An aerobic fermentation method for organic waste

Abstract

The invention discloses an aerobic fermentation method for organic waste, comprising the following steps: S1. The waste is sequentially loaded and weighed, sorted and transported, crushed, squeezed and dehydrated through a pretreatment unit to obtain waste to be fermented; S2. The waste after squeezing and dehydration is then put into a main reaction chamber of a composting bin for high-temperature aerobic fermentation treatment, and then the waste is transported to a secondary reaction chamber of the composting bin for secondary fermentation and rapid drying treatment to obtain a primary compost product; S3. After the primary compost product, secondary composting is performed outside the fermentation chamber to obtain a secondary compost product with better quality; wherein the composting bin used in the method comprises a shell, a fermentation chamber is arranged inside the shell, the fermentation chamber comprises a condensation heat recovery chamber and a reaction chamber, a main reaction chamber and a secondary reaction chamber are formed in the reaction chamber, a condensation heat recovery mechanism is arranged in the condensation heat recovery chamber, and the condensation heat recovery mechanism comprises a condensation plate and a drainage trough. The invention fully retains the heat energy released by condensed water and reduces the energy consumption of fermentation.

Description

Technical Field

[0001] The invention relates to the technical field of garbage disposal, and in particular to an aerobic fermentation method for organic garbage. Background Art

[0002] Organic waste, mainly kitchen waste and agricultural and forestry green waste, will face a series of new problems such as storage, transportation and treatment. The problems faced are also the key to breaking the bottlenecks in garbage source classification, source reduction, harmlessness and resource utilization.

[0003] Using decentralized small and medium-sized fermentation equipment to reduce, render harmless and recycle organic waste is an effective way to reduce the cost of waste transfer and treatment under the current waste classification and "dual carbon" target environment. At present, many organic waste fermentation treatment equipment on the market use high-temperature drying to reduce the amount of organic waste. The organic matter in the waste is not stabilized and does not meet the conditions for resource utilization. The few equipment that do use high-temperature aerobic fermentation have insufficient understanding of the fermentation principle and the change law of the three-phase materials of water, gas and solid in the fermentation process, resulting in excessive treatment costs for organic waste, especially excessive treatment energy consumption. For example, taking the actual treatment volume of 1 ton / day as an example, the daily energy consumption exceeds 200kWh, which limits the application and promotion of organic waste resource technology equipment.

[0004] After investigation, it was found that most of the existing small and medium-sized garbage aerobic fermentation equipment on the market are of fully enclosed structure, and the fermentation chamber inside it only plays the role of stirring and fermenting the garbage. The water vapor generated during the garbage fermentation process is repeatedly condensed and vaporized in the fermentation chamber. However, since each vaporization requires the absorption of a large amount of heat energy, the fermentation temperature in the fermentation chamber cannot be maintained at a high level, and the moisture in the garbage pile and generated by the fermentation cannot be quickly removed, and the fluffiness of the garbage pile cannot be maintained. In order to maintain the high-temperature fermentation of the garbage in the fermentation chamber, it is necessary to use the method of intra-cavity heating to heat the fermentation pile in the fermentation chamber for a long time to compensate for the heat taken away by the vaporization of water, that is, basically the method of "baking" and "stuffing" is used to evaporate the water in the fermentation pile, and then the high-temperature saturated water vapor (the same temperature as the fermentation temperature) is "extracted" or "blown" out of the fermentation chamber by a fan. This is one of the main reasons for the high energy consumption of traditional aerobic fermentation equipment.

[0005] Another type of aerobic fermentation system currently available on the market is a semi-closed structure, which is mainly based on a strip-type fermentation bed. It belongs to a large-scale aerobic fermentation process. Thanks to its semi-closed structure, the high-temperature saturated water vapor generated during the fermentation process can escape quickly, avoiding the "useless work" phenomenon of small and medium-sized fermentation equipment falling back into the fermentation pile after condensation in the fermentation chamber and repeated vaporization and condensation. However, since condensation is an exothermic process, the escape of high-temperature saturated water vapor in the semi-closed fermentation process will cause a large amount of condensation heat loss, and the condensation heat cannot be efficiently recovered and utilized, resulting in a lot of energy waste. Summary of the invention

[0006] The present invention aims to provide an aerobic fermentation method for organic waste to solve the above-mentioned technical problems.

[0007] To achieve the above object, the technical solution of the present invention is: an aerobic fermentation method for organic waste, comprising the following steps:

[0008] S1. The garbage is sequentially loaded, weighed, sorted, transported, crushed, squeezed, and dehydrated through the pretreatment unit to obtain the garbage to be fermented;

[0009] S2. After squeezing and dehydrating the garbage, the garbage is put into the main reaction chamber of the composting bin for high-temperature aerobic fermentation, and then the garbage is transported to the secondary reaction chamber of the composting bin for secondary fermentation and rapid drying to obtain a compost product;

[0010] S3. After the primary composting product is subjected to secondary composting outside the fermentation chamber, a secondary composting product of better quality is obtained;

