Biological drying device and method

Abstract

The invention relates to a biological drying device and method.The biological drying device comprises a drying bin set, a cold exhaust pipe, a hot exhaust pipe, a multi-way valve, a tail gas heat exchanger and a tail gas circulating pipeline, and the drying bin set comprises a plurality of drying bins arranged in parallel; each drying bin is connected with the cold exhaust pipe and the hot exhaust pipe through the multi-way valve, the multi-way valve is used for controlling connection and disconnection between the drying bins and any one of the cold exhaust pipe and the hot exhaust pipe, one end of the tail gas circulation pipeline is communicated with the hot exhaust pipe through the tail gas heat exchanger, and the other end of the tail gas circulation pipeline is communicated with the hot exhaust pipe through the tail gas heat exchanger. And the other end of the tail gas circulating pipeline is communicated with the plurality of drying bins. The biological drying device disclosed by the invention can improve the utilization efficiency of heat and is relatively high in economic benefit.

Description

Technical Field

[0001] The present invention relates to the technical field of biological desiccation, and in particular to a biological desiccation device and method. Background Art

[0002] Organic solid waste (such as domestic garbage, sludge, etc.) has the characteristics of large processing volume and complex pollutant types. Organic solid waste with high moisture content has low calorific value and is easy to corrupt, which increases the difficulty of pollution control in subsequent treatment of landfill and incineration. Bio-drying is a new type of biological treatment technology evolved from the principle of aerobic fermentation. Bio-drying has the advantages of low energy consumption and no need for external heating. It is a very economical, energy-saving and environmentally friendly drying technology.

[0003] However, in the related art, the waste heat recovery and utilization of the biological drying device is not sufficient, a lot of heat is lost during the heat exchange process, the heat utilization efficiency is low, and the economy is poor. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention proposes a bio-drying device, which can improve the utilization efficiency of heat and has high economic benefits.

[0006] An embodiment of the present invention also provides a biological drying method.

[0007] The biological drying device of an embodiment of the present invention includes: a drying bin group, which includes a plurality of drying bins arranged in parallel; a cold exhaust pipe, a hot exhaust pipe and a multi-way valve, each of the drying bins is connected to the cold exhaust pipe and the hot exhaust pipe through the multi-way valve, and the multi-way valve is used to control the conduction and shutdown of the drying bin and any one of the cold exhaust pipe and the hot exhaust pipe; an exhaust gas circulation pipeline, one end of the exhaust gas circulation pipeline is connected to the hot exhaust pipe, and the other end of the exhaust gas circulation pipeline is connected to a plurality of the drying bins; an exhaust gas heat exchanger, the exhaust gas heat exchanger having a first heat exchange circuit and a second heat exchange circuit that can exchange heat with each other, one end of the first heat exchange circuit is connected to the hot exhaust pipe, and the other end of the first heat exchange circuit and the cold exhaust pipe are both connected to the odor treatment device, one end of the second heat exchange circuit is used to introduce air, and the other end of the second heat exchange circuit is connected to the exhaust gas circulation pipeline.

[0008] According to the biological drying device of the embodiment of the present invention, since the multi-way valve is used to control the conduction and disconnection between the drying bin and any one of the cold exhaust pipe and the hot exhaust pipe, when the temperature in the drying bin is higher than the set threshold, the gas in the drying bin can be introduced into the hot exhaust pipe through the multi-way valve, and then refluxed to each drying bin through the tail gas circulation pipeline. When the exhaust temperature in the drying bin is lower than the set threshold, the gas in the drying bin is introduced into the cold exhaust pipe through the multi-way valve, so that the gas with a temperature lower than the set threshold does not participate in the tail gas circulation of the biological drying device, thereby avoiding the mixing of low-temperature tail gas and high-temperature tail gas, so as to enhance the effect of waste heat recovery and utilization of the biological drying device, improve the heat utilization efficiency, and have high economic benefits.

[0009] In some embodiments, the bio-drying device also includes an odor treatment device for purifying harmful substances in the exhaust gas so that the exhaust gas meets emission standards.

[0010] In some embodiments, one end of the hot exhaust pipe is connected to the multi-way valve of each of the drying bins, and the other end of the hot exhaust pipe is connected to the exhaust gas heat exchanger; one end of the cold exhaust pipe is connected to the multi-way valve of each of the drying bins, and the other end of the cold exhaust pipe is connected to the odor treatment device.

