JP2018172272A - Composting apparatus and method of controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composting apparatus and a method of controlling the same, in a configuration in which continuous composting is performed in a hermetic type composting apparatus, capable of stably producing compost by accurately monitoring a fermentation state.SOLUTION: A composting apparatus 1 is a hermetic type composting apparatus that includes a revolving shaft 3 disposed in a container 2, plural impeller blades 4 attached to the revolving shaft, air feeding means 6, and exhausting means 9. The composting apparatus continuously performs composting processing by, while introducing ambient air into the container 2 by the air feeding means 6 and exhausting inside air from inside the container 2 by the exhausting means 9, stirring with the impeller blades 4 and fermenting organic waste introduced from an inlet port 2a into the container, drying and discharging the fermented waste as compost from the outlet port 2b and further includes fermentation parameter output means 10 that can calculate and output fermentation calories and an evaporated water amount per a predetermined time period as fermentation parameters on the basis of a temperature and a volume of the ambient air introduced into the container 2 and a temperature and a volume of the inside air exhausted from inside the container 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a composting apparatus (sealed composting apparatus) for processing organic waste such as livestock excrement and food residues, and a waste processing method using the apparatus.

  Organic waste, such as livestock excreta discharged from livestock management bodies and food residues discharged from food industry establishments, has recently increased in type and discharge, and its disposal has become a major social issue. Yes. When these wastes are incinerated, the cost is high and there is a problem of dioxin generation. Further, when landfilling is performed, there are problems of securing a disposal place and odor damage. In addition, in recent years, the promotion of the reuse of organic waste has been demanded by legislation such as the Food Recycling Law. In view of these points, organic waste is composted and recycled as a recycling resource. Even when composting, organic wastes such as food residues have a high water content. Therefore, if drying and fermentation are not sufficient, weight loss will not proceed and there is a risk of decay.

  As an apparatus for performing such composting, a sealed vertical composting apparatus (also referred to as “component”) using a fermentation action of microorganisms is known. This component is in the shape of a cylindrical vertical tank, and is dried and fermented while forcibly ventilating the organic waste charged in the sealed container. In addition, compost raw materials are sequentially input and compost discharged, and composting is continuously performed.

  As another composting apparatus, Patent Document 1 discloses a fermenter, a ventilation means for compost material provided in the fermenter, a thermometer for measuring the temperature of the compost material, and the measured temperature. An apparatus provided with means for controlling the air volume of the ventilation means has been proposed (see Patent Document 1). In this apparatus, the power cost applied to the blower can be reduced by appropriately controlling the amount of blown air in accordance with the fermentation status of the compost material.

  Patent Document 2 discloses that as an apparatus for efficient composting, a temperature sensor is used to measure the temperature of the compost raw material once a day in an apparatus for performing fermentation by depositing compost raw material in an aging tank having an aeration pipe and a temperature sensor. The apparatus which has a means to increase / decrease aeration volume in consideration of the present temperature of the compost raw material and the aging stage of the compost raw material which were measured in 1 is proposed.

  Furthermore, Patent Document 3 discloses a batch-type suction ventilation as a device that can be sufficiently deodorized with small size and energy consumption, and that effectively uses exhaust heat by continuing the composting process while maintaining aerobic fermentation. An apparatus provided with a predetermined ammonia component recovery unit in a type composting apparatus has been proposed.

JP 2012-229136 A JP 2003-146783 A JP 2007-269517 A

  Each fermentation apparatus described above decomposes organic waste by aerobic fermentation using the fermentation action of microorganisms. As an existing fermentation index for judging whether the fermentation state is good or bad, the compost temperature, the concentration of carbon dioxide or oxygen contained in the exhaust gas, etc. are generally known. Based on these indices, aeration control, judgment of turning over (stirring), judgment of the end of fermentation, and the like are performed. In Patent Documents 1 and 2, thermometers such as thermocouples, resistance temperature detectors, and infrared radiation thermometers are used in order to use compost temperature as an index.

  However, when operating conditions are determined using the compost temperature, carbon dioxide concentration, or the like as a fermentation index, there are the following problems. The compost temperature is determined by the amount of heat input, the amount of exhaust heat, the amount of heat of fermentation, the heat capacity of compost (moisture), and the heat balance from heat release from the fermenter, and has many uncertain factors. The compost temperature is based on arbitrary test conditions, and it is necessary to adjust conditions and empirically correct the actual set values. Further, most of the exhaust heat quantity is water vapor, and the exhaust heat quantity varies greatly depending on the temperature and the amount of ventilation.

  It can be said that the concentration of oxygen and carbon dioxide can directly evaluate microbial activity. However, it is difficult to achieve both sensor durability and measurement accuracy. In particular, since the measurement accuracy decreases with an increase in the air flow rate, it is not suitable for air flow control. There is also a problem of dust adhesion to the sensor.

  Patent Document 3 describes that the output of the intake means is adjusted in consideration of the heat balance, but relates to a batch-type composting device, and is a continuous composting device such as a component. The adjustment method in is not considered.

