JP2012241110A - Sludge carbonization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new sludge carbonization method by which the formation of clinker in a carbonization furnace can be effectively prevented.SOLUTION: There is provided a method of drying a material to be carbonized using a dryer 1 and forming the resulting dried material into carbonized material using the carbonization furnace 2. In the method, a carbonization exhaust gas exhausted from the carbonization furnace 2 is combusted in a re-combustion furnace 3 and is discharge to the outside as re-combustion exhaust gas in which harmful substance are made harmless. The heat contained in the re-combustion exhaust gas is supplied to one of or a plurality of the dryer 1, the carbonization furnace 2 and the re-combustion furnace cell 3 as a heat source. As the carbonization furnace 2, a rotary kiln type or a rotary drum type apparatus is used, and as the dryer 1, a conductive heat transfer type apparatus for conducting the heat indirectly to the material to be treated from a heating medium is used, and as a result, a dryer exhaust gas containing moisture evaporated from the material to be treated is supplied to the carbonization furnace 1.

Description

  The present invention relates to the treatment of sludge discharged from, for example, human waste treatment facilities, sewage treatment facilities and various production factories, and in particular, a carbonization treatment method of sludge capable of effectively preventing the generation of clinker in a carbonization furnace. It is related to.

Conventionally, when processing waste such as sludge and municipal waste that contain a large amount of water discharged from human waste, sewage treatment facilities and various production plants, this is subjected to drying treatment in order to improve the efficiency of the treatment. A treatment method is adopted in which after moisture is removed, it is subsequently dried and further carbonized.
As an example, when sludge is dried and carbonized, a carbonization apparatus S ′ as shown in FIG. 3 is used. Sludge M0 that has been subjected to dehydration in advance is put into the dryer 1 ′ for drying. Processing is performed, and the dry matter M1 obtained here is put into a carbonization furnace 2 'to obtain a carbide M2. Further, the exhaust gas exhausted from the rotary kiln type or rotary drum type device used as the carbonization furnace 2 'is combusted in the recombustion furnace 3' to obtain a recombustion exhaust gas G3 'in which harmful substances are detoxified (for example, patents). This high-temperature reburning exhaust gas G3 ′ is provided as hot air for the dryer 1 ′.

By the way, as said dryer 1 ', while supplying hot air in a rotating drum and stirring the sludge M0 supplied in this rotating drum, a contact with a hot air and sludge M0 is aimed at, and it is contained in sludge M0. A so-called rotary drum type device or a rotary kiln type device for evaporating moisture is widely used.
The reason why this type of apparatus is employed is that when a high-viscosity object such as sludge M0 is handled, the object to be processed is dispersed by a stirring blade, so that the temperature is high (700 to 800 ° C. in the configuration shown in FIG. 3). This is because the contact area between the heating medium and the object to be processed can be increased and efficient drying can be performed.
The rotary drum dryer 1 'or the rotary kiln dryer 1' is relatively inexpensive, so that the initial cost can be suppressed. This is also a factor that these dryers 1 'are widely adopted. It has become.

However, in such a carbonization apparatus S ′, the outlet temperature of the carbonization furnace 2 ′ is set to about 800 ° C., and the outlet temperature of the reburning furnace 3 ′ is set to about 730 ° C. so that the apparatus can be efficiently and stably provided. It is necessary for operation, and for this reason, it is essential to supply combustion air (outside air) into each furnace.
When such an operation is continued, it is inevitable that the clinker adheres in the carbonization furnace 2 'and the reburning furnace 3'. Furthermore, when the clinker grows and falls off, it is necessary to periodically remove the clinker because the path of the object to be processed and the combustion air may be blocked or the equipment may be damaged. The fact is that this work has taken a lot of time.

Japanese Patent No. 4255066

  The present invention has been made in view of such a background. In particular, it is a technical problem to develop a novel sludge carbonization method that can effectively prevent the generation of clinker in a carbonization furnace. .

