JP5504959B2 - Sludge carbonization equipment - Google Patents

Description

  The present invention relates to a sludge carbonization facility for carbonizing organic matter-containing sludge.

Wastewater containing organic matter discharged from homes and the like is generally treated by an activated sludge method or the like in a sewage treatment facility.
Sewage sludge containing excess organic matter is generated along with this wastewater treatment, but the amount of generated sewage sludge increases year by year as the amount of wastewater treatment increases, and disposal of such wastewater is a major problem.
When disposing of sewage sludge, the sewage sludge contains a large amount of water and cannot be disposed as it is, where it is concentrated and dehydrated for reduction, or incinerated or melted. Various treatments are applied.

However, if sewage sludge is incinerated or melted, a large amount of energy is consumed, resulting in high processing costs.
Therefore, as one method of treating sewage sludge with low energy consumption, it has been proposed to carbonize sewage sludge by dry distillation treatment.
In this carbonization treatment, since the sewage sludge contains about 45% by mass of carbon in the substrate, the carbon in the sludge is not consumed like incineration and melting treatment, but the sludge is oxygen-free or low. By pyrolysis (carbonization) in an oxygen state, the carbon content remains, and is produced as a carbide (carbonized product) having a new composition.

Conventionally, in this carbonization treatment, surplus sewage sludge generated in a sewage treatment plant is agglomerated by adding a polymer flocculant, etc., and then dehydrated by a dehydrator to have a water content of about 70 to 85% (usually Is about 80%) dewatered sludge.
Thereafter, this dewatered sludge is put into the dryer, where it is dried to a moisture content of about 25 to 45% (usually about 40%).
The dried sludge thus obtained is put into a carbonization furnace, and this is subjected to dry distillation treatment in the carbonization furnace to obtain sludge as a carbonized product, which is discharged from the carbonization furnace.

FIG. 4 shows a specific configuration of a conventional carbonization treatment facility for performing this carbonization treatment.
In the figure, reference numeral 200 denotes a hot air generating furnace in which hot air serving as a heat source for drying the dewatered sludge is generated.
Reference numeral 201 denotes a receiving hopper, and dewatered sludge dehydrated to a moisture content of about 80% is first received by the receiving hopper 201.
The dewatered sludge accepted here is sent to a dryer 206 which also serves as a granulator by a quantitative supply device 204 and a transfer device 205 via a relay hopper 202, where a predetermined moisture content, specifically 40%, is sent. It is dried to a moisture content of about a degree and granulated into dumpling-like grains having a particle size of about 10 mm.

The dryer 206 has a stirring shaft 210 inside a rotary drum 208 as shown in FIG. Here, the stirring shaft 210 is provided at a position eccentric from the center of the rotary drum 208.
A plurality of stirring blades 212 extend radially from the stirring shaft 210.
On the other hand, a plurality of plate-like lifters 214 are provided on the inner peripheral surface of the rotating drum 208 at a predetermined interval in the circumferential direction so as to rotate integrally with the rotating drum 208.
As a result, the sludge (dehydrated sludge) inside the rotary drum 208 is lifted upward from the bottom by the lifter 214 as the rotary drum 208 rotates, and falls by its own weight near the top.
The sludge that has fallen is finely crushed by the high-speed rotation of the stirring blade 212 located on the lower side, and falls to the bottom side of the rotary drum 208.

The sludge in the rotating drum 208 is subjected to such a stirring action, and is subjected to a drying process by being exposed to hot air guided from the hot air generating furnace 200 of FIG. 4 to the inside of the dryer 206, so that moisture gradually decreases.
The sludge is gradually sent in the axial direction while being granulated into an appropriate particle size inside the rotary drum 208 by the inclination gradient of the rotary drum 208 and further by the crushing by the stirring blade 212 and the scattering action at that time.
The dried sludge that has been dried and granulated by the dryer 206 in this way is then transported to the carbonization furnace 222 via the relay hopper 218 by the transport devices 216 and 220, where it has an appropriate particle size of about 10 mm. The granulated dried sludge having a moisture content of about 40% is carbonized by dry distillation.

  This carbonization furnace 222 is a self-combustion type with an externally heated rotary kiln type jet pipe, and the carbonization furnace 222 has a dry distillation vessel comprising a rotating drum inside a furnace body 224 as shown in FIG. A cylindrical retort 226 is provided, and the dried sludge dried and granulated by the preceding dryer 206 is put into the retort 226 by a screw feeder (not shown).

The input dried sludge is first heated by the atmospheric heating inside the external heat chamber 230 by the auxiliary combustion burner (external heat chamber burner) 228 disposed inside the furnace body 224.
Then, the combustible gas contained in the dried sludge is ejected into the atmosphere of the external heat chamber 230 through the ejection pipe 232 provided in the retort 226, and after this combustible gas is ignited, the combustible gas is burned. The sludge inside the retort 226 is heated.
At this stage, the auxiliary burner 228 is stopped from burning.

As shown in FIG. 6, an exhaust gas treatment chamber 234 that is partitioned from the external heat chamber 230 is provided inside the furnace body 224, and the exhaust gas from the external heat chamber 230 is led here.
The exhaust gas treatment chamber 234 is provided with an exhaust gas treatment chamber burner 236, and unburned gas in the exhaust gas introduced into the exhaust gas treatment chamber 234 is subjected to secondary combustion in the exhaust gas treatment chamber burner 236. .

The sludge inside the retort 226 moves from the left end in the figure to the right in the figure along with the rotation of the retort 226 (the retort 226 has a slight gradient), and finally the carbonization residue (carbonized product) is retort. 226 is discharged from the right end outlet 238, that is, the carbonization furnace 222.
On the other hand, the exhaust gas discharged from the carbonization furnace 222 is discharged from the chimney to the atmosphere through a heat exchanger as shown in FIG.
This kind of sludge carbonization equipment is disclosed in, for example, Patent Document 1 and Patent Document 2 below.

  However, in the case of the conventional sludge carbonization equipment shown in FIG. 4, it is necessary to install a hot air generating furnace 200 for generating hot air for drying in the dryer 206, and the cost for the installation is low. In addition, the installation of the hot air generating furnace 200 inevitably increases the size of the equipment, and the generation of hot air in the hot air generating furnace 200 increases the running cost of the equipment.