  The present invention has been made to cope with such problems, and in a configuration in which composting is continuously performed in a closed-type composting apparatus, the state of fermentation can be accurately grasped to enable stable production of compost. An object of the present invention is to provide a composting apparatus and a control method therefor.

  The composting apparatus of the present invention comprises a rotating shaft provided in a container, a plurality of stirring blades attached thereto, an air supply means for taking outside air into the container, and an internal air accumulated in the container. A closed-type composting apparatus comprising an exhaust means for discharging to the outside of the container, wherein the composting apparatus introduces outside air into the container by the air feeding means, and the exhaust means While combusting the inside air from the inside of the container, the composting process in which the organic waste introduced from the inlet into the container is fermented and dried while being stirred with the stirring blade and composted to be discharged from the outlet is continuously performed. The composting apparatus includes a temperature (inlet air temperature) and an amount of outside air introduced into the container (inlet air amount), and a temperature of the inside air exhausted from the container (exhaust temperature). Based on the volume (displacement) It characterized by having a fermentation index output means can be calculated and output the Rino fermentation heat and evaporate the water content.

  In this composting apparatus, the rotating shaft is provided in the container in the vertical direction, the inlet is provided in the upper part of the container, the outlet is provided in the lower part of the container, and the stirring blade is provided in the container. In order to introduce outside air from the air supply means into the container, the lower agitation blade is provided in multiple stages with a predetermined interval from the lower part to the upper part of the rotating shaft, and is communicated with the air supply means. It has the vent hole of this.

  The composting control method of the present invention is a composting control method using the composting apparatus of the present invention, wherein in the composting apparatus, outside air is introduced into the container by the air feeding means, and the above Composting treatment that exhausts the inside air from the inside of the container by the exhaust means, and ferments and dries the organic waste that is input from the inlet into the container while stirring with the stirring blade and discharges it from the outlet as compost In the step of continuously performing the above, the organic to be a compost raw material based on at least one fermentation index selected from the amount of fermentation heat and the amount of evaporated water obtained from the fermentation index output means at any timing in the step At least one of the input amount of radioactive waste, the temperature of the outside air introduced into the container (inlet air temperature), the amount of outside air introduced into the container (inlet air amount), and the input amount of the highly exothermic raw material One And having a control step of controlling the progress of the composting and integer.

  In this composting control method, the control step is a step of adjusting the input amount of the highly exothermic raw material based on the amount of fermentation heat. Further, the control step is based on the amount of evaporated water, the amount of the organic waste to be used as a compost raw material, the temperature of the outside air (inlet temperature) introduced into the container, and the amount introduced into the container It is characterized by adjusting at least one of the amount of outside air (intake amount).

  In this composting control method, the control step includes an intake air amount adjustment step of adjusting the amount of outside air introduced into the container based on the fermentation heat amount, and the intake air amount adjustment step includes a predetermined time. The amount of fermentation heat was calculated at intervals, and the amount of outside air introduced into the vessel was increased and decreased when the amount of fermentation heat at the time of any calculation increased compared to the amount of fermentation heat previously calculated. In this case, the amount of outside air introduced into the container is reduced. In particular, the air volume adjustment step is automatically performed by the control device provided in the composting apparatus at the predetermined time interval set by the operator and the adjustment range of the amount of outside air. To do.

  In the above control process, the composting efficiency represented by (fermentation heat amount / power consumption amount) is calculated from the fermentation heat amount at the time of arbitrary calculation and the power consumption amount of the composting apparatus at that time, and the composting efficiency is calculated. On the basis of the amount of the organic waste used as compost material, the temperature of the outside air introduced into the container (inlet temperature), the amount of outside air introduced into the container (intake amount), and It is characterized in that the progress of composting is controlled by adjusting at least one of the input amounts of the high exothermic raw materials.

  The composting apparatus of the present invention is a closed-type composting apparatus that continuously performs composting processing, and the amount of fermentation heat per predetermined time serving as a fermentation index based on the inlet temperature and the amount of intake air, the exhaust temperature and the amount of exhaust. Furthermore, since the fermentation index output means that can calculate and output the amount of evaporated water is provided, there are no uncertainties as compared with the case where the fermentation state is determined only by the temperature and the exhaust component concentration, and it can be accurately grasped. For this reason, based on the fermentation index obtained from the output means, the worker inputs the amount of organic waste used as compost material, the input temperature, the amount of input, and the high exothermic raw materials such as waste white clay and rice bran. It is possible to efficiently produce high quality compost by adjusting the amount of input.

It is a longitudinal cross-sectional view which shows an example of the composting apparatus of this invention. It is a figure which shows a water vapor | steam total heat specific enthalpy relational expression. It is a figure which shows the relationship between the inverter frequency of a blower, and an air intake amount. It is a figure which shows the relationship between the amount of fermentation heat, and the amount of evaporating water. It is a figure which shows the calorie | heat amount change by a blower heat_generation | fever and a fermentation heat_generation | fever. It is a figure which shows the time-dependent change of fermentation calorie | heat amount, evaporative water content, and exhaust temperature. It is a figure which shows the relationship between the space | interval of intake air amount control, and an inverter frequency. It is a figure which shows the relationship between the space | interval of intake air amount control, and an inverter frequency. It is a figure which shows the relationship between the space | interval of intake air amount control, and an inverter frequency. It is a figure which shows the time-dependent change of the frequency in the case of accompanying air_entry volume control. It is a figure which shows the relationship between a frequency and the electric power consumption per the air volume of a blower.