  That is, the method for carbonizing sludge according to claim 1 is a method in which the carbonized exhaust gas exhausted from the carbonization furnace is reburned in a method in which the object to be treated is dried using a dryer and then further converted into carbide using a carbonization furnace. It is exhausted to the outside as a reburning exhaust gas that has been detoxified by decomposing harmful substances by burning in the furnace, and the heat contained in the reburning exhaust gas is transferred to any one of the dryer, carbonization furnace or reburning furnace, or Conductive heat transfer device that serves as a plurality of heat sources, uses a rotary kiln type or rotary drum type device as the carbonization furnace, and indirectly conducts heat from a heating medium to an object to be processed as the dryer By using this, dry exhaust gas containing water evaporated from the object to be treated is supplied to the carbonization furnace.

  The sludge carbonization method according to claim 2 is characterized in that, in addition to the above requirements, the humidity of the dry exhaust gas is adjusted by removing a part of the vapor component in the dry exhaust gas using a condenser. Is.

  Furthermore, in addition to the above requirements, the method for carbonizing sludge according to claim 3 is characterized in that the dry exhaust gas is heated to the heat contained in the reburning exhaust gas and then supplied to the carbonization furnace. .

Furthermore, in the sludge carbonization method according to claim 4, in addition to the above requirements, as the dryer, a multi-tube heating pipe is provided in a main body shell provided on a machine frame, and the multi-tube heating pipe is provided. The heating steam is made to flow and rotate inside, and the object to be processed is put into the main body shell, and the object to be processed is brought into contact with the multi-tubular heating tube while being retained in the main body shell. It is characterized by using an apparatus for drying an object.
The above-described problems can be solved by using the requirements described in these claims as means.

  First, according to the first aspect of the present invention, by reducing the oxygen partial pressure in the carbonization furnace by the steam component contained in the dry exhaust gas, it is possible to suppress the combustion rate of the object to be processed. It is possible to effectively prevent the generation of clinker by suppressing a significant temperature rise.

  According to the second aspect of the present invention, the combustion rate of the workpiece can be adjusted by adjusting the amount of the steam component contained in the dry exhaust gas supplied to the carbonization furnace.

  Furthermore, according to the invention described in claim 3, the ratio of heat contained in the dry exhaust gas is increased in the amount of heat required for carbonization of the workpiece in the carbonization furnace, and the burner fuel in the carbonization furnace is reduced. Can do.

  Furthermore, according to the invention of claim 4, the humidity of the dry exhaust gas exhausted from the dryer provided with the multi-tube heating tube is significantly higher than that of a so-called rotary kiln type or rotary drum type device. Therefore, the production | generation of clinker in a carbonization furnace can be suppressed effectively.

It is a block diagram which shows the carbonization processing apparatus of the sludge provided for implementation of this invention. It is a side view which shows a dryer partially broken. It is a block diagram which shows the carbonization processing apparatus of the existing sludge.

The mode for carrying out the “sludge carbonization method” of the present invention is the one shown in the following examples as one of the best modes, and includes modes modified based on this technical idea.
Hereinafter, after describing the carbonization apparatus S, the “sludge carbonization method” of the present invention will be described together with the operation mode of the apparatus.

In FIG. 1, what is indicated by a symbol S is a carbonization treatment apparatus, which is a dried product M1 in which the sludge M0 is once dried to reduce moisture, and subsequently heated to obtain a carbide M2. is there.
Specifically, the carbonization treatment apparatus S includes a dryer 1, a carbonization furnace 2, and a reburning furnace 3 as main devices, and the carbonization exhaust gas G2 exhausted from the carbonization furnace 2 is regenerated as a reburning furnace. 3, the configuration is adopted in which the exhaust gas G3 from which harmful substances are rendered harmless can be exhausted to the outside by performing the combustion treatment.
Moreover, the carbonization processing apparatus S collect | recovers the heat | fever contained in the said recombustion waste gas G3, and this heat can be provided as any one or several heat sources of the said dryer 1, the carbonization furnace 2, or the recombustion furnace 3. It is configured.
Hereinafter, the components of the carbonization apparatus S will be described in detail.

