JP2000044372A - Composting facility of circulated air-conditioning type - Google Patents

Abstract

(57) [Summary] [Objective] An object of the present invention is to provide an energy-saving and environmentally-friendly composting facility capable of stably and efficiently composting sludge and the like. [Constitution] In a facility for composting sludge, etc., a continuous primary fermentation step 1, a secondary fermentation step 2, and a drying step 3 are surrounded by a heat insulating material 4, and a blowing section 5 is provided at an end of the drying step 3, and a primary fermentation on the opposite side. At the end of step 1, a suction unit 6 and a suction unit 6
An air conditioner is provided in a path of a duct 7 that communicates with the air outlet 5, and air circulated in the duct 7 from the suction unit 6 to the air outlet 5 and in the enclosure 4 from the air outlet 5 to the air inlet 6. Characterized in that a blower 11 for forming a flow is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a facility for composting sewage sludge.

[0002]

2. Description of the Related Art As a conventional technique, a typical example of a sludge composting facility is shown in FIG. The compost 15 put into the primary fermenter 41 is subjected to the primary fermentation treatment, and then the secondary fermenter 42 and the dryer 4
They are transported by the belt conveyor 44 and the like in the order of 3, and each processing is performed. Primary and secondary fermenters 41, 42
In the dryer 4, an air supply 45 for supplying oxygen necessary for fermentation and an exhaust 46 for suppressing the emission of offensive odor to the outside of the tank are provided.
In 3, hot air supply 47 required for drying and generated gas exhaust 4
8 has been done. Such a facility has the following problems. The primary and secondary fermenters 41 and 42 are easily affected by the outside air temperature, and the efficiency of composting is reduced depending on the outside air temperature. Especially in the winter season, fermentation takes a long time and fermentation may not be possible. The water vapor generated by the fermentation becomes saturated in the tank and forms dew, thereby preventing water evaporation of the compost 15. The primary and secondary fermenters 41 and 42, the dryer 43, and the movement of the compost between the respective steps are sources of foul odors and cause deterioration of the working environment and the surrounding environment. When taking countermeasures against odors, it is necessary to install exhaust and deodorizing equipment at each generation source, which increases the size of the equipment and increases costs. Emission of generated gas 4 from dryer 43 using fuel 49
No. 8 causes air pollution and global warming.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to achieve the following effects, thereby achieving a stable high composting of sludge and the like. An object of the present invention is to provide an energy-saving and environmentally-friendly composting facility that can be performed efficiently. Air conditioning in the fermenter, adjusting temperature, humidity, oxygen concentration, etc., and setting environmental conditions suitable for microbial reactions to promote fermentation, shorten fermentation period, and improve water evaporation efficiency . It suppresses the release of fermentation heat and waste heat after drying to the outside air, recovers heat, and aims for effective utilization. By increasing the efficiency of composting above, the fermenters and dryers, which are the sources of offensive odors, will be made more compact, and the exhaust and deodorizing equipment will be made smaller, thereby suppressing the emission of offensive odors to the surrounding environment. Be easy. For drying, hot air from fuel that causes air pollution and global warming is not used, but dry and warm air with high drying efficiency is used. Even when the fermentation temperature does not rise sufficiently, pathogenic bacteria, parasite eggs or weed seeds in the compost can be reliably killed or inactivated.

[0004]

The present invention has the following configuration to achieve the above object. That is, in a facility for composting sludge or the like, a continuous primary fermentation step 1, a secondary fermentation step 2, and a drying step 3 are surrounded by a heat insulating material 4, and a blowing section 5 is provided at an end of the drying step 3, and a primary fermentation step on the opposite side. At one end, an air conditioner such as a heat exchanger 8, a cooling coil 9, and a heating coil 10 is provided in a path of a suction section 6 and a duct 7 for circulating air that communicates the suction section 6 and the blowing section 5,
A circulating air blower 11 for forming a flow of air circulating in a duct 7 for circulating air from the suction section 6 to the blowing section 5 and in the enclosure 4 from the blowing section 5 to the suction section 6 is provided. I do.