An outline of the composting apparatus of the present invention will be described with reference to FIG. FIG. 1 is a longitudinal sectional view showing an example of the configuration of a composting apparatus. As shown in FIG. 1, a composting apparatus 1 includes a cylindrical vertical container 2, a rotating shaft 3 provided in the container 2 in a vertical direction, and a plurality of stirring members attached in multiple stages around the rotating shaft 3. A sealed vertical composting apparatus (component) comprising wings 4, air supply means 6 for taking outside air into the container 2, and exhaust means 9 for discharging the inside air accumulated in the container 2 to the outside of the container. ). The apparatus according to the present invention is mainly intended for a large-sized apparatus for business in which the internal volume of the container 2 is 10 m ³ or more. The shape of the stirring blade 4 is not particularly limited, and may be, for example, a pitched paddle shape linearly extending from the rotation shaft 3 toward the inner wall side of the container 2 and a shape having an inclined surface on the front side in the rotation direction.

  A vent hole 4a is provided at the lower part of the lowermost stirring blade, and outside air (intake air) sent from the air feeding means 6 is introduced into the container through the vent hole 6a provided in the rotating shaft. Yes. The container 2 that is a fermenter is a heat-insulating container having a metal outer layer and a heat insulating layer, and is an airtight container that is difficult to come into contact with outside air other than that introduced from a vent hole. In addition, the container 2 has an input port 2a for organic waste as an input material and an exhaust port 2c at the top, and an outlet 2b for compost (organic waste after treatment) at the bottom. The exhaust port 2 c is connected to the exhaust means 9. The inlet 2a and the outlet 2b are provided with lids that can be opened and closed to ensure the hermeticity of the container.

  In the form shown in FIG. 1, a machine room 5 is provided below the container 2, and the drive means 8 of the rotating shaft 3 and the above-described air supply means 6 are provided in the machine room. The rotating shaft 3 penetrates into the machine room 5 and is rotated at a predetermined number of rotations by the driving means 8. Further, a heater 7 for heating the outside air sent from the air supply means 6 is provided as necessary. A blower is used for the air supply means 6. As the blower, it is preferable to use a blower that can control the rotational speed of the blower with an inverter frequency so that the amount of intake air can be adjusted. The exhaust means 9 may be a simple vent connected to the exhaust port 2c. In the form shown in FIG. 1, the exhaust means 9 is a simple vent, and the exhaust amount is subordinately adjusted by adjusting the intake amount.

  The composting apparatus 1 of the present invention has a fermentation index output means 10. The fermentation index output means 10 includes the temperature of the outside air introduced into the container 2 (inlet air temperature), the amount of outside air introduced into the container 2 (inlet air amount), and the temperature of the inside air exhausted from the container 2 ( It is a means that can calculate and output the amount of heat of fermentation and the amount of evaporated water per predetermined time as a fermentation index based on the exhaust gas temperature) and the amount of internal air exhausted from the container 2 (exhaust gas amount). For this reason, the means includes a temperature sensor that can measure the intake air temperature and the exhaust gas temperature necessary for the calculation, a means that can acquire the intake air amount, a means that can acquire the exhaust air amount, a means that performs a calculation based on these, and the like. . If the exhaust amount can be determined dependently from the intake amount or the like, the exhaust amount acquisition means is not necessary. Further, in the figure, the fermentation index output means 10 is disposed in the machine room 5, but is not limited thereto, and may be provided as an arbitrary part of the apparatus or an external device.

  In order to acquire the humidity (intake air humidity) of the outside air introduced into the container 2, a humidity sensor may be provided as necessary. However, the humidity sensor is severely degraded, the amount of heat input is very small compared to the amount of exhaust heat, and the effect of relative humidity on the amount of heat is limited in the temperature range of the input air temperature. The humidity may be a fixed value (for example, 70% RH). Moreover, since the humidity (exhaust humidity) of the inside air exhausted from the inside of the container 2 which is a closed composting apparatus is approximately 100% RH, a humidity sensor for measuring the exhaust humidity is unnecessary.

  In the fermentation index output means 10, “output” means that an operator directly displays the amount of heat of fermentation and the amount of evaporated water per predetermined time on a display device attached to the apparatus in order to grasp the fermentation index. Display on a display device of a terminal electronically connected wirelessly or by wire. Further, when the control process is automated by AI or the like, the data may be directly given to the control device without the display process. A specific calculation method and calculation example of the fermentation index will be described later.

