JP2021159801A - Fermentation-drying apparatus, cement production system, fermentation-drying method, method for producing cement clinker, and method for using fermentation-dried product - Google Patents

Abstract

To accurately calculate a fermentation heat quantity in a fermentation-drying apparatus.SOLUTION: A fermentation-drying system has: a container which houses a fermentation raw material including sewage sludge, and performs fermentation-drying treatment while agitating the fermentation raw material; air feeding means for feeding air into the container; exhaust means for performing exhaustion from the container; an inner pressure information acquisition part which acquires information regarding air pressure inside the container; and an exhaust control part which controls an exhaust amount from the exhaust means such that the air pressure inside the container acquired by the inner pressure information acquisition part becomes slightly negative pressure as compared to the atmospheric pressure.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a fermentation and drying apparatus, a cement production system, a fermentation and drying method, a method for producing cement clinker, and a method for using a fermented and dried product.

Patent Document 1 describes that in a vertical fermentation processing apparatus for fermenting sewage sludge, the amount of heat of fermentation is used as an index indicating the state of fermentation in the fermenter.

Japanese Unexamined Patent Publication No. 2018-172272

In the case of Patent Document 1, the amount of air supplied is constantly changed by the change in fermentation heat estimated based on the exhaust gas properties (composition, flow rate, temperature, relative humidity). In this case, if the displacement is not changed according to the change in the amount of air supplied and the amount of water vapor generated in the fermenter (changes depending on the amount of air supplied and the fermentation condition), the pressure in the fermenter will fluctuate, and the product discharge port of the fermenter and the product discharge port of the fermenter will be affected. Leaked air is generated at the raw material inlet (it is not realistic to have a completely sealed structure due to the structure). That is, when the pressure inside the fermenter is negative, gas may flow in from the outside, and when the pressure inside the fermenter is positive, gas may be discharged to the outside. It can be said that both the inflow and outflow of gas are leaked air related to the fermenter. When the fermenter pressure becomes excessive negative pressure or positive pressure, the leak air flow rate increases, the effect on the exhaust gas properties cannot be ignored, and the calculation accuracy of the fermentation heat estimated from the exhaust gas properties decreases. It is feared that the based air supply control will not function effectively and, as a result, fermentation will become unstable.

The present disclosure provides a technique capable of accurately calculating the amount of heat of fermentation in a fermentation / drying apparatus.

The fermentation / drying apparatus according to one embodiment of the present disclosure includes a container for containing a fermentation raw material containing sewage sludge and performing a fermentation / drying treatment while stirring the fermentation raw material, and an air supply means for supplying air into the container. , The exhaust means for exhausting from the inside of the container, the internal pressure information acquisition unit for acquiring information related to the pressure inside the container, and the pressure inside the container acquired by the internal pressure information acquisition unit are smaller than the atmospheric pressure. It has an exhaust amount control unit that controls the amount of exhaust air from the exhaust means so that the pressure becomes negative.

Further, in the fermentation and drying method according to one embodiment of the present disclosure, a fermentation raw material containing sewage sludge is placed in a container, and the fermentation and drying treatment is performed while stirring the fermentation raw material in the container, and the fermentation and drying process is performed. When performing the treatment, air is supplied into the container, when the fermentation and drying treatment is performed, exhaust is performed from the container, and information on the pressure inside the container is acquired. This includes controlling the amount of exhaust air from the container so that the pressure inside the container becomes a slightly negative pressure as compared with the atmospheric pressure.

According to the above-mentioned fermentation / drying apparatus and fermentation / drying method, information on the pressure inside the container is acquired, and the amount of exhaust air from the inside of the container is controlled so that the pressure inside the container becomes a slight negative pressure compared to the atmospheric pressure. NS. Therefore, since the outflow of gas from the container or the inflow of gas from the outside of the container can be reduced, the environment inside the container is prevented from changing due to leakage, and the amount of heat of fermentation in the fermentation drying device is calculated accurately. It becomes possible.

The slight negative pressure can be in the range of −0.2 kPa with respect to the atmospheric pressure.

As described above, when the amount of exhaust from the container is controlled so as to be within the range of -0.2 kPa with respect to the atmospheric pressure, the influence of leaked air on the calculation of fermentation heat can be further reduced and is stable. The fermentation process can be carried out.

The exhaust means includes an exhaust line and a flow rate adjusting valve on the exhaust line, and the exhaust amount control unit can control the exhaust amount by adjusting the flow rate adjusting valve.

The exhaust means includes an exhaust line and an exhaust fan on the exhaust line, and the exhaust amount control unit can control the exhaust amount by adjusting the rotation speed of the exhaust fan. ..

The exhaust means includes an exhaust line, an exhaust fan on the exhaust line, and an outside air intake line that joins the exhaust line on the upstream side of the exhaust fan, and the exhaust amount control unit is the outside air intake line. By adjusting the amount of outside air taken in from the air, the exhaust amount can be controlled.

The cement manufacturing system according to one embodiment of the present disclosure includes the above-mentioned fermentation and drying apparatus, and a cement manufacturing apparatus that uses a fermented and dried product obtained by the fermentation and drying treatment in the fermentation and drying apparatus.

By producing cement in a cement manufacturing apparatus using the fermented and dried product obtained by the above fermentation and drying apparatus, the fermented and dried product produced in a state where the calorific value of fermentation can be accurately controlled can be used for cement production. Can be done.

The method for producing cement clinker according to one embodiment of the present disclosure is to produce cement clinker using the fermented dried product obtained by the above method as a raw material.

By producing cement clinker using the fermented dried product obtained by the above method as a raw material, cement clinker can be produced using the fermented dried product obtained from sewage sludge as a raw material, so that the waste intensity can be increased. be able to.

In the method of using the fermented dried product according to one embodiment of the present disclosure, the fermented dried product obtained by the above method is used as a heat energy source.

When the fermented dried product obtained by the above method is used as a heat energy source, the fermented dried product can be converted into heat energy and used, so that the use of fossil fuel can be reduced.

According to the present disclosure, there is provided a technique capable of accurately calculating the amount of heat of fermentation in a fermentation / drying apparatus.

FIG. 1 is a schematic configuration diagram of a production system for producing a fermented dried product according to an embodiment of the present disclosure. FIG. 2 is a schematic configuration diagram of the fermenter. FIG. 3 is a diagram illustrating the inflow and outflow of gas into and out of the fermenter. FIG. 4 is a schematic configuration diagram of a cement clinker manufacturing apparatus. 5 (a) and 5 (b) are views for explaining a modified example of the exhaust means. 6 (a) to 6 (d) are diagrams showing measured values of the air supply flow rate to the fermenter. 7 (a) to 7 (d) are diagrams showing measured values of pressure in the fermenter. 8 (a) to 8 (d) are diagrams showing the estimation results of the leaked air amount. 9 (a) to 9 (d) are diagrams showing the estimation results of the leaked air amount.

Hereinafter, embodiments for carrying out the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

[Manufacturing system for fermented dried products]
FIG. 1 is a schematic configuration diagram of a production system for producing a fermented dried product according to an embodiment of the present disclosure. As shown in FIG. 1, the manufacturing system 1 includes a fermenter 2, an air heater 4, an air blower 5, a dust removal tower 6, an exhaust fan 7, a cleaning and deodorizing tower 8, and a control unit 9. What is produced in the production system 1 is a fermented dried product (dried sludge) obtained by fermenting and drying sewage sludge. In addition, the exhaust gas generated by the fermentation of sewage sludge is subjected to a predetermined treatment.

The fermenter 2 has a function of adding sewage sludge to perform fermentation treatment. In the fermenter 2, aerobic treatment with aerobic microorganisms is performed. In addition to sewage sludge, raw materials that contribute to fermentation are put into the fermentation tank 2. Further, the fermented dried product (dried sludge) after fermentation is discharged from the fermenter 2, and the gas and steam (hereinafter referred to as exhaust) generated by the fermentation are discharged via the line L1. The raw materials to be put into the fermenter 2 will be described later, but in the present embodiment, fermented chicken manure is used as an auxiliary raw material.

