Sludge drying device

Abstract

The utility model provides a sludge drying device which comprises a drying bin internally provided with a stirring shaft, heating strips are installed on the inner wall of the drying bin, a sludge inlet and a sludge outlet are formed in the drying bin, the drying bin is cylindrical, the side wall of the drying bin is a hollow layer, and a steam channel surrounding the drying bin is arranged in the hollow layer. A steam inlet of the steam channel is communicated with the interior of the drying bin, a steam outlet of the steam channel is connected with the sewage purification device, and a steam extraction fan is installed in the sewage purification device. High-temperature steam can heat the inner wall of the drying bin when passing through the steam channel, the temperature is gradually reduced, the drying bin can be evenly and gradually heated through the steam channel, heat in the steam can be fully absorbed by the drying bin, and the heat utilization efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of environmental cleanup, and in particular to a sludge drying device that can fully utilize the steam heat generated during sludge heating. Background Technology

[0002] Many enterprises in industries such as printing and dyeing, electroplating, hardware, pharmaceuticals, circuit boards, food, and chemicals generate wastewater during their production processes. This wastewater poses a significant threat to the environment and, according to national regulations, must be treated into purified water before discharge. The suspended impurities and colloidal particles in the wastewater, after being dewatered by a plate and frame filter press or screw press, form sludge. However, even after sedimentation or pressing, the sludge still has a relatively high water content, generally around 50% to 80%. Therefore, whether the sludge is reused or landfilled, its water content must be reduced to below 30% to minimize pollution and transportation costs during transport.

[0003] The commonly used method for sludge drying is heat dehumidification, which involves heating and drying sludge with high water content. After removing the predetermined amount of water, subsequent treatments are carried out, such as landfilling or use as fertilizer.

[0004] Taking CN222331771U patent as an example, it discloses a sludge drying and recycling structure. The sludge is treated by drying, stirring and heating in a drying drum. At the same time, the hollow jacket sidewall of the drying drum is used to utilize steam heat energy. This solution can accelerate the drying speed of sludge and thus reduce drying costs.

[0005] However, by directly introducing steam into the interlayer of the drying cylinder side wall, the steam cannot form a good circulation. Utility Model Content

[0006] The purpose of this invention is to provide a sludge drying device that can fully utilize the steam heat generated during sludge heating.

[0007] This utility model provides a sludge drying device, including a drying chamber with an internal stirring shaft, heating strips installed on the inner wall of the drying chamber, and a sludge inlet and a sludge outlet on the drying chamber.

[0008] The drying chamber is cylindrical with hollow side walls. A steam channel is arranged around the drying chamber inside the hollow layer. The steam inlet of the steam channel is connected to the interior of the drying chamber, and the steam outlet of the steam channel is connected to a sewage purification device. A steam extraction fan is installed inside the sewage purification device.

[0009] In one embodiment of this utility model, the steam channel is composed of a spiral plate wound in the hollow layer of the drying chamber, the pitch between the spiral plates ensures that the steam flow rate is ≤5m / s, and the inclination angle of the spiral plate relative to the drying chamber is 4~8 degrees.

[0010] In one embodiment of the present invention, the steam channel is composed of partitions spaced apart and vertically arranged in the sandwich layer of the drying chamber. One end of the partition is in contact with the top or bottom of the drying chamber, and the other end has an opening. The opening positions of adjacent partitions are opposite.

[0011] In one embodiment of this utility model, the partition is isolated into independent closed areas within the hollow layer at positions corresponding to each of the heating strips.

[0012] In one embodiment of the present invention, a drainage groove is provided at the bottom of the hollow layer, and an adsorbent layer is filled in the drainage groove. The end of the partition that contacts the bottom of the hollow layer is in contact with the adsorbent layer.

[0013] In one embodiment of this utility model, a flexible concave box is movably inserted into the drainage trough, the adsorbent layer is placed inside the flexible concave box, and the outer wall of the drying chamber is provided with a maintenance door for cleaning the steam passage in the hollow layer and a movable door for taking out and placing the flexible concave box.