  The composting apparatus 1 is good also as an aspect which has an external heat insulation panel installed so that at least one part of the outer periphery of the container 2 may be covered through space. By providing an external heat insulating panel and having a double heat insulating structure with the container, more stable processing can be performed in the apparatus installed outdoors. Examples of the shape of the external heat insulating panel include a rectangular tube shape in which an outer wall of the device constituted by the panel substantially circumscribes the outer periphery of the cylinder of the container.

  In the composting apparatus of the present invention, examples of the organic waste that is an object to be processed and is a compost raw material include livestock excrement, food waste, septic tank sludge, or a mixture thereof containing a large amount of organic components. Specifically, livestock excretion includes chicken excrement, pig excrement, cattle excrement, horse excrement, etc., food waste includes garbage, food production by-products, etc. Examples include sludge extracted from sludge septic tanks. In addition, composting of waste is performed by aerobic fermentation while aeration is performed in the presence of aerobic fermentation bacteria in a container. As the aerobic fermenting bacteria, fermenting bacteria that are activated at about 30 to 90 ° C. are preferable, and examples thereof include Diovatisul and Bacillus.

  In this apparatus, the compost raw material is input into the container 2 from the input port 2a, and the processed material is composted in the container and taken out from the outlet 2b at the bottom of the container. Fermentation and composting are performed by introducing outside air with a predetermined amount of air from the vent hole 4a of the lowermost stirring blade by the air supply means 6, and exhausting the inside air from the exhaust port 2c and the exhaust means 9 (vent hole). Meanwhile, each stirring blade 4 is rotated at a low speed, and the compost raw material is aerated and aerobically fermented. It is also dried simultaneously by ventilation. The air exhausted from the exhaust port 2c contains gas and water vapor generated from the compost raw material in the air introduced into the container through the vent and flowing upward while passing through the processed material.

  As an operation procedure, first, the composting apparatus is charged with leaving a space (head space) of 10 to 20% with respect to the internal volume of the composting apparatus. By adding the compost raw material while leaving a space of 10 to 20%, the compost raw material is sufficiently stirred, so that fermentation and drying are efficiently performed. The charging is carried out every day, and a predetermined residence period (about 3 to 20 days) is fermented and dried, and a predetermined amount (for example, about 20% by mass) of compost is taken out every fixed period (for example, every day). The above input is performed after the compost is taken out. In this way, the composting process is continuously performed by repeating a part of the compost raw material input and a part of the compost take-out in a certain time cycle. The resulting compost is a complex mixture containing solids, liquids, semi-liquids, etc., and is partially agglomerated. In addition, when the composting apparatus is used for the first time, it is preferable to add in advance about 30% by mass of the previous compost fermented and taken out from this apparatus. This is because acclimated fermentative bacteria are used.

  In the composting control method of the present invention, in the configuration in which composting is continuously performed with the above-described predetermined closed composting apparatus, as a fermentation index, aeration amount (intake amount, exhaust amount), inlet temperature, It is characterized in that composting is controlled by paying attention to “amount of fermentation heat” and “amount of evaporated water” per predetermined time, which is calculated based on the exhaust gas temperature, as a fermentation index. Fermentation heat is generated in the organic matter decomposition process by opportunity microorganisms in the composting process, so that the fermentation heat amount can directly evaluate the microbial activity as well as the oxygen and carbon dioxide concentration. Based on the obtained fermentation index, the operator adjusts the input amount of organic waste, combusting raw material, the input air temperature, the input air amount, and the input amount of waste white clay so that the heat of fermentation can be maximized. To do.

FIG. 6 shows an example of changes over time in the amount of fermentation heat, the amount of evaporated water, and the exhaust temperature. The data shown in FIG. 6 is a composting device provided with a fermentation index output means in a component S36 (volume: 39 m ³ ) manufactured by Chubu Ecotech. Feces 4m ³ to compost raw material, the use of sewage treatment tank sludge 1 m ^3, intake air amount was 5.5 m ³ / min. An operator uses the said apparatus, for example, acquires the data of fermentation calorie | heat amount and evaporative water content by the day integration | accumulation as shown in FIG. 6 (a figure is 20 hours). If these values per day in the basic steady state are set in advance, and the data on the measurement date falls below this value, the worker will input organic waste as composting raw materials. And waste white clay, and setting the ventilation rate. In particular, if the required amount of heat can be quantified, waste white clay without excess or deficiency can be input and the air flow rate can be set, so that high efficiency and energy saving can be achieved.

Regarding the amount of heat of fermentation and the amount of evaporated water, outside air temperature (inlet air temperature) 5 ° C, exhaust temperature 70 ° C, inlet air relative humidity (fixed 70% RH), exhaust air relative humidity (fixed 100% RH), Table 1 below shows a specific calculation example when the inverter frequency is 40 Hz.

  In the said table | surface, fermentation calorie | heat amount is calculated | required by fermentation calorie | heat amount (kJ / min) = exhaust calorie | heat amount (kJ / min) -intake calorie | heat amount (kJ / min). The exhaust heat quantity and the intake heat quantity are generally calculated as follows.