Therefore, there have been proposed proposals aimed at solving such problems.
For example, Patent Document 3 below discloses that the exhaust gas from the carbonization furnace is led to the dryer shown in FIG. 5 and used as a heat source for drying in the dryer instead of installing a hot-air generator. .
According to the one disclosed in Patent Document 3, it is possible to eliminate the installation of a hot air generating furnace, and hence it is possible to reduce the equipment cost required for the hot air generating furnace and to reduce the size of the entire equipment by omitting the hot air generating furnace. In addition, it is possible to reduce running costs due to hot air generation in the hot air generating furnace.

The following Patent Document 4 discloses that the exhaust gas from the carbonization furnace is guided to a dryer and used as a heat source for drying in the dryer.
In the one disclosed in Patent Document 4, an air-flow dryer as a dryer, specifically, a mixture obtained by adding dehydrated sludge dry powder to a part of the dehydrated sludge is crushed, and hot air is blown to the crushed material. The airflow dryer is used to convey the crushed material and dry it into dry powder, which is discharged together with the airflow.

  In the case of the dryer of FIG. 5 used in Patent Document 3, the entire amount of high water content sludge having a water content of about 80% is put into it and dried, and the contact area between the dewatered sludge and hot air is small. In combination with this, it takes a long time to dry (about 30 minutes), which results in a problem of poor thermal efficiency and high consumption of thermal energy, which increases the running cost of the equipment.

  However, in the case of the above-mentioned airflow type dryer, the time required for drying is in seconds, and it is possible to perform the drying process in an extremely short time almost instantly, and the drying efficiency is very high. Less heat energy.

  By the way, it is desirable that the heat energy applied from the outside can be reduced as much as possible during the carbonization treatment of sludge. In this respect, the above-mentioned Patent Document 3, which uses the hot air of the high-temperature exhaust gas from the carbonization furnace as the heat source for drying in the dryer. The one disclosed in Patent Document 4 is desirable because it can reduce the heat energy to be applied from the outside.

  However, in the conventional sludge carbonization equipment including those disclosed in Patent Document 3 and Patent Document 4, it is necessary to apply heat energy from the outside when the exhaust gas discharged outside the system is deodorized by the deodorizer. This has been an obstacle to further reducing the supply of heat energy from the outside to the carbonization equipment.

Conventionally, a deodorizing apparatus usually used is of a combustion deodorization type in which an odor component in exhaust gas is burned to deodorize, and it is inevitably necessary to add heat energy from the outside for the deodorization treatment.
However, in the device disclosed in Patent Document 4, a catalyst deodorization type deodorizing device is used as a deodorization device. Even in this catalyst deodorization type, heat is applied from the outside in order to effectively perform the catalyst reaction. In addition, it is necessary to raise the temperature up to a certain temperature, for example, about 300 ° C., to cause a catalytic reaction.

  In carbonization equipment that supplies high-temperature exhaust gas from the carbonization furnace to the dryer for drying treatment, another problem is that the exhaust gas from the carbonization furnace is used as a heat source for drying due to fluctuations in the properties of the dewatered sludge. The following difficulties have arisen when using as:

That is, the moisture content of the dewatered sludge is not constant in each sewage treatment plant, and the moisture content of the dewatered sludge varies depending on the sewage treatment plant.
On the other hand, for a carbonization furnace, it is desirable to use a self-combustion type carbonization furnace, that is, a furnace that ignites and burns combustible gas generated from sludge and carbonizes sludge by its heat. The amount of heat also varies depending on the properties of the dewatered sludge, specifically, by changing the amount of combustible components contained in the sludge for each sewage treatment plant.

Thus, if the moisture content of the dewatered sludge increases as described above, the amount of heat required for drying increases, and if the moisture content decreases, the amount of heat required for drying can be reduced.
In addition, the calorific value of the exhaust gas generated in the self-burning type carbonization furnace increases as the combustible component increases, and the calorific value of the exhaust gas generated decreases as the combustible component decreases.
Therefore, it is difficult to satisfactorily perform drying in the dryer simply by introducing the exhaust gas generated in the carbonization furnace to the dryer and using it as a heat source for drying.

JP-A-11-37644 Japanese Patent Laid-Open No. 11-33599 JP 11-37645 A JP 2008-238129 A

The present invention has been made for the purpose of providing a sludge carbonization treatment facility capable of reducing as much as possible the heat energy applied from the outside during the sludge carbonization treatment.
Another object of the present invention is to provide a sludge carbonization treatment facility that can perform a drying treatment satisfactorily in a dryer using carbonization furnace exhaust gas, regardless of fluctuations in the properties of the dewatered sludge. To do.

Thus, according to the first aspect of the present invention, (A) a dryer for drying the dewatered sludge after dewatering the organic matter-containing sludge, and (B) carbonization by carbonizing the dry sludge by carbonization to obtain a carbonized product. A furnace, (C) a carbonization furnace exhaust gas supply path that extends from the carbonization furnace and is connected to the dryer, and supplies the carbonization furnace exhaust gas as hot air to the dryer as a heat source for drying, and (D) outside the system In the sludge carbonization equipment comprising a deodorizing device for deodorizing the exhaust gas discharged, the deodorizing device is configured to contact the exhaust gas discharged out of the system with contact with the deodorizing liquid in the exhaust gas. A wet deodorizing device that removes and deodorizes the odor component of the carbon dioxide , and (a) bypasses the dryer by branching from the carbonization furnace exhaust gas supply path, and is connected to an exhaust gas flow channel downstream of the dryer A bypass path; (b) provided in the bypass path; A bypass path valve for controlling the exhaust gas, and (c) extending from a downstream side of the wet deodorization device in the exhaust gas flow path, connected to a downstream side of a branch portion of the bypass path in the carbonization furnace exhaust gas supply path, An exhaust gas circulation path for returning a part of the exhaust gas flowing out from the wet deodorization apparatus to the carbonization furnace exhaust gas supply path and supplying it to the dryer; (d) provided in the exhaust gas circulation path; And a circulation path valve to be controlled .