[0014] In one embodiment of this utility model, a spraying device for spraying medicine or cleaning liquid into the steam channel is installed on the drying chamber at a position corresponding to the steam inlet. The spraying device is connected to the sewage purification device through a water suction pipe.

[0015] In one embodiment of this utility model, a debris cleaner is provided at the conveyor belt of the sludge. The debris cleaner includes a rotating shaft, multiple sets of arc-shaped rakes mounted on the rotating shaft, and a storage box for holding debris.

[0016] In one embodiment of this utility model, the number of the arc-shaped rake groups is 4 to 6, the angle between the arc-shaped rake groups and the rotating shaft is 45 degrees, and the rake blades in the arc-shaped rake groups are mounted on the rotating shaft by an adjustable limiting device.

[0017] In one embodiment of the present invention, the adjustable limiting device includes a trapezoidal fixing block on which the rake blade is mounted, and a fixing bolt that passes radially through the fixing block. A slot is provided on the rotating shaft, the slot including an insertion section into which the fixing block can be inserted, and an adjustment section to prevent the fixing block from radially disengaging.

[0018] In this invention, high-temperature steam heats the inner wall of the drying chamber as it passes through the steam channel, gradually decreasing in temperature. The steam channel ensures uniform and gradual heating of the drying chamber, allowing it to fully absorb the heat from the steam. This avoids the problem in existing technologies where steam directly enters the entire hollow layer, resulting in uneven distribution of steam at different temperatures and some steam escaping from the outlet without fully utilizing its heat. A steam extraction fan can adjust the residence time of the steam within the steam channel, improving heat utilization efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the sludge drying device of this utility model;

[0020] Figure 2 This is a schematic diagram of a steam channel structure formed by a winding plate in one embodiment;

[0021] Figure 3 This is a schematic diagram of a steam channel structure formed by partitions in one embodiment;

[0022] Figure 4 This is a schematic diagram of the enclosed area structure formed by the partitions in one embodiment;

[0023] Figure 5 This is a schematic diagram of the structure of the flexible concave box in one embodiment;

[0024] Figure 6 This is a schematic diagram of the debris cleaner in one embodiment;

[0025] Figure 7 This is a schematic diagram of the installation of the adjustable limit block of the rake blade in one embodiment;

[0026] Figure 8 This is a schematic diagram of a slot structure on a rotating shaft in one embodiment. Detailed Implementation

[0027] The specific structure and implementation process of this solution are described in detail below through specific embodiments and accompanying drawings. This solution is an improvement on the existing drying equipment. For structural descriptions of parts not involved in the improvement, please refer to the prior art, such as patent CN 222331771 U. The following only describes the improvement points of this solution in detail.

[0028] like Figure 1As shown, in one embodiment of this utility model, a sludge drying device is disclosed, including a drying chamber 1 with an internal stirring shaft 11. Heating strips 12 are installed on the inner wall of the drying chamber 1. The drying chamber 1 is connected to a sludge feed pipe (belt) 2 and a sludge discharge pipe (belt) 3. In this embodiment, the drying chamber 1 is cylindrical with a hollow sidewall 13. A steam channel 14 is arranged around the drying chamber 1 within the hollow layer 13. The steam inlet 141 of the steam channel 14 communicates with the interior of the drying chamber 1, and the steam outlet 142 of the steam channel 14 is connected to a wastewater purification device. A steam extraction fan is installed inside the wastewater purification device (not shown in the figure).

[0029] The working process is as follows: The sludge to be dried enters the drying chamber 1 through the sludge feed pipe 2 via the conveying device 4. The sludge is heated by the heating strip 12 in the drying chamber 1. During the heating process, the stirring shaft 17 is driven to stir the sludge with the stirring blades 171 on it, so that the sludge inside is fully heated. Finally, the water content in the sludge is reduced from 50%~80% to below 30%. The water content in the final discharged sludge can be adjusted according to specific requirements.

[0030] The steam generated during the sludge drying process enters the hollow layer 13 of the drying chamber 1 through the steam inlet 141, and after swirling around the drying chamber 1 along the steam channel 14, it is discharged through the steam outlet 142 to the wastewater purification device for wastewater purification and gas treatment.