[0011] The compost bin used in the method includes a shell, a fermentation chamber is arranged inside the shell, the fermentation chamber includes a condensation heat recovery chamber and a reaction chamber which are arranged in layers up and down and are connected to each other, the reaction chamber is divided into a main reaction chamber and a secondary reaction chamber by front and back separation, a partition is arranged between the main reaction chamber and the secondary reaction chamber, a feeding port is arranged on the partition, a condensation heat recovery mechanism is arranged in the condensation heat recovery chamber, a stirring mechanism is arranged in the reaction chamber, a feeding port and a discharging port connected to the reaction chamber are respectively arranged at the front and rear ends of the shell, the condensation heat recovery chamber located between the shell and the condensation heat recovery mechanism is a ventilation space, an air inlet is arranged on the shell, the air inlet end of the ventilation space is connected to the air inlet, the air outlet end of the ventilation space is connected to the feeding port or the discharging port, an air inlet fan is arranged at the air inlet end of the ventilation space for supplying air into the fermentation chamber, a heating layer is arranged outside the shell, and an insulation layer is arranged outside the heating layer, the condensation heat recovery mechanism includes a condensation plate and a drainage groove, the end of the drainage groove extends to the outside of the shell, and the condensation plate is located above both sides of the drainage groove in the length direction, and is used to guide the condensed water to the drainage groove for discharge.

[0012] In one embodiment, there are multiple condensation plates on both sides of the length direction of the drainage groove, and the multiple condensation plates on each side are distributed obliquely and staggered, and staggered openings are formed between two adjacent condensation plates, and the staggered openings are gradually inclined downward toward the center of the drainage groove.

[0013] In one embodiment, the cross-section of the condensation plate is an obtuse triangle, and the condensation plate includes a condensation surface and a guide surface. In two adjacent condensation plates above and below, the staggered opening is formed between the condensation surface of the upper condensation plate and the guide surface of the lower condensation plate, wherein the condensation surface is a rough surface and the guide surface is a smooth surface.

[0014] In one embodiment, a condensation nucleus for promoting condensation of water vapor is provided above the corresponding drainage groove inside the condensation heat recovery mechanism.

[0015] In one embodiment, the ventilation space includes a first ventilation channel, a second ventilation channel, and a third ventilation channel. The first ventilation channel is located above the condensation heat recovery mechanism, the second ventilation channel is located below the condensation heat recovery mechanism, and the third ventilation channel is located on the side of the condensation heat recovery mechanism away from the feeding port. The air inlet is located at the front end of the first ventilation channel, the upper end of the third ventilation channel is connected to the rear end of the first ventilation channel, the lower end of the third ventilation channel is connected to the discharge port, the rear end of the second ventilation channel is connected to the middle part of the third ventilation channel, and the front end of the second ventilation channel is connected to the feeding port. An induced draft fan is arranged at the air outlet end of the ventilation space to exhaust air from the fermentation chamber.

[0016] In one embodiment, the condensation heat recovery mechanism also includes an extruder, an elastic water-absorbing member, and a perforated plate. The perforated plate is installed on the drainage groove, the elastic water-absorbing member is installed on the perforated plate, and the two sides of the elastic water-absorbing member correspond to the staggered openings respectively. The extruder is located above the elastic water-absorbing member and is used to squeeze the elastic water-absorbing member to drain water.

[0017] In one embodiment, the condensation nuclei are spikes distributed on the bottom of the extruder.

[0018] In one embodiment, the feeding port is a trumpet-shaped feeding port that gradually expands downward, and a conveyor belt for feeding is provided at the feeding port, and the channel area at the upper end of the feeding port is not less than 3 times the channel area of ​​the conveyor belt.

[0019] In one embodiment, the volume of the main reaction chamber is not less than 80% of the volume of the reaction chamber, the daily garbage processing capacity is 0.1-30 tons, and the stacking volume of 1 ton of garbage can be simply regarded as 1m 3 The design and manufacture shall ensure that the volume of the main reaction chamber is not less than 5 times the daily garbage processing capacity.

[0020] In one embodiment, infrared temperature control probes are installed in the main reaction chamber and the auxiliary reaction chamber respectively.

[0021] In one embodiment, a driving mechanism is further included, wherein the stirring mechanism includes a stirring shaft and a stirring paddle disposed on the stirring shaft, and one end of the stirring mechanism extends out of the shell and is connected to the driving mechanism.

[0022] In one embodiment, the feed port between the main reaction chamber and the auxiliary reaction chamber is located at the highest point of the partition; the feed port is located above the side of the main reaction chamber away from the auxiliary reaction chamber, the discharge port is located on the side of the auxiliary reaction chamber away from the main reaction chamber, and the discharge port is located below the stirring shaft.

[0023] In one embodiment, the pretreatment unit includes a lifting and loading mechanism, a horizontal conveying and sorting platform, a crushing mechanism and an extrusion dehydration mechanism; the condensation heat recovery mechanism is a plurality of mechanisms arranged side by side; the heating layer is a heating belt, or a water bath heating layer, or an oil bath heating layer; the shell includes an upper shell and a lower shell that cooperate with each other, the upper shell is a rectangular shell, and the lower shell is a semi-cylindrical shell.

[0024] In one embodiment, the ventilation volume of the air inlet fan is not less than 3000m 3 / h, wind pressure not less than 124Pa.

[0025] In one embodiment, the output torque range of the stirring mechanism is 5-35 Nm and is variable frequency controlled.