[0011] In some embodiments, the biodrying device also includes a first valve and a second valve, the first valve is installed on the exhaust gas circulation pipeline, and the second valve is installed on the pipeline between the second heat exchange loop and the exhaust gas circulation pipeline, the first valve is used to control the flow rate of the circulating exhaust gas, and the second valve is used to control the flow rate of air.

[0012] In some embodiments, the biological drying device also includes several first temperature sensors and one second temperature sensor. The first temperature sensor is arranged on the pipeline between each of the drying bins and the multi-way valve, and the second temperature sensor is arranged on the pipeline between the first heat exchange circuit and the odor treatment device. When the detection temperature of the first temperature sensor is lower than the detection temperature of the second temperature sensor, the multi-way valve controls the drying bin to be connected to the cold exhaust pipe. When the detection temperature of the first temperature sensor is higher than the detection temperature of the second temperature sensor, the multi-way valve controls the drying bin to be connected to the hot exhaust pipe.

[0013] In some embodiments, the biological drying device also includes a controller and an air flow distributor, the exhaust gas circulation pipeline is connected to the multiple drying bins through the air flow distributor, the controller is electrically connected to the air flow distributor and the multi-way valve, and the controller is used to control the ventilation flow of each drying bin and the exhaust switching of the multi-way valve.

[0014] In some embodiments, the bio-drying device further includes a demister, which is connected in series to the exhaust gas circulation pipeline and is used to remove condensed water in the exhaust gas circulation pipeline.

[0015] In some embodiments, the bio-drying device further includes a fan and a flow meter, wherein the fan is connected in series to the exhaust gas circulation pipeline, and the flow meter is arranged at the air inlet end of the bio-drying device.

[0016] In some embodiments, the number of the drying chambers is three or more.

[0017] A biological drying method according to another embodiment of the present invention comprises a biological drying device according to any one of the above embodiments, and the biological drying method comprises the following steps:

[0018] Adding drying materials into the plurality of drying bins to perform biological drying;

[0019] When the exhaust temperature in any of the drying bins is higher than a set threshold, the gas in the drying bin is introduced into the hot exhaust pipe through the multi-way valve, and then flows back to each of the drying bins through the tail gas circulation pipeline;

[0020] When the exhaust temperature in any of the drying bins is lower than a set threshold, the gas in the drying bin is introduced into the cold exhaust pipe through the multi-way valve so that the gas below the temperature set threshold does not participate in the exhaust gas circulation of the biological dry process device.

[0021] According to the biological drying method of the embodiment of the present invention, since the multi-way valve is used to control the conduction and disconnection between the drying bin and any one of the cold exhaust pipe and the hot exhaust pipe, when the temperature in the drying bin is higher than the set threshold, the gas in the drying bin can be introduced into the hot exhaust pipe through the multi-way valve, and then refluxed to each drying bin through the tail gas circulation pipeline. When the exhaust temperature in the drying bin is lower than the set threshold, the gas in the drying bin is introduced into the cold exhaust pipe through the multi-way valve, so that the gas with a temperature lower than the set threshold does not participate in the tail gas circulation of the biological drying device, thereby avoiding the mixing of low-temperature tail gas and high-temperature tail gas, so as to enhance the effect of waste heat recovery and utilization of the biological drying device, improve the utilization efficiency of heat, and have high economic benefits.

[0022] In some embodiments, the number of the drying bins is n, and the drying cycle of the dried material is m days. After the drying operation starts in the first drying bin, the drying operation of the next drying bin is performed every m / n days, so as to stagger the drying cycles of the materials in each drying bin. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the process of the biological drying device according to an embodiment of the present invention.

[0024] Reference numerals:

[0025] 1. Drying warehouse;

[0026] 21. Cold exhaust pipe; 22. Hot exhaust pipe; 23. Exhaust gas circulation pipeline;

[0027] 31. Multi-way valve; 32. First valve; 33. Second valve;

[0028] 4. exhaust gas heat exchanger; 41. first heat exchange circuit; 42. second heat exchange circuit;

[0029] 51. First temperature sensor; 52. Second temperature sensor; 53. Odor treatment device; 54. Controller; 55. Air flow distributor; 56. Defogger; 57. Fan; 58. Flow meter. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0031] Please refer to the following Figure 1 The biological drying device and method according to the embodiments of the present invention are described.