[0031] In this design, high-temperature steam heats the inner wall of the drying chamber 1 as it passes through steam channel 14, gradually reducing the temperature. Steam channel 14 ensures uniform and gradual heating of the drying chamber 1, allowing it to fully absorb the heat from the steam. This avoids the problem in existing technologies where steam directly enters the entire hollow layer 13, resulting in uneven steam distribution at different temperatures and some steam escaping from the steam outlet 142 before its heat is fully utilized. A steam extraction fan can adjust the residence time of the steam within steam channel 14, improving heat utilization efficiency.

[0032] like Figure 2 As shown, in one embodiment of the present invention, the steam channel 14 is composed of a spiral plate 143 that is spirally wound inside the hollow layer 13 of the drying chamber 1. If two spiral plates 143 are spaced apart and arranged side by side in the hollow layer 13, a spirally rising and falling steam channel 14 is formed, and the steam can be fully heated by circulating around the drying chamber 1 along the steam channel 14.

[0033] The pitch between the two winding plates 143 can be set according to the size of the drying chamber 1 and the steam flow rate. For example, in this scheme, the steam flow rate is controlled to be ≤5m / s. In addition, in order to facilitate the smooth discharge of wastewater in the steam from the hollow layer 13, the tilt angle of the winding plates 143 relative to the drying chamber 1 is 4~8 degrees in this scheme.

[0034] like Figure 3 As shown, in another embodiment of this utility model, the steam channel 14 can be composed of partitions 144 spaced apart and vertically arranged in the sandwich layer 13 of the drying chamber 1. The number and spacing of the partitions 144 are set according to the size of the drying chamber 1 and the flow rate of the steam channel 14. One end of the partition 144 contacts the top or bottom of the drying chamber 1, and the other end has an opening. The opening positions of adjacent partitions 144 are opposite. Through the steam channel 14 formed by the spaced partitions 144, the steam can move more evenly in the steam channel 14 and gradually release heat, so that the heat is utilized more fully.

[0035] like Figure 4 As shown, in order to prevent the steam in the hollow layer 13 from absorbing the heat at the heating band 12, the partition 144 isolates the positions in the hollow layer 13 corresponding to each heating strip 12 into corresponding independent closed areas 15. The closed areas 15 can limit the heat transferred from the heating band 12 to the hollow layer 13 within the area and reduce the heat absorbed by the steam when passing through the heating band 12.

[0036] In various embodiments of this solution, the outer surface of the drying chamber 1 on one side of the hollow layer 13 can be coated with heat insulation material, or the outer surface of the drying chamber 1 can be made directly with heat insulation material, which can reduce the loss of internal heat.

[0037] In one embodiment of this invention, to facilitate the discharge of wastewater condensed by steam within the steam channel 14 formed by the partition 144, a drainage trough 16 is provided at the bottom of the hollow layer 13. The drainage trough 16 is filled with an adsorbent layer 161, which can be made of materials such as silica gel, activated carbon, zeolite, or molecular sieves. The end of the partition 144 located at the bottom of the hollow layer 13, which needs to be sealed, contacts the adsorbent layer 161 to prevent steam from being directly discharged from this point. The adsorbent layer 161 can contain wastewater and discharge it into the purification treatment device through the steam outlet 142.

[0038] like Figure 5 As shown, furthermore, to facilitate the replacement of the adsorbent layer 161, a flexible recessed box 162 is movably inserted into the drainage trough 16, and the adsorbent layer 161 is placed inside the flexible recessed box 162. The flexible recessed box 162 can be made of a high-temperature resistant organic material, and its shape can be the same as that of the drainage trough 16, allowing it to be directly inserted into the drainage trough 16 from one end and easily moved along it. After the adsorbent layer 161 has been used for a period of time, the flexible recessed box 162, along with the adsorbent layer 161, can be directly pulled out of the drainage trough 16. At this time, the adsorbent layer 161 can be replaced or cleaned. After cleaning, the flexible recessed box 162, along with the adsorbent layer 161, can be inserted back into the drainage trough 16.