[0026] In one embodiment, a waste gas treatment unit is further included, which includes an acid wash absorption tank and an alkali wash absorption tank connected in sequence, and one end of the acid wash absorption tank away from the alkali wash absorption tank is connected to the fermentation chamber of the composting bin.

[0027] In one embodiment, the compost bin is controlled by a PLC control system, and the control conditions are as follows:

[0028] (1) Based on the temperature in the main reaction chamber, the temperature of the space at the top of the garbage pile in the main reaction chamber is controlled to be maintained at 50-55°C. When the temperature is lower than 50°C, the heating layer will work to raise the temperature in the main reaction chamber to 55°C and then stop. When the temperature is higher than 60°C and lasts for 2-3 hours, the stirring mechanism will work regularly to allow the water vapor inside the pile to escape and condense to cool down.

[0029] (2) The stirring mechanism works intermittently at a fixed time, with a working frequency of stirring the garbage pile 2-6 times every 2-12 hours, with forward and reverse rotations performed alternately;

[0030] (3) The air intake fan is linked with the stirring mechanism. The air intake fan will work for 0.5-3 minutes before the stirring mechanism starts working, and will be turned off after a delay of 0-5 minutes after the stirring mechanism stops working.

[0031] The present invention has the following beneficial effects:

[0032] (1) The condensation heat recovery mechanism of the present invention can efficiently promote the condensation of water vapor in the high-temperature (50°C and above) saturated steam in the fermentation chamber, so that the condensation heat released by the condensation of steam is retained in the fermentation chamber to avoid heat loss. Therefore, the present invention only needs to provide auxiliary heating at the initial start-up of the equipment to maintain the high fermentation temperature in the fermentation chamber. After normal operation, the high temperature self-sustaining effect of the fermentation chamber can be achieved, and the moisture in the garbage pile and generated by fermentation can be quickly removed, thereby maintaining the fluffiness and fermentation temperature of the garbage and reducing the processing energy consumption. That is, on the one hand, it can quickly promote the condensation and discharge of water vapor, avoiding the water vapor generated in the garbage fermentation process to be repeatedly condensed and cooled in the fermentation chamber. The condensed water falls back to the fermentation pile and then absorbs heat to rise in temperature and vaporize, thus avoiding the absorption of a large amount of heat energy by vaporization, ensuring that the fermentation temperature in the fermentation chamber is always maintained at a high level, thereby reducing the insulation and heating energy consumption of the fermentation chamber, achieving energy saving, and avoiding excessive condensed water falling back to the fermentation pile, causing water accumulation in the pile and forming an anaerobic environment, thereby reducing the treatment effect. On the other hand, the high-temperature saturated water vapor generated during the garbage fermentation process can be condensed inside the fermentation chamber and discharged to the outside, so that the large amount of heat released by the condensed water can be efficiently retained in the fermentation chamber and utilized, and it can avoid the air taking away too much heat in the fermentation chamber during ventilation, saving energy to a great extent and avoiding energy waste.

[0033] (2) The structural design of the ventilation channel allows the cold air to flow fully around the condensation heat recovery mechanism. The staggered condensation plates and artificially set condensation nuclei are used to ensure that the water vapor can be fully condensed, thereby releasing more heat. The condensed waste cold air is discharged through two flow paths, which makes the discharge faster and improves the water vapor condensation efficiency.

[0034] (3) When the garbage in the main reaction chamber exceeds the discharge port, it will automatically enter the secondary reaction chamber, which will not cause the garbage to accumulate in the main reaction chamber and occupy the ventilation space. It can ensure the sustainable supply of fresh air from the outside. At the same time, the flow direction of the fresh cold dry air from the outside and the high-temperature saturated steam in the fermentation chamber is convection, which can not only promote the saturated steam above the secondary reaction chamber and the adjacent main reaction chamber to condense and release heat more efficiently, but also preheat and heat the fresh cold air in the air inlet space to the greatest extent, and ensure that the high-temperature and high-humidity air with relatively high humidity in the fermentation chamber flows from the secondary reaction chamber to the main reaction chamber, which can avoid the cooling of the local fermentation pile after the fresh air is blown into the fermentation chamber and affect the fermentation effect, and avoid the relatively humid air on the feeding end side of the fermentation chamber from affecting the moisture content of the pile at the end of the main reaction chamber and the secondary reaction chamber due to ventilation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a longitudinal cross-sectional view of a compost bin according to an embodiment of the present invention;

[0036] Figure 2is a top view of a compost bin according to an embodiment of the present invention;

[0037] Figure 3 is a transverse cross-sectional view of a compost bin according to an embodiment of the present invention;

[0038] Figure 4 It is a partial structural schematic diagram of a condensation heat recovery chamber according to an embodiment of the present invention;

[0039] The accompanying drawings are marked with: 1 upper shell, 2 lower shell, 3 condensation heat recovery chamber, 4 reaction chamber, 41 main reaction chamber, 42 auxiliary reaction chamber, 5 condensation heat recovery mechanism, 51 condensation plate, 511 condensation surface, 512 guide surface, 52 drainage groove, 53 staggered opening, 54 extruder, 541 condensation nucleus, 55, elastic water absorbing part, 56 perforated plate, 6 stirring mechanism, 61 stirring shaft, 62 stirring paddle, 7 feeding port, 8 discharging port, 9 air inlet, 10 heating layer, 11 insulation layer, 12 first ventilation channel, 13 second ventilation channel, 14 third ventilation channel, 15 partition, 16 feeding port, 17 driving mechanism. DETAILED DESCRIPTION