[Exhaust heat quantity]
The exhaust heat quantity is calculated from (1) specific enthalpy in exhaust, (2) exhaust quantity, and (3) specific volume.
(1) This specific enthalpy is calculated from absolute humidity, exhaust temperature, and a predetermined approximate expression. The predetermined approximate expression in the exhaust gas temperature zone is as shown in the lower part of FIG. This approximate expression is created as an approximate expression by plotting a data set of a steam table of temperature and total heat of water vapor.
(2) The exhaust amount is determined depending on the intake air amount, and is calculated from the number of mols of moist air, the mol fraction of dry air, and the exhaust temperature.
(3) The specific volume is calculated from the wet air unit volume and the wet air molecular weight.
Absolute humidity is calculated using the water vapor pressure in humid air. The moist air mol number is calculated from the displacement and the humid air unit volume. The dry air mol fraction is calculated using absolute humidity. The humid air unit volume is calculated using the exhaust temperature. The wet air molecular weight is calculated from the dry air mol fraction and the water vapor mol fraction. The water vapor pressure in the humid air is calculated using the relative humidity and the saturated water vapor pressure at the dry bulb temperature.
Note that the relative humidity (% RH) at the time of calculating the exhaust heat quantity is fixed to 100% RH as described above.

[Intake heat quantity]
The amount of heat input is calculated from (1) the specific enthalpy of the input air, (2) the amount of input air, and (3) the specific volume.
(1) This specific enthalpy is calculated from absolute humidity, inlet air temperature, and a predetermined approximate expression. The predetermined approximate expression in the inlet temperature zone is as shown in the upper part of FIG. Similar to the exhaust heat quantity, this approximate expression is created as an approximate expression by plotting a data set of the steam table of temperature and total steam heat.
(2) The intake air amount is calculated from the relational expression of FIG. 3 using the inverter frequency of the blower, for example. This method can be employed when there is a linear relationship between the inverter frequency for controlling the blower rotation speed and the air flow rate. In addition, as a calculation method of the intake air amount, a method of calculating from the wind speed of the intake pipe, a method of calculating from the wind speed of the exhaust pipe, or the like may be adopted.
(3) The specific volume is calculated from the wet air unit volume and the wet air molecular weight.
Absolute humidity is calculated using the water vapor pressure in humid air. The humid air unit volume is calculated using the outside air temperature. The wet air molecular weight is calculated from the dry air mol fraction and the water vapor mol fraction. The water vapor pressure in the humid air is calculated using the relative humidity and the saturated water vapor pressure.
Note that the relative humidity (% RH) at the time of calculating the amount of heat input is fixed at 70% RH as described above.

In the above table, the amount of evaporated water is obtained by the following equation: evaporated water amount (kg / min) = exhaust water vapor amount (kg / min) −intake water vapor amount (kg / min).
The exhaust water vapor amount is calculated from the number of moles of moist air and the water vapor mol fraction in the exhaust gas. Further, the amount of incoming water vapor is calculated from the number of moist air mols and the water vapor mol fraction in the incoming air.

  FIG. 4 shows the relationship between the amount of heat of fermentation and the amount of evaporated water, which is a fermentation index used in the present invention. The upper part of FIG. 4 shows the above relationship when the inverter frequency (air flow rate) of the blower fluctuates at an exhaust temperature of 60 ° C., outside air of 5 ° C., and a relative humidity of 70%. The lower part of FIG. 4 is a diagram showing the above relationship when the exhaust gas temperature fluctuates at an inverter frequency of 50 Hz, outside air of 5 ° C., and relative humidity of 70%. As shown in FIG. 4, it can be seen that in a sealed vertical composting apparatus in which exhaust air having a relative humidity of 100% is discharged, a linear forward correlation is established between the amount of heat of fermentation and the amount of evaporated water.

  Moreover, the change of the calorie | heat amount and water vapor | steam amount by the difference of a blower heat_generation | fever and fermentation heat_generation | fever is shown in FIG. As shown in FIG. 5, if there is no fermentation heat, the amount of evaporated water is very small. In order to obtain the amount of evaporated water equivalent to that of fermentation at an exhaust temperature of 50 ° C., it is necessary to increase the aeration amount by about 7 times, which is extremely inefficient.

  There is a large difference in the characteristics of the forced-aeration batch composting device (for example, as in Patent Document 3) and the forced-aeration continuous composting device of the present invention, and as an index for controlling the composting I can't think of it as well. Below, the usefulness of the control by the said fermentation parameter | index in this invention is demonstrated, contrasting a batch type and a continuous type for every item which concerns on fermentation.

[Moisture adjustment of raw materials]
In the batch type, organic waste such as livestock excrement is mixed with auxiliary materials such as sawdust and wood chips, and the moisture (moisture content) is adjusted to about 70% to ensure the permeability of the compost material. It is important for composting, which is aerobic fermentation. In addition, basically, moisture adjustment is performed only at the start of composting, and moisture is not adjusted during composting, such as when turning over.