The air supply heater 4 has a function of heating the gas introduced into the line L3 and supplying it to the line L2. The temperature of the air introduced into the fermenter 2 is, for example, about 50 ° C. to 80 ° C. The air supply heater 4 has a function of heating the gas to be introduced into the line L2 so as to be within a predetermined temperature range. A heat exchange means (not shown) may be provided upstream of the air supply heater 4, for example, by using the heat of the exhaust gas of the line L1 to heat the outside air introduced into the container from the air supply fan. The form of the heat exchange means is not particularly limited, and the exhaust gas from the line L1 is cooled by the heat exchange. On the other hand, the heated air is introduced into the fermenter 2 via the line L2.

The air supply blower 5 has a function of supplying gas to the line L2. A motor M1 is connected to the air supply blower 5, and air from the outside is introduced into the line L3 and supplied to the line L2 by the air supply blower 5 operated by the operation of the motor M1.

The dust removal tower 6, the exhaust fan 7, and the cleaning and deodorizing tower 8 are provided on the line L1 for discharging the exhaust gas from the fermenter 2. The dust removal tower 6 and the cleaning deodorization tower 8 function as a wet deodorizing device that deodorizes the exhaust gas. The above line L1 corresponds to an exhaust line that exhausts air from the fermentation tank 2 that functions as a fermentation / drying device. That is, the line L1 and the exhaust fan 7 function as exhaust means from the fermentation / drying apparatus.

The dust removal tower 6 has a function of introducing the exhaust gas flowing through the line L1 and removing the dust contained in the exhaust gas. Equipment such as a scrubber is used as the dust removal tower. The gas from which the dust has been removed is sent to the cleaning / deodorizing tower 8 via the exhaust fan 7.

The exhaust fan 7 has a function of moving the exhaust gas on the line L1. A motor M2 is connected to the exhaust fan 7, and the exhaust gas is moved to the downstream side by driving the exhaust fan 7 by the operation of the motor M2. As the fan, a fan whose rotation speed can be controlled by the inverter frequency can be used.

The washing and deodorizing tower 8 has a function of removing trace odor components such as ammonia contained in the exhaust gas from the fermenter. As an example, the cleaning and deodorizing tower is a wet cleaning tower, and can be an acid cleaning and deodorizing tower using sulfuric acid. The cleaning and deodorizing tower 8 is not limited to the acid cleaning and deodorizing tower, and various configurations can be adopted as long as it is configured to perform and remove alkaline cleaning and deodorizing, alkaline / hyposalt cleaning and deodorizing, and the like. .. Cleaning and deodorizing can be appropriately selected according to the gas to be treated. For example, an acid scrubber is used when ammonia is the target of deodorization. Further, depending on the type and number of gases contained in the exhaust gas, a plurality of cleaning and deodorizing towers can be connected in series. If hydrogen sulfide may be generated, an alkali / hypochlorous acid washing / deodorizing tower that combines sodium hydroxide and sodium hypochlorite may be further provided.

The wet deodorizing device is not limited to the above configuration. For example, it may include an adsorption tower that is filled with activated carbon and removes odorous components that cannot be sufficiently removed by the action of the above liquid by the adsorption action of the activated carbon. The adsorption tower may be installed at the last stage of the plurality of processing devices.

The control unit 9 has a function of controlling each of the above units. The control unit 9 receives output signals from sensors and the like provided in various parts of the manufacturing system 1 and each of the above-mentioned parts, and transmits an input signal for controlling the operation to each of the above-mentioned parts. The control unit 9 functions as an internal pressure information acquisition unit 91 that acquires information related to the pressure inside the container, and the pressure inside the container acquired by the internal pressure information acquisition unit becomes a slight negative pressure as compared with the atmospheric pressure. In addition, it has a function as an exhaust amount control unit 92 that controls the exhaust amount from the container 21 of the fermenter 2. This point will be described later.

As shown in FIG. 1, in the manufacturing system 1, sensors are provided at various places. A weigh scale W for measuring the weight of the fermenter 2 is provided, and a pressure gauge P1 for measuring the pressure (atmospheric pressure) in the fermenter 2 (more accurately, in the container 21 described later) is provided. Further, a thermometer T4 for measuring the temperature of the gas discharged from the fermenter 2 is provided on the line L1. Further, a thermometer T5 for measuring the temperature of the air introduced into the fermenter 2 is provided between the air supply heater 4 on the line L2 and the inlet to the fermenter 2. Further, a flow meter F, a thermometer T6, and a pressure gauge P2 are provided on the line L3 for introducing air from the outside. A frequency meter Hz1 is provided on the motor M1 connected to the air supply blower 5. Similarly, the motor M2 connected to the exhaust fan 7 is provided with a frequency meter Hz2. As described above, the manufacturing system 1 is provided with various sensors for confirming its operation. The control unit 9 can acquire the measurement results of these sensors as output signals and change the control contents based on the measurement results.

[Fermenter]
Next, the fermenter 2 will be described. FIG. 2 is a schematic configuration diagram of the fermenter 2. The fermenter 2 is a closed vertical fermenter. The fermenter 2 has a container 21 extending in the vertical direction (direction A in the drawing) with respect to the installation surface. Above the container 21, a charging port 22 for charging sewage sludge, auxiliary raw materials, and the like is provided. Further, below the container 21, a discharge port 23 for discharging the fermented and dried product after the treatment in the container 21 is provided. Both the inlet 22 and the outlet 23 are provided with a lid-like member (not shown) that can be opened / closed or detached, such as a lid. By attaching the lid-shaped member to the inlet 22 and the outlet 23, the container 21 in the fermenter 2 can be sealed. In this way, the fermentation tank 2 enables aerobic fermentation in a closed system. From the viewpoint of further improving the drying efficiency of the contents by the aerobic fermentation heat, the fermenter 2 may have a heat insulating structure by, for example, arranging a heat insulating material on the outer peripheral surface of the container 21.

It is also preferable that the fermenter 2 is provided with a stirring device 24 for mixing the raw materials in the fermenter. As an example, the stirring equipment 24 includes, for example, a stirring blade 24a provided inside the container 21, a rotating shaft 24b connected to the stirring blade 24a, and a rotation driving device (not shown) provided outside the container 21. I have. The stirring blade 24a is connected to a rotation driving device provided outside the container 21 via a rotating shaft 24b, and rotates in a certain direction using a hydraulic cylinder as a driving source. The stirring blades 24a may be provided in multiple stages at predetermined intervals from the lower part to the upper part of the rotating shaft 24b. By further providing the stirring equipment 24, it is possible to suppress an excessive consolidation state of the contents such as sewage sludge, and it is possible to improve the aerobic fermentation efficiency.

Further, the fermenter 2 includes an air supply means 25 for supplying an oxygen-containing gas such as air into the fermenter 2, and an exhaust means 26 capable of exhausting the gas in the container 21 to the outside of the container 21. The oxygen-containing gas F can be, for example, air. As an example, the oxygen-containing gas F is sent from the air supply means 25 provided outside the container 21 to the lower side in the vertical direction of the stirring blade 24a via the hollow rotating shaft 24b and the ventilation hole of the stirring blade 24a. It may be able to supply. In the example shown in FIG. 2, a plurality of gas flow holes through which the oxygen-containing gas F can flow are provided on the lower side of the stirring blade 24a provided at the lowermost position in the vertical direction. In this case, the oxygen-containing gas F can be evenly supplied to the container 21 while stirring the contents by the stirring blade 24a. The oxygen-containing gas F existing in the container 21 and the gas generated by aerobic fermentation are exhausted to the line L1 (see FIG. 1) as exhaust gas via the exhaust means 26 provided above the container 21. ..

From the viewpoint of increasing the contact efficiency between the oxygen-containing gas and the contents and increasing the aerobic fermentation efficiency of the sewage sludge in the container 21, the oxygen-containing gas F is supplied from the lower side in the vertical direction of the container 21 and contains oxygen. The exhaust gas containing the gas F can be configured to be exhausted from the upper side of the container 21 in the vertical direction.

The fermentation raw material containing sewage sludge is continuously or intermittently charged into the container 21 in the fermenter 2 from the inlet 22. The fermentation raw material is aerobically fermented in the fermenter 2 and then discharged as a fermented dried product from the discharge port 23.