(2 ) A dryer for drying the dewatered sludge after dewatering the organic substance-containing sludge, (B) a carbonization furnace for carbonizing the dry sludge by carbonization, (C) a carbonization furnace exhaust gas supply path that extends from the carbonization furnace and is connected to the dryer and supplies the carbonization furnace exhaust gas as hot air to the dryer as a heat source for drying; and (D) is discharged outside the system. In the sludge carbonization equipment comprising a deodorizing device for deodorizing the exhaust gas, the deodorizing device is brought into contact with a deodorizing liquid against the exhaust gas discharged outside the system, and the odor component in the exhaust gas In addition, a wet deodorizing apparatus that removes and deodorizes the mixture is used, and as the dryer, a mixture obtained by adding a dry powder of the dehydrated sludge to a part of the dehydrated sludge is crushed and the hot air is blown onto the crushed material. The crushed material is conveyed by an air flow and dried to燥粉and without using an airflow dryer is discharged together with the air flow, further (a) branched from the carbonization furnace exhaust gas supply path to bypass the dryer, connected downstream exhaust gas flow path of the dryer A bypass path, (b) a bypass path valve provided in the bypass path for controlling the opening degree of the bypass path, and (c) extending from the downstream side of the wet deodorizer in the exhaust gas path, An exhaust gas circulation path that is connected to the downstream side of the branch portion of the bypass path in the carbonization furnace exhaust gas supply path and returns a part of the exhaust gas flowing out from the wet deodorization device to the carbonization furnace exhaust gas supply path and supplies it to the dryer And (d) a circulation path valve provided in the exhaust gas circulation path for controlling the opening degree of the exhaust gas circulation path .

The invention according to claim 3 includes: (A) a dryer for drying the dewatered sludge after dewatering the organic substance-containing sludge; and (B) a carbonization furnace for carbonizing by carbonizing the dried sludge to obtain a carbonized product; (C) a carbonization furnace exhaust gas supply path that extends from the carbonization furnace and is connected to the dryer and supplies the carbonization furnace exhaust gas as hot air to the dryer as a heat source for drying; and (D) is discharged outside the system. In the sludge carbonization equipment comprising a deodorizing device for deodorizing the exhaust gas, the deodorizing device is brought into contact with a deodorizing liquid against the exhaust gas discharged outside the system, and the odor component in the exhaust gas Using a wet deodorizing apparatus that removes and deodorizes, and (a) bypasses the dryer by branching from the carbonization furnace exhaust gas supply channel, and a bypass channel connected to an exhaust gas channel downstream of the dryer; (B) provided in the bypass passage to control the opening degree of the bypass passage. A bypass passage valve to be controlled; and (c) extending from the downstream side of the wet deodorization device in the exhaust gas passage, connected to a downstream side of the branch portion of the bypass passage in the carbonization furnace exhaust gas supply passage, An exhaust gas circulation path for returning a part of the exhaust gas flowing out from the deodorizing apparatus to the carbonization furnace exhaust gas supply path and supplying it to the dryer; (d) provided in the exhaust gas circulation path and controlling the opening degree of the exhaust gas circulation path And a controller for controlling the degree of opening of the bypass valve and the circulation valve, and a temperature detector and a flow detector for detecting the temperature and flow rate of the exhaust gas on the outlet side of the dryer, respectively. And when the temperature detected by the temperature detector is higher than a set temperature, the controller increases the opening of the bypass passage valve to increase the flow rate of the carbonization furnace exhaust gas flowing to the bypass passage side. When the flow rate detected by the discharger is smaller than the set flow rate, the flow rate of the circulating exhaust gas supplied to the dryer is increased by increasing the opening degree of the circulation path valve .

The invention according to claim 4 includes: (A) a dryer for drying the dehydrated sludge after the organic substance-containing sludge is dehydrated; and (B) a carbonization furnace for carbonizing the dried sludge by carbonization to obtain a carbonized product; (C) a carbonization furnace exhaust gas supply path that extends from the carbonization furnace and is connected to the dryer and supplies the carbonization furnace exhaust gas as hot air to the dryer as a heat source for drying; and (D) is discharged outside the system. In the sludge carbonization facility comprising a deodorizing device for deodorizing exhaust gas, the deodorizing device is used to contact the exhaust gas discharged out of the system with a deodorizing liquid so that the odor component in the exhaust gas is removed. Using a wet deodorizing apparatus that removes and deodorizes, and as the dryer, a mixture obtained by adding a dry powder of the dehydrated sludge to a part of the dehydrated sludge is crushed and the hot air is blown onto the crushed material, and the air flow of the hot air The crushed material is transported and dried by Without using powder, using an airflow dryer that discharges with the airflow, (a) branching off from the carbonization furnace exhaust gas supply path, bypassing the dryer, and connected to the exhaust gas flow path downstream of the dryer A bypass passage; (b) a bypass passage valve provided in the bypass passage for controlling the opening of the bypass passage; and (c) extending from the downstream side of the wet deodorization device in the exhaust gas passage, An exhaust gas circulation path which is connected to a downstream side of a branch portion of the bypass path in the furnace exhaust gas supply path and returns a part of the exhaust gas flowing out from the wet deodorizing apparatus to the carbonization furnace exhaust gas supply path and supplies the carbonizer to the dryer , (d) provided in the exhaust gas circulation passage, together comprising a circulation path valve for controlling the opening of the exhaust gas circulation passage, a pre-drier for the delivery side of the exhaust gas temperature, the temperature detector for detecting the flow rate, respectively , Flow detector and bypass E Bei a controller that performs way valve and opening control of the circulation path valve, said controller, when the temperature detected by said temperature detector is higher than the set temperature in the bypass path side the opening degree of the bypass passage valve as large The flow rate of flowing carbonization furnace exhaust gas is increased, and when the flow rate detected by the flow rate detector is smaller than the set flow rate, the flow rate of the circulating exhaust gas supplied to the dryer is increased by increasing the opening of the circulation path valve. It is characterized by being.

Effects and effects of the invention

  As described above, the present invention configures the carbonization treatment equipment so as to use the carbonization furnace exhaust gas as a heat source for drying in the dryer, and as a deodorizing device, removes the deodorizing liquid from the exhaust gas discharged outside the system. Is used to remove the odorous components in the exhaust gas and to deodorize, thereby using a wet deodorizing apparatus.

In the present invention, it is not necessary to add heat energy from the outside for deodorization by the deodorizing apparatus, and supply of heat energy from the outside, which has been conventionally required for deodorization, can be made unnecessary.
Thereby, combined with the use of the carbonization furnace exhaust gas as a heat source for drying in the dryer, the heat energy applied from the outside during the carbonization treatment of the sludge can be further reduced compared to the conventional case.