[0040] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0041] See also Figure 1-4 As shown, as an embodiment of the present invention, an organic waste aerobic fermentation method is provided, comprising the following steps:

[0042] S1. The garbage is sequentially loaded, weighed, sorted, transported, crushed, squeezed, and dehydrated through the pretreatment unit to obtain the garbage to be fermented;

[0043] S2. After the extruded and dehydrated garbage is put into the main reaction chamber 41 of the composting bin for high-temperature aerobic fermentation, the garbage is then transported to the secondary reaction chamber 42 of the composting bin for secondary fermentation and rapid drying to obtain a compost product;

[0044] S3. After the primary composting product is subjected to secondary composting outside the fermentation chamber, a secondary composting product of better quality is obtained;

[0045] The compost bin used in the method includes a shell, a fermentation chamber is arranged inside the shell, the fermentation chamber includes a condensation heat recovery chamber 3 and a reaction chamber 4 which are arranged in layers and connected to each other, the reaction chamber 4 is divided into a main reaction chamber 41 and a secondary reaction chamber 42 in front and back, a partition 15 is arranged between the main reaction chamber 41 and the secondary reaction chamber 42, a feed port 16 is arranged on the partition 15, a condensation heat recovery mechanism 5 is arranged in the condensation heat recovery chamber 3, a stirring mechanism 6 is arranged in the reaction chamber 4, a feeding port 7 and a discharging port 8 which are connected to the reaction chamber 4 are respectively opened at the front and back ends of the shell, and the shell and the condensation heat recovery chamber 4 are connected to each other. The condensation heat recovery chamber 3 between the mechanisms 5 is a ventilation space, and an air inlet 9 is opened on the shell. The air inlet end of the ventilation space is connected with the air inlet 9, and the air outlet end of the ventilation space is connected with the feeding port 7 or the discharging port 8. The air inlet end of the ventilation space is provided with an air inlet fan for supplying air into the fermentation chamber. A heating layer 10 is provided outside the shell, and an insulation layer 11 is provided outside the heating layer. The condensation heat recovery mechanism 5 includes a condensation plate 51 and a drainage trough 2. The end of the drainage trough 52 extends to the outside of the shell. The condensation plate 51 is located above both sides of the drainage trough 52 in the length direction, and is used to guide the condensed water to the drainage trough 52 for discharge.

[0046] In the above technical scheme, the garbage is fed, weighed, sorted, conveyed, crushed, squeezed and dehydrated in sequence by the pretreatment unit to obtain the garbage to be fermented. Then, the extruded and dehydrated garbage is put into the reaction chamber 4 through the feeding port 7, and the stirring mechanism 6 is driven to stir and ferment the garbage. The garbage is first put into the main reaction chamber 41 of the compost bin for high-temperature aerobic fermentation treatment, and then, under the push of the stirring mechanism 6, it enters the secondary reaction chamber 42 through the feeding port 16 for secondary fermentation and rapid drying treatment. At the same time, the heating layer 10 heats the garbage, so that the garbage fermentation produces a large amount of high-temperature saturated or nearly saturated water vapor, and the water vapor rises to the condensation heat recovery chamber 3, and cold air is introduced into the air inlet 9. The cold air enters the ventilation space and flows to react with the water vapor. The water vapor is cooled and liquefied into condensed water, releasing a large amount of heat energy in the fermentation chamber to reduce heat loss. Finally, the condensed water flows down to the drainage trough 52 through the condensation plate 51 and is discharged to the outside. The condensation heat recovery mechanism 5 of the present invention only needs to provide auxiliary heating at the initial start-up of the equipment to maintain the high fermentation temperature in the fermentation chamber. After normal operation, the high temperature self-maintaining effect of the fermentation chamber can be achieved, and the moisture in the garbage pile and generated by fermentation can be quickly removed, so that the fluffiness and fermentation temperature of the garbage are maintained, and the processing energy consumption is reduced; the technical scheme of the present invention, on the one hand, can prevent the water vapor generated in the garbage fermentation process from being repeatedly condensed and vaporized in the fermentation chamber, thereby avoiding the absorption of a large amount of heat energy by vaporization, ensuring that the fermentation chamber always maintains a high fermentation temperature, thereby reducing the insulation and heating energy consumption of the fermentation chamber and achieving energy saving; on the other hand, the high-temperature saturated water vapor generated in the garbage fermentation process can be condensed inside the fermentation chamber and discharged to the outside, so that a large amount of heat released by the condensed water can be efficiently recovered to the fermentation chamber for reuse, and it can avoid that the air takes away too much heat in the fermentation chamber during ventilation, which saves energy to a great extent and avoids energy waste. Moreover, the condensation mechanism promotes the condensation and discharge of high-temperature water vapor, which also avoids excessive condensed water falling back into the fermentation pile, causing the moisture content of the pile material to be too high, causing a local anaerobic environment and reducing the fermentation effect.