In the fermenter 2 described above, the fermentation raw material is charged into the container 21 from the input port 22, the processed product is fermented in the container, and then the fermented dried product is taken out from the discharge port 23 at the bottom of the container 21. In the fermenter 2, the air supply means 25 introduces the outside air from the ventilation holes of the lowermost stirring blade 24a with a predetermined amount of air, and exhausts the outside air from the exhaust means 26. In this state, each stirring blade 24a is rotated at a low speed, the fermentation raw material is aerated and stirred, and aerobic fermentation is performed to carry out fermentation. In addition, the contents are dried at the same time by the heat of fermentation due to fermentation. The air discharged from the exhaust means 26 is a gas such as carbon dioxide or ammonia generated in the process of fermentation with respect to the gas that is introduced into the container through the ventilation holes and flows upward while passing through the processed product. It contains water vapor.

An example of the operation procedure of the fermenter 2 is as follows. First, a fermentation raw material such as sewage sludge is charged into the fermentation tank 2 from the inlet 22 leaving a space of 10 to 30% with respect to the internal volume of the container 21. By adding the fermentation raw material while leaving the above-mentioned space, the fermentation raw material is sufficiently and uniformly agitated and aerated. Therefore, fermentation and drying in the container 21 can be efficiently performed. As an example, the fermented raw material is added daily. That is, the fermentation raw material can be added a plurality of times (at regular intervals) at predetermined intervals. Further, the fermentation and drying of the fermentation raw material are continued for a predetermined residence period (about 3 to 20 days) in the fermenter 2, and a predetermined amount of the fermented dried product is taken out from the discharge port 23 at regular intervals (for example, every day). .. The fermentation raw material is added after the fermented dried product is taken out from the discharge port 23. In this way, the fermentation process is continuously performed while repeating a part of the sewage sludge fermentation raw material and a part of the fermented product in a fixed time cycle. The fermented and dried product obtained by the above procedure is a powdery or granular solid material, and is partially agglomerated.

The control unit 9 accurately estimates the amount of heat of fermentation in the fermenter 2 by controlling the pressure in the fermenter 2, and controls the amount of air supplied to the fermenter based on the estimation, thereby controlling the amount of air supplied to the fermenter 2. The fermentation rate of the contents can be maintained at a high level. As an example, the control unit 9 adjusts the amount of air supplied to the container 21 of the fermenter 2 by the air supply means 25, and the motor M of the exhaust fan 7 used for exhausting the gas in the fermenter 2 adjusts the amount of exhaust gas. Adjustments can be made.

[Fermentation raw material]
As the fermentation raw material used for producing the fermented dried product in the fermenter 2, in addition to the sewage sludge which is the main raw material, an auxiliary raw material or the like is used. Hereinafter, details of each raw material and its mixing ratio and the like will be described.

[Sewage sludge]
The sewage sludge is a sludge-like or paste-like substance containing organic substances, inorganic substances and water, which is obtained by dehydrating excess sludge generated in the process of activated sludge treatment of sewage with a dehydrator such as a filter press. As the sewage sludge, this may be used as it is, or a self-fermented product of sewage sludge such as digestive sludge may be used. The water content of the sewage sludge is not particularly limited, but is, for example, about 70% to 90%.

The sewage sludge used as a fermentation raw material may be selected based on its water content, the presence or absence of digestion, and at least one of the dehydration treatment methods.

[Auxiliary raw material]
The fermentation raw material may contain auxiliary raw materials in addition to sewage sludge. The auxiliary raw material is a material for promoting stable aerobic fermentation of sewage sludge when the fermentation raw material containing sewage sludge is subjected to fermentation by containing it together with sewage sludge. Specifically, the auxiliary raw material reduces the water content of sewage sludge, enhances the air permeability of the fermentation raw material containing the sewage sludge and the auxiliary raw material, and easily decomposes as a nutrient source for microorganisms that contribute to aerobic fermentation. It is used to supply aerobic organic components and to supply aerobic microorganisms for efficiently advancing aerobic fermentation.

The shape of the auxiliary raw material used is not particularly limited, and may be, for example, a solid shape, a granular shape, a powder shape, a paste shape, or the like. The total content of the auxiliary raw material can be appropriately adjusted according to the physical properties and purpose of the auxiliary raw material used, but the total weight part of the auxiliary raw material with respect to 100 parts by weight of the sewage sludge is preferably 5 parts by weight or more and 100 parts by weight or less. It can be preferably 5 parts by weight or more and 50 parts by weight or less, and more preferably 5 parts by weight or more and 40 parts by weight or less. At this time, the weight of the reference sewage sludge is the weight in the water-containing state.

Aeration aids, nutritional aids, and fermented chicken manure that can be used as examples of auxiliary materials will be described.

[Ventilation aid]
The fermentation raw material may contain a ventilation aid for the purpose of reducing the water content and improving the air permeability. Examples of the aeration aid include organic aeration aids such as rice straw, fir tree, sawdust, bark, vegetation or dried or crushed products thereof, and inorganic aeration aids such as perlite, zeolite, diatomaceous earth and coal ash. Materials and the like are used. By including the aeration auxiliary material, it is possible to secure the aerobic fermentation of the sewage sludge while suppressing the excessive consolidation state, which is advantageous in that the aerobic fermentation of the sewage sludge can proceed stably and effectively. be.

The shape of the ventilation auxiliary material is not particularly limited, and may be, for example, a solid, granular, powdery, paste-like, fluid-like, or liquid-like shape. The content of the ventilation auxiliary material can be appropriately adjusted according to the physical properties and purpose of the auxiliary raw material used, but the total weight part of the ventilation auxiliary material with respect to 100 parts by weight of the sewage sludge is preferably 5 parts by weight or more and 80 parts by weight or less. More preferably, it can be 5 parts by weight or more and 50 parts by weight or less. At this time, the weight of the reference sewage sludge is the weight in the water-containing state.

Among the above-mentioned ventilation aids, fly ash can be included as an example. Fly ash is a type of coal ash produced by burning coal. For example, coal ash produced when pulverized coal is burned at a coal-fired power plant and is recovered by an electrostatic collector or the like. Be done. Fly ash, its bulk density is preferably 0.2 g / cm ³ or more 1.5 g / cm ³ or less, the Blaine specific surface area of preferably those 1000 cm ² / g or more 20000cm of ² / g or less, silica, alumina, Includes calcium oxide (CaO), magnesium oxide and the like.

By using fly ash for fermentation treatment of sewage sludge, aerobic fermentation can proceed stably from an initial stage. The reason for this is not clear, but it is considered that the fly ash itself has high dispersibility due to the relatively fine particles. Further, it is considered that the CaO component contained in the fly ash easily aggregates the particles of the sewage sludge to form flocs and easily lowers the density of the sewage sludge fermentation raw material.

[Nutrition aid]
From the viewpoint of promoting aerobic fermentation of sewage sludge, the fermentation raw material may further contain a nutritional auxiliary material. Nutrient aids are auxiliary raw materials that can be used to supply easily degradable organic matter that is a nutrient source for microorganisms that contribute to aerobic fermentation. Examples of nutritional aids include food processing residues such as food sludge, sake lees and shochu lees, waste white clay, paper sludge, waste cooking oil, waste solid fuel (RDF), meat bone powder, food waste, urine, livestock manure, compost, etc. Activated sludge, scum, etc. can be mentioned. These can be used alone or in combination.

Among the above-mentioned nutritional aids, meat-and-bone meal can be adopted because it further promotes aerobic fermentation and increases the temperature-increasing effect of fermentation. Meat-and-bone meal is, for example, obtained by removing meat from beef, pork, and chicken and then heat-treating it together with internal organs, offal, and the like. For example, it is a dry pulverized product crushed into powder. The meat-and-bone meal powder can improve the mixing efficiency with other fermentation raw materials such as sewage sludge. The content of the nutritional auxiliary material is preferably 5 parts by weight or more and 100 parts by weight or less, and more preferably 5 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of sewage sludge. At this time, the weight of the reference sewage sludge is the weight in the water-containing state.