Here, as the wet deodorization apparatus, it is preferable to use an apparatus that introduces exhaust gas into the container, sprays the deodorizing liquid from the nozzle into the container, contacts the exhaust gas, and removes odor components from the exhaust gas. it can.
Further, the wet deodorization apparatus can be provided with an activated carbon layer so that odor components that cannot be sufficiently removed by the action of the liquid can be removed by the adsorption action of the activated carbon layer.

In the present invention, it is possible to use the rotary drum type dryer or other dryer shown in FIG. 5 as the dryer, but as such a dryer, dry powder of the dehydrated sludge is added to a part of the dehydrated sludge. mixture crushed and the blowing hot air to the crushed and dried to a dry powder and without conveys the crushed by a gas stream of hot air, it is desirable to use an air flow dryer for discharging with the air flow (claim 2 and claim Item 4 ).
This air-flow dryer has very high drying efficiency and requires less heat energy for drying.
Therefore, by using such an air flow dryer, it is possible to further reduce the heat energy applied from the outside during the carbonization treatment.

  In the case of using this airflow dryer, the carbonization equipment includes (a) a first mixing means for mixing a part of dehydrated sludge and dry powder to generate a mixture for supply to the dryer; (B) A separator that separates the dried powder discharged from the dryer from the air stream, and (c) a portion of the dried powder from the separator is supplied to the dryer, and the remaining part is supplied to the carbonization furnace. And (d) dry sludge for supply to the carbonization furnace, with the remaining part of the dry powder separated for supply to the carbonization furnace added to the remaining part of the dewatered sludge and mixed. And a second mixing means, and the dried sludge mixed by the second mixing means is passed through a carbonization furnace to be carbonized.

In the present invention, a bypass is connected to the exhaust gas passage on the downstream side of the dryer, branched from the carbonization furnace exhaust gas supply passage for supplying exhaust gas from the carbonization furnace to the dryer, and provided in the bypass passage. And a bypass passage valve for controlling the opening degree, and a part of the exhaust gas is taken out from the downstream side of the wet deodorization apparatus and returned to the carbonization furnace exhaust gas supply passage and returned downstream from the branch portion of the bypass passage for drying. an exhaust gas circulation path for supplying the machine, provided in an exhaust gas circulation path and a circulation path valve for controlling the opening constitutes a carbonization treatment facilities Contact Ku.

  In this way, when the carbonization furnace exhaust gas is used as a heat source for drying in a dryer, the amount of heat of the carbonization furnace exhaust gas can be appropriately and efficiently used for drying according to fluctuations in the properties of the dewatered sludge. .

  Specifically, when the moisture content of the dewatered sludge is high and the amount of heat required for drying is large, the bypass passage valve is closed or the opening degree is small, and the amount of carbonization furnace exhaust gas supplied to the dryer is increased (carbonization). Including supplying the entire amount of furnace exhaust gas).

Conversely, when the moisture content of the dewatered sludge is low, the bypass passage valve is opened or the opening degree is increased, a part of the carbonization furnace exhaust gas is branched to the bypass passage side, and the amount of carbonization furnace exhaust gas, that is, the amount of heat supplied to the dryer side is reduced. Excessiveness can be avoided.
And by doing in this way, calorie | heat amount only required with a dryer can be supplied appropriately.

Also, if the air flow for drying in the dryer is insufficient, such as by branching part of the carbonization furnace exhaust gas to the bypass passage, open the circulation passage valve or increase the opening to discharge it outside the system. By returning a part of the exhaust gas to be discharged to the carbonization furnace exhaust gas supply path and supplying it to the dryer, it is possible to prevent a shortage of air flow for drying in the dryer.
In particular, in the case of the above-described airflow dryer, the crushed material is transported and dried by the airflow of hot air, so that a certain amount of airflow is required in order to perform airflow transportation and drying appropriately.
Providing the exhaust gas circulation path and the circulation path valve according to the present invention is useful when such an air flow type dryer is used as the dryer.

On the contrary, when the amount of air sent to the dryer through the carbonization furnace exhaust gas supply passage is sufficient, closing the circulation path valve or reducing the opening degree may cause excessive exhaust gas to be supplied to the dryer side. Can be prevented.
That is, according to the present invention , it is possible to appropriately secure the air volume for drying in the dryer by the exhaust gas circulation path and the circulation valve.

In this case, since the exhaust gas after being cooled sufficiently by the wet deodorization device and sufficiently cooled in temperature is taken out from the exhaust gas circulation path, when the circulating exhaust gas from the exhaust gas circulation path is supplied to the dryer, an excess is supplied to the dryer. It is possible to avoid the amount of heat being applied.
That is, by supplying the exhaust gas from the exhaust gas circulation path to the dryer, it is possible to avoid fluctuations in the amount of heat on the dryer side.

In the present invention, it is desirable to use a self-burning type carbonization furnace that burns combustible gas emitted from sludge as a carbonization furnace and carbonizes sludge with the heat of combustion, but such a self-burning type carbonization furnace was used. If, by the nature of heat is dewatered sludge having a heat i.e. carbonization furnace exhaust gas generated in the carbonization furnace, but in particular varies by some amount of combustible component contained in the dewatered sludge, according to the present invention that Despite such fluctuations, the amount of calorific furnace exhaust gas heat supplied to the dryer can be appropriately controlled by the bypass path, bypass path valve, exhaust gas circulation path, and circulation path valve.
By using such a self-combustion type carbonization furnace as the carbonization furnace, it is possible to reduce the external heat energy to be added to the carbonization furnace itself as much as possible. Is also possible.

  Thus, the present invention can eliminate the need for external heat energy required for the deodorization apparatus, so the carbonization furnace facility of the present invention does not add external heat energy, and the heat energy of combustible components contained in the sludge. In some cases, it is possible to cover the entire thermal energy required for carbonization by itself.

In the present invention , there are provided a temperature detector and a flow detector for detecting the temperature and flow rate of the exhaust gas on the outlet side of the dryer, and a controller for controlling the opening of the bypass valve and the circulation valve. When the temperature detected by the detector is higher than the set temperature, the controller increases the opening of the bypass valve to increase the flow rate of the carbonization furnace exhaust gas flowing to the bypass path, and when the flow rate detected by the flow detector is lower than the set flow rate The carbonization equipment can be configured so that the flow rate of the circulating exhaust gas supplied to the dryer is increased by increasing the degree of opening of the circulation path valve by the controller ( claims 3 and 4).