First, the dryer 1 is a conductive heat transfer type device that conducts heat indirectly from the heating medium A to the object to be processed without directly contacting the sludge M0 that is the object to be processed and the heating medium A, In this embodiment, as an example, an apparatus provided with a multi-tube heating tube 11 is adopted.
Specifically, as shown in FIG. 2, a multi-tube heating tube 11 is provided in a main body shell 10 provided on the machine frame F, and the multi-tube heating tube 11 is provided inside the heating medium A ( The steam is heated and rotated, and the object to be processed is put into the main body shell 10, and the object to be processed is brought into contact with the multi-tube heating tube 11 while staying in the main body shell 10. Is a device for drying.

The main body shell 10 is a hollow member having an oblong cross section as an example, and has an inlet 101, an overflow outlet 102, a carrier gas outlet 103, and an exhaust outlet 104.
Here, the inlets 101 are formed at a plurality of locations on the upper part of the main body shell 10. First, in FIG. 1, a first inlet 101a is formed in the vicinity of the exhaust port 104 formed on the upper left side. Further, a second inlet 101b is formed in a portion closer to the center than the exhaust port 104, and further between the second inlet 101b and the carrier gas port 103 formed at the upper right side in FIG. A third inlet 101c is formed. In this embodiment, the input ports 101 are formed at three locations, but the input ports 101 may be formed at one location, two locations, or four locations or more according to the specifications of the dryer 1.

The main body shell 10 and the multi-tube heating pipe 11 are installed in the machine frame F in a horizontal state, or the main body shell 10 and the multi-tube heating pipe 11 are inclined so that the exhaust port 104 side is somewhat higher than the carrier gas port 103 side. Installed in frame F.
Furthermore, the main body shell 10 has a double jacket structure, and a steam passage path is formed from a steam supply port 105 formed in the vicinity of the charging port 101a to a drain port 106 formed below the overflow port 102. The structure which can heat up the inside of the main body shell 10 is taken. In addition, it can replace with such a double jacket structure and can also install trace piping.
The overflow outlet 102 is formed on the side surface of the body shell 10 at a high position. Further, a chute 12 is provided so as to cover the overflow outlet 102, and a dry matter discharge port 121 formed in the chute 12 is provided. A rotary valve 122 is provided.

Next, the multi-tube heating tube 11 includes end plates 112 on both sides of a tube bundle 116 formed by arranging a plurality of tubes in a cylindrical shape, and a shaft body 113 at the center of the end plate 112. The shaft body 113 is rotatably supported by a bearing block 114 provided in the machine frame F. A motor (not shown) is provided on the machine frame F as a driving device for rotating the multi-tube heating tube 11.
Rotary joints 115 (115a, 115b) are attached to both ends of the shaft body 113 and connected to the tube bundle 116. Further, a seal mechanism 13 is provided between the shaft body 113 and the main body shell 10 for shielding from the outside air.
In addition, the side periphery of the tube bundle 116 is provided with a number of angles 111 (12 in this embodiment) to which a plurality of lifters 117 and feed blades 118 having appropriate angles are attached. The object to be treated (sludge M0) is scraped up to come into contact with each tube of the tube bundle 116 and proceeds from the inlet 101 side to the overflow outlet 102 side.

During operation of the dryer 1, carrier gas is supplied into the main body shell 10 from the carrier gas port 103, and volatile components volatilized from the sludge M0 as the object to be treated by heating of the multi-tube heating tube 11 are The carrier gas is carried away from the main body shell 10 through the exhaust port 104.
The dryer 1 has a different configuration as long as it is a conduction heat transfer type apparatus that conducts heat indirectly from the heating medium A to the object to be processed, in addition to the apparatus provided with the multi-tube heating pipe 11 described above. Things can be adopted.