  In the continuous type, no auxiliary material is required for the purpose of adjusting moisture. Since it is continuous composting, the moisture content of the high-moisture raw material is adjusted by stirring the new high-moisture compost raw material with the compost raw material in a low-moisture container. If the moisture content of the compost raw material in the container is high, even if the high-moisture compost raw material and the compost raw material in the container are agitated, the total water content does not decrease sufficiently, and (1) air permeability is insufficient, (2 Aerobic fermentation does not proceed, (3) the amount of evaporated water is small due to lack of fermentation heat, and (4) the moisture content of the compost material in the container rises. That is, in order to maintain the compost raw material in the container at a low moisture content, it is important to balance the introduction of moisture into the container by introducing the compost raw material and the removal of moisture from the container by the amount of evaporated water.

  In the composting apparatus of the present invention, if the amount of evaporated water per day and the average amount of evaporated water in the staying days (about 15 days) are used as indicators, it is easy to grasp the water balance in the container, and the fermentation state It becomes possible to prevent deterioration.

[Compost moisture]
In the batch type, the compost moisture gradually decreases in the process of composting, and finally becomes about 40-50%. Even if the raw material moisture is high at the end of composting, drying proceeds during the subsequent secondary fermentation period, so the compost water at the end of composting does not become a big problem.

  In the continuous type, when the compost moisture is high, a compost lump having a diameter of about several centimeters is formed, which closes the outlet at the bottom of the container, and there is a risk that compost discharge becomes physically difficult. If compost cannot be discharged out of the container, the head space for compost raw material input cannot be made in the container, and the continuous composting operation fails. Further, in the overdried state, compost dust is generated, which may cause blockage in the ventilation pipe (including the vent hole and the exhaust port). If the inside of the aeration pipe is closed, it is hermetically sealed so that no moisture is taken out of the container, and aeration necessary for aerobic fermentation cannot be secured, which may lead to deterioration of the fermentation state. Since the staying days are about 15 days, there is a time lag of at least several days for the effect to be clarified even if measures such as reducing the amount of raw material input are taken when the trouble occurs.

  In the composting apparatus of the present invention, if the amount of evaporated water per day and the average amount of evaporated water in the staying days (about 15 days) are used as indices, it is determined whether the moisture in the container is increasing or decreasing. I can judge. For this reason, it is possible to take measures earlier than taking measures by judging from the state of compost taken out by the worker.

[Adjusting the calorie content of compost]
The batch type does not adjust the calories of the raw materials.
In the continuous type, when the fermentation status is poor and the amount of fermentation heat generated is small, when compost raw materials with higher moisture content than normal are input, or when more compost raw materials are input than normal, the raw materials are put into the container. The balance between bringing in moisture and taking out moisture outside the container due to evaporation of water is lost. In this case, fermentation can be controlled by introducing a highly exothermic raw material such as waste white clay and promoting moisture evaporation by increasing the amount of fermentation heat. However, the generation of an excessive amount of fermentation heat due to excessive input of waste white clay leads to overdrying of the compost in the container. In an over-dried state, compost dust is generated, which may cause blockage in the vent pipe (including vents and exhaust ports). If the inside of the aeration pipe is closed, it will be sealed, so there will be no moisture being taken out of the container, a compost mass will be formed, and aeration necessary for aerobic fermentation will not be secured, leading to deterioration of the fermentation state There is also.

  That is, the introduction of a highly exothermic raw material such as waste clay is effective for improving the fermentation state, but excessive use leads to pipe maintenance and deterioration of the fermentation state. In addition, since waste clay is a valuable resource, it is economically desirable to use the minimum necessary amount, but in the present situation, the judgment of the “minimum requirement” must be relied on for experience. Since the staying days are about 15 days, there is a time lag of at least several days for the effect to be clarified even if measures such as reducing the amount of raw material input are taken when the trouble occurs.

  In the composting apparatus of the present invention, if the amount of evaporated water per day and the average amount of evaporated water in the staying days (about 15 days) are used as indices, it is determined whether the moisture in the container is decreasing or increasing. I can judge. For this reason, for example, in the case of an increasing tendency, it is possible to implement measures earlier than when the worker confirms the formation of a compost lump with a diameter of several centimeters and then determines whether to introduce waste white clay, thereby preventing deterioration of the fermentation state. It is possible. In addition, if the heat of fermentation per day in the steady state is known, waste white clay can be input without excess or shortage using the difference in heat between the most recent daily heat of fermentation and the amount of steam exhausted per day in the steady state as an index. It becomes possible to do.

[Continuation of poor fermentation]
In the batch type, since the compost raw material is changed in the next batch, the fermentation state does not adversely affect the next batch.
In the continuous type, if the moisture content of the compost raw material in the container is high, even if the high-moisture compost raw material and the compost raw material in the container are agitated, the entire water content is not sufficiently lowered, and the vicious circle described above is caused. If this cannot be escaped, it is necessary to discharge all the compost raw materials in the container and start fermentation again.

  In the composting apparatus of the present invention, if the amount of evaporated water per day and the average amount of evaporated water in the staying days (about 15 days) are used as indicators, it is easy to grasp the water balance in the container, and the fermentation state It becomes possible to prevent deterioration.