  The self-burning type carbonization furnace is an externally heated rotary kiln type carbonization furnace with a jet pipe. Specifically, a jet pipe is provided in a retort composed of a rotating drum, and a combustible gas discharged from sludge in the retort is jetted out. It is possible to suitably use a carbonization furnace in which the air is discharged into the external heat chamber, ignited and burned in the external heat chamber, the retort is heated with the heat, and the sludge inside is carbonized.

It is the figure which showed the carbonization processing equipment of the sludge of one Embodiment of this invention. It is an enlarged view of the dryer in FIG. 1, and its peripheral part, and the enlarged view of the principal part of the mixer in FIG. It is the figure which showed the discharge route of the waste gas in the carbonization processing equipment of FIG. It is the figure which showed an example of the conventional carbonization processing equipment of sludge. It is the figure which showed the structure of the dryer in FIG. It is the figure which showed the carbonization furnace in FIG.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, 10 is a carbonization furnace having an externally heated rotary kiln type and a jet pipe, and its structure and function are the same as those shown in FIG. 6 (in FIG. 1, exhaust gas from the carbonization furnace is discharged outside the system). The exhaust gas line, which will be described later, is omitted).
That is, the carbonization furnace 10 has a cylindrical retort 14 as a dry distillation vessel made of a rotating drum inside a furnace body 12, and the moisture content is about 40% inside the left end side of the retort 14 in the figure. The dry sludge adjusted to is introduced.
The input dried sludge is first heated by atmospheric heating inside the external heat chamber 18 by the auxiliary burner 16 disposed inside the furnace body 12.
Then, the combustible gas contained in the dried sludge is ejected into the atmosphere of the external heat chamber 18 through the ejection pipe 20 provided in the retort 14, and after the combustible gas is ignited, the combustible gas is burned. The sludge inside the retort 14 is heated.
At this stage, the auxiliary burner 16 is stopped from burning.

An exhaust gas treatment chamber 24 partitioned from the external heat chamber 18 is provided inside the furnace body 12, and exhaust gas from the external heat chamber 18 is led here.
An exhaust gas treatment chamber burner 26 is provided in the exhaust gas treatment chamber 24, and unburned gas in the exhaust gas introduced into the exhaust gas treatment chamber 24 is subjected to secondary combustion in the exhaust gas treatment chamber burner 26.

The exhaust gas in the exhaust gas treatment chamber 24 is subsequently discharged from the exhaust port 28.
In this embodiment, the exhaust gas from the carbonization furnace 10 discharged from the exhaust port 28 is supplied as a heat source (hot air) for drying to the dryer 54 described later through the carbonization furnace exhaust gas supply path 30.

  On the other hand, the sludge in the retort 14 moves from the left end in the figure to the right in the figure along with the rotation of the retort 14 (the retort 14 has a slight gradient), and finally a dry distillation residue (carbonized product) is formed. The retort 14 is discharged from the rightmost outlet in the drawing, that is, from the carbonization furnace 10.

Reference numeral 32 denotes a receiving hopper, and dewatered sludge dehydrated to a moisture content of about 80% is first received by the receiving hopper 32.
Part of the dewatered sludge accepted here (about 85% of the whole in this case) is sent to the mixer (first mixing means) 40 by the fixed amount supply device 36 and the transport device 38 via the relay hopper 34.

The mixer 40 is also supplied with dry powder obtained by previously drying dewatered sludge from a cyclone separator 72 described later.
A part of the dewatered sludge supplied to the mixer 40 and a part of the dried powder supplied from the cyclone separator 72 are mixed with each other by the mixer 40.

  The mixer 40 is composed of a paddle mixer, and a pair of rotating shafts 44 and 46 (see FIG. 2B) are provided inside the casing 42, and mixing blades 48 and 50 are radially fixed respectively. The rotating shafts 44 and 46 rotate in opposite directions to mix the dewatered sludge and the dry powder so as to knead at the overlapping portions of the mixing blades 48 and 50, and further rotate the rotating shafts 44 and 46. In contrast, the mixing blades 48 and 50 each having an inclined shape are fed in the axial direction by the feeding action, and in the process, the mixing of the dewatered sludge and the dry powder proceeds.

Here, the rotating shafts 44 and 46 rotate at unequal speed. Accordingly, there is a difference in peripheral speed between the mixing blades 48 and 50, and the dewatered sludge and the dry powder are kneaded and mixed with high efficiency based on the difference in peripheral speed.
And the mixture of the fully mixed dehydrated sludge and the dry powder is discharged from the outlet at the axial end. The discharged mixture is supplied into the dryer 54 by the feeder 52.

The dryer 54 is an air-flow dryer, and has a casing 56 that has a vertically long cylindrical shape.
A crushing portion 58 is provided inside and below the casing 56 as shown in FIG.
The crushing part 58 has a pair of rotating shafts 60 and 62 and crushing blades 64 and 66 fixed radially, respectively. By rotating these at high speed, the feeder 52 has an inside of the casing 56 of the dryer 54. The above-mentioned mixture supplied to the container, that is, the mixture of dewatered sludge and dry powder is finely crushed.

The casing 56 is also provided with a blowing port 68, and the exhaust gas from the carbonization furnace 12 is blown into the casing 56 from the blowing port 68 as hot air.
The hot air blown in is blown vigorously against the crushed material of the mixture of dehydrated sludge and dry powder, and the crushed material is conveyed upward in the casing 56 by the upward airflow of hot air, and in the process, the dried air is dried. Is done.

  The crushed particles of the mixture conveyed inside the casing 56 together with the hot air flow become dry powder at the rising end thereof, are discharged to the outside together with the air flow from the discharge port 70, and are supplied to the cyclone separator 72.

In the present embodiment, the time required for drying by the dryer 54 is about 1 second.
The particle size of the dry powder is in the range of 75 to 590 μm, and the average particle size is 350 μm. However, this is the particle size after sieving, and the sieve has a minimum opening of 75 μm and a maximum of 590 μm.

This dryer 54 can transport powder particles having a size of up to 800 μm when the hot air flow rate is 20 m ³ / min (corresponding to a flow rate of 3.5 m / second at the discharge port 70 of the dryer 54) (however, Assuming that specific gravity is 1).