[0032] like Figure 1 As shown, the biological drying device of the embodiment of the present invention includes: a drying chamber group, a cold exhaust pipe 21, a hot exhaust pipe 22, a multi-way valve 31 and an exhaust gas circulation pipeline 23. The drying chamber group includes a plurality of drying chambers 1 arranged in parallel, each drying chamber 1 is connected to the cold exhaust pipe 21 and the hot exhaust pipe 22 through a multi-way valve 31, and the multi-way valve 31 is used to control the conduction and disconnection of the drying chamber 1 and any one of the cold exhaust pipe 21 and the hot exhaust pipe 22, one end of the exhaust gas circulation pipeline 23 is connected to the hot exhaust pipe 22, and the other end of the exhaust gas circulation pipeline 23 is connected to a plurality of drying chambers 1.

[0033] It is understandable that multiple drying bins 1 are connected in parallel to the cold exhaust pipe 21 and the hot exhaust pipe 22. The multi-way valve 31 can control the connection and disconnection between the exhaust port of the drying bin 1 and the cold exhaust pipe 21, and the multi-way valve 31 can also control the connection and disconnection between the exhaust port of the drying bin 1 and the hot exhaust pipe 22.

[0034] According to the biological drying device of the embodiment of the present invention, since the multi-way valve 31 is used to control the conduction and disconnection between the drying bin 1 and any one of the cold exhaust pipe 21 and the hot exhaust pipe 22, when the temperature in any drying bin 1 is higher than the set threshold, the gas of the corresponding drying bin 1 can be introduced into the hot exhaust pipe 22 through the multi-way valve 31, and then refluxed into each drying bin 1 through the exhaust gas circulation pipeline 23. When the exhaust temperature in the drying bin 1 is lower than the set threshold, the gas of the drying bin 1 is introduced into the cold exhaust pipe 21 through the multi-way valve 31, so that the gas with a temperature lower than the set threshold does not participate in the exhaust gas circulation of the biological drying device, thereby avoiding the mixing of low-temperature exhaust gas and high-temperature exhaust gas, so as to enhance the effect of waste heat recovery and utilization of the biological drying device, improve the utilization efficiency of heat, and have high economic benefits.

[0035] The biological drying device of the embodiment of the present invention can reduce the pile heating required for water evaporation through multi-bin collaborative efficient waste heat recovery, thereby reducing the consumption of organic matter in the dried material, improving the fuel quality of the dried material, and making it have a higher calorific value and better combustion performance.

[0036] It is understandable that the material drying cycles of each drying bin 1 are staggered, and there are situations where some drying bins 1 are in a high temperature period, while other drying bins 1 are in the early and late stages of drying. The exhaust gas discharged from the drying bin 1 in the high temperature period has a higher temperature and has a higher waste heat recovery value, while the exhaust gas discharged from the drying bin 1 in the early and late stages of drying has a lower temperature and a lower waste heat recovery value. If the low-temperature exhaust gas is mixed with the high-temperature exhaust gas, the temperature of the high-temperature exhaust gas will be reduced, reducing the amount of heat that can be recovered and utilized by the device. Therefore, the biological drying device of the embodiment of the present invention can avoid the mixing of low-temperature exhaust gas and high-temperature exhaust gas to enhance the waste heat recovery and utilization effect of the biological drying device, improve the heat utilization efficiency, and have higher economic benefits.

[0037] For example, the multi-way valve 31 is a three-way valve, and the three-way valve can be an automatic switching valve such as a steam three-way valve, an electric three-way valve, or other manually controlled three-way valve.

[0038] Optionally, the biological drying device further includes an exhaust gas heat exchanger 4 and an odor treatment device 53. The odor treatment device 53 is used to purify harmful substances in the exhaust gas so that the exhaust gas meets emission standards.