Next, the carbonization furnace 2 will be described. This is a rotary kiln type or rotary drum type device for converting the dry matter M1 sent from the dryer 1 into the carbide M2, and from the combustion furnace 20 to the rotary drum 25. The apparatus is configured to heat the object to be processed in the rotary drum 25 by supplying hot air.
The combustion furnace 20 is lined with an appropriate refractory material, and is a device that generates hot air at a desired temperature by burning fuel with a burner 21.
Further, as an example, the rotary drum 25 is mounted on four support rollers 25a and is driven to rotate by a variable speed motor. Both ends of the rotary drum 25 are appropriately sealed at the boundary by lid members. It is blocked by the state. Further, the rotary drum 25 is provided with a lifter, and the workpiece is picked up by the lifter.
The lid that closes both ends of the rotary drum 25 is formed with an input port 22, an air supply port 23, an air supply port 24, an exhaust port 28, and an exhaust port 29.

  Next, the reburning furnace 3 will be described. This is a device for converting the carbonized exhaust gas G2 sent from the carbonizing furnace 2 into a reburning exhaust gas G3, and supplying hot air from the burner 31 into the combustion drum 30. Thus, the carbonized exhaust gas G2 can be combusted in the combustion cylinder 30. An air supply port 32 and an exhaust port 33 are formed in the combustion cylinder 30.

These dryer 1, carbonization furnace 2 and reburning furnace 3 are connected by interposing peripheral equipment as shown in FIG. 1 to constitute a carbonization processing apparatus S. It demonstrates along the flow of the dry waste gas G1 exhausted from the dryer 1. FIG.
Specifically, a dust collector 4 to which a bag filter, a cyclone or the like is applied is connected to the exhaust port 104 of the dryer 1, and a condenser 5 is further connected to the dust collector 4. The dust collector 4 is exhausted from the exhaust port 104. It is possible to remove dust and excess water in the dry exhaust gas G1.
The condenser 5 is a device that cools the dry exhaust gas G1 in the casing by condensing the vapor component by supplying the refrigerant from the cooling tower 52 to the cooling pipe 51 wound around the outer periphery of the casing 50.

And the exhaust part of the said capacitor | condenser 5 is connected to the inlet 61 in the heat exchanger 6, and the outlet 62 is connected to the inlet 23 and the inlet 24 in the carbonization furnace 2.
In this embodiment, an apparatus capable of independently raising the temperature of two kinds of gases is adopted as the heat exchanger 6. Specifically, an air supply port 61 and an exhaust port 62 are formed in the housing 60, and the air supply port 61 and the exhaust port 62 are connected by a heat transfer pipe 63. Further, an air supply port 64 and an exhaust port 65 are formed for the housing 60, and the air supply port 64 and the exhaust port 65 are connected by a heat transfer tube 66. The housing 60 is formed with an introduction port 67 and an exhaust port 68. The heated gas introduced into the housing 60 from the introduction port 67 (in this embodiment, the reburning exhaust gas G3), and the heat transfer tube 63 are formed. In addition, heat exchange is performed with the heated gas located in the heat transfer tube 66.

The exhaust port 28 of the carbonization furnace 2 is connected to an air supply port 32 in the reburning furnace 3 so that the carbonized exhaust gas G2 is supplied to the reburning furnace 3. The exhaust port 33 in the reburning furnace 3 is connected to the introduction port 67 in the heat exchanger 6 so that the reburning exhaust gas G3 is supplied to the heat exchanger 6.
Further, the exhaust port 68 of the heat exchanger 6 is connected to an air supply port 71 in the waste heat boiler 7, and the exhaust port 72 is further connected to a dust collector 8 to which a bag filter, a cyclone or the like is applied.
In addition, outside air is supplied to the air supply port 64 in the heat exchanger 6, and the gas heated by passing through the heat transfer tube 66 is supplied to the air supply port 23, the air supply port 24, or the reburning in the carbonization furnace 2. It is configured to be supplied to an air supply port 32 in the furnace 3.

