the treatment system 2000 of this embodiment, for example, corrosion (damage) of the ceiling portion 60a caused by the supply of excess sludge (high-temperature excess sludge) to the digestion tank 60 can also be suppressed.

[0066] Furthermore, as in the first embodiment, the ceiling portion 60a of the digestion tank 60 may be provided with, for example, agitator blades (not shown) for agitating the excess sludge supplied to the digestion tank 60.

[0067] As a result, similar to the first embodiment, the treatment system 2000 of this embodiment can, for example, more uniformly maintain the temperature of the excess sludge supplied to the digestion tank 60. Therefore, the treatment system 2000 of this embodiment can, for example, prevent the anticorrosive coating applied to the inner wall of the digestion tank 60 from being deteriorated (damaged) due to contact with the heated excess sludge (high-temperature excess sludge).

[0068] In the above example, the supply pipe 63 is described as line L3 (a circulation pipe that circulates digested sludge inside the digestion tank 60 between the inside and outside of the digestion tank 60), but this is not limited to this. Specifically, the supply pipe 63 may be, for example, another pipe. Even more specifically, the supply pipe 63 may be, for example, a pipe that directly supplies excess sludge that has been heated in the heater 110 to the digestion tank 60. [Explanation of symbols]

[0069] 10: Primary sedimentation tank 20: Reaction tank 30: Final settling tank 40: Thickener 50: Concentrator 60: Digestion tank 60a: Ceiling portion 61: Supply member 61a: flange portion 62: insertion pipe 62a: Flange portion 63: Supply pipe 63a: Flange part 64: Bolt 65: Nut 66: Insulation material 100: Temperature control system 110: Heater 200: Control device 201: CPU 202: Memory 203: Communication device 204: Storage medium 205: Bus 210: Program 230: Information storage area 1000: Processing system 2000: Processing system L1: Line L2: Line L3: Line P1: Pump P2: Pump T: Thermometer WL:Liquid level

Claims

1. a tank for digesting sludge; a first pipe for circulating the digested sludge in the tank between the tank and the outside; a second pipe for supplying excess sludge to the first pipe; a heater for heating the excess sludge in the second pipe; A digestion system comprising: a control device that controls the supply of digested sludge from the tank to the first pipe based on at least one of the temperature of the excess sludge in the first pipe and the temperature of the excess sludge in the second pipe.

2. further comprising a measuring device provided between the tank and a junction of the first pipe with the second pipe, The digestion system described in claim 1, wherein the control device controls the supply of the digested sludge from the tank to the first piping based on measurement results of at least one of the excess sludge and the digested sludge in the first piping by the measuring device.

3. The digestion system according to claim 2 , wherein the control device increases the amount of digested sludge supplied from the tank to the first pipe when the temperature measured by the measuring device is equal to or higher than a threshold value.

4. a tank for digesting sludge; a first pipe for supplying at least one of excess sludge and digested sludge into the tank; a supply unit provided on the ceiling of the tank, the lower end of which extends from the ceiling of the tank toward the bottom of the tank, and which is capable of supplying at least one of the excess sludge and the digested sludge supplied from the first pipe into the tank; a third pipe inserted into the supply unit and having a lower end extending to a position lower than the lower end of the supply unit; A fire extinguishing system in which the supply unit, the third pipe, and the first pipe are fixed to each other by fastening a flange portion provided at the end of the supply unit outside the tank, a flange portion provided at the end of the third pipe outside the tank, and a flange portion provided at the end of the first pipe on the tank side.

5. A piping installation method for a digestion system including a tank for digesting sludge and a first pipe for supplying at least one of excess sludge and digested sludge to the tank, comprising: a supply unit is provided on a ceiling portion of the tank, the supply unit extending from the ceiling portion of the tank toward a bottom portion of the tank and capable of supplying at least one of the excess sludge and the digested sludge supplied from the first piping into the tank; a third pipe is inserted into the supply unit, so that a lower end of the third pipe is extended to a position lower than a lower end of the supply unit; A piping installation method in which the supply unit, the third pipe, and the first pipe are fixed to each other by fastening a flange portion provided at the end of the supply unit outside the tank, a flange portion provided at the end of the third pipe outside the tank, and a flange portion provided at the end of the first pipe on the tank side.

Images