[0039] The exhaust gas heat exchanger 4 has a first heat exchange circuit 41 and a second heat exchange circuit 42 that can exchange heat with each other. One end of the first heat exchange circuit 41 is connected to the hot exhaust pipe 22, and the other end of the first heat exchange circuit 41 and the cold exhaust pipe 21 are both connected to the odor treatment device 53. One end of the second heat exchange circuit 42 is used to introduce air, and the other end of the second heat exchange circuit 42 is connected to the exhaust gas circulation pipeline 23.

[0040] It can be understood that a part of the exhaust gas flowing out from the hot exhaust pipe 22 flows back to each drying bin 1 through the exhaust gas circulation pipeline 23, and the other part of the exhaust gas is heat exchanged through the exhaust gas heat exchanger 4, and the heat after the heat exchange can be returned to each drying bin 1 through the exhaust gas circulation pipeline 23. Therefore, the biological drying device of the embodiment of the present invention cooperates with the two waste heat recovery methods of "partial circulation of exhaust gas" and "exhaust gas-air heat exchange" to recover the waste heat generated by the drying bin 1, thereby further enhancing the waste heat recovery and utilization effect of the biological drying device and improving the heat utilization efficiency.

[0041] On the other hand, since the biological drying device of the embodiment of the present invention adopts the "partial exhaust gas circulation" method to recover waste heat, compared with the "exhaust gas-air heat exchange" scheme, it can reduce the amount of odor generated, reduce the operating costs of odor treatment facilities, and reduce the impact of biological drying operations on the environment.

[0042] Specifically, one end of the hot exhaust pipe 22 is connected to the multi-way valve 31 of each drying bin 1, and the other end of the hot exhaust pipe 22 is connected to the exhaust heat exchanger 4. One end of the cold exhaust pipe 21 is connected to the multi-way valve 31 of each drying bin 1, and the other end of the cold exhaust pipe 21 is connected to the odor treatment device 53. Therefore, each drying bin 1 can selectively pass the exhaust gas to the hot exhaust pipe 22 or to the cold exhaust pipe 21 through the multi-way valve 31.

[0043] It should be noted that the cold exhaust pipe 21 can directly pass the low-temperature exhaust gas into the odor purification device, or the cold exhaust pipe 21 can be connected to the outlet of the first heat exchange circuit 41 of the exhaust heat exchanger 4, and the low-temperature exhaust gas is mixed with the exhaust gas after heat exchange and then passed into the odor treatment device 53. The biological drying device of the embodiment of the present invention adopts a combination of two waste heat recovery methods, which has a simple structure and is easy to operate, and can improve the waste heat recovery effect compared with a single waste heat recovery method.

[0044] Optionally, the biological drying device further includes a first valve 32 and a second valve 33, wherein the first valve 32 is installed on the exhaust gas circulation pipeline 23, and the second valve 33 is installed on the pipeline between the second heat exchange loop 42 and the exhaust gas circulation pipeline 23, wherein the first valve 32 is used to control the flow rate of the circulating exhaust gas, and the second valve 33 is used to control the flow rate of the air. It is understandable that the first valve 32 and the second valve 33 can change the opening size to control the flow rate of the exhaust gas circulation in the "exhaust gas partial circulation" mode and the flow rate of the air in the "exhaust gas-air heat exchange" mode, so as to accurately control the waste heat recovery process and ventilation flow rate of the biological drying device.

[0045] Specifically, the biological drying device further includes a first temperature sensor 51 and a second temperature sensor 52. The first temperature sensor 51 is disposed on the pipeline between the drying bin 1 and the multi-way valve 31, and the second temperature sensor 52 is disposed on the pipeline between the first heat exchange loop 41 and the odor treatment device 53. When the detection temperature of the first temperature sensor 51 is lower than the detection temperature of the second temperature sensor 52, the multi-way valve 31 controls the drying bin 1 to communicate with the cold exhaust pipe 21. When the detection temperature of the first temperature sensor 51 is higher than the detection temperature of the second temperature sensor 52, the multi-way valve 31 controls the drying bin 1 to communicate with the hot exhaust pipe 22. It can be understood that the biological drying device of the embodiment of the present invention controls the timing of switching the valve plate of the multi-way valve 31 by comparing the detection temperatures of the first temperature sensor 51 and the second temperature sensor 52.