Here, the waste heat boiler 7 may employ either a so-called water tube type or a smoke tube type, but in this embodiment, a water tube type was adopted. Specifically, an air supply port 71 and an exhaust port 72 are formed in the housing 70 so that high-temperature gas is supplied into the housing 70, and a water pipe 73 is further provided in the housing 70. The water supplied into the water pipe 73 from the water supply port 74 is heated by the high-heat gas (reburned exhaust gas G3) in contact with the outer peripheral portion of the water pipe 73, and is discharged from the exhaust port 75 as steam. It is composed of.
By adopting the above-described configuration, the dried exhaust gas G1 exhausted from the dryer 1 becomes the carbonized exhaust gas G2 in the carbonization furnace 2, and then reaches the recombustion furnace 3, where it is burned, thereby causing harmful substances. Becomes the reburned exhaust gas G3 rendered harmless, and then the temperature is lowered and exhausted to the outside with the dust removed.

Next, a configuration for supplying steam as the heating medium A to the dryer 1 will be described. Specifically, the condensed water discharged from the rotary joint 115b in the dryer 1 is collected in the drain collecting unit 9, and then heated by the waste heat boiler 7 to generate steam. The medium A is supplied to the rotary joint 115a. The drain recovery unit 9 can also be supplied with water from the outside.
Further, in this embodiment, a pipe connecting the exhaust port 75 in the waste heat boiler 7 and the rotary joint 115a in the dryer 1 is branched. First, the pipe is connected to the heat transfer pipe 6b in the heat exchanger 6B and the heat transfer pipe. The other end of 6b was connected to the drain recovery unit 9. The outside air supplied to the heat exchanger 6B is supplied to the carrier gas port 103 in a state where the heat is exchanged with the steam through the heat transfer tube 6b and the temperature is raised.
Further, a pipe connecting the exhaust port 75 and the rotary joint 115 a is further branched and connected to the steam supply port 105.

Furthermore, in this embodiment, a boiler is provided as the auxiliary heater 7B, and water supplied from the drain recovery unit 9 is heated to generate steam, which is then used as the rotary joint 115a and the heat exchanger 6B. And the steam supply port 105 can be supplied.
Further, the pipe connecting the rotary joint 115a, the heat exchanger 6B and the steam supply port 105, the exhaust port 75 and the auxiliary heater 7B is branched and connected to the air supply port 26 in the carbonization furnace 2. There is a valve on this branch.
The auxiliary heater 7B is mainly used when the carbonizing apparatus S is started, and the waste heat boiler 7 is mainly used during steady operation.

  The carbonization treatment apparatus S is configured as described above as an example. Hereinafter, the operation state of this apparatus will be described, and the “sludge carbonization method” of the present invention will be described.

(1) [Generation of heating medium at startup]
First, water is supplied to the auxiliary heater 7B to generate heated steam. As an example, the heating medium A that is saturated steam at 158 ° C. (0.5 MPaG) is generated. In addition, the heating medium A is supplied to the heat exchanger 6B to heat the outside air into high-temperature air, and this is supplied to the carrier gas port 103 to carry the water evaporated from the sludge M0. It serves as a carrier gas.

(2) [Production of dried product]
Next, the heating medium A is supplied to the rotary joint 115a in the dryer 1, and the sludge M0 (70 to 85% W.B. as an example) that has been appropriately dehydrated is supplied to the main body through the inlets 101a, 101b, and 101c. It is thrown into the shell 10.
The carrier gas is introduced into the main body shell 10 from the carrier gas port 103.
Then, the sludge M0 stays in the main body shell 10 and is brought into contact with the multi-tubular heating tube 11, whereby the moisture in the sludge M0 is evaporated and dried. At this time, the sludge M0 is heated from the heating medium A. Indirect heat conduction.
Eventually, the water of the sludge M0 is evaporated, and becomes a dry matter M1 (as an example, 10 to 30% W. B.), which is discharged from the dry matter discharge port 121 and from the charging port 22 in the carbonization furnace 2 into the rotary drum 25. To be supplied.