[0039] To facilitate cleaning of the steam passage 14, a maintenance door for cleaning the steam passage 14 inside the hollow layer 13 is provided on the outer wall of the drying chamber 1. The number and location of the maintenance door are determined according to the specific location of the steam passage 14, and multiple maintenance doors can be provided. Furthermore, to facilitate the loading and unloading of the flexible concave box 162, a movable door leading to the hollow layer 13 can be provided at the bottom of the drying chamber 1; multiple movable doors can also be provided. Alternatively, the flexible concave box 162 can be directly loaded and unloaded using the steam outlet 142.

[0040] In one embodiment of this utility model, to facilitate cleaning of the steam passage 14, a spraying device 5 is installed at the position corresponding to the steam inlet 141 in the drying chamber 1 to spray medicine or cleaning liquid into the steam passage 14. The spraying device 5 is connected to a wastewater purification device through a suction pipe. The spraying device 5 is turned on as needed. The spraying device 5 can use a specific solution for dissolving medicine, or it can directly extract water purified by the purification device to reduce costs through recycling.

[0041] In one embodiment of this utility model, a debris cleaner 6 is provided at the sludge inlet of the sludge feed pipe. The debris cleaner 6 is used to remove debris mixed in with the sludge, such as plastic bags, wooden sticks, iron wires, etc. Figure 6 As shown, the specific debris cleaner 6 includes a rotating shaft 61, multiple sets of arc-shaped rakes 62 mounted on the rotating shaft 61, and a collection box 63 for holding debris. The specific installation position of the debris cleaner 6 can be set at the sludge inlet 2 or at the conveyor belt 4 for conveying sludge, and the direction of movement of the arc-shaped rakes 62 after installation is perpendicular to the direction of sludge conveying.

[0042] During operation, the rotating shaft 61 rotates, driving the arc-shaped rake assembly 62 to cut into the sludge, thereby hooking out any debris that may be present in the sludge. As the arc-shaped rake assembly 62 rotates to the other side, the debris falls naturally into the collection box 63 on one side. The debris cleaner 6 can be manually controlled to start depending on the type of sludge.

[0043] In this embodiment, the number of arc-shaped rake groups 62 is 4 to 6, evenly distributed around the circumference of the rotation axis 61, and the angle between each arc-shaped rake group 62 and the rotation axis 61 is 30 to 45 degrees. Figure 7 As shown, each arc-shaped rake group 62 can have 3 to 6 rake blades 621. The distance between each rake blade 621 in the same arc-shaped rake group 62 can be adjusted. In this embodiment, each rake blade 621 in each arc-shaped rake group 62 is mounted on the rotating shaft 61 by an adjustable limiting device 63. The distance between each rake blade 621 can be adjusted within a certain range by the adjustable limiting device 64.

[0044] like Figure 7 , 8As shown, the adjustable limiting device 63 of this solution includes a trapezoidal fixing block 631, on which a radially penetrating fixing bolt 632 is installed. A slot 64 is provided on the rotating shaft 61. The slot 64 includes a rectangular insertion section 641 and an adjustment section 642 with an internal trapezoidal cross-section corresponding to the shape of the fixing block 631. The fixing block 631 is inserted into the slot 64 through the insertion section 641, then moves laterally into the adjustment section 642, and is locked by the adjustment section 642, preventing it from radially dislodging and allowing only axial movement. After determining the position, the position is fixed by the fixing bolt 631 on the fixing block 631. The rake blades 621 are fixed to the upper surface of the fixing block 631 by welding or bolting. The spacing between the two rake blades 621 can be adjusted by adjusting the position of the fixing block 631 within the adjustment section 642.

[0045] In this design, the slot 64 is perpendicular to the movement direction of the rake blades 621, so the fixed block 631 will not move axially after fixing. This also allows for easy adjustment of the distance between the rake blades 621 according to the properties of debris in different sludge samples, thus improving debris removal. Furthermore, the adjustable limit device 63 facilitates the removal of the rake blades 621 for maintenance.