[0046] When the exhaust gas temperature discharged from a drying bin 1 is higher than the exhaust gas temperature discharged from the exhaust gas heat exchanger 4, it is determined that the heat of the exhaust gas discharged from the drying bin 1 can be recycled. If the exhaust gas temperature discharged from a drying bin 1 is lower than the exhaust gas temperature discharged from the exhaust gas heat exchanger 4, it is determined that the waste heat contained in this exhaust gas cannot be recycled by the system, thereby improving the waste heat recovery effect of the biological drying device and improving energy utilization.

[0047] In other words, the above-mentioned exhaust method can prevent the low-temperature exhaust gas generated by the drying chamber 1 at the initial and final stages of drying from entering the waste heat recovery system, keeping the exhaust gas in the hot exhaust pipe 22 at a higher temperature, so that the biological drying device has a higher waste heat recovery efficiency.

[0048] Specifically, the biological drying device also includes a controller 54 and an airflow distributor 55. The tail gas circulation pipeline 23 is connected to multiple drying bins 1 through the airflow distributor 55. The controller 54 is electrically connected to the airflow distributor 55 and the multi-way valve 31. The controller 54 is used to control the ventilation flow of each drying bin 1 and the exhaust switching of the multi-way valve 31. The controller 54 is electrically connected to the first temperature sensor 51 and the second temperature sensor 52. The controller 54 can automatically control the exhaust switching of the multi-way valve 31 according to the temperature of the first temperature sensor 51 and the second temperature sensor 52, and the ventilation flow of each drying bin 1 can be adjusted by the controller 54 to improve the automation of the biological drying device and save manpower.

[0049] For example, the controller 54 may be an automatic control device such as a PLC controller 54, a microcontroller 54 or a distributed control system.

[0050] Optionally, the biological drying device also includes a demister 56, which is connected in series to the exhaust gas circulation pipeline 23, and the demister 56 is used to remove condensed water in the exhaust gas circulation pipeline 23. The biological drying device of the embodiment of the present invention can reduce the moisture content in the exhaust gas by providing the demister 56, which is beneficial to improve the drying efficiency of the drying bin 1 and shorten the drying cycle. The demister 56 can be a cyclone demister 56, a metal cyclone plate demister 56, a corrugated plate demister 56, etc. Alternatively, the demister 56 can be replaced by a moisture adsorber or a moisture absorber to eliminate droplets and water vapor in the gas, which is not limited in this application.

[0051] Optionally, the biological drying device further includes a fan 57 and a flow meter 58, the fan 57 is connected in series to the exhaust gas circulation pipeline 23, and the flow meter 58 is arranged at the air inlet end of the biological drying device. It can be understood that the fan 57 is installed at the air inlet end of the second heat exchange loop 42, and the flow meter 58 is used to detect the flow rate of the gas in the exhaust gas circulation pipeline 23, so as to facilitate the real-time monitoring of the exhaust gas circulation of the exhaust gas circulation pipeline 23, and to facilitate the control and management of the biological drying device.

[0052] In the example of the present application, the number of drying chambers 1 is three or more, thereby enhancing the coordinated effect of the multiple drying chambers 1 and helping to improve the overall heat utilization rate of the biological drying device.

[0053] A biological drying method according to another embodiment of the present invention comprises using the biological drying apparatus according to the present invention, and the biological drying method comprises the following steps:

[0054] Adding drying materials into a plurality of drying bins 1 to perform biological drying;

[0055] When the exhaust temperature in any drying bin 1 is higher than the set threshold, the gas in the drying bin 1 is introduced into the hot exhaust pipe 22 through the multi-way valve 31, and then flows back to each drying bin 1 through the exhaust gas circulation pipeline 23;

[0056] When the exhaust temperature in any drying chamber 1 is lower than a set threshold, the gas in the drying chamber 1 is introduced into the cold exhaust pipe 21 through the multi-way valve 31, so that the gas with a temperature lower than the set threshold does not participate in the exhaust gas circulation of the biological dry process device.