(3) [Humidity control and flow of dry exhaust gas]
On the other hand, the water evaporated from the sludge M0 is carried by the carrier gas and becomes the dry exhaust gas G1 (100 ° C. as an example) exhausted from the exhaust port 104. Dust is removed in the dust collector 4 and the humidity in the condenser 5 is increased. After the adjustment, the air is supplied to the air supply port 61 in the heat exchanger 6.
Here, the humidity adjustment of the dry exhaust gas G1 is preferably performed in conjunction with, for example, the burnup degree of the object to be treated (dry matter M1) in the carbonization furnace 2, and when the burnup degree is higher than a reference value, the dry exhaust gas G1 is dried. While the humidity of the exhaust gas G1 is increased, the humidity of the dry exhaust gas G1 is decreased when the burnup is lower than the reference value.
The burnup is detected by an operator's visual inspection or a temperature sensor.

Furthermore, in the heat exchanger 6, when the dried exhaust gas G1 passes through the heat transfer tube 63, the heat is exchanged with the reburning exhaust gas G3 (800 ° C. as an example) and the temperature is raised (500 ° C. as an example). Thus, the air is supplied to the air supply port 23 and the air supply port 24 in the carbonization furnace 2. The reburning exhaust gas G3 will be described in detail later.
Also, outside air is supplied to the air supply port 64 in the heat exchanger 6 (as an example, 20 ° C.), and when this outside air passes through the heat transfer tube 66, the reheated exhaust gas G 3 (as an example, 800 ° C.) In a state where the temperature is increased by heat exchange between them (as an example, 500 ° C.), the heat is supplied to the air supply port 23 and / or the air supply port 24 in the carbonization furnace 2 and the air supply port 32 in the reburning furnace 3.

(4) [Production of carbides]
In the carbonization furnace 2, the dry matter M <b> 1 is picked up and dropped by the lifter as the rotary drum 25 rotates, and is dispersed, and the heat exchanger 6 has a temperature of 500 ° C. as an example. The dried exhaust gas G1 whose temperature has been raised and the hot air supplied from the combustion furnace 20 are brought into contact with each other, and eventually become carbide M2 and are discharged from the discharge port 29.
Thus, in the carbonization furnace 2, the heat contained in the reburning exhaust gas G3 is provided as a heat source.
Further, since the dry exhaust gas G1 is supplied to the charging port 22 side and / or the discharging port 29 side in the carbonizing furnace 2, the vicinity of the charging port 22 and / or the vicinity of the discharging port 29 in the carbonizing furnace 2 can be brought to a high temperature state. It becomes possible to favorably promote carbonization of the object to be processed (dried material M1).
Furthermore, according to the present invention, by reducing the oxygen partial pressure in the carbonization furnace 2 by the steam component contained in the dry exhaust gas G1, the combustion rate of the object to be treated (dry matter M1) can be suppressed, The rapid increase in temperature of the product (dried product M1) is suppressed, and the production of clinker is effectively prevented.
Further, since a part of the path for sending steam generated from the waste heat boiler 7 or the auxiliary heater 7B is connected to the air supply port 26 of the carbonization furnace 2, the steam can be supplied into the carbonization furnace 2. For this reason, it is possible to reliably supply steam into the carbonization furnace 2 immediately after startup or during steady operation, and even when the steady operation is being performed, steam exceeding the amount of steam that can be supplied from the dry exhaust gas G1. Can be supplied within. By adopting such a configuration, for example, when the physical property of the sludge M0 is changed, the physical property of the dry matter M1 is changed accordingly, so that the carbonization state is also changed. Even if it occurs, the amount of steam supplied into the carbonization furnace 2 can be varied in a wide range, so that a good carbonization state can be adjusted. Further, when the amount of evaporated water from the sludge M0 is small, the amount of steam in the dry exhaust gas G1 is reduced. Even in such a case, steam is directly supplied into the carbonization furnace 2 from the waste heat boiler 7 or the auxiliary heater 7B. Can be compensated for.