[Fermentation failure]
In the batch type, if the moisture adjustment and ventilation of the compost raw material are appropriate, the fermentation will not be stopped.
In the continuous method, even if the fermentation state is relatively good, if the balance between bringing moisture into the container by introducing compost raw material and taking water out of the container by evaporating water is lost, Moisture gradually increases, and the fermentation situation may gradually deteriorate. In this case, the worker does not notice the deterioration of fermentation until he visually recognizes the formation of a compost mass having a diameter of several centimeters.

  In the composting apparatus of the present invention, if the amount of evaporated water per day and the average amount of evaporated water during the staying days (about 15 days) are used as indices, it is determined whether the moisture in the container is decreasing or increasing. Judge early.

  As described above, the composting apparatus of the present invention is a closed-type composting apparatus that continuously performs the composting process, and is a predetermined time serving as a fermentation index based on the intake air temperature and the intake air amount, the exhaust gas temperature and the exhaust air amount. Since it has a fermentation index output means that can calculate and output the amount of heat of fermentation and the amount of evaporated water per unit, the fermentation state can be accurately grasped. By using this apparatus, the operator can adjust the input amount of the organic waste as the compost raw material, the input air temperature, the input air amount, the input amount of waste white clay, and the like based on this fermentation index. As a result, it is possible to produce compost of good quality more efficiently than when the fermentation state is determined only by temperature and exhaust component concentration and control is optimized.

The intake air amount control logic in the composting control method of the present invention will be described.
This is due to an intake air amount adjustment step of adjusting the amount of outside air (inlet air amount) introduced into the container based on the fermentation heat amount. In this intake air amount adjustment step, the amount of fermentation heat is calculated at predetermined time intervals, and the amount of fermentation heat at the time of arbitrary calculation is compared with the amount of fermentation heat calculated last time. That is, when measuring the heat of fermentation at intervals of several minutes, the heat of fermentation A several minutes ago is compared with the current heat of fermentation B. Then, when this is increasing (B> A), the amount of intake is increased, and when this is decreasing (B <A), the amount of intake is decreased. The increase / decrease in the amount of intake air can be adjusted by increasing / decreasing the inverter frequency of the blower. The measurement interval of the amount of fermentation heat becomes the interval for changing the inverter frequency. This interval can be set as appropriate. For example, the interval may be as short as 1 minute to 10 minutes or as long as 1 day. The change width of the inverter frequency can be set as appropriate, for example, about 0.1 Hz to 1 Hz. If the change frequency of the inverter frequency is made too small, it may not be possible to supply the required amount of intake air when the fermentation temperature rises (about 6 hours after the raw material is charged). It is.

  The control in the intake air amount adjustment step is automatically performed by the control device provided in the composting device at a predetermined time interval set by the operator and the adjustment amount of the air intake amount (change width of the inverter frequency). be able to. In addition, you may control manually as needed.

The influence of the difference between the inverter frequency change interval and the change width of the inverter frequency will be described with reference to FIGS. FIG. 7 shows the results when the inverter frequency change interval is 3 minutes and the inverter frequency change width is 1 Hz (corresponding to 0.25 m ³ ). FIG. 8 shows the results when the inverter frequency change interval is 2 minutes and the inverter frequency change width is 0.42 Hz (corresponding to 0.105 m ³ ). FIG. 9 shows the results when the inverter frequency change interval is 2 minutes and the inverter frequency change width is 0.1 Hz (corresponding to 0.025 m ³ ). In each figure, the vertical axis represents the inverter frequency of the blower, and the horizontal axis represents time.

  As shown in FIG. 7 to FIG. 9, the relationship between the set value of the inverter frequency of the blower and its one-hour moving average is particularly high by reducing the change width of the inverter frequency (for example, 0.3 Hz or less). It can be seen that it has a following ability. This follow-up property can be said to be a follow-up property between the supply air intake amount and the theoretical required air flow rate. By increasing this follow-up property, the amount of fermentation heat (composting efficiency) per power consumption can be improved.

  FIG. 10 shows how the inverter frequency set value fluctuates when the intake air amount adjustment is automatically performed under the conditions shown in FIG. 9 over a long period of time. In FIG. 10, the vertical axis represents the inverter frequency of the blower, and the horizontal axis represents the test date and time. It can be seen that by controlling the air intake amount, the air can be vented at the minimum air intake amount when the raw material is not input, and the necessary air intake amount can be secured when necessary. As a result, it can be seen that the heat of fermentation (composting efficiency) per power consumption is improved. Compared with the case where the inverter frequency was fixed at 38 Hz without performing the control, an improvement effect of 8% was recognized in composting efficiency (amount of fermentation heat / power consumption).