[0057] According to the biological drying method of the embodiment of the present invention, since the multi-way valve 31 is used to control the conduction and disconnection of the drying bin 1 and any one of the cold exhaust pipe 21 and the hot exhaust pipe 22, when the temperature in any drying bin 1 is higher than the set threshold, the gas of the corresponding drying bin 1 can be introduced into the hot exhaust pipe 22 through the multi-way valve 31, and then refluxed to each drying bin 1 through the exhaust gas circulation pipeline 23. When the exhaust temperature in the drying bin 1 is lower than the set threshold, the gas of the drying bin 1 is introduced into the cold exhaust pipe 21 through the multi-way valve 31, so that the gas with a temperature lower than the set threshold does not participate in the exhaust gas circulation of the biological drying device, thereby avoiding the mixing of low-temperature exhaust gas and high-temperature exhaust gas, so as to make full use of the waste heat in the high-temperature exhaust gas, improve the heat utilization efficiency of the biological drying device, and have high economic benefits.

[0058] Optionally, the number of drying bins 1 is n, the drying cycle of the dried material is m days, and after the first drying bin 1 starts the drying operation, the drying operation of the next drying bin 1 is performed every m / n days, so as to stagger the drying cycles of the materials in each drying bin 1. It is understandable that after the drying operation of the material in the first drying bin 1 is completed, new drying material is loaded to continue the drying operation, thereby realizing the semi-continuous operation of the entire device and staggering the operation cycles of each drying bin 1.

[0059] Since the material drying cycles of each drying bin 1 are staggered, there are situations where some drying bins 1 are in a high temperature period, while other drying bins 1 are in the early and late stages of drying. The exhaust gas discharged from the drying bin 1 in the high temperature period has a higher temperature and has a higher waste heat recovery value, while the exhaust gas discharged from the drying bin 1 in the early and late stages of drying has a lower temperature and a lower waste heat recovery value. If the low-temperature exhaust gas is mixed with the high-temperature exhaust gas, the temperature of the high-temperature exhaust gas will decrease, reducing the amount of heat that can be recovered and utilized by the device. Therefore, in order to ensure that the device obtains a higher waste heat recovery efficiency, the multi-way valve 31 is switched so that the low-temperature exhaust gas is directly passed into the odor treatment device 53 through the cold exhaust period pipeline so that it does not participate in the waste heat recovery process.

[0060] A specific embodiment of the biological drying device of the present invention is described below.

[0061] The domestic waste with an initial moisture content of 60% was used as the drying material and the device of the present invention was used for biological drying. There were 4 drying bins 1, each with a capacity of 5t domestic waste, and a drying cycle of 8 days. The ventilation flow rate into each drying bin 1 was controlled by a program written in the PLC. The control logic of the ventilation flow rate was: on the 1st to 2nd day of drying, the ventilation flow rate was 0.3m 3 / (t*min), 3-8 days of drying, ventilation flow rate is 1m 3 / (t*min). At the same time, the air flow rate entering the device is maintained at 50% of the total ventilation volume of each drying bin 1. The first drying bin 1 is loaded with domestic garbage, and the fan 57, flow distributor and PLC are turned on to start the drying operation. Then the drying operation of the next drying bin 1 is carried out every 2 days. On the 8th day, the first drying bin 1 completes the material drying operation, takes out the drying product, and loads domestic garbage to continue the drying operation. At this time, the device enters the semi-continuous biological drying process. The temperature of the exhaust gas discharged from the drying bin 1 in the early stage of drying is 30-60°C, the temperature of the exhaust gas discharged from the drying bin 1 in the high temperature period is 60-70°C, and the temperature of the exhaust gas discharged from the drying bin 1 in the late stage of drying is 40-60°C. The average air temperature entering the device is 20°C, the temperature of the exhaust gas in the hot exhaust pipe 22 is stable at 50-55°C, the temperature of the exhaust gas discharged from the exhaust heat exchanger 4 is about 40°C, and the air temperature after heat exchange is 35°C. The temperature of the heated air and the circulating exhaust gas after mixing is about 45°C. When the exhaust temperature of the drying chamber 1 is lower than 40°C at the beginning and end of drying, the multi-way valve 31 introduces the exhaust gas into the cold exhaust pipe 21, and the exhaust gas does not participate in the waste heat recovery process. After 8 days of drying, the moisture content of the domestic garbage is reduced from 60% to 35%, the reduction rate reaches 55.6%, and the low calorific value increases from 6.4MJ / kg to 11.5MJ / kg.