Fermented chicken manure is made by subjecting chicken manure to aerobic fermentation treatment. The water content of fermented chicken manure is reduced by the fermentation treatment, and the water content is usually less than 30%. The amount of fermented chicken manure charged into the fermenter 2 can be 3% by weight to 20% by weight with respect to the sewage sludge charged into the fermenter 2. The above-mentioned input amount is an example of the input amount when fermented chicken manure is added every time the fermentation raw material is input to the fermenter 2. By adding fermented chicken manure in the above range, the fermented state can be maintained well. In addition, when fermented chicken manure is added when fermentation is poor, the fermentation situation can be improved at an early stage. As the fermented chicken manure, for example, egg-collected chicken manure, meat chicken manure, primary fermented chicken manure, secondary fermented chicken manure can be used, and primary fermented chicken manure of egg-collected chicken manure can also be used.

On the other hand, fermented chicken manure may be added as a recovery material at the time of poor fermentation. When fermented chicken manure is charged into the fermenter 2 as a recovery material in this way, 3% by weight to 30% by weight may be charged with respect to the total weight of the contents (processed product) of the container 21, preferably 3% by weight. It may be% to 20% by weight. By adding fermented chicken manure in the above range, the fermented state can be maintained well. In addition, when fermented chicken manure is added when fermentation is poor, the fermentation situation can be improved at an early stage.

In general, the nitrogen concentration of fermented chicken manure may change depending on the purpose of breeding the chicken manure, the fermentation period, the fermentation method, etc., but the production conditions of the fermented chicken manure that can be included in the fermentation raw material are not particularly limited. Further, the shape of the fermented chicken manure is not particularly limited, and various fermented chicken manure can be included in the fermentation raw material.

Fermented chicken manure may contain microorganisms involved in fermentation. It is considered that this microorganism contributes to the improvement of the fermentation condition in the fermentation tank 2. The fermented chicken manure can be used in combination with seed sludge from sewage sludge that has undergone fermentation treatment to some extent during the fermentation treatment in the fermenter 2, or can be used as a substitute for seed sludge.

[Mixing of fermentation raw materials and water content]
The fermentation raw material can be, for example, a mixture of sewage sludge and an auxiliary raw material. As an example, a mixture of fermentation raw materials may be prepared by premixing sewage sludge and auxiliary raw materials before supplying them to a device for fermentation such as a fermentation tank 2. Further, the fermentation raw material may be prepared indoors or outdoors as a deposit in which the other is deposited on one of the sewage sludge and the auxiliary raw material. Further, one of the sewage sludge and the auxiliary raw material may be supplied to a container for fermentation, and then the other may be supplied into the container to form a deposit in which each raw material is alternately deposited in the container. In this case, fermentation may be started from the state of sediment, or fermentation may be started after the sediment is mixed in a container and mixed.

From the viewpoint of ensuring a sufficient amount of water for the stable progress of aerobic fermentation from the initial stage of fermentation, the water content of the fermentation raw material can be 30% or more and 70% or less. Further, when the water content is 40% or more and 60% or less, aerobic fermentation can proceed more stably. The water content can be measured based on the difference in weight before and after drying when dried at a heating temperature of 100 ° C. to 120 ° C. using, for example, a commercially available infrared moisture meter or halogen moisture meter. Alternatively, the measurement can be performed according to JIS A 1203 “Soil water content ratio test method”. The water content of the fermentation raw material can be appropriately adjusted, for example, by selecting the raw material so as to have a desired water content, or by adding water to the raw material or the fermentation raw material.

The above-mentioned fermentation raw material can be subjected to aerobic fermentation treatment by supplying the above-mentioned fermentation raw material in the state of a deposit or a mixture to the container 21 of the fermentation tank 2 as described above.

[Calculation of heat of fermentation and pressure control in the container of the fermenter]
In the fermenter 2, the internal pressure information acquisition unit 91 acquires information related to the pressure inside the container 21, and the displacement control unit 92 makes the pressure inside the container 21 slightly negative compared to the atmospheric pressure. The amount of air pressure from the container 21 of 2 is controlled. In addition, the control unit 9 calculates a fermentation index in order to grasp the fermentation status in the fermentation tank 2. Specifically, as a fermentation index, the "heat of fermentation" per predetermined time, which is calculated based on the aeration amount (air intake amount, exhaust amount), intake air temperature, exhaust temperature, intake air humidity, and exhaust humidity, is used. Used as a fermentation index. That is, the control unit 9 has a function of calculating the amount of heat of fermentation. Further, the control unit 9 may have a function of outputting the calculated amount of heat of fermentation. Further, it may have a function of controlling the amount of air supply based on the output amount of heat of fermentation.

The amount of heat for fermentation is obtained from the difference between the amount of heat of the exhaust gas discharged from the fermentation tank 2 and the amount of heat of the air supplied to the fermentation tank 2. That is, the amount of heat of fermentation satisfies the relationship shown in the following mathematical formula (1).
Fermentation heat quantity (kJ / min) = Exhaust heat quantity (kJ / min) -Air supply heat quantity (kJ / min) ... (1)

FIG. 3 shows the balance of air supply and exhaust in the container 21 of the fermenter 2. As described above, in the fermenter 2 (container 21), the fermentation process is performed while supplying and exhausting air. At this time, it is assumed that the air supply to the container 21 is under the conditions of a dry gas amount V0 (Nm ³ / min), a water vapor amount S0 (kg / min), and an air supply temperature T0 (° C.). Further, in the container 21, gas is discharged from the fermentation raw material (fermented dried product) into the container 21 as the fermentation proceeds in the fermented raw material that has received the air supply. Assuming that the exhaust gas discharged from the fermentation raw material is the exhaust gas 1, the exhaust gas 1 has a dry gas amount V1 (Nm ³ / min), a water vapor amount S1 (kg / min), and an exhaust temperature T1 (° C.). .. Further, the gas is discharged from the container 21 to the outside through the exhaust line L1. Assuming that the exhaust gas discharged from the container 21 is the exhaust gas 2, the exhaust gas 2 has a dry gas amount V2 (Nm ³ / min), a water vapor amount S2 (kg / min), and an exhaust temperature T2 (° C.). ..

Here, as described above, the amount of heat of fermentation can be calculated based on the above mathematical formula (1). As shown in the formula (1), the amount of heat of fermentation is obtained from the difference between the amount of heat of exhaust gas and the amount of heat of air supply. It refers to the amount of heat, and the amount of heat supplied to the air refers to the amount of heat supplied to the air 1 shown in FIG.

Here, the calorific value of the air supply 1 is calculated by, for example, the following method:
1) Based on the relative humidity of the atmosphere (if there is no measured value, it may be fixed at 75%), the outside air temperature, and the saturated water vapor pressure at that time (according to the Japan Mechanical Society, steam table, etc.), the air supply gas dries. Calculate the molar ratio (-) of gas to water vapor.
^{2) The amount of moist gas (Nm 3} / min) is calculated from the measured values of F, T6, and P2 on the air supply line L3 in FIG.
3) The amount of moist gas is the sum of the ^{amount of dry gas V0 (Nm 3} / min) and the amount of water vapor (Nm ^{3 / min). From the amount of moist gas (Nm 3} / min) of No. 2, the amount of dry gas V0 (Nm ³ / min) and the amount of water vapor S0 (kg / min) are calculated.
4) Using the enthalpy of air and water vapor (according to the Japan Mechanical Society, steam table, etc.) in the measured value of T5 in FIG. 1, the amount of dry gas V0 (Nm ³ / min) and the amount of water vapor S0 (kg / min) in 3 above. ), Calculate the amount of heat supplied.