[0047] In the present embodiment, there are multiple condensation plates 51 on both sides of the length direction of the drainage groove 52, and the multiple condensation plates 51 on each side are obliquely and staggeredly distributed. Staggered openings 53 are formed between any two adjacent condensation plates 51. The staggered openings 53 are gradually inclined downward toward the center direction of the drainage groove 52, that is, the condensation plates 51 adopt a louver structure, so that the staggered openings 53 serve as a channel for the escape of water vapor in the cavity. The openings are staggered and inclined downward, so that the condensed water in the fermentation cavity can be smoothly diverted to the drainage groove 52 through the staggered openings 53, thereby preventing it from flowing back into the fermentation cavity for repeated condensation and vaporization.

[0048] In this embodiment, the cross-section of the condensation plate 51 is an obtuse triangle, and the condensation plate 51 includes a condensation surface 511 and a guide surface 512. In the two adjacent condensation plates 51 above and below, the staggered opening 53 is formed between the condensation surface 511 of the upper condensation plate 51 and the guide surface 512 of the lower condensation plate 51, wherein the condensation surface 511 serves as the air-facing surface, which is a rough surface of a non-mirror material, that is, a high-temperature and acid-base resistant material with a rough surface and a large specific surface area is adopted, which is conducive to the rapid condensation of water vapor on its surface, and the guide surface 512 is a smooth surface, so that the condensed water can be quickly and smoothly guided to the drain groove 52 for discharge.

[0049] In the present embodiment, the ventilation space includes a first ventilation channel 12, a second ventilation channel 13, and a third ventilation channel 14. The first ventilation channel 12 is located above the condensation heat recovery mechanism 5, the second ventilation channel 13 is located below the condensation heat recovery mechanism 5, and the third ventilation channel 14 is located on the side of the condensation heat recovery mechanism 5 away from the feeding port 7. The air inlet 9 is located at the front end of the first ventilation channel 12, the upper end of the third ventilation channel 14 is connected to the rear end of the first ventilation channel 12, the lower end of the third ventilation channel 14 is connected to the discharge port 8, the rear end of the second ventilation channel 13 is connected to the middle part of the third ventilation channel 14, and the front end of the second ventilation channel 13 is connected to the feeding port 7. An induced draft fan is arranged at the air outlet end of the ventilation space for exhausting air from the fermentation chamber. That is, the ventilation space adopts a single-inlet and double-outlet structure, and there are two circulation paths for cold air in the ventilation space, namely A1: air inlet 9→first ventilation channel 12→third ventilation channel 14→second ventilation channel 13→feeding port 7, A2: air inlet 9→first ventilation channel 12→third ventilation channel 14→discharge port 8, that is, the feeding port 7 and the discharge port 8 are both used as waste gas outlets, and the first ventilation channel 12 is located above the condensation heat recovery mechanism 5, and the second ventilation channel 13 is located below the condensation heat recovery mechanism 5, so that the cold air can fully flow around the condensation heat recovery mechanism 5 to ensure that the water vapor can be fully condensed, thereby releasing excess heat, and the condensed waste cold air is discharged through two circulation paths, the discharge is faster, and the water vapor condensation efficiency is improved.

[0050] Of course, the induced draft fan arranged at the air outlet end of the ventilation space can also be replaced by an air inlet fan for supplying air into the fermentation chamber, that is, the ventilation space adopts a double-inlet and single-outlet structure. Correspondingly, the two flow paths of cold air in the ventilation space are A1: air inlet 9→first ventilation channel 12→third ventilation channel 14→second ventilation channel 13→feeding port 7, A2: outlet 8→third ventilation channel 14→second ventilation channel 13→feeding port 7, that is, only the feeding port 7 serves as the exhaust gas outlet.

[0051] In this embodiment, the condensation heat recovery mechanism 5 also includes an extruder 54, an elastic water-absorbing member 55, and a perforated plate 56. The perforated plate 56 is installed on the drainage groove 52, and the elastic water-absorbing member 55 is installed on the perforated plate 56, and the two sides of the elastic water-absorbing member 55 correspond to the staggered openings 53 respectively. The extruder 54 is located above the elastic water-absorbing member 55, and the extruder 54 is connected to a motor, and the motor drives the extruder 54 to move downward to squeeze and drain the elastic water-absorbing member 55. This setting enables the condensed water condensed on the condensation plate 51 to flow smoothly through the staggered openings 53 to the elastic water-absorbing member 55 to be absorbed by it, and will not flow back into the fermentation chamber through the staggered openings 53; the perforated plate 56 plays a bearing and drainage role, and is used to discharge the condensed water generated by the extrusion of the elastic water-absorbing member 55 to the drainage groove 52 below in time. The distance between the bottom of the perforated plate 56 and the drainage groove 52 ranges from 1 to 5 cm to ensure the drainage effect. Of course, in other cases, it is also possible not to need an extruder 54 or an elastic water-absorbing member 55.