The cyclone separator 72 allows the dry powder to flow into the inside along with the air stream, and separates the dry powder from the air stream by centrifugal force based on rotation.
Then, the separated dry powder is dropped downward in the figure, and a part thereof is supplied to the mixer 40 again.

This dry powder has a low moisture content of about 15% or less while the moisture content of the dehydrated sludge is about 80%, and the dry powder is mixed with the dehydrated sludge. Thus, the water content of the mixture is set to a low water content suitable for drying in the dryer 54.
The water content in the mixture at this time can be easily adjusted by the mixing ratio of the dewatered sludge and the dry powder.

In this embodiment, only a part of the dry powder separated by the cyclone separator 72 is supplied to the dryer 54, and the remaining part is used for the carbonization treatment by the carbonization furnace 10 as a mixer (second mixing means). ) 78.
That is, the dry powder from the cyclone separator 72 is distributed to the dryer 54 side and the carbonization furnace 10 side.

The distribution is performed by a distribution damper 75 provided on the dry powder supply path.
Accordingly, here, the distribution damper 75 constitutes distribution means for distributing the dry powder from the cyclone separator 72 to the dryer 54 side and the carbonization furnace 10 side.
Reference numerals 74 and 76 are rotary valves for discharging the dry powder.

Further, the remaining part of the dewatered sludge in the receiving hopper 32 (here, about 15% of the whole) is supplied to the mixer 78 by bypassing the dryer 54 by the transport device 79.
The mixer 78 is also composed of a paddle mixer, and its structure is basically the same as that of the mixer 40, and includes a pair of rotating shafts 44 and 46 and mixing blades 48 and 50 fixed thereto. The dry powder is mixed with the dewatered sludge that has been transported by the transport device 79 by their rotation.

The mixer 78 has the following meaning.
That is, the dried powder after being dried by the dryer 54 is not suitable for carbonization in the carbonization furnace 10 as it is, and it is not desirable to supply it directly to the carbonization furnace 10.

Therefore, in the mixer 78, dehydrated sludge having a water content of about 80% is added to the dried powder and mixed to form dry sludge composed of dumpling particles having a water content of about 40% and a size of about 10 mm. Then, the dried sludge after granulation is supplied to the carbonization furnace 10 by the transfer device 82 through the relay hopper 80.
Subsequent carbonization of dried sludge is as described above.

FIG. 3 is a view mainly showing a route (exhaust gas line) until exhaust gas from the carbonization furnace 10 is discharged out of the system in the sludge carbonization treatment facility shown in FIG. 1.
In the figure, reference numeral 30 denotes a carbonization furnace exhaust gas supply path extending from the carbonization furnace 10 and connected to a dryer 54. The exhaust gas from the carbonization furnace 10 serves as a heat source for drying, and the dryer 54 is passed through the carbonization furnace exhaust gas supply path 30. Supplied as hot air.

Reference numeral 90 denotes an exhaust gas passage for discharging the exhaust gas from the dryer 54 to the outside of the system. A dust collector 92, a furnace pressure adjusting damper 94, an exhaust gas fan 96, and a deodorizing device (wet deodorizing device) 98 are provided in the exhaust gas passage 90. Each is provided.
Here, the furnace pressure adjusting damper 94 adjusts the opening of the exhaust gas passage 90 to control the flow rate of the exhaust gas discharged through the exhaust gas passage 90, thereby adjusting the furnace pressure inside the carbonization furnace 10. It is.

  The exhaust gas that has flowed out of the dryer 54 flows along the exhaust gas flow path 90, and is collected through the dust collector 92 in the process, and the deodorizing device 98 removes odorous components contained in the exhaust gas, that is, deodorization is performed. Then, it is discharged out of the system from the chimney 100.

The deodorizing device 98 introduces exhaust gas into the container 101, sprays deodorizing water (liquid) 104 containing a chemical such as sulfuric acid from the nozzle 102, and brings the sprayed water 104 into contact with the exhaust gas. The odor component contained in the exhaust gas is removed with water 104 and deodorized.
In this deodorizing device 98, an activated carbon layer 108 is provided as a second deodorizing section following the wet deodorizing section 106.
Therefore, the exhaust gas that has passed through the wet deodorizing unit 106 is adsorbed and removed by the activated carbon layer in the course of passing through the activated carbon layer 108, which is not sufficiently removed by the wet deodorizing unit 106.
In addition, when the odor component can be sufficiently removed by the wet deodorizing unit 106, the activated carbon layer 108 may not be provided.

In FIG. 3, reference numeral 110 is branched from the carbonization furnace exhaust gas supply path 30, bypasses the dryer 54, and is connected to the exhaust gas flow path 90, specifically the downstream portion of the cyclone separator 72. A bypass passage valve 112 and a heat exchanger 114 are provided to open and close the valve.
The bypass passage valve 112 may change not only the opening and closing of the bypass passage 110 but also its opening degree.

  116 is an exhaust gas circulation path that branches off from the downstream portion of the deodorizing device 98 in the exhaust gas flow path 90 and is connected to the downstream side of the branch portion of the bypass path 110 in the carbonization furnace exhaust gas supply path 30, and flows out from the deodorizing apparatus 98. A part of the exhausted gas is returned to the carbonization furnace exhaust gas supply path 30 through the exhaust gas circulation path 116 and can be supplied to the dryer 54.

The exhaust gas circulation path 116 is provided with a circulation path valve 118 for opening and closing the exhaust gas circulation path 116.
In addition, this circulation path valve 118 may change not only the opening / closing valve of the exhaust gas circulation path 116 but also the opening degree thereof.

A temperature detector 120 and a flow rate detector 122 are provided on the exit side of the dryer 54 in the exhaust gas flow path 90, specifically, a portion between the dryer 54 and the cyclone separator 72. The temperature and flow rate of the discharged exhaust gas are detected.
The detection results by the temperature detector 120 and the flow rate detector 122 are input to the controller 124.
The controller 124 controls opening and closing of the bypass valve 112 and the circulation valve 118 based on these inputs.