[0046] Furthermore, to enhance safety, the debris cleaner 6 also includes an external mesh protective cover (not shown in the figure). The mesh protective cover surrounds each arc-shaped rake assembly 62 and the rotating shaft 61. A movable door can be installed on the mesh protective cover for maintenance 6 of the internal arc-shaped rake assembly 6. At the same time, a control box for controlling the operation of the debris cleaner 6 is installed so that the operator can determine whether to start the debris cleaner based on the type of sludge.

[0047] Furthermore, a flushing device (not shown in the figure) can be installed inside the debris cleaner 6 to clean the sludge adhering to the arc-shaped rake assembly 62. In this solution, the water nozzle of the flushing device is installed on one side of the sludge conveyor belt 4, with the water outlet direction facing the rotation direction of the arc-shaped rake assembly 62. This not only washes away the sludge on the arc-shaped rake assembly 62, but also washes away any debris that may adhere to the rake blades 621. The scooped-out debris and sludge can fall directly into the collection box 63 below, or a receiving inclined conveyor trough can be installed to transfer the fallen debris or sludge into the collection box 63.

[0048] Therefore, those skilled in the art should recognize that although many exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A sludge drying device, comprising a drying chamber with an internal stirring shaft, heating strips installed on the inner wall of the drying chamber, and a sludge inlet and a sludge outlet provided on the drying chamber, characterized in that, The drying chamber is cylindrical with hollow side walls. A steam channel is arranged around the drying chamber inside the hollow layer. The steam inlet of the steam channel is connected to the interior of the drying chamber, and the steam outlet of the steam channel is connected to a sewage purification device. A steam extraction fan is installed inside the sewage purification device.

2. The sludge drying device according to claim 1, characterized in that, The steam channel is composed of spiral plates wound in the hollow layer of the drying chamber. The pitch between the spiral plates ensures that the steam flow rate is ≤5m / s, and the inclination angle of the spiral plates relative to the drying chamber is 4~8 degrees.

3. The sludge drying device according to claim 1, characterized in that, The steam passage is composed of partitions spaced apart and vertically arranged in the sandwich layer of the drying chamber. One end of the partition is in contact with the top or bottom of the drying chamber, and the other end has an opening. The openings of adjacent partitions are in opposite positions.

4. The sludge drying device according to claim 3, characterized in that, The partition isolates each heating strip within the hollow layer into an independent, enclosed area.

5. A sludge drying device according to claim 3, characterized in that, A drainage trough is provided at the bottom of the hollow layer, and an adsorbent layer is filled in the drainage trough. The end of the partition that contacts the bottom of the hollow layer is in contact with the adsorbent layer.

6. A sludge drying device according to claim 5, characterized in that, A flexible concave box is movably inserted into the drainage trough, and the adsorbent layer is placed inside the flexible concave box. The outer wall of the drying chamber is provided with a maintenance door for cleaning the steam passage in the hollow layer, and a movable door for taking out and placing the flexible concave box.

7. The sludge drying device according to claim 1, characterized in that, A spraying device is installed on the drying chamber at a position corresponding to the steam inlet to spray medicine or cleaning liquid into the steam channel. The spraying device is connected to the wastewater purification device through a water suction pipe.

8. A sludge drying device according to claim 1, characterized in that, A debris cleaner is installed at the sludge conveyor belt. The debris cleaner includes a rotating shaft, multiple sets of arc-shaped rakes mounted on the rotating shaft, and a collection box for holding debris.

9. A sludge drying device according to claim 8, characterized in that, The number of arc-shaped rake groups is 4 to 6, the angle between the arc-shaped rake group and the rotating shaft is 45 degrees, and the rake blades in the arc-shaped rake group are mounted on the rotating shaft by an adjustable limiting device.

10. A sludge drying device according to claim 9, characterized in that, The adjustable limiting device includes a trapezoidal fixing block on which the rake blade is mounted, and a fixing bolt that passes radially through the fixing block. A slot is provided on the rotating shaft, the slot including an insertion section into which the fixing block can be inserted, and an adjustment section to prevent the fixing block from radially disengaging.

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