[0052] In the present embodiment, a condensation nucleus 541 for promoting condensation of water vapor is arranged directly above the corresponding drainage groove 52 inside the condensation heat recovery mechanism 5. Specifically, the condensation nucleus 541 is a spur regularly distributed on the bottom of the extruder 54 (i.e., the extrusion contact surface). The condensation nucleus 541 is a stalactite-like spur formed by spraying fiberglass anti-corrosion oil (i.e., epoxy resin) and then solidifying. Of course, the spur may also be irregularly distributed on the bottom of the extruder 54; in addition, the condensation nucleus 541 may also be obtained by lining or spraying medium and high temperature resistant anti-corrosion and plastic materials.

[0053] In this embodiment, the cross section of the drainage groove 52 is V-shaped, and the end of the drainage groove 52 is inclined downward, so the drainage effect is better.

[0054] In this embodiment, the elastic water-absorbing member 55 is an inverted trapezoidal sponge, and the squeezer 54 is an inverted trapezoidal squeezer corresponding to the sponge, which has a higher degree of fit and better drainage volume and drainage effect.

[0055] In this embodiment, the feed port 16 is located at the highest point of the partition 15, so that the garbage in the main reaction chamber 41 will automatically enter the auxiliary reaction chamber 42 when it exceeds the discharge port 8, and will not cause the garbage to accumulate in the main reaction chamber 41 and occupy the ventilation space. It can ensure the sustainable supply of cold air and the timely condensation and heat release of water vapor. Similarly, the garbage in the auxiliary reaction chamber can also be automatically discharged.

[0056] In this embodiment, the feed port 7 is located above the side of the main reaction chamber 41 away from the auxiliary reaction chamber 42, the discharge port 8 is located on the side of the auxiliary reaction chamber 42 away from the main reaction chamber 41, and the discharge port 8 is located below the rotating shaft. The feed port 7 is a trumpet-shaped feed port 7 that gradually expands downward, and the feeding is smoother. A conveyor belt for feeding is provided at the feed port 7, and the channel area at the upper end of the feed port 7 is not less than 3 times the channel area of ​​the conveyor belt.

[0057] In this embodiment, the volume of the main reaction chamber 41 is not less than 80% of the volume of the reaction chamber 4, and the daily waste processing capacity is 0.1-30 tons, 1 ton is equivalent to 1m 3 The volume of the main reaction chamber shall not be less than 5 times the daily garbage processing volume, and the optimal volume shall be 10 times or more.

[0058] In this embodiment, infrared temperature control probes are installed in the main reaction chamber 41 and the auxiliary reaction chamber 42 respectively, so as to facilitate the temperature measurement and control in the chambers.

[0059] In this embodiment, a driving mechanism 17 is further included. One end of the stirring mechanism 6 extends out of the shell and is connected to the driving mechanism 17. The driving mechanism 17 is a motor or a reducer.

[0060] In this embodiment, a plurality of condensation heat recovery mechanisms 5 are arranged side by side to ensure the condensation heat recovery effect.

[0061] In this embodiment, the heating layer 10 is a heating belt, or a water bath heating layer, or an oil bath heating layer, as long as it can achieve a heating effect.

[0062] In this embodiment, the shell includes an upper shell 1 and a lower shell 2 that cooperate with each other. The upper shell 1 is a rectangular shell, and the lower shell 2 is a semi-cylindrical shell. The upper shell 1 and the lower shell 2 cooperate with each other so that the cross-section of the shell is U-shaped. Correspondingly, the fermentation chamber is a U-shaped fermentation chamber, which is convenient for the reasonable layout of the condensation heat recovery mechanism 5 and the stirring mechanism 6, and is more conducive to the stirring and fermentation of garbage.

[0063] In this embodiment, the stirring mechanism 6 includes a stirring shaft 61 and a stirring paddle 62 disposed on the stirring shaft 61. The stirring paddle 62 rotates to stir the garbage and push the garbage toward the rear end. Of course, the stirring paddle can also be replaced by a stirring blade.

[0064] In this embodiment, the thermal insulation layer 11 is thermal insulation cotton, which has a better thermal insulation effect.

[0065] In this embodiment, the ventilation volume of the air inlet fan is not less than 3000m3 / h, and the wind pressure is not less than 124Pa, and the best is 4700-5000m 3 / h, 200-350Pa.

[0066] In this embodiment, the output torque range of the stirring mechanism 6 is 5-35 Nm, and it is frequency conversion controlled.

[0067] In this embodiment, the pretreatment unit includes a lifting and loading mechanism, a horizontal conveying and sorting platform, a crushing mechanism and an extrusion and dehydration mechanism; the lifting and loading mechanism is used to load and weigh the garbage, the horizontal conveying and sorting platform transports the garbage horizontally, and then allows manual sorting of the garbage to remove impurities and obtain fermentable garbage, the crushing mechanism crushes the garbage, and the extrusion and dehydration mechanism squeezes and dehydrates the garbage to obtain garbage to be fermented.

[0068] In the present embodiment, a waste gas treatment unit is also included, which includes a pickling absorption tank and an alkali washing absorption tank connected in sequence, and one end of the pickling absorption tank away from the alkali washing absorption tank is connected to the waste gas outlet of the fermentation chamber of the composting bin, and the waste gas of the composting bin is treated in sequence through the pickling absorption tank and the alkali washing absorption tank, and then the tail gas is discharged; the effective water depth of the pickling absorption tank and the alkali washing absorption tank is not less than 10 cm, and a relay fan is arranged between the two tanks, and the relay fan is also the air inlet fan of the fermentation chamber; the installation height of the relay fan is higher than the liquid level of the pickling absorption tank and the alkali washing absorption tank (when treating organic waste with a high protein content, acid washing absorption is used instead of water washing absorption).