In this embodiment, the temperature of the exhaust gas in the carbonization furnace exhaust gas supply passage 30 is about 850 to 900 ° C. on the outlet side of the carbonization furnace 10 and about 300 to 450 ° C. on the inlet side of the dryer 54.
Further, the temperature of the exhaust gas on the exit side of the dryer 54 is around 100 ° C., and the exhaust gas temperature on the exit side of the deodorizer 98 is a low temperature of about 40 ° C.
Therefore, the temperature of the exhaust gas taken out in the exhaust gas circulation path 116 is a low temperature of about 40 ° C., and the low temperature exhaust gas is returned to the carbonization furnace exhaust gas supply path 30 and supplied to the dryer 54 together with the carbonization furnace exhaust gas. The

In this embodiment, the sludge is carbonized by the heat generated by the combustion of the combustible gas in the sludge in the carbonization furnace 10.
The exhaust gas generated by the combustion of sludge in the carbonization furnace 10 is supplied as hot air to the dryer 54 as a heat source for drying through the carbonization furnace exhaust gas supply path 30.
The dryer 54 basically performs drying with the hot air.

  The amount of heat of the exhaust gas discharged from the carbonization furnace 10 may exceed the amount of heat required for drying in the dryer 54. In this case, the bypass passage valve 112 opens to open the bypass passage 110. Then, a part of the exhaust gas sent through the carbonization furnace exhaust gas supply passage 30 is taken out to the bypass passage 110, and after the residual heat is recovered by the heat exchanger 114, this is bypassed to the dryer 54 to the exhaust gas passage 90. Lead.

Water used for deodorization by the deodorizing device 98 is guided to the heat exchanger 114 on the bypass passage 110, and the water is warmed by the residual heat of the exhaust gas taken out to the bypass passage 110.
In addition, when a part of the exhaust gas in the carbonization furnace exhaust gas supply path 30 is taken out to the bypass path 110 in this way, the flow rate of the exhaust gas supplied to the dryer 54 may be insufficient.

  Since the airflow dryer 54 performs drying by airflow conveyance with hot air, if the supplied exhaust gas flow rate is insufficient, the amount of air for drying is insufficient and drying cannot be performed properly.

Therefore, in this embodiment, the circulation path valve 118 of the exhaust gas circulation path 116 is opened, and a part of the exhaust gas is returned from the exhaust gas flow path 90 to the carbonization furnace exhaust gas supply path 30 through the exhaust gas circulation path 116 to the dryer 54. Supplied with.
That is, in this embodiment, even when the flow rate of the exhaust gas sent to the dryer 54 through the carbonization furnace exhaust gas supply path 30 is reduced, the exhaust gas can be reliably supplied to the dryer 54 at a necessary flow rate.

  Here, the temperature of the exhaust gas taken out to the exhaust gas circulation path 116 is a low temperature of about 40 ° C. Therefore, even when the exhaust gas is supplied to the dryer 54 through the exhaust gas circulation path 116, the supply to the dryer 54 is thereby performed. The amount of heat does not become excessive.

  In this embodiment, when the temperature detected by the temperature detector 120 is higher than the set temperature, the controller 124 automatically opens the bypass valve 112, and the flow rate detected by the flow rate detector 122 is insufficient with respect to the set flow rate. In this case, the controller 124 automatically opens the circulation path valve 118 to supply exhaust gas to the dryer 54 through the exhaust gas circulation path 116.

If the dehydrated sludge contains a large amount of combustible matter or the water content of the dehydrated sludge is low, the amount of heat of the exhaust gas from the carbonization furnace 10 may be greater than the amount of heat required for drying in the dryer 54. The temperature detected by the temperature detector 120 is higher than the set temperature. In such a case, the bypass valve 112 is automatically opened.
On the other hand, when the temperature detected by the temperature detector 120 is equal to or lower than the set temperature, the bypass passage valve 112 is automatically closed so that the entire amount of exhaust gas from the carbonization furnace 10 flows into the dryer 54. .
When the total amount of exhaust gas from the carbonization furnace 10 flows into the dryer 54, if the amount of heat is still insufficient, the burner provided in the exhaust gas outlet of the carbonization furnace 10 or the carbonization furnace exhaust gas flow path 30 is burned. Can make up for the lack of heat.

  As described above, in the present embodiment, the controller 124 automatically optimizes the supply of exhaust gas to the dryer 54 to maintain the drying conditions appropriately.

  According to this embodiment, the thermal energy applied from the outside during the carbonization treatment of sludge can be reduced as much as possible.

Although the embodiment of the invention has been described in detail above, this is merely an example.
For example, in the present invention, it is desirable to use the airflow type dryer as described above as the dryer, but in the case where the moisture content of the sludge is low and the amount of heat for drying may be small, the rotating drum type shown in FIG. It is also possible to use a dryer, and it is also possible to use other wet deodorization apparatuses other than the above examples as wet deodorization apparatuses, and the present invention is in a form in which various changes are made without departing from the spirit of the present invention. It is configurable.

DESCRIPTION OF SYMBOLS 10 Carbonization furnace 14 Retort 18 External heat chamber 20 Ejection pipe 30 Carbonization furnace exhaust gas supply path 40 Mixer (1st mixing means)
54 dryer 72 cyclone separator 78 mixer (second mixing means)
90 Exhaust gas flow path 98 Deodorizer (wet deodorizer)
DESCRIPTION OF SYMBOLS 110 Bypass path 112 Bypass path valve 116 Exhaust gas circulation path 118 Circulation path valve 120 Temperature detector 122 Flow rate detector 124 Controller

Claims (4)