[0005]

Next, the operation will be described. The circulating air sucked from the suction section 6 at the end of the primary fermentation step 1 by the circulating air blower 11 recovers heat in the heat exchanger 8, cools and dehumidifies in the cooling coil 9, and cools the heating coil 10.
, And is blown out from the blowing section 5 at the end of the drying step 3 to promote evaporation of water in the drying step 3. The circulating air whose temperature has been reduced and humidified in the drying step 3 has a temperature and humidity suitable for each of the microbial reactions of the secondary and primary fermentation, flows in the order of secondary and primary, and promotes each fermentation. The heat exchanger 8 is sucked by the air supply blower 12.
The outside air that has entered is heated and then supplied to the floor via an air supply duct 13 to supply oxygen necessary for fermentation. Is supplied with air. By surrounding the primary and secondary fermentation steps 1, 2 and the drying step 3 with the heat insulating material 4, the release of fermentation heat and exhaust heat after drying to the outside air is suppressed, and the effective use in the enclosure 4 is achieved. Suppresses the release of offensive odors to the surrounding environment. If the fermentation temperature does not rise sufficiently,
By raising the temperature of the circulating air by adjusting the temperature, the pathogens, parasite eggs or weed seeds in the compost can be reliably killed or inactivated.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Two preferred embodiments of the present invention will be described with reference to the drawings. (1) First Embodiment FIG. 1 is an explanatory diagram showing an embodiment of a circulating air-conditioning type composting facility according to the present invention. The compost 15 input from the input port 16 is processed in the order of the primary fermentation step 1, the secondary fermentation step 2, and the drying step 3, and the composted product is discharged from the discharge port 17. The entire three processes are surrounded by a heat insulating material 4, and the boundaries between the processes are opened and closed rectifying plates 18, 1 and 2.
It is divided by nine. Reference numeral 20 denotes a turning machine which scans three steps to move and agitate the compost 15. Next, the operation of this embodiment will be described. The circulating air sucked from the suction part 6 at the end of the primary fermentation step 1 by the circulating air blower 11 recovers heat in the heat exchanger 8, cools and dehumidifies in the cooling coil 9 using the cooling tower 21, and collects the solar heat collector 22. Is heated by the heating coil 10 using the auxiliary heat source 23, and is dried and becomes hot air, and is blown out from the blowing portion 5 at the end of the drying step 3, thereby promoting the evaporation of water in the drying step 3. The circulating air whose temperature has been reduced and humidified in the drying step 3 has a temperature and humidity suitable for each of the microbial reactions of the secondary and primary fermentation, flows in the order of secondary and primary, and promotes each fermentation. In addition, the rectifying plates 18 and 19 at the boundary of the three processes suppress the flow of the circulating air in the enclosure 4 to form environmental conditions suitable for each process, and reduce the flow of the circulating air in the enclosure 4. Takes the role of trimming. The heat exchanger 8 is sucked by the air supply blower 12.
The outside air that has entered is heated and then supplied to the floor via an air supply duct 13 to supply oxygen necessary for fermentation. Is supplied with air. By opening and closing the flow control damper 24, the amount of circulating air blown out is made smaller than the amount of suction, thereby reducing the pressure inside the enclosure 4 and suppressing the emission of offensive odors outside the enclosure 4. The amount obtained by subtracting the blowing amount from the suction amount is processed by the deodorization tower 26 from the flow control damper 24 through the exhaust duct 25,
Released to the atmosphere. (2) Second Example If the water content of the compost to be fed into the primary fermentation step is high and fluctuates, it is necessary to adjust the water content in the previous step. The second embodiment is an application of the first embodiment. Conventionally, the mixing performed in the previous step of fermentation is performed at the upper part of the primary fermentation step, and a part of the circulating air of dry and warm air is placed in the mixing place. To dry the compost while mixing and adjust the water content. FIG. 2 is an explanatory diagram showing the second embodiment. 31 is a stirring type mixer, 32 is a blowing section provided in the mixer, and 33 is a suction section. The air volume of the circulating air blower 11 is increased, and the heating coil 35, the blowing unit 32, the inside of the mixer 31,
The amount of circulating air flowing in the order of the suction unit 33 is adjusted.
The circulating air sucked into the suction part 33 is connected to the communication port 37.
Through the suction section 6 of the primary fermentation step 1. The mixer 31 has a hermetic structure, the inside of the mixer is made negative pressure, and emission of offensive odor is suppressed. The compost 15 input from the input port 38 of the mixer is dried while being mixed with the auxiliary material by stirring, and then input into the primary fermentation step 1 from the input port 16. Adjustment of the water content of the compost 15
This is performed based on the temperature of the heating coil 35, the amount of circulating air flowing in the mixer 31, and the drying time.

