CN112479541B

CN112479541B - Sludge drying device and use method thereof

Info

Publication number: CN112479541B
Application number: CN201910864513.XA
Authority: CN
Inventors: 谭玮
Original assignee: Guangzhou Zhengsheng Technology Co ltd
Current assignee: Guangzhou Zhengsheng Technology Co ltd
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2024-05-24
Anticipated expiration: 2039-09-12
Also published as: CN112479541A

Abstract

The invention provides an axial air supply type sludge drying device which comprises a shell, wherein a drying chamber is arranged in the shell, and is provided with a sludge feed inlet, a tail gas exhaust port and a sludge discharge port; a flipping unit having a flipping assembly; the axial air supply assembly comprises an air supply pipe with an axial hole and an air vent, a spiral piece with shaft holes with different inner diameters, and a rotating shaft, wherein the spiral piece is fixedly connected with the rotating shaft through a part of the shaft holes; the axial air supply assembly is arranged at the lower part of the drying chamber of the shell, the turning device is arranged above the axial air supply assembly, and the discharge hole on the end wall of the shell is arranged between the turning device and the axial air supply assembly. The invention also provides a method for drying sludge by using the axial air supply type sludge drying device.

Description

Sludge drying device and use method thereof

Technical Field

The application relates to the field of sludge drying, in particular to an axial air supply type sludge drying device for sludge treatment and a method for drying sludge by using the axial air supply type sludge drying device.

Background

At present, common sludge treatment devices are indirect and direct drying equipment. The indirect drying apparatus is to convey steam, hot oil or hot water into a hollow shaft and a stirring blade running in a drying chamber to heat the shaft and the stirring blade, and then transfer heat to wet sludge in the drying chamber by using a heat conduction hollow shaft and the stirring blade to evaporate moisture in the sludge and gradually dry the same. However, since heat transfer is achieved by the flow of hot oil or steam at high temperature in the hollow shaft and the stirring blades, the stirring blades are easily worn and broken, and the treated sludge has high water content and high tackiness. This results in not only a high failure rate of the sludge treatment equipment, high energy consumption, but also a very low drying efficiency of the sludge. The direct drying apparatus directly acts hot air on sludge to evaporate moisture in the sludge, but the heat transfer efficiency is improved, but the ventilation holes are easily blocked due to high viscosity of the sludge, which not only affects the stability of the drying process, but also makes it difficult to realize sludge reduction due to uneven drying of the sludge, and the drying efficiency of the sludge is low, resulting in failure to dry a large amount of sludge.

Therefore, it is necessary to provide a sludge drying device with low energy consumption, small volume and high drying efficiency and a use method thereof.

Disclosure of Invention

In order to overcome the drawbacks of the prior art, the present invention proposes a fluid transfer assembly for a sludge treatment device, which may be arranged in a chamber or treatment chamber of the sludge treatment device and which comprises a fluid transfer tube having an axial bore, a screw member having a shaft bore of at least a first inner diameter and a second inner diameter, and a rotation shaft, wherein the screw member is fixedly connected together by means of the shaft bore of the first inner diameter and the rotation shaft, and a part of the screw member is rotatably nested on the fluid transfer tube by means of the shaft bore of the second inner diameter, and a part of the rotation shaft is rotatably arranged in the axial bore of the fluid transfer tube. The rotating shaft may be connected to the driving means at an end adjacent to the connection portion of the rotating shaft to the screw member, and the fluid delivery tube may be connected to the fluid supply means at an end remote from the rotating shaft, so that after the rotating shaft and the screw member are fitted to the delivery tube, the rotating shaft, the screw member and the delivery tube remain substantially on the same axis, whereby the fluid delivered into the axial bore of the fluid delivery tube can be distributed more uniformly or in a predetermined manner to the area adjacent to the fluid delivery tube. The spiral piece can rotate relative to the fluid conveying pipe under the driving of the rotating shaft while conveying the fluid into the cavity. The fluid conveying assembly not only can distribute fluid to the cavity through the fluid conveying holes distributed on the pipe wall of the fluid conveying pipe, but also can continuously scrape or clean sludge attached to the pipe wall through the rotation of the spiral piece, so that the smooth flow of the fluid is ensured.

The invention also provides an axial air supply type sludge drying device, such as a single-body type axial air supply type sludge drying device. The axial air supply type sludge drying device comprises a shell with a drying chamber, a feeding hole, an exhaust hole and a discharging hole, wherein the feeding hole is arranged at the upper part of the drying chamber and used for drying sludge to be dried, the exhaust hole is used for discharging drying gas after drying the sludge, and the discharging hole is far away from the feeding hole and is arranged on the end wall of the drying chamber and used for drying the sludge; a flipping unit having at least one flipping assembly; and an axial air supply assembly. The axial air supply assembly is arranged at the lower part of the drying chamber in the vertical direction, the turning device is arranged above the axial air supply assembly, and the discharge hole is positioned between the turning device and the axial air supply assembly. The sludge is frequently contacted with the drying gas through the direct action of the drying gas from the axial air supply assembly on the sludge at the lower part of the drying chamber, the stirring or stirring and pushing of the sludge by the spiral piece of the axial air supply assembly, and the continuous shearing, crushing and stirring of the sludge by the stirring assembly of the stirring device, so that the problem of uneven internal and external drying degrees in the sludge drying process is solved.