(A) a dryer for drying the dehydrated sludge after dehydrating the organic substance-containing sludge, (B) a carbonization furnace for carbonizing by carbonizing the dried sludge, and (C) from the carbonization furnace A carbonization furnace exhaust gas supply path that extends and is connected to the dryer and supplies the carbonization furnace exhaust gas as a heat source for drying as hot air to the dryer; and (D) a deodorization apparatus that deodorizes the exhaust gas discharged outside the system. In the sludge carbonization equipment comprising the above, as the deodorizing device, the deodorizing liquid is contacted with the exhaust gas discharged out of the system to remove the odor component in the exhaust gas and deodorize it. Using the equipment ,
Further, (a) bypassing the dryer branched off from the carbonization furnace exhaust gas supply passage, and connected to an exhaust gas passage on the downstream side of the dryer; (b) provided in the bypass passage; A bypass valve that controls the degree of opening of the bypass path; and (c) a downstream side of the bypass path in the carbonization furnace exhaust gas supply path that extends from the downstream side of the wet deodorization device in the exhaust gas path. An exhaust gas circulation path for returning a part of the exhaust gas flowing out from the wet deodorization apparatus to the carbonization furnace exhaust gas supply path and supplying it to the dryer; and (d) the exhaust gas circulation path provided in the exhaust gas circulation path. A sludge carbonization facility comprising a circulation valve for controlling the opening of the passage . (A) a dryer for drying the dehydrated sludge after dehydrating the organic substance-containing sludge, (B) a carbonization furnace for carbonizing by carbonizing the dried sludge, and (C) from the carbonization furnace A carbonization furnace exhaust gas supply path that extends and is connected to the dryer and supplies the carbonization furnace exhaust gas as a heat source for drying as hot air to the dryer; and (D) a deodorization apparatus that deodorizes the exhaust gas discharged outside the system. A sludge carbonization facility comprising
As the deodorizing device, a wet deodorizing device that removes the odor component in the exhaust gas by causing the deodorizing liquid to contact with the exhaust gas discharged outside the system to remove the odor is used,
Further, as the dryer, a mixture obtained by adding the dried powder of the dehydrated sludge to a part of the dehydrated sludge is crushed, the hot air is blown onto the crushed material, and the crushed material is conveyed and dried by an air current of the hot air. Without the dry powder, using an airflow dryer that discharges with the airflow ,
Further, (a) bypassing the dryer branched off from the carbonization furnace exhaust gas supply passage, and connected to an exhaust gas passage on the downstream side of the dryer; (b) provided in the bypass passage; A bypass valve that controls the degree of opening of the bypass path; and (c) a downstream side of the bypass path in the carbonization furnace exhaust gas supply path that extends from the downstream side of the wet deodorization device in the exhaust gas path. An exhaust gas circulation path for returning a part of the exhaust gas flowing out from the wet deodorization apparatus to the carbonization furnace exhaust gas supply path and supplying it to the dryer; and (d) the exhaust gas circulation path provided in the exhaust gas circulation path. A sludge carbonization facility comprising a circulation valve for controlling the opening of the passage . (A) a dryer for drying the dehydrated sludge after dehydrating the organic substance-containing sludge, (B) a carbonization furnace for carbonizing by carbonizing the dried sludge, and (C) from the carbonization furnace A carbonization furnace exhaust gas supply path that extends and is connected to the dryer and supplies the carbonization furnace exhaust gas as a heat source for drying as hot air to the dryer; and (D) a deodorization apparatus that deodorizes the exhaust gas discharged outside the system. A sludge carbonization facility comprising
As the deodorizing device, a wet deodorizing device that removes the odor component in the exhaust gas by causing the deodorizing liquid to contact with the exhaust gas discharged outside the system to remove the odor is used,
Further, (a) bypassing the dryer branched off from the carbonization furnace exhaust gas supply passage, and connected to an exhaust gas passage on the downstream side of the dryer; (b) provided in the bypass passage; A bypass valve that controls the degree of opening of the bypass path; and (c) a downstream side of the bypass path in the carbonization furnace exhaust gas supply path that extends from the downstream side of the wet deodorization device in the exhaust gas path. An exhaust gas circulation path for returning a part of the exhaust gas flowing out from the wet deodorization apparatus to the carbonization furnace exhaust gas supply path and supplying it to the dryer; and (d) the exhaust gas circulation path provided in the exhaust gas circulation path. A circulation path valve for controlling the opening of the path ,
A temperature detector for detecting the temperature and flow rate of the exhaust gas on the outlet side of the dryer, a flow rate detector, and a controller for controlling the opening degree of the bypass valve and the circulation valve,
When the temperature detected by the temperature detector is higher than a set temperature, the controller increases the flow rate of the carbonization furnace exhaust gas flowing to the bypass path side by increasing the opening of the bypass path valve,
The sludge carbonization characterized in that when the flow rate detected by the flow rate detector is smaller than a set flow rate, the flow rate of the circulating exhaust gas supplied to the dryer is increased by increasing the opening of the circulation path valve. Processing equipment. (A) a dryer for drying the dehydrated sludge after dehydrating the organic substance-containing sludge, (B) a carbonization furnace for carbonizing by carbonizing the dried sludge, and (C) from the carbonization furnace A carbonization furnace exhaust gas supply path that extends and is connected to the dryer and supplies the carbonization furnace exhaust gas as a heat source for drying as hot air to the dryer; and (D) a deodorization apparatus that deodorizes the exhaust gas discharged outside the system. A sludge carbonization facility comprising
As the deodorizing device, a wet deodorizing device that removes the odor component in the exhaust gas by causing the deodorizing liquid to contact with the exhaust gas discharged outside the system to remove the odor is used,
Further, as the dryer, a mixture obtained by adding the dried powder of the dehydrated sludge to a part of the dehydrated sludge is crushed, the hot air is blown onto the crushed material, and the crushed material is conveyed and dried by an air current of the hot air. Without the dry powder, using an airflow dryer that discharges with the airflow,
Further, (a) bypassing the dryer branched off from the carbonization furnace exhaust gas supply passage, and connected to an exhaust gas passage on the downstream side of the dryer; (b) provided in the bypass passage; A bypass valve that controls the degree of opening of the bypass path; and (c) a downstream side of the bypass path in the carbonization furnace exhaust gas supply path that extends from the downstream side of the wet deodorization device in the exhaust gas path. An exhaust gas circulation path for returning a part of the exhaust gas flowing out from the wet deodorization apparatus to the carbonization furnace exhaust gas supply path and supplying it to the dryer; and (d) the exhaust gas circulation path provided in the exhaust gas circulation path. A circulation path valve for controlling the opening of the path,
Before Dryer the outlet side of the exhaust gas temperature, the temperature detector for detecting the flow rate, respectively, and the flow detector, Bei example a controller controlling the opening degree of the bypass passage valve and the circulation path valve,
When the temperature detected by the temperature detector is higher than a set temperature, the controller increases the flow rate of the carbonization furnace exhaust gas flowing to the bypass path side by increasing the opening of the bypass path valve,
The sludge carbonization characterized in that when the flow rate detected by the flow rate detector is smaller than a set flow rate, the flow rate of the circulating exhaust gas supplied to the dryer is increased by increasing the opening of the circulation path valve. Processing equipment.

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