[0062] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0063] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0064] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0067] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A biological drying device, characterized in that: include: A drying bin group, the drying bin group comprising a plurality of drying bins arranged in parallel; A cold exhaust pipe, a hot exhaust pipe and a multi-way valve, each of the drying bins is connected to the cold exhaust pipe and the hot exhaust pipe through the multi-way valve, and the multi-way valve is used to control the conduction and disconnection of the drying bin and any one of the cold exhaust pipe and the hot exhaust pipe; An exhaust gas circulation pipeline, one end of which is connected to the hot exhaust pipe, and the other end of which is connected to the plurality of drying bins.

2. The biological drying device according to claim 1, characterized in that: The biological drying device also includes an exhaust gas heat exchanger and an odor treatment device. The exhaust gas heat exchanger has a first heat exchange circuit and a second heat exchange circuit that can exchange heat with each other. One end of the first heat exchange circuit is connected to the hot exhaust pipe, and the other end of the first heat exchange circuit and the cold exhaust pipe are both connected to the odor treatment device. One end of the second heat exchange circuit is used for introducing air, and the other end of the second heat exchange circuit is connected to the exhaust gas circulation pipeline.

3. The biological drying device according to claim 2, characterized in that: One end of the hot exhaust pipe is connected to the multi-way valve of each drying bin, and the other end of the hot exhaust pipe is connected to the exhaust gas heat exchanger; one end of the cold exhaust pipe is connected to the multi-way valve of each drying bin, and the other end of the cold exhaust pipe is connected to the odor treatment device.

4. The biological drying device according to claim 2, characterized in that: The biological drying device also includes a first valve and a second valve, the first valve is installed on the exhaust gas circulation pipeline, and the second valve is installed on the pipeline between the second heat exchange loop and the exhaust gas circulation pipeline, the first valve is used to control the flow rate of the circulating exhaust gas, and the second valve is used to control the flow rate of air.

5. The biological drying device according to claim 2, characterized in that: The biological drying device also includes a plurality of first temperature sensors and a second temperature sensor. The first temperature sensor is arranged on the pipeline between each of the drying bins and the multi-way valve, and the second temperature sensor is arranged on the pipeline between the first heat exchange circuit and the odor treatment device. When the detection temperature of the first temperature sensor is lower than the detection temperature of the second temperature sensor, the multi-way valve controls the drying bin to be connected to the cold exhaust pipe. When the detection temperature of the first temperature sensor is higher than the detection temperature of the second temperature sensor, the multi-way valve controls the drying bin to be connected to the hot exhaust pipe.

6. The biological drying device according to claim 2, characterized in that: The biological drying device also includes a controller and an air flow distributor. The exhaust gas circulation pipeline is connected to the multiple drying bins through the air flow distributor. The controller is electrically connected to the air flow distributor and the multi-way valve. The controller is used to control the ventilation flow of each drying bin and the exhaust switching of the multi-way valve.

7. The biological drying device according to any one of claims 1 to 6, characterized in that: The biological drying device also includes a demister, which is connected in series to the exhaust gas circulation pipeline and is used to remove condensed water in the exhaust gas circulation pipeline.

8. The biological drying device according to any one of claims 1 to 6, characterized in that: The biological drying device also includes a fan and a flow meter. The fan is connected in series on the tail gas circulation pipeline, and the flow meter is arranged at the air inlet end of the biological drying device.

9. The biological drying device according to any one of claims 1 to 6, characterized in that: The number of the drying bins is three or more.

10. A biological drying method, characterized in that: Using the biological drying device according to any one of claims 1 to 9, the biological drying method comprises the following steps: Adding drying materials into the plurality of drying bins to perform biological drying; When the exhaust temperature in any of the drying bins is higher than a set threshold, the gas in the drying bin is introduced into the hot exhaust pipe through the multi-way valve, and then flows back to each of the drying bins through the tail gas circulation pipeline; When the exhaust temperature in any of the drying bins is lower than a set threshold, the gas in the drying bin is introduced into the cold exhaust pipe through the multi-way valve so that the gas with a temperature lower than the set threshold does not participate in the exhaust gas circulation of the biological dry process device.

11. The biological drying method according to claim 10, characterized in that: The number of the drying bins is n, and the drying cycle of the dried material is m days. After the first drying bin starts the drying operation, the drying operation of the next drying bin is performed every m / n days, so as to stagger the drying cycles of the materials in each drying bin.

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