The invention also provides a method for drying sludge by using the axial air supply type sludge drying device, which comprises the steps of driving a turning device arranged in a drying chamber of the sludge drying device to enable a turning component of the turning device to rotate around a rotating shaft of the turning device, so as to turn, shear and crush sludge entering through a feed inlet of the drying chamber and located in the drying chamber. The air supply device is started to send the drying gas for the sludge to be dried into the air supply pipe of the air supply assembly arranged in the drying chamber and make the drying gas enter the drying chamber. The induced draft device is started to discharge the drying gas of the dried sludge through an exhaust port positioned at the upper part of the drying chamber. The air supply assembly is driven to rotate the rotating shaft, and the spiral piece which is sleeved on the air supply pipe and connected with the rotating shaft is driven to rotate relative to the air supply pipe, so that sludge attached to the pipe wall of the air supply pipe is scraped, and the sludge is turned and pushed to move towards a discharge hole which is arranged on the end wall of the drying chamber and positioned between the turning device and the air supply assembly. The dried sludge is discharged from the discharge hole of the drying chamber under the synergistic effect of the turning device and the air supply component. The drying gas is conveyed into the drying chamber through the air supply assembly, so that the drying gas permeates into the sludge, and the sludge is continuously crushed and loosened in the running process along with the turning, shearing, crushing, pushing and the turning and pushing of the spiral piece of the air supply assembly of the turning device, thereby being beneficial to increasing the direct contact area of the drying gas and the sludge and improving the drying efficiency.

In the axial air supply type sludge drying device, the spiral piece in the air supply assembly rotates relative to the air supply pipe, so that sludge attached to the pipe wall of the air supply pipe can be effectively scraped and removed, further, the ventilation hole of the air supply pipe is prevented from being blocked, the spiral piece turns and pushes the sludge, the contact frequency of the sludge and drying gas can be increased, the drying efficiency is improved, the bottom of the drying chamber is used for configuring the design of an arc-shaped channel of the axial air supply assembly, and the position of the discharge hole is arranged, so that the operation of the sludge along the longitudinal direction of the shell or the drying chamber is facilitated, the sludge is continuously turned in the continuous accumulation of the dried sludge, and the drying process of the sludge is further accelerated. In the application of the invention, the axial air supply type sludge drying device can be designed into a single form, so that the sludge drying device with low energy consumption, small volume, compact structure and high drying efficiency can be obtained, and can be combined with other sludge treatment equipment. In the method for drying sludge by axial air supply, the moisture in the sludge is continuously evaporated by continuously inputting drying gas into a drying chamber and turning, shearing and crushing the sludge, so that the time for drying the sludge is shortened and the sludge reduction ratio is improved.

Specifically, the invention provides an axial air supply type sludge drying device, which comprises:

A housing, in which a drying chamber is formed. A feed inlet for the sludge to be dried and an exhaust outlet for the drying gas after drying the sludge are provided on the upper part or the top of the drying chamber, and a discharge outlet for the dried sludge is provided on the end wall of the drying chamber away from the feed inlet. At least one flipping device, wherein the at least one flipping device has at least one flipping assembly. An axial air supply assembly comprising an air supply tube for delivering air, the air supply tube having an axial bore and first and second ends and at least one vent formed in a tube wall thereof, wherein the at least one vent is in fluid communication with the axial bore. A screw member having shaft holes of different inner diameters and first and second ends, wherein a first portion of the screw member having the shaft hole of the first inner diameter is located at the first end, and a second portion including the shaft hole of the second inner diameter extends from the first portion to the second end, the second inner diameter of the shaft hole of the second portion being larger than the outer diameter of the air supply duct. A rotating shaft having a first end and a second end, wherein a first portion of the rotating shaft is disposed in the shaft bore of the first portion of the screw member having the first inner diameter near the first end and fixedly coupled together, and a second portion of the rotating shaft extends from the first portion to the second end and is disposed in the shaft bore of the second portion of the screw member having the second inner diameter; the rotary shaft and the screw are fitted to the air supply duct from a first end of the air supply duct, wherein a second part of the rotary shaft is rotatably arranged in an axial hole of the air supply duct and a second part of the screw is rotatably nested on the air supply duct. The axial air supply assembly is arranged at the lower part of the drying chamber, and the at least one turning device is arranged above the axial air supply assembly, wherein a discharge hole on the end wall is arranged between the at least one turning device and the axial air supply assembly.

According to the sludge drying device, one end of the axial air supply assembly can be connected with the driving device by means of the first end of the rotating shaft, and the other end of the axial air supply assembly can be fixedly connected with the air supply device by means of the second end of the air supply pipe, and the air supply pipe is in fluid communication with the air supply device, so that the rotating shaft and the spiral piece are driven to rotate relative to the air supply pipe.

According to the sludge drying apparatus described above, the first portion of the rotation shaft has a first diameter, and the second portion has a second diameter.

According to the sludge drying apparatus described above, the first diameter of the first portion of the rotary shaft is larger than or smaller than the second diameter of the second portion thereof, and the first inner diameter of the shaft hole of the first portion of the screw member is smaller than or larger than the second inner diameter of the shaft hole of the second portion thereof.

According to the sludge drying device, at least one large-diameter section is provided on at least a part of the second end rotating shaft, wherein the at least one large-diameter section is provided in the axial hole of the air supply pipe and its diameter is slightly smaller than the diameter of the axial hole.

According to the sludge drying apparatus, at least one large diameter section is two cylinders which are spaced apart and fixedly mounted on the rotating shaft.

According to the sludge drying device, the air supply device is a blower, a fan or a gas pressurizing device.

According to the sludge drying device, at least one large diameter section may be a sliding bearing or a rolling bearing.

According to the sludge drying device, the drying chamber is provided with the concave bottom, so that a longitudinal arc-shaped channel is formed in the longitudinal direction of the shell, and the axial air supply assembly is positioned in the longitudinal arc-shaped channel.

According to the sludge drying device, the shell comprises the shell body, the bottom plate and the cover, wherein the feed inlet and the exhaust outlet can be arranged on the upