Negative pressure drying device

Abstract

The utility model discloses a negative pressure drying device, which relates to the technical field of sludge treatment and comprises a drying main body, a conveying device arranged in the drying main body, a heating pipe arranged at the bottom of the conveying device, a first hot air source connected to one end of the heating pipe, a hot air inlet arranged at the bottom of the drying main body, and a second hot air source connected to the hot air inlet through a pipeline. A feeding port is formed in the top of the drying body, a plurality of exhaust ports are further formed in the top of the drying body, each exhaust port is connected with an exhaust branch pipe, each exhaust branch pipe is provided with a negative-pressure moisture removal fan and a temperature sensor, and when the temperature sensor senses that the temperature in the drying body reaches the predicted temperature, the negative-pressure moisture removal fans are started to remove moisture in the drying body. And one end, far away from the exhaust branch pipes, of the exhaust main pipe is connected with a gas treatment device. According to the sludge drying device, sludge can be dried, the overall energy consumption is low, and final gas can be treated and then discharged.

Description

Technical Field

[0001] The utility model relates to the technical field of sludge treatment, in particular to a negative pressure drying device. Background Art

[0002] Sludge refers to a mixture of feces and sewage. The water content in sludge reaches 99%. Sludge appears in the form of bound water in the cell membrane. The current way to treat bound water in the cell membrane in sewage treatment plants is to add coagulants to break the cell membrane. This method of breaking the cell membrane is expensive and inefficient. After breaking the cell membrane, a press is used to press the water to discharge it. However, the water content after treatment in this way still reaches more than 80%, that is, the solidified sludge can only reach a maximum of 20%. The sludge treated in this way is then landfilled. However, since a large amount of viruses are concentrated in feces (feces is also a type of sludge), treatment using the above method will lead to fecal-oral transmission of the virus.

[0003] Since most of the existing sludge disposal is landfill, less than 5% of the sludge is used as a resource. Therefore, the utilization rate is low and the landfill method has many disadvantages.

[0004] In order to overcome the disadvantages of landfill, a sludge drying method has emerged in the existing technology to treat sludge. This not only dries the sludge, but also sterilizes it at high temperature during the drying process, thereby blocking the fecal-oral transmission of the virus.

[0005] Existing sludge drying devices, such as the "sludge dryer" disclosed in patent number CN105417927B, include a main shaft that runs through the entire length of the box and is driven to rotate by an electric motor at one end; a number of circular discs are interspersed on the main shaft, and a number of angle steels are fixed on the outer periphery of the discs. The length of the angle steels is slightly shorter than the length of the box and is radially distributed parallel to the main shaft; sludge pushing inclined shovels and sludge turning flat shovels are arranged at equal intervals on the angle steels and fixed at intervals on the angle steels.

[0006] However, the aforementioned patent utilizes an electric motor to drive the main shaft, requiring continuous rotation of the motor during the sludge drying process. Furthermore, the dried sludge is also transported away via a screw conveyor. This indicates that the patent consumes a significant amount of electrical energy to maintain its operation in practice, resulting in high energy consumption. Furthermore, the evaporated water vapor is discharged directly from the water vapor outlet without being treated, potentially polluting the environment.

[0007] Therefore, there is an urgent need in the art for a new type of negative pressure drying device to solve the above problems. Utility Model Content

[0008] The purpose of the utility model is to provide a negative pressure drying device to solve the problems existing in the above-mentioned prior art, save electricity on the basis of being able to dry sludge, and also process the discharged gas.

[0009] To achieve the above purpose, the present invention provides the following solutions:

[0010] The utility model discloses a negative pressure drying device, comprising a drying main body, a conveying device is provided in the drying main body, a heating pipe is provided at the bottom of the conveying device, one end of the heating pipe is connected to a first hot air source, a hot air inlet is provided at the bottom of the drying main body, and the hot air inlet is connected to a second hot air source through a pipeline, a feed port is provided at the top of the drying main body, sludge can pass through the feed port and fall onto the conveying device, a plurality of exhaust ports are also provided at the top of the drying main body, each of the exhaust ports is connected to an exhaust branch pipe, a negative pressure dehumidification fan and a temperature sensor are provided on the exhaust branch pipe, when the temperature sensor senses that the temperature in the drying main body reaches the expected temperature, the negative pressure dehumidification fan is turned on, and each of the exhaust branch pipes is connected to an exhaust main pipe, and the exhaust main pipe is connected to a gas treatment device at one end away from the exhaust branch pipe.

[0011] Preferably, the conveying device is a mesh chain conveyor.

[0012] Preferably, the expected temperature is 60°C.

[0013] Preferably, a partition plate is fixed in the drying main body, and a plurality of hot air passage holes are provided on the partition plate.

[0014] Preferably, a strip cutter is provided at one end of the feed inlet close to the drying body.

[0015] Preferably, the gas processing device includes a gas filtering device and an exhaust fan, the gas filtering device and the exhaust fan are connected via a negative pressure pipeline, and the gas filtering device is closer to the exhaust main pipe than the exhaust fan.

[0016] Preferably, the gas filtration device includes a first spray tower and a second spray tower connected in sequence, the spray water source of the first spray tower and the second spray tower comes from a grey water source, the water outlet of the second spray tower is connected to a grey water discharge container, the grey water in the grey water discharge container can be poured into the hydro-generator, and the water at the hydro-generator flows into the sewage pool.

[0017] Preferably, activated carbon is provided in the first spray tower and the second spray tower.

[0018] Preferably, a discharge port is provided on the side wall of the drying body, and a sealing door is provided at the discharge port.

[0019] Preferably, humidity sensors are provided at both the feed port and the discharge port.

[0020] Compared with the prior art, the utility model has achieved the following technical effects:

[0021] This utility model uses hot air to dry the sludge, which is then transported to the next process for processing. The generated gas can be treated and discharged. Since only the conveying device is equipped with a motor, the entire process requires minimal electricity, resulting in lower energy consumption. Furthermore, the wastewater can be sterilized at a centralized high temperature, blocking the fecal-oral transmission pathway for viruses. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic structural diagram of a negative pressure drying device according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the position of the heating tube in the negative pressure drying device according to an embodiment of the present invention;

[0025] In the figure: 1-drying body; 2-conveying device; 3-heating pipe; 4-feeding port; 5-strip cutter; 6-negative pressure dehumidification fan; 7-temperature sensor; 8-partition plate; 9-first spray tower; 10-second spray tower; 11-exhaust fan; 12-graywater discharge container; 13-hydraulic generator; 14-sewage tank; 15-graywater source. DETAILED DESCRIPTION

[0026] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] The purpose of the utility model is to provide a negative pressure drying device to solve the problems existing in the above-mentioned prior art, save electricity on the basis of being able to dry sludge, and also process the discharged gas.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0029] like Figure 1-Figure 2 As shown, the present invention provides a negative pressure drying device comprising a drying body 1, which can be secured to a sealed structure by several sealing plates. The drying body 1 includes a conveying device 2, and a heating pipe 3 is provided at the bottom of the conveying device 2. The heating pipe 3 is arranged in an S-shaped pattern at the bottom of the conveying device 2. One end of the heating pipe 3 is connected to a first hot air source, and the other end is connected to a bag filter. Hot air from the first hot air source is dissipated through the heating pipe 3 before passing through the bag filter and ultimately discharged into the atmosphere. A hot air inlet is provided at the bottom of the drying body 1, which is connected via a pipeline to a second hot air source. Hot air from the second hot air source enters the bottom of the drying body 1 through the hot air inlet and then moves upward along the drying body 1, drying the sludge above. It should be noted that both the first and second hot air sources include, but are not limited to, existing devices capable of generating hot air, such as gasifiers or boilers. An inverted conical feed port 4 is provided at the top of the drying body 1, through which sludge can pass and fall onto the conveying device 2 below. The top of the drying body 1 is also provided with several exhaust ports, which are arranged in sequence and spaced apart. Each exhaust port is connected to an exhaust branch pipe. The hot air from the second hot air source (i.e., the hot air inlet) passes through the sludge heat exchange process and is finally discharged from the exhaust port. The exhaust branch pipe is equipped with a negative pressure dehumidification fan 6 and a temperature sensor 7. When the temperature sensor 7 senses that the temperature inside the drying body 1 has reached the expected temperature, the negative pressure dehumidification fan 6 is turned on. The exhaust branch pipes are connected to a main exhaust pipe. The end of the exhaust main pipe away from the exhaust branch pipe is connected to a gas treatment device. The gas discharged from the exhaust port is processed by the gas treatment device and finally discharged into the atmosphere.

[0030] In actual use, sludge falls from the feed port 4 and lands precisely on the conveying device 2 below, where it is driven by the conveying device 2. During this process, hot air from the first hot air source passes through the heating tube 3 inside the drying body 1, raising its temperature. This heats and dries the sludge on the conveying device 2. The gas passing through the heating tube 3 is filtered by the bag filter and discharged directly into the atmosphere. Simultaneously, hot air from the second hot air source enters the bottom of the drying body 1 through the pipeline and the hot air inlet. The hot air from the second hot air source moves upward within the drying body 1, drying the sludge on the conveying device 2. After the hot air from the second hot air source completes the drying and heat exchange, some of the hot air, along with the evaporated gas from the sludge, is transported to the exhaust port. The hot air is then collected by various exhaust branch pipes into a main exhaust pipe, which then transports it to the gas treatment device. After being processed by the gas treatment device, it is finally discharged into the atmosphere.

[0031] In this embodiment, the conveying device 2 is an existing mesh chain conveyor, and its conveying mesh chain is made of stainless steel. Its hollow conveying mesh chain can better transfer heat to the sludge on the conveying mesh chain to dry it.

[0032] In this embodiment, the expected temperature for manure is 60°C. That is, when temperature sensor 7 detects that the internal temperature of drying body 1 is 60°C, negative pressure dehumidification fan 6 is activated to extract the gas from drying body 1. The purpose of the expected temperature of 60°C is to keep the manure in a low-temperature evaporation state. At this temperature, manure does not decompose and produce odor, so the exhaust gas is not odorous. It also ensures the calorific value of the dried sludge, allowing it to be burned as fuel.

[0033] In this embodiment, a partition plate 8 is fixed horizontally in the drying main body 1, and a plurality of hot air holes are provided on the partition plate 8. The purpose of providing the hot air holes is to allow the hot air from the second hot air source to pass through and flow upward. At the same time, the sludge falling from above can fall onto the partition plate 8 instead of falling to the bottom of the drying main body 1, and can be cleaned later.

[0034] In this embodiment, a slitter 5 is provided at one end of the feed inlet 4 near the drying body 1. This slitter 5 is a conventional mechanism comprising a slitter motor, the output shaft of which is connected to a slitter shaft. The slitter shaft is evenly equipped with multiple slitter blades. These blades cut the sludge into individual strips and evenly distribute the sludge onto the conveyor chain for uniform heating. As slitter 5 is a mature technology, existing commercially available slitter 5 can be readily employed in actual installations. Therefore, a detailed description of its structure will not be provided here.

[0035] In this embodiment, the gas processing device includes a gas filter device and an exhaust fan 11 . The gas filter device and the exhaust fan 11 are connected via a negative pressure pipeline. The gas filter device is closer to the exhaust main pipe than the exhaust fan 11 .

[0036] In actual use, under the negative pressure power of the exhaust fan 11, the gas in the exhaust branch and the exhaust main line passes through the gas filter device and the exhaust fan 11 in turn, and is filtered at the gas filter device. The gas treated by the gas filter device is finally discharged into the atmosphere through the exhaust fan 11.

[0037] In this embodiment, the gas filtration device comprises a first spray tower 9 and a second spray tower 10 connected in sequence. The spray water source for the first and second spray towers 9 and 10 is a reclaimed water source 15, which can be recycled water from within the factory. The outlet of the second spray tower 10 is connected to a reclaimed water discharge container 12. This reclaimed water discharge container 12 can be an open-top container, allowing the reclaimed water in the reclaimed water discharge container 12 to be poured into a hydro-generator 13. To ensure that the reclaimed water in the reclaimed water discharge container 12 can be poured into the hydro-generator 13 below, the reclaimed water discharge container 12 can be fixed to a rotating shaft, with both ends of the shaft rotatably connected to a rotating bracket via bearings. A rotating motor is connected to one end of the shaft. The rotation of the motor can tilt the reclaimed water discharge container 12 and discharge the water within. The height of the reclaimed water discharge container 12 is higher than that of the hydro-generator 13, utilizing the gravitational potential energy of the water to drive the hydro-generator 13, thereby generating electricity. The water generated by the hydro-generator 13 will also flow into the sewage pool 14 to wait for subsequent treatment.

[0038] There are two types of connection relationships between the first spray tower 9 and the second spray tower 10:

[0039] First, the reclaimed water in the reclaimed water source 15 is connected to the water inlets of the first spray tower 9 and the second spray tower 10 respectively through two outlet pipes, the outlet end of the exhaust main line is connected to the air inlet of the first spray tower 9, the air outlet of the first spray tower 9 is connected to the air inlet of the second spray tower 10, and the water outlets of the first spray tower 9 and the second spray tower 10 are both connected to the reclaimed water discharge container 12.

[0040] In actual use, the reclaimed water from the reclaimed water source 15 flows into the first spray tower 9 and the second spray tower 10 respectively to provide spray water therefor, and the gas after spraying in the first spray tower 9 will enter the second spray tower 10. The gas after the second spraying in the second spray tower 10 is discharged into the atmosphere through the exhaust fan 11, and the reclaimed water after spraying in the first spray tower 9 and the second spray tower 10 flows back to the reclaimed water discharge container 12.

[0041] Secondly, the grey water source 15 is connected to the water inlet of the first spray tower 9 through the outlet pipe, the outlet end of the exhaust main is connected to the air inlet of the first spray tower 9, the air outlet of the first spray tower 9 is connected to the air inlet of the second spray tower 10, and the water outlet of the first spray tower 9 is connected to the water inlet of the second spray tower 10 through a connecting pipe. Of course, a water pump is provided on the connecting pipe to provide power, and the water outlet of the second spray tower 10 is connected to the grey water discharge container 12 through a pipeline.

[0042] In actual use, the gas in the exhaust manifold enters the air inlet of the first spray tower 9. Simultaneously, reclaimed water from the reclaimed water source 15 flows into the first spray tower 9, providing spray water. The gas after spraying in the first spray tower 9 then enters the second spray tower 10, while the reclaimed water after spraying in the first spray tower 9 flows into the water inlet of the second spray tower 10. In this way, the reclaimed water from the first spray tower 9 sprays the gas from the first spray tower 9 a second time in the second spray tower 10. The gas after the second spraying in the second spray tower 10 is discharged into the atmosphere via the exhaust fan 11, and the reclaimed water after spraying in the second spray tower 10 flows back into the reclaimed water discharge container 12.

[0043] In this embodiment, the packing layer in the first spray tower 9 and the second spray tower 10 is provided with activated carbon, and no other packing is required. This is because the gas extracted from the drying body 1 is mostly clean gas without toxic gas, so it only needs to be simply filtered before being discharged.

[0044] In this embodiment, a discharge port is provided on the side wall of the drying body 1, through which the material on the conveying device 2 is ultimately discharged. A sealed door is also provided at the discharge port. When drying is in progress within the drying body 1, the sealed door is closed. When drying is complete and the dried sludge needs to be discharged, the sealed door is opened again.

[0045] As for the specific structure of the sealing door, an existing manual door or an electric door can be used.

[0046] Similarly, a sealing cover is provided at the feed inlet 4, which is closed when drying in the drying body 1 to prevent hot air from overflowing. The sealing cover can be opened again when it is necessary to pour materials into the drying body 1.

[0047] The sealing cover can be manually or electrically operated. A manual operation can be achieved by providing a slot on one side of the feed port 4, through which the sealing cover passes to block the feed port 4. An electrically operated operation can be achieved by adding a telescopic air cylinder or hydraulic cylinder connected to the sealing cover, which drives the sealing cover in and out through its telescopic action.

[0048] In this embodiment, humidity sensors are provided at both the feed port 4 and the discharge port. The moisture changes before and after drying can be calculated using the temperature sensors 7 at the feed port 4 and the discharge port. In addition, a weighing sensor can be provided at the feed port 4 to detect the weight of the sludge feed. The weighing sensor can be provided on the sealing cover. After the weight is detected, the sealing cover is pulled out to achieve quantitative pouring of the sludge. A weighing scale can be provided at the discharge port. The sludge delivered falls onto the weighing scale and its weight is measured to monitor the weight changes before and after drying. The temperature sensor 7 is used to monitor the drying humidity changes, and the weight sensor and weighing scale are used to monitor the weight changes before and after drying. This effectively controls the volatile organic calorific value of the sludge and suppresses the odor of sludge cracking.

[0049] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A negative pressure drying device, characterized in that: It includes a drying main body, a conveying device is provided in the drying main body, a heating pipe is provided at the bottom of the conveying device, one end of the heating pipe is connected to a first hot air source, a hot air inlet is provided at the bottom of the drying main body, and the hot air inlet is connected to a second hot air source through a pipeline, a feed port is provided at the top of the drying main body, sludge can pass through the feed port and fall onto the conveying device, a plurality of exhaust ports are also provided at the top of the drying main body, each of the exhaust ports is connected to an exhaust branch pipe, a negative pressure dehumidification fan and a temperature sensor are provided on the exhaust branch pipe, when the temperature sensor senses that the temperature in the drying main body reaches the expected temperature, the negative pressure dehumidification fan is turned on, and each of the exhaust branch pipes is connected to an exhaust main pipe, and the exhaust main pipe is connected to a gas treatment device at one end away from the exhaust branch pipe.

2. The negative pressure drying device according to claim 1, characterized in that: The conveying device is a mesh chain conveyor.

3. The negative pressure drying device according to claim 1, characterized in that: The expected temperature was 60°C.

4. The negative pressure drying device according to claim 1, characterized in that: A partition plate is fixed in the drying main body, and a plurality of hot air passing holes are provided on the partition plate.

5. The negative pressure drying device according to claim 1, characterized in that: A strip cutter is provided at one end of the feed inlet close to the drying main body.

6. The negative pressure drying device according to claim 1, characterized in that: The gas processing device includes a gas filter device and an exhaust fan. The gas filter device and the exhaust fan are connected via a negative pressure pipeline. The gas filter device is closer to the exhaust main pipe than the exhaust fan.

7. The negative pressure drying device according to claim 6, characterized in that: The gas filtration device includes a first spray tower and a second spray tower connected in sequence. The spray water source of the first spray tower and the second spray tower comes from a reclaimed water source. The water outlet of the second spray tower is connected to a reclaimed water discharge container. The reclaimed water in the reclaimed water discharge container can be poured into a hydro-generator, and the water at the hydro-generator flows into a sewage pool.

8. The negative pressure drying device according to claim 7, characterized in that: Activated carbon is provided in the first spray tower and the second spray tower.

9. The negative pressure drying device according to claim 1, characterized in that: A discharge port is provided on the side wall of the drying body, and a sealing door is provided at the discharge port.

10. The negative pressure drying device according to claim 9, characterized in that: Humidity sensors are provided at the feed inlet and the discharge outlet.

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