Next, the calorific value of the exhaust 1 is calculated by, for example, the following method:
5) Exhaust 1 is assumed to have a relative humidity of 100%. (Assumptions more reasonable than the structure of a closed vertical fermenter) (Assumption A)
6) Since the exhaust 1 is discharged from the fermentation raw material filling portion in the container 21 (FIG. 3) into the space above the container 21, the amount of dry gas of the exhaust 1 required for calculating the exhaust heat V1 (Nm ³ / min). It is difficult (to accurately grasp) to directly measure the amount of water vapor S1 (kg / min) and T2.
7) Therefore, it is assumed that the exhaust 1 and the exhaust 2 are exactly the same, and V1 = V2, S1 = S2, T1 = T2. (Assumption B)
8) Further, assuming that the amount of dry gas when the insufflation gas passes through the fermenter does not change (a reasonable assumption from the reaction formula of aerobic fermentation), V1 = V2 = V0. (Assumption C)
9) From P1 and T4 in FIG. 1 and assumption A, the saturated water vapor pressure of the exhaust gas 2 and the partial pressure of the dry gas are set, and S2 is calculated from V2 (= V1 = V0).
10) Using the enthalpy of air and water vapor in the measured value of T4 in FIG. 1 ^{, calculate the amount of exhaust heat from the above dry gas amount V2 (= V0) (Nm 3} / min) and water vapor amount S2 (kg / min). do.
11) It is also possible to actually measure V2 instead of 8 above. A flow meter, a thermometer, and a pressure gauge are installed in the exhaust line L1. The dry gas flow rate V2 (Nm3 / min) may be calculated from the wet gas flow rate (measured value of the flow meter) and the saturated water vapor pressure, assuming that the relative humidity at the measurement point is 100%.

From the above, the mathematical formula (1) can also be expressed as the following and (3).
Fermentation heat = Exhaust heat (V1, S1, T1) -Air supply heat (V0, S0, T0) (... (1))
= Exhaust heat amount (V2, S2, T2) -Air supply heat amount (V0, S0, T0)
= Exhaust heat amount (V0, S2, T2) -Air supply heat amount (V0, S0, T0) ... (3)
It is difficult to calculate V1, S1, T1 included in the above mathematical formula (1) from the measured values or the measured values, but V0, S0, S2, T0, T2 included in the mathematical formula (3) are actually measured values or The calculated value from the measured value can be used. Therefore, the amount of heat of fermentation can be calculated using the above formula (3).

However, in reality, as shown in FIG. 3, there is leaked air from the raw material input portion of the container 21 of the fermenter 2. That is, when the tank internal pressure is negative pressure, it may flow into the container 21, or when the tank internal pressure is positive pressure, it may flow out from the container 21. It is assumed that the amount of gas of the leaked air is V3 (Nm ³ / min), the amount of water vapor is S3 (kg / min), and the exhaust temperature is T3 (° C.). When the amount of leaked air increases, assumptions A to C for establishing the above mathematical formula (3) do not hold, and the amount of heat of the exhaust 2 discharged to the container 21 does not match the amount of heat of the exhaust 1. Specifically, when leaked air having a gas amount of V3 is present, the above relationship of V0 = V1 = V2 does not hold. Further, the assumption that the temperature T1 of the exhaust 1 and the temperature T2 of the exhaust 2 are constant does not hold, and there is a possibility that the exhaust 2 does not satisfy the saturation condition. Even if the amount of heat of fermentation is calculated under such conditions, the accuracy may be low. If V3, S3, and T3 of the leaked air can be measured, it is conceivable to make corrections in consideration of these, but since it is difficult to measure these, it is also difficult to correct them.

On the other hand, the control unit 9 compares the atmospheric pressure with the pressure inside the container 21 and controls the displacement so that the pressure inside the container 21 becomes a slightly negative pressure compared to the atmospheric pressure, thereby causing a leak. You can reduce the air pressure. That is, the amount of gas V3 shown in FIG. 3 can be reduced to a extent that does not interfere with the calculation of the amount of heat of fermentation. Therefore, it is possible to prevent the calculation accuracy of the amount of heat of fermentation from being lowered due to the presence of leaked air, and it is possible to calculate the amount of heat of fermentation with high accuracy.

Specifically, the control unit 9 can adjust the air supply amount and the exhaust amount as described above. The control unit 9 adjusts the amount of air supplied according to the amount of heat of fermentation regardless of the pressure in the fermentation tub and the amount of exhaust. In parallel with this, in the control unit 9, the internal pressure information acquisition unit 91 acquires information related to the pressure inside the container 21, and the displacement control unit 92 determines that the pressure inside the container 21 is a slight negative pressure as compared with the atmospheric pressure. The displacement from the container 21 of the fermenter 2 is controlled so as to be. As an example, information on the atmospheric pressure in the container 21 can be obtained from the pressure gauge P1 that measures the pressure (atmospheric pressure) in the fermenter 2 (more accurately, in the container 21 described later). The control unit 9 controls the displacement so that the pressure inside the container 21 becomes a slight negative pressure as compared with the atmospheric pressure. "Slight negative pressure" means within -0.2 kPa with respect to atmospheric pressure. In particular, by setting the pressure inside the container 21 to −0.2 kPa as compared with the atmospheric pressure, the influence of making the inside of the container 21 a negative pressure can be reduced.

The displacement control unit 92 that controls the pressure in the container 21 may be configured by, for example, a differential pressure transmitter. The differential pressure transmitter may include a micro pressure sensor and a transmitter (transducer), a micro negative pressure transmitter, and the like.

The exhaust amount control unit 92 adjusts the frequency of the motor M of the exhaust fan 7 used for exhausting the gas in the fermenter 2, for example, to make the pressure in the container 21 a slightly negative pressure. Can be adjusted.

If the fermenter pressure is maintained at 0 to −0.2 kPa by the control by the control unit 9, the leaked air can be reduced to about 20% or less of the displacement. The ratio of leaked air can be calculated using a known leaked air amount calculation formula. (In the example, when the damper gap of the raw material input port is 1 mm x 0.5 m)

Further, the fermenter pressure is reduced from 0 to −0 by the control by the control unit 9. If maintained at lkPa, leaked air can be reduced to about 10% or less of the displacement. (In the example, when the damper gap of the raw material input port is 1 mm x 0.5 m)

When the exhaust amount is controlled so as to have a "slightly negative pressure", there may be a time zone in which the pressure inside the container 21 is higher than the atmospheric pressure. Even if the time zone in which the pressure in the container 21 is higher than the atmospheric pressure is included to some extent, the time zone in which the difference between the pressure in the container 21 and the atmospheric pressure is small and the pressure in the container 21 is high is included. For a short time (for example, within several tens of seconds), the generation of leaked gas can be minimized. As an example, it is conceivable to adjust the displacement so that the difference between the pressure in the container 21 and the atmospheric pressure is in the range of −0.2 kPa to +0.05 kPa. Further, if the difference between the pressure in the container 21 and the atmospheric pressure is adjusted to be in the range of −0.1 kPa to 0 kPa, the generation of leak gas can be further suppressed and the pressure in the container 21 is stabilized. be able to.

[Use of fermented dried products]
As the fermentation of the fermentation raw material progresses, the water content of the fermentation raw material gradually decreases. As a result, in the state of the fermented and dried product, the water content is about 10% to 40%, preferably about 15% to 35%. The fermented dried product can be used, for example, for the production of cement such as a cement clinker raw material and a heat energy source. Further, as the heat energy source, for example, it may be used in a plant other than cement manufacturing, and examples thereof include various plants that require a heat source such as a power plant.

In the following, as an example, a case where a fermented dried product is used as a raw material for cement clinker will be described. FIG. 4 is a diagram showing an example of the cement clinker manufacturing apparatus 100. The cement clinker manufacturing apparatus 100 includes, for example, a suspension preheater 110, a rotary kiln 120, a calcining furnace 130, and a rotary kiln inlet foot portion 140. The suspension preheater 110 is provided with a raw material supply port 135A and an exhaust portion 150 at the upper portion. Further, the rotary kiln inlet foot portion 140 is also provided with the raw material supply port 135B, and the calcining furnace 130 is also provided with the raw material supply ports 135C and 135D. The rotary kiln 120 is provided with a burner 170 and a cooler 180.

The fermented dried product is introduced into the upper part of the suspension preheater 110 via, for example, the raw material supply port 135A, and is lowered in the suspension preheater 110 while being heated. Then, the fermented dried product is further heated in the calcining furnace 130 connected to the suspension preheater 110, and then introduced into the rotary kiln 120 via the rotary kiln inlet foot portion 140. The fermented and dried product introduced into the rotary kiln 120 is fired by the flame generated in the rotary kiln 120 by the burner 170. The fired raw material is cooled through the cooler 180 to become a target cement clinker and is discharged to the outside. By the above procedure, a cement clinker can be produced from a fermented dried product as a raw material.