  The eco air intake amount control logic in the composting control method of the present invention will be described. In the control step, the composting efficiency represented by (fermentation heat amount / power consumption amount) is calculated from the fermentation heat amount at the time of arbitrary calculation and the power consumption amount of the composting apparatus at that time, and the compost Based on the conversion efficiency, the input amount of organic waste as compost raw material, the temperature of the outside air introduced into the container (inlet air temperature), the amount of outside air introduced into the container (inlet air amount), and This is a method of controlling the progress of composting by adjusting at least one of the input amounts of the high exothermic raw materials. In particular, it is preferable to adjust the air intake amount.

  As described above, the intake air amount control logic increases or decreases the intake air amount using the fermentation heat amount as an index. However, in a state with a large amount of air intake (several hours of fermentation), the power consumption increases because the blower load is large. As shown in FIG. 11, generally, the power consumption per air volume tends to increase in a quadratic function. This is because, if the pressure loss in the component is constant, the static pressure is proportional to the square of the wind speed. For this reason, instead of using the amount of fermentation heat directly as an index, the amount of intake air by the blower is reduced without reducing the composting efficiency by using the amount of fermentation heat per unit of power consumption (composting efficiency) as an index. Can be reduced.

  The composting apparatus of the present invention is configured to perform continuous composting in a closed-type composting apparatus and can accurately grasp the fermentation state and stably produce compost, so that the livestock discharged from the livestock management body It can be suitably used as an apparatus for composting organic waste such as excrement and food residues discharged from food industry establishments.

DESCRIPTION OF SYMBOLS 1 Composting apparatus 2 Container 2a Input port 2b Outlet 2c Exhaust port 3 Rotating shaft 4 Stirring blade 4a Vent 5 Machine room 6 Air supply means 7 Heater 8 Drive means 9 Exhaust means 10 Fermentation index output means

Claims (8)

A rotating shaft provided in the container, a plurality of stirring blades attached thereto, an air feeding means for taking outside air into the container, and an exhaust for discharging the inside air accumulated in the container to the outside of the container A closed-type composting device comprising means,
The composting apparatus is configured to introduce organic air into the container by the air supply means, and discharge organic air from the container by the exhaust means, and introduces organic waste into the container from an inlet. Is subjected to a composting process that is fermented and dried while stirring with the stirring blade and discharged from the outlet as compost,
The composting apparatus calculates the amount of fermentation heat and the amount of evaporated water per predetermined time as a fermentation index based on the temperature and amount of outside air introduced into the vessel and the temperature and amount of inside air exhausted from the vessel. A composting apparatus characterized by having fermentation index output means that can output as a result. The rotating shaft is provided in the container in the vertical direction,
The inlet is provided in the upper part of the container, and the outlet is provided in the lower part of the container;
The stirring blade is provided in multiple stages in the container with a predetermined interval from the lower part to the upper part of the rotating shaft, and is communicated with the air supply means to the lowermost stirring blade. The composting apparatus according to claim 1, further comprising a vent hole for introducing the outside air into the container. A composting control method using the composting apparatus according to claim 1 or 2,
In the composting apparatus, the organic waste introduced into the container from the inlet while introducing the outside air into the container by the air feeding means and exhausting the inside air from the container by the exhaust means. In the step of continuously performing a composting treatment that is fermented and dried while stirring with the stirring blade and discharged from the outlet as compost,
Based on at least one fermentation index selected from the amount of heat of fermentation and the amount of evaporated water obtained from the fermentation index output means at an arbitrary timing during the process, the input amount of the organic waste as a compost raw material, It has a control step of controlling composting by adjusting at least one of the temperature of the outside air introduced into the container, the amount of outside air introduced into the container, and the amount of high heat-generating raw material introduced. Composting control method.   The composting control method according to claim 3, wherein the control step is a step of adjusting an input amount of the highly exothermic raw material based on the amount of fermentation heat.   Based on the amount of evaporated water, the control step includes at least an input amount of the organic waste as a compost raw material, a temperature of outside air introduced into the container, and an amount of outside air introduced into the container. 4. The composting control method according to claim 3, wherein one is adjusted. The control step includes an intake air amount adjustment step of adjusting the amount of outside air introduced into the container based on the fermentation heat amount,
The air intake amount adjustment step calculates the fermentation heat quantity at predetermined time intervals, and is introduced into the container when the fermentation heat quantity at the time of arbitrary calculation increases with respect to the fermentation heat quantity calculated last time. 4. The composting control method according to claim 3, wherein the amount of outside air is increased and the amount of outside air introduced into the container is reduced when the amount is reduced.   The air intake amount adjusting step is automatically performed by the control device provided in the composting device at the predetermined time interval set by an operator and the adjustment amount of the amount of outside air. Item 7. The composting control method according to Item 6.   In the control step, the composting efficiency expressed by (fermentation heat amount / power consumption amount) is calculated from the amount of fermentation heat at the time of arbitrary calculation and the power consumption amount of the composting apparatus at that time, and the composting efficiency is calculated. At least one of the input amount of the organic waste as the compost raw material, the temperature of the outside air introduced into the container, the amount of the outside air introduced into the container, and the input amount of the highly exothermic raw material 4. The composting control method according to claim 3, further comprising a control step of adjusting compost to control composting.