[0069] In this embodiment, the compost bin is controlled by a PLC control system, and the control conditions are as follows:

[0070] 1. Based on the temperature in the main reaction chamber 41, the temperature of the space at the top of the garbage pile in the main reaction chamber 41 is controlled to be maintained at 50-55°C. When the temperature is lower than 50°C, the heating layer 10 works to raise the temperature in the main reaction chamber 41 to 55°C and then stops. When the temperature is higher than 60°C and lasts for 2-3 hours, the stirring mechanism 6 works regularly to allow the water vapor inside the pile to escape and condense to cool down.

[0071] 2. The stirring mechanism 6 works intermittently at a fixed time, with a working frequency of stirring the garbage pile 2-6 times every 2-12 hours, with forward and reverse rotations performed alternately;

[0072] 3. The air inlet fan is linked with the stirring mechanism 6. The air inlet fan works for 0.5-3 minutes before the stirring mechanism 6 starts working, and the air inlet fan is turned off after a delay of 0-5 minutes after the stirring mechanism 6 stops working.

[0073] 4. Every 0.5-4 hours, the squeezer 54 on the top of the sponge works 1-5 times, and each squeeze lasts 30 seconds.

[0074] Low-frequency stirring combined with efficient condensation technology can quickly remove moisture from the pile and fermentation, thereby maintaining the bulkiness of the pile and the high temperature of fermentation, and reducing processing energy consumption. See Lin Xiangyu, Meng Hanyu, Wang Xiaojun, Zhou Tingjin, Shen Junhuang, Chen Shaohua. Analysis of the treatment efficiency and energy consumption of vegetable waste by decentralized composting equipment combined with secondary composting [J]. Environmental Sanitation Engineering, 2022, 30(05): 40-46. In the technical solution of the present invention, during the fermentation process, the latent heat of vaporization of the water inside the garbage pile Q4 = 69.5kWh, accounting for about 70% of the total energy consumption of 99.1kWh; in addition, the condensation heat recovery mechanism 5 built into the fermentation chamber can also preheat the air entering the fermentation chamber, thereby achieving low-energy operation. The existing technology only recovers the heat energy of the air preheating and heating entering the fermentation chamber, which only accounts for 19% of all fermentation energy consumption, and the existing technology uses an external heat exchanger to recover part of the heat energy of this part of the exhaust gas, which is less efficient.

[0075] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes in form and details made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims will fall within the scope of protection of the present invention.

Claims

1. An aerobic fermentation method for organic waste, characterized in that: Includes the following steps, structural design and control conditions: S1. The garbage is sequentially loaded, weighed, sorted, transported, crushed, squeezed, and dehydrated through the pretreatment unit to obtain the garbage to be fermented; S2. After squeezing and dehydrating the garbage, the garbage is put into the main reaction chamber of the composting bin for high-temperature aerobic fermentation, and then the garbage is transported to the secondary reaction chamber of the composting bin for secondary fermentation and rapid drying to obtain a compost product; S3. After the primary compost product is subjected to secondary composting outside the fermentation chamber, a secondary compost product is obtained; The composting bin used in the method includes a shell, a fermentation chamber is arranged inside the shell, the fermentation chamber includes a condensation heat recovery chamber and a reaction chamber which are arranged in upper and lower layers and are connected to each other, the reaction chamber is divided into a main reaction chamber and a secondary reaction chamber front and back, a partition is arranged between the main reaction chamber and the secondary reaction chamber, a feed port is arranged on the partition, a condensation heat recovery mechanism is arranged in the condensation heat recovery chamber, a stirring mechanism is arranged in the reaction chamber, a feeding port and a discharging port connected to the reaction chamber are respectively provided at the front and rear ends of the shell, the condensation heat recovery chamber between the shell and the condensation heat recovery mechanism is a ventilation space, an air inlet is provided on the shell, the air inlet end of the ventilation space is connected to the air inlet, the air outlet end of the ventilation space is connected to the feeding port or the discharging port, an air inlet fan is provided at the air inlet end of the ventilation space for supplying air to the fermentation chamber, a heating layer is provided outside the shell, and the heating layer An insulation layer is arranged outside, and the condensation heat recovery mechanism includes a condensation plate and a drainage groove, the end of the drainage groove extends outside the shell, and the condensation plate is located above both sides of the length direction of the drainage groove, and is used to guide the condensed water to the drainage groove for discharge; there are multiple condensation plates on both sides of the length direction of the drainage groove, and the multiple condensation plates on each side are obliquely and staggeredly distributed, and staggered openings are formed between two adjacent condensation plates, and the staggered openings are gradually inclined downward toward the center direction of the drainage groove; the cross-section of the condensation plate is an obtuse triangle, and the condensation plate includes a condensation surface and a guide surface, and in the two condensation plates adjacent to each other, the staggered opening is formed between the condensation surface of the upper condensation plate and the guide surface of the lower condensation plate, wherein the condensation surface is a rough surface and the guide surface is a smooth surface; a condensation nucleus for promoting condensation of water vapor is arranged above the corresponding drainage groove inside the condensation heat recovery mechanism; The composting bin is controlled by a PLC control system, and the control conditions are as follows: (1) Based on the temperature in the main reaction chamber, the temperature of the space at the top of the garbage pile in the main reaction chamber is controlled to be maintained at 50-55°C. When the temperature is lower than 50°C, the heating layer will work to raise the temperature in the main reaction chamber to 55°C and then stop. When the temperature is higher than 60°C and lasts for 2-3 hours, the stirring mechanism will work regularly to allow the water vapor inside the pile to escape and condense to cool down. (2) The stirring mechanism works intermittently at a fixed time, with a working frequency of stirring the garbage pile 2-6 times every 2-12 hours, with forward and reverse rotations performed alternately; (3) The air intake fan is linked with the stirring mechanism. The air intake fan will work for 0.5-3 minutes before the stirring mechanism starts working, and will be turned off after a delay of 0-5 minutes after the stirring mechanism stops working.