As a method for treating the fermented dried product, for example, in addition to the above-mentioned introduction from the raw material supply port 135A, the introduction from the raw material supply port 135B provided on the side surface of the rotary kiln inlet foot portion 140, or a calcining furnace. It may be introduced from the raw material supply port 135C provided on the upper part of the 130, or may be introduced from the raw material supply port 135D provided on the side surface of the calcining furnace 130. Further, as a method of utilizing it as a fuel during cement production, the fermented dried product may be directly blown into the rotary kiln 120 from the burner 170 to be introduced, or a raw material supply port may be further provided near the burner to be blown into the rotary kiln 120. good. In these cases, the fermented and dried product has the advantage that it can be treated as a heat energy source in addition to being able to be treated as a cement clinker raw material. From the viewpoint of ease of operation, it is conceivable to introduce the fermented dried product from the vicinity of the foot portion 140 at the entrance of the rotary kiln. In any case, when the fermented dried product is introduced into the cement clinker manufacturing apparatus 100, the fermented dried product may be introduced alone or mixed with other cement clinker raw materials. good. The introduction of the fermented dried product may be carried out continuously or intermittently. Further, the fermented dried product may be introduced through one raw material supply port, or may be introduced through a plurality of raw material supply ports.

In cement factories, it is important to control the composition of the cement clinker produced. Therefore, from the viewpoint of ease of management, the amount of the fermented dried product used is pre-designed based on the composition of the target cement clinker, and the fermented product is introduced into the cement clinker manufacturing apparatus based on the designed amount of use. The fermented dried product may be treated as a raw material for cement clinker. Specifically, the production of cement such as the amount of auxiliary raw material added to the fermented raw material, the production rate of the fermented product (fermentation rate), the composition of the cement clinker raw material used at the same time other than the fermented dried product, and the mixing ratio thereof. The relationship between (at least one of) the information related to the conditions and the composition of the cement clinker produced is grasped in advance. Then, based on this information, the amount of fermented dried product used is designed. By performing such work in advance, stable operation management of the manufacturing apparatus can be performed. Further, by designing so as to increase the amount of the fermented and dried product used in the above design, it is possible to realize an increase in the waste intensity.

[Action]
As described above, according to the fermentation / drying apparatus and the fermentation / drying method described in the above embodiment, information on the pressure inside the container is acquired so that the pressure inside the container becomes a slight negative pressure as compared with the atmospheric pressure. The amount of air pressure from inside the container is controlled. Therefore, since the outflow of gas from the container and the inflow of gas from the outside of the container can be reduced, it is possible to prevent the environment inside the container from being changed due to the leakage of gas from the fermentation / drying apparatus. Therefore, it is possible to accurately calculate the amount of heat of fermentation in the fermentation / drying apparatus.

As described above, in order to accurately calculate the amount of heat of fermentation, which is important as a fermentation index, it is necessary to more accurately grasp the state of gas in the fermentation / drying apparatus. However, the presence of leaked gas from the fermentation / drying apparatus to the outside or inside the fermentation / drying apparatus is expected to change the situation inside the apparatus. On the other hand, as in the above-mentioned fermentation / drying device and fermentation / drying method, by controlling the pressure inside the container so that it becomes a slightly negative pressure by comparing the atmospheric pressure, the leakage of gas to the outside of the device is suppressed. can do. Therefore, since the environment inside the fermentation / drying apparatus can be estimated more accurately, the amount of heat of fermentation in the fermentation / drying apparatus can be calculated accurately.

Further, as described above, the amount of air supplied is constantly changed due to the change in the fermentation index. In this case, if the displacement is not changed according to the change in the amount of air supplied and the amount of water vapor generated in the fermenter (changes depending on the amount of air supplied and the fermentation condition), the pressure in the fermenter will fluctuate, and the product discharge port of the fermenter and the product discharge port of the fermenter will be affected. Leaked air is generated at the raw material inlet (it is not realistic to have a completely sealed structure due to the structure). That is, when the pressure inside the fermenter is negative, gas may flow in from the outside, and when the pressure inside the fermenter is positive, gas may be discharged to the outside. In this case, the influence on the exhaust gas properties (composition, flow rate, temperature, relative humidity) cannot be ignored, and the calculation accuracy of the fermentation heat estimated from the exhaust gas properties is lowered. In this case, the air supply control based on the calculation of the heat of fermentation does not function effectively, and as a result, there is a concern that the fermentation becomes unstable. As a means for solving the above problems, a method of controlling the exhaust amount according to the air supply amount can be considered. For example, the motor rotation speed of the exhaust fan is proportionally controlled by the motor rotation speed of the air supply blower. However, since the amount of water vapor generated in the fermenter changes depending on the fermentation state, this method still produces leaked air due to pressure fluctuations in the fermenter, and there is a possibility that the influence on the exhaust gas properties cannot be ignored.

On the other hand, in the fermentation / drying apparatus and fermentation / drying method described in the above embodiment, the exhaust amount is adjusted so that the fermentation tub pressure is in the slightly negative pressure region, so that the amount of leaked air is always within a certain range. The effect on the exhaust gas properties (composition, flow rate, temperature, relative humidity) can be suppressed within the permissible range, the estimation accuracy of fermentation heat is improved, and the appropriate amount of air supply is set according to the fermentation heat. Therefore, fermentation can proceed stably.

Further, as described above, when the exhaust amount from the inside of the container is controlled so as to be within the range of -0.2 kPa, preferably -0.1 kPa with respect to the atmospheric pressure, the influence of setting the negative pressure is low. And stable fermentation processing can be performed.

As an example, the exhaust means includes an exhaust line and an exhaust fan on the exhaust line, and the control unit can control the exhaust amount by adjusting the rotation speed of the exhaust fan. With such a configuration, the exhaust amount cannot be controlled only by controlling the operation of the exhaust fan, and it is possible to create an environment in which the amount of heat of fermentation in the fermentation / drying device can be calculated accurately without changing the device configuration. ..

In addition, the cement manufacturing system according to one embodiment of the present disclosure includes the above-mentioned fermentation and drying apparatus, and a cement manufacturing apparatus that uses a fermented and dried product obtained by the fermentation and drying treatment in the fermentation and drying apparatus. By producing cement in a cement manufacturing apparatus using the fermented and dried product obtained by the above fermentation and drying apparatus, the fermented and dried product produced in a state where the calorific value of fermentation can be accurately controlled can be used for cement production. Can be done.

In addition, a cement clinker may be produced from the fermented dried product obtained by the above method as a raw material. In this case, since the cement clinker can be produced from the fermented dried product obtained from the sewage sludge as a raw material, it is possible to realize an increase in the waste basic unit.

Further, the fermented dried product obtained by the above method may be used as a heat energy source. In this case, since the fermented dried product can be converted into heat energy and used, it is possible to reduce fossil fuels and the like.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made.

For example, the configurations of the production system 1, the fermenter 2, the cement clinker production apparatus 100 and the like described above are examples, and can be appropriately changed.

Further, in the production system 1, a plurality of fermentation drying devices (fermentation tanks 2) may be installed. When a plurality of fermentation and drying devices are provided, the exhaust treatment devices may be installed individually for each of the plurality of fermentation and drying devices, or may be collectively processed by one exhaust treatment device. Even when the treatment is performed collectively, it is preferable to install the dust removal tower for each fermenter. In this case, the exhaust fan may be installed in each dust removal tower installed in each fermenter, and the exhaust lines may be merged downstream of the exhaust fan and connected to the cleaning / deodorizing tower, or the exhaust lines at the outlets of a plurality of dust removal towers may be connected. May be merged and connected to an exhaust fan and connected to a downstream cleaning / deodorizing tower inlet for processing. As the displacement control system in the latter, the methods of FIGS. 5 (a) and 5 (b) described later are applied.

When the production system 1 includes a plurality of fermenters, it is preferable that the control unit 9 controls the air supply individually for each fermenter. If different dust removal towers are installed for each of the multiple fermenters, the exhaust flow rate adjusting means can be installed on the downstream side of the dust removal tower and on the upstream side of the point where the exhaust lines meet. , The exhaust flow rate can be adjusted individually for each fermenter.