(5) [Flow of carbonized exhaust gas and generation of reburning exhaust gas]
On the other hand, the carbonized exhaust gas G2 (700 ° C. as an example) exhausted from the exhaust port 28 is supplied to the air supply port 32 in the reburning furnace 3.
In the reburning furnace 3, the carbonized exhaust gas G2 is burned in contact with the outside air heated to 500 ° C. and the hot air supplied from the burner 31 as an example in the heat exchanger 6, thereby detoxifying harmful substances. Reheated exhaust gas G3 (800 ° C. as an example) is discharged from the exhaust port 33.
Thus, in the reburning furnace 3, the heat contained in the reburning exhaust gas G3 is provided as a heat source.

(6) [Flow of re-burning exhaust gas]
Next, as described above, the reburning exhaust gas G3 is supplied to the air supply port 71 of the waste heat boiler 7 after the dry exhaust gas G1 and the outside air are heated in the heat exchanger 6 and the temperature is lowered (as an example, 550 ° C.). .
In the waste heat boiler 7, heat exchange is performed between the reburning exhaust gas G3 and the water passing through the water pipe 73, and the reburning exhaust gas G3 is discharged from the exhaust port 72 in a state where the temperature is lowered ( As an example, 350 ° C.).
Further, when the outside air (20 ° C. as an example) is mixed into the reburning exhaust gas G3 in this state, the temperature of the reburning exhaust gas G3 is reduced to 200 ° C. as an example, and dust or the like is removed in the dust collector 8. After that, it is exhausted to the outside.

(7) [Production of heating medium using heat contained in flue gas and production of dried product]
The carbonization processing apparatus S shifts to the steady operation by performing the above-described series of operations, and here, generation of the heating medium A in the state shifted to the steady operation will be described.
That is, immediately after start-up, water is supplied to the auxiliary heater 7B to generate heated steam, and as an example, the heating medium A at 158 ° C. is generated. However, the heat contained in the reburning exhaust gas G3 is discharged from the waste heat boiler 7 during steady operation. It collect | recovers and this produces | generates the saturated water vapor | steam for heating, ie, the heating medium A.
Specifically, heating steam is generated with high efficiency in the waste heat boiler 7, and as an example, the heating medium A at 158 ° C. is generated.
The heating medium A is supplied to the dryer 1, and in the dryer 1, the heat contained in the reburning exhaust gas G <b> 3 is provided as a heat source.

The carbonization method of the present invention is carried out as described above as an example, and the vapor humidity contained in the dry exhaust gas G1 is significantly higher than that of a so-called rotary kiln type or rotary drum type device. By supplying the dry exhaust gas G1 into the carbonization furnace 2, the production of clinker in the carbonization furnace 2 can be effectively suppressed. This is because when the dry exhaust gas G1 having a high steam humidity is introduced into the carbonization furnace 2, the oxygen partial pressure in the carbonization furnace 2 can be reduced and the combustion rate of the workpiece can be suppressed. It is. In addition, since the water | moisture content in the dry waste gas G1 is condensed by the capacitor | condenser 5, and the quantity of the vapor | steam component in the dry waste gas G1 is adjusted by it, the oxygen partial pressure in the carbonization furnace 2 will also be adjusted.
As a result, when the physical property of the sludge M0 changes, that is, the physical property of the dry matter M1 changes, the oxygen partial pressure can be adjusted in accordance with the physical property of the dry matter M1, and thus the occurrence of clinker is generated. Suppressed good carbide M2 can be obtained.

Further, supplying the dry exhaust gas G1 to the air supply port 23 and / or the air supply port 24 adjusts the distribution of the oxygen partial pressure in the direction of the rotation axis in the rotary drum 25, that is, from the input port 22 to the discharge port 29. It makes it possible.
Thereby, when the physical property of the sludge M0 is changed as described above, the oxygen distribution can be adjusted in accordance with the physical property of the dry matter M1, so that a better carbide M2 in which generation of clinker is suppressed is obtained. Can do.

  Furthermore, since the steam from the waste heat boiler 7 or the auxiliary heater 7B can be supplied into the carbonization furnace 2 from the air supply port 26, the oxygen partial pressure in the carbonization furnace 2 can be adjusted in a wider range. Thus, even if the change in the physical properties of the sludge M0 is large, a stable carbide M2 in which the generation of clinker is suppressed can be obtained.