2. The organic waste aerobic fermentation method according to claim 1, characterized in that: The ventilation space includes a first ventilation channel, a second ventilation channel, and a third ventilation channel. The first ventilation channel is located above the condensation heat recovery mechanism, the second ventilation channel is located below the condensation heat recovery mechanism, and the third ventilation channel is located on the side of the condensation heat recovery mechanism away from the feeding port. The air inlet is located at the front end of the first ventilation channel, the upper end of the third ventilation channel is connected with the rear end of the first ventilation channel, the lower end of the third ventilation channel is connected with the discharge port, the rear end of the second ventilation channel is connected with the middle part of the third ventilation channel, and the front end of the second ventilation channel is connected with the feeding port. An induced draft fan is arranged at the air outlet end of the ventilation space for exhausting air from the fermentation chamber.

3. The organic waste aerobic fermentation method according to claim 1, characterized in that: The condensation heat recovery mechanism also includes an extruder, an elastic water-absorbing member, and a perforated plate. The perforated plate is installed on the drainage groove, the elastic water-absorbing member is installed on the perforated plate, and the two sides of the elastic water-absorbing member correspond to the staggered openings respectively. The extruder is located above the elastic water-absorbing member and is used to squeeze the elastic water-absorbing member to drain water.

4. The organic waste aerobic fermentation method according to claim 3, characterized in that: The condensation nuclei are spikes distributed at the bottom of the extruder.

5. The organic waste aerobic fermentation method according to claim 1, characterized in that: The feeding port is a trumpet-shaped feeding port which gradually expands downwards. A conveyor belt for feeding is arranged at the feeding port. The channel area at the upper end of the feeding port is not less than 3 times the channel area of ​​the conveyor belt.

6. The organic waste aerobic fermentation method according to claim 1, characterized in that: The volume of the main reaction chamber is not less than 80% of the volume of the reaction chamber. The daily garbage processing capacity is 0.1-30 tons, and the volume of the main reaction chamber is not less than 5 times the daily garbage processing capacity.

7. The organic waste aerobic fermentation method according to claim 1, characterized in that: Infrared temperature control probes are installed in the main reaction chamber and the auxiliary reaction chamber respectively.

8. The organic waste aerobic fermentation method according to claim 1, characterized in that: The housing also includes a driving mechanism, wherein the stirring mechanism includes a stirring shaft and a stirring paddle arranged on the stirring shaft, and one end of the stirring mechanism extends out of the housing and is connected to the driving mechanism.

9. The organic waste aerobic fermentation method according to claim 8, characterized in that: The feeding port between the main reaction chamber and the auxiliary reaction chamber is located at the highest point of the partition; the feeding port is located above the side of the main reaction chamber away from the auxiliary reaction chamber, the discharging port is located on the side of the auxiliary reaction chamber away from the main reaction chamber, and the discharging port is located below the stirring shaft.

10. The organic waste aerobic fermentation method according to claim 1, characterized in that: The pretreatment unit includes a lifting and loading mechanism, a horizontal conveying and sorting platform, a crushing mechanism and an extrusion dehydration mechanism; the condensation heat recovery mechanism is a plurality of mechanisms arranged side by side; the heating layer is a heating belt, or a water bath heating layer, or an oil bath heating layer; the shell includes an upper shell and a lower shell that cooperate with each other, the upper shell is a rectangular shell, and the lower shell is a semi-cylindrical shell.

11. The organic waste aerobic fermentation method according to claim 1, characterized in that: The ventilation volume of the air inlet fan shall not be less than 3000m 3 / h, wind pressure not less than 124Pa.

12. The organic waste aerobic fermentation method according to claim 1, characterized in that: The output torque range of the stirring mechanism is 5-35Nm and it is frequency-controlled.

13. The organic waste aerobic fermentation method according to claim 1, characterized in that: It also includes a waste gas treatment unit, which includes an acid wash absorption tank and an alkali wash absorption tank connected in sequence, and one end of the acid wash absorption tank away from the alkali wash absorption tank is connected to the fermentation chamber of the compost bin.

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