Further, in the above embodiment, the case where the line L1 as the exhaust line and the exhaust fan are included as the exhaust means from the fermenter 2 has been described, but the configuration of the exhaust means can also be changed.

5 (a) and 5 (b) are examples of modification of the configuration of the exhaust means. FIG. 5A shows an example in which the flow rate adjusting valve 95 is provided on the exhaust line L5 that exhausts air from the fermenter 2. The exhaust line L5 corresponds to the line L1 in the above embodiment, and exhaust treatment equipment (dust removal tower 6 and cleaning / deodorizing tower 8) is provided on the line. In such a configuration, in the above embodiment, the displacement control unit 92 of the control unit 9 controls the exhaust fan 7, but the exhaust amount control unit 92 controls the opening degree of the flow rate adjusting valve 95. By doing so, the displacement can be controlled. Therefore, as in the above embodiment, by controlling the pressure inside the container so that it becomes a slightly negative pressure by comparing the atmospheric pressure, the outflow of gas to the outside of the device and the inflow of gas from the outside of the device are suppressed. be able to.

In FIG. 5B, the outside air intake line L6 is connected to the exhaust line L5 that exhausts air from the fermenter 2. Further, an example in which the flow rate adjusting valve 95 is provided on the outside air intake line L6 is shown. The exhaust line L5 corresponds to the line L1 in the above embodiment, and exhaust treatment equipment (dust removal tower 6 and cleaning / deodorizing tower 8) is provided on the line. In such a configuration, instead of the exhaust amount control unit 92 of the control unit 9 controlling the exhaust fan 7 in the above embodiment, the exhaust fan 7 always operates at a constant flow rate, and the exhaust amount control unit In 92, the opening degree of the flow rate adjusting valve 95 on the outside air intake line L6 is controlled so that the pressure in the fermenter becomes a slight negative pressure, and the amount of outside air taken in is changed. As a result, even if the amount of gas flowing through the exhaust line L5, that is, the amount of exhaust gas is operated to a constant value, the inside of the fermenter can always be maintained at a slight negative pressure. Therefore, as in the above embodiment, by controlling the pressure inside the container so that it becomes a slightly negative pressure by comparing the atmospheric pressure, the leakage of gas to the outside of the device and the inflow of gas from the outside of the device are suppressed. be able to.

Hereinafter, the contents of the present disclosure will be described in more detail with reference to Examples. However, the present disclosure is not limited to the following examples.

(Examples and Comparative Examples)
^{Sewage sludge is added to a fermenter (capacity 39 m 3} , manufactured by Chubu Ecotech Co., Ltd .: C-40ET) having the same shape as the fermenter 2 described in the above embodiment, and various auxiliary materials are added to use seed sludge. The fermented and dried product was produced. The component of the sewage sludge was sludge-like sludge (moisture content 80% to 85%) dehydrated by a filter press.

While adjusting the amount of sewage sludge and auxiliary materials in consideration of the fermentation situation in the fermenter, basically every day, at a predetermined time (between 9:00 am and 11:00 am), fermented and dried products are discharged from the sewage sludge outlet. It was taken out and the fermentation raw material was put in from the inlet. The fermentation process was continued while controlling the weight of the contents in the fermenter to be within a predetermined range.

After continuing the operation of the fermenter 2 for several days, comparative examples 1 to 3 and the implementation were carried out while changing the pressure control contents in the fermenter during a predetermined operation period (March 6 to March 11). The data related to the example was acquired. Table 1 shows the weight and water content of the fermented dried product taken out on each day.

When the raw material is input and the fermented dried product is extracted, the input port and the discharge port of the fermentation tank 2 are temporarily released to the atmosphere, so that the sealed state of the fermentation tank 2 may change. Therefore, after the above-mentioned predetermined time (9:00 to 11:00 am), it is estimated that the sealed state in the fermenter 2 has been maintained to some extent, and the evaluation target time is from 6:00 pm to 6:00 am the next day. As a band, the amount of air sent and discharged from the fermenter 2 was evaluated, and data corresponding to Comparative Examples 1 to 3 and Examples were obtained. The control conditions and results in Comparative Examples 1 to 3 and Examples are as follows.

Amount of air supplied to the fermenter:
In all the cases of Comparative Examples 1 to 3 and Examples, the air supply amount control (automatic control of the rotation speed of the air supply blower by the fermentation index) was applied. 6 (a) to 6 (d) show the time course of the air supply amount in each case. 6 (a) shows Comparative Example 1, FIG. 6 (b) shows Comparative Example 2, FIG. 6 (c) shows Comparative Example 3, and FIG. 6 (d) shows Examples. The vertical axis in FIGS. 6 (a) to 6 (d) is the air supply flow rate (Nm ³ / min).

For the air supply amount control, an automatic control program was used in which the exhaust temperature was selected as the fermentation index and the air supply blower rotation speed was increased as the measured exhaust temperature (T4 in FIG. 3) increased. In Comparative Examples 1 and 2 and Examples, the above control was applied during the entire period of the evaluation target time zone. In Comparative Example 3, the air supply blower rotation speed was fixed (manual) in the first half time zone H1, and switched to automatic control in the latter half time zone H2. The small fluctuations common to all cases are due to the intermittent operation of the stirring blade of the fermenter 2.

Displacement from fermenter:
In Comparative Examples 1 to 3, the rotation speeds of the exhaust fan (rated capacity 30 m ² / min × 320 mm AQ) of the exhaust treatment device were fixed at 41, 40, and 39 Hz, respectively, for operation. In the example, the rotation speed of the exhaust fan was automatically controlled so that the pressure in the fermenter became −0.1 kPa.

[Evaluation results]
7 (a) to 7 (d) show the time course of the measured pressure value in the fermenter 2 in each case. 7 (a) shows Comparative Example 1, FIG. 7 (b) shows Comparative Example 2, FIG. 7 (c) shows Comparative Example 3, and FIG. 7 (d) shows Examples. The vertical axis in FIGS. 7 (a) to 7 (d) is the pressure (kPa). The small variation (± 0.05 kPa) in the span of several minutes, which is common to all cases, is due to the intermittent operation of the fermenter stirring blade.

In Comparative Example 1 (FIG. 7 (a)), the fermentation tank pressure gradually decreased from -0.1 ± 0.05 kPa to -0.23 ± 0.05 kPa, and the fermentation in the tank became sluggish. It is considered that the amount of air supply and the amount of water vapor generated in the tank have decreased, and the displacement tends to be excessive with respect to the decrease in the air volume. In Comparative Example 2 (FIG. 7 (b)), the fermentation tank pressure gradually increased from -0.3 ± 0.05 kPa to -0.15 ± 0.05 kPa, and fermentation in the tank became active. It is considered that the amount of air supply and the amount of water vapor generated have increased, and the displacement tends to be insufficient with respect to the increase in the air volume. In Comparative Example 3 (FIG. 7 (c)), it is considered that the amount of air supplied suddenly decreased and the amount of exhaust was excessive at the timing when the air supply blower rotation speed setting was switched from manual to automatic (see FIG. 6). .. These are because when the exhaust fan frequency is fixed and operated, the amount of air supplied and the amount of water vapor generated change as the fermentation conditions change, and the balance of the air supply and exhaust gas flow rate (wet gas flow rate) in the fermenter changes. Is.

On the other hand, in the embodiment (FIG. 7 (d)), the rotation speed of the exhaust fan is automatically controlled so that the pressure in the fermenter becomes −0.1 kPa. Therefore, even if the amount of air supplied to the fermenter (depending on the fluctuation of the fermentation index) and the amount of water vapor generated in the tank (depending on the fermentation state) change, the displacement will change accordingly, so the fermenter pressure will change. It was confirmed that it was always in the range of −0.1 ± 0.05 kPa.

Next, when the pressure in the fermenter 2 becomes negative, there is a gap between the raw material input damper at the input port 22 and the product extraction damper at the discharge port 23 due to the pressure difference from the outside air (atmospheric pressure) (structurally strict sealing mechanism). Is not realistic), the outside air flows into the system (leak air is generated). The result of evaluating the amount of leaked air will be described.