[0007]

According to the present invention, composting of sewage sludge and the like has the following remarkable effects. Air conditioning in the fermenter, adjusting temperature, humidity, oxygen concentration, etc., and setting environmental conditions suitable for microbial reactions to promote fermentation, shorten fermentation period, and improve water evaporation efficiency be able to. Composting can be performed stably with high efficiency without being affected by the temperature and humidity of the outside air. By making the fermenter smaller by the above,
By performing the three steps of primary and secondary fermentation and drying continuously at the same location, it is possible to reduce the size of the facility, thereby reducing the site area and setting up the facility. However, there are advantages such as low cost and easy operation management of facilities. The exhaust and deodorizing equipment can be reduced in size, the odor can be easily diffused into the surrounding environment, and the cost of odor control can be reduced. It is an energy-saving type with effective use and heat recovery of fermentation heat and waste heat after drying. The heat source for drying is an environmental conservation type that uses dry and warm air with high drying efficiency using solar heat without using fuel that causes air pollution and global warming. The dry and warm air of the circulating air is different from the hot air of a conventional dryer, and does not kill or weaken the fermentation bacteria due to high heat.
Therefore, by returning the compost completed as a seed fungus, the ability of the fungus can be enhanced. Therefore, there is no need to purchase expensive inoculum. Even if the fermentation temperature does not rise, by raising the temperature of the circulating air using an auxiliary heat source, it is possible to reliably kill or inactivate pathogens, parasite eggs, or weed seeds in the compost to be composted. High safety. With the above effects, it is possible to provide an energy-saving and environment-conserving composting facility that can stably and efficiently compost sewage sludge and the like. Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to these embodiments. For example, although the embodiment here is a horizontal facility, it can also be installed in a conventional vertical multi-stage paddle or multi-stage door fermenter, in which case the upper stage is the primary fermentation step and the middle stage is the second stage. The next fermentation step and the lower step are the drying step, and the blowing part is provided on the floor and the suction part is provided on the ceiling. Further, in this embodiment, solar heat is used as a heat source for air conditioning, but exhaust heat of a garbage incinerator can also be used. Many other modifications can be made without departing from the spirit of the invention.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a first embodiment.

FIG. 2 is an explanatory diagram showing a second embodiment.

FIG. 3 is an explanatory diagram showing a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Primary fermentation process 2 ... Secondary fermentation process 3 ... Drying process 4 ... Enclosure of heat insulating material 5 ... Blow-out part 6 ... Suction part 7 ... Circulation air duct 8 ... heat exchanger 9 ... cooling coil 10 ... heating coil 11 ... blower for circulating air 12 ... blower for air supply 13 ... duct for air supply 14 ... air supply section 15 ... compostable material 16 ... inlet 17 ... outlet 18 ... rectifier plate (a) 19 ... rectifier plate (b) 20 ... turning machine 21 ... cooling tower 22. ..Solar heat collector 23 ... Auxiliary heat source 24 ... Flow rate adjustment damper 25 ... Exhaust duct 26 ... Deodorization tower 31 ... Mixer 32 ... Blow-out part 33 ... Suction part 34 ... Flow adjustment damper 35 ... Heating coil 36 ... Auxiliary heat source 37 ... Communication port 8 ... Inlet of mixer 41 ... Primary fermenter 42 ... Secondary fermenter 43 ... Dryer 44 ... Belt conveyor 45 ... Air supply 46 ... Exhaust 47 ...・ Air supply of hot air 48 ・ ・ ・ Exhaust of generated gas 49 ・ ・ ・ Fuel

Claims (1)

[Claims] In a facility for composting sludge, etc., a continuous primary fermentation step, a secondary fermentation step, and a drying step are surrounded by a heat insulating material, and a blowing section is provided at an end of the drying step, and an end of the primary fermentation step on the opposite side. An air conditioner is provided in a duct path that communicates the suction section and the suction section and the blowout section, and a flow of air circulated in a duct from the suction section to the blowout section and in an enclosure from the blowout section to the suction section. A fan to be formed is provided.