Furthermore, since the dry exhaust gas G1 receives heat from the heat exchanger 6 and becomes a high temperature, the fuel consumed by the burner 21 in the carbonization furnace 2 can be reduced, and the dry exhaust gas G1 is supplied to the air inlet 23 and / or the air inlet. The supply from 24 can adjust the temperature distribution in the direction from the inlet 22 to the outlet 29 of the carbonization furnace 2.
Thereby, when the physical property of the sludge M0 is changed, the temperature distribution can be adjusted in accordance with the physical property of the dried product M1, as described above, so that a better carbide M2 in which the generation of clinker is suppressed is obtained. Can do.

DESCRIPTION OF SYMBOLS 1 (Horizontal continuous conduction heat transfer type) Dryer 10 Main body shell 101 Input port 101a Input port 101b Input port 101c Input port 102 Overflow port 103 Carrier gas port 104 Exhaust port 105 Steam supply port 106 Drain port 11 Multi-tube heating tube 111 Angle 112 End plate 113 Shaft body 114 Bearing block 115 Rotary joint 115a Rotary joint 115b Rotary joint 116 Tube bundle 117 Lifter 118 Feed blade 12 Chute 121 Dry matter discharge port 122 Rotary valve 13 Seal mechanism 2 Carbonization furnace 20 Combustion furnace 21 Burner 22 Input port 23 Air supply port 24 Air supply port 25 Rotating drum 25a Support roller 26 Air supply port 28 Exhaust port 29 Exhaust port 3 Reburning furnace 30 Combustion cylinder 31 Burner 32 Air supply port 33 Exhaust port 4 Dust collector And bug filters)
5 Capacitor 50 Housing 51 Cooling Tube 52 Cooling Tower 6 Heat Exchanger 60 Housing 61 Air Supply Port 62 Exhaust Port 63 Heat Transfer Tube 64 Air Supply Port 65 Exhaust Port 66 Heat Transfer Tube 67 Inlet Port 68 Discharge Port 6B Heat Exchanger (Air Heater)
6b Heat transfer tube 7 Waste heat boiler 70 Case 71 Air supply port 72 Exhaust port 73 Water tube 74 Water supply port 75 Exhaust port 7B Auxiliary heater (boiler)
8 Dust collector 9 Drain recovery unit A Heating medium F Machine frame G1 Dry exhaust gas G2 Carbonized exhaust gas G3 Reburning exhaust gas M0 Sludge M1 Dry matter M2 Carbide S Carbonization equipment

Claims (4)

In the method of drying the object to be processed using a dryer and then converting it into a carbide using a carbonization furnace, the carbonized exhaust gas exhausted from the carbonization furnace is burned in a reburning furnace to detoxify harmful substances. The exhaust gas is exhausted to the outside as a treated re-burning exhaust gas, and the heat contained in the re-burning exhaust gas is provided as one or a plurality of heat sources of the dryer, the carbonization furnace, or the re-burning furnace. By using a rotary kiln type or rotary drum type device, and using a conductive heat transfer type device that conducts heat indirectly from the heating medium to the object to be processed as the dryer, moisture evaporated from the object to be processed is removed. A method for carbonizing sludge, comprising supplying the dry exhaust gas contained in the carbonization furnace. The method for carbonizing sludge according to claim 1, wherein the humidity of the dry exhaust gas is adjusted by removing a part of the vapor component in the dry exhaust gas using a condenser. The method for carbonizing sludge according to claim 1 or 2, wherein the temperature of the dry exhaust gas is raised by heat contained in the reburning exhaust gas and then supplied to a carbonization furnace. As the dryer, a multi-tube heating tube is provided in a main body shell provided on a machine frame, and this multi-tube heating tube is rotated while flowing steam for heating inside the main shell. The apparatus according to claim 1, 2 or 2, wherein an apparatus is used for charging the object to be processed and drying the object to be processed by contacting the multi-tube heating tube while retaining the object to be processed in the main body shell. 3. The method for carbonizing sludge according to item 3.

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