The amount of leaked air depends on the pressure difference between the inside and outside of the fermenter 2, and can be estimated by a known method using the size of the leak hole and the like. Since the damper gap (leak hole size) in the fermenter 2 cannot be accurately grasped, the damper gap at the raw material input port is 1 mm x 0.5 m (when there is a 1 mm gap in 1/6 of the entire circumference of the raw material input damper). ) And 1 mm × 3 m (when there is a gap of 1 mm on the entire circumference of the raw material input damper), the results of trial calculation are shown in FIGS. 8 (a) to 8 (d) and 9 (a) to 9 (d). ). The vertical axis in FIGS. 8 (a) to 8 (d) and 9 (a) to 9 (d) is an estimated leak air amount (Nm ³ / min).

FIG. 8 shows a trial calculation result when the damper gap of the raw material input port is 1 mm × 0.5 m. 8 (a) shows Comparative Example 1, FIG. 8 (b) shows Comparative Example 2, FIG. 8 (c) shows Comparative Example 3, and FIG. 8 (d) shows Examples. According to the results shown in FIG. 8, the amount of leaked air in Comparative Examples 1, 2 and 3 is relatively large with respect to Example. Further, it was confirmed that the leaked air amounts of Comparative Examples 1 to 3 had an increasing tendency, a decreasing tendency, or a rapid increase / decrease, respectively, whereas the leaked air amounts of the Examples fluctuated within a substantially constant range. Was done.

FIG. 9 shows a trial calculation result when the damper gap of the raw material input port is 1 mm × 3 m. 9 (a) shows Comparative Example 1, FIG. 9 (b) shows Comparative Example 2, FIG. 9 (c) shows Comparative Example 3, and FIG. 9 (d) shows Examples. According to the results shown in FIG. 9, the tendency of the leaked air amount described above becomes more remarkable, and it is confirmed that the leaked air amount in Comparative Examples 1 to 3 is a non-negligible amount with respect to the air supply amount (FIG. 6). In particular, it was confirmed that the amount of air supplied (see FIG. 6C) was exceeded in Comparative Example 3.

As described above, when the amount of leaked air becomes a non-negligible amount with respect to the amount of air supplied, the assumptions ((A), (B), (C) below) at the time of calculating the amount of heat of fermentation do not hold.
A) Exhaust 1 has a relative humidity of 100%.
B) Exhaust 1 and exhaust 2 are considered to be exactly the same, and V1 = V2, S1 = S2, T1 = T2.
C) Considering that the amount of dry gas when the insufflation gas passes through the fermenter does not change, V1 = V2 = V0.

When the above assumption is no longer established, the relationship of "exhaust heat amount (V1, S1, T1) = exhaust heat amount (V2, S2, T2) = exhaust heat amount (V0, S2, T1)" (see formula (3)) It will not be established, and the calculation accuracy of the amount of heat of fermentation will decrease. As a result, it is expected that the air supply control system using this calculation result as a fermentation index will not function effectively. Further, when the exhaust gas 1 is cooled by mixing with a considerable amount of leaked air, the water vapor contained in the exhaust gas 1 is condensed in the fermenter and cannot be taken out of the system, and it is expected that the thermal efficiency of the fermenter is lowered.

On the other hand, in the examples, the amount of leaked air is smaller than that of the comparative example, and particularly when the damper gap is 1 mm × 0.5 m, the leaked air is always 10% or less of the air supply amount. Therefore, the influence on the premise "exhaust heat amount (V1, S1, T1) = exhaust heat amount (V2, S2, T2) = exhaust heat amount (V0, S2, T1)" is smaller and more limited than in the comparative example. it is conceivable that.

Further, instead of the fermentation index described above, the carbon dioxide concentration (carbon dioxide production amount) or oxygen concentration (oxygen loss amount) of exhaust 1 and the amount of change thereof may be used as the fermentation index. The carbon dioxide concentration or oxygen concentration meter may be installed on the exhaust line 2 (exhaust line from the fermenter 2). In this case, as in Comparative Examples 1 to 3, if a non-negligible amount of leaked air with respect to the amount of air supplied enters the fermenter 2 irregularly (mixed in the system), the leaked air exhausts 1 Can be diluted irregularly. Therefore, it becomes difficult to accurately grasp the carbon dioxide concentration (carbon dioxide production amount) or oxygen concentration (oxygen loss amount) of the exhaust gas 1. On the other hand, in the examples, since the amount of leaked air is small, the influence of the carbon dioxide concentration (carbon dioxide production amount) or oxygen concentration (oxygen loss amount) and the change amount thereof on the measurement accuracy is limited.

Further, it was confirmed that the amount of leaked air in the examples was relatively smaller than that in Comparative Examples 1 to 3 (FIGS. 8 and 9). From this, according to the control shown in the examples, the passing flow rate of the exhaust fan is suppressed to be low and the exhaust fan power is reduced as compared with the control contents in Comparative Examples 1 to 3.

As described above, it is considered that the examples are superior to the comparative examples from the three viewpoints of the estimation accuracy of the fermentation index such as fermentation heat, the thermal efficiency of the fermenter, and the required power of the exhaust fan.

1 ... Manufacturing system, 2 ... Fermenter, 4 ... Air supply heater, 5 ... Air supply blower, 6 ... Dust removal tower, 7 ... Exhaust fan, 8 ... Cleaning and deodorizing tower, 9 ... Control unit, 21 ... Container, 22 ... Input Port, 23 ... Discharge port, 24 ... Stirring equipment, 24a ... Stirring blade, 24b ... Rotating shaft, 25 ... Air supply means, 26 ... Exhaust means, 91 ... Internal pressure information acquisition unit, 92 ... Exhaust volume control unit, 100 ... Cement Clinker manufacturing equipment.

Claims (9)

A container that accommodates fermentation raw materials containing sewage sludge and performs fermentation drying treatment while stirring the fermentation raw materials.
An air supply means for supplying air into the container and
Exhaust means for exhausting from the inside of the container and
An internal pressure information acquisition unit that acquires information related to the atmospheric pressure in the container, and
A fermentation and drying apparatus having an exhaust amount control unit that controls the amount of exhaust gas from the exhaust means so that the pressure inside the container acquired by the internal pressure information acquisition unit becomes a slightly negative pressure as compared with the atmospheric pressure. .. The fermentation and drying apparatus according to claim 1, wherein the slight negative pressure is in the range of −0.2 kPa with respect to atmospheric pressure. The exhaust means includes an exhaust line and a flow control valve on the exhaust line.
The fermentation / drying apparatus according to claim 1 or 2, wherein the exhaust amount control unit controls the exhaust amount by adjusting the flow rate adjusting valve. The exhaust means includes an exhaust line and an exhaust fan on the exhaust line.
The fermentation / drying apparatus according to claim 1 or 2, wherein the exhaust amount control unit controls the exhaust amount by adjusting the rotation speed of the exhaust fan. The exhaust means includes an exhaust line, an exhaust fan on the exhaust line, and an outside air intake line that joins the exhaust line on the upstream side of the exhaust fan.
The fermentation / drying apparatus according to claim 1 or 2, wherein the exhaust amount control unit controls the exhaust amount by adjusting the amount of outside air taken in from the outside air intake line. The fermentation / drying apparatus according to any one of claims 1 to 5.
A cement manufacturing apparatus using a fermented and dried product obtained by the fermentation and drying treatment in the fermentation and drying apparatus, and a cement manufacturing apparatus.
Has a cement manufacturing system. Fermentation raw materials containing sewage sludge are housed in a container, and the fermentation drying process is performed while stirring the fermentation raw materials in the container.
When performing the fermentation and drying process, air is supplied into the container and
When performing the fermentation and drying process, exhausting from the container and
Acquiring information on the air pressure inside the container
Controlling the amount of exhaust from the container so that the pressure inside the container becomes a slightly negative pressure compared to the atmospheric pressure,
Fermentation and drying methods, including. A method for producing cement clinker, wherein the cement clinker is produced from the fermented dried product obtained by the method according to claim 7. A method for using a fermented dried product, which uses the fermented dried product obtained by the method according to claim 7 as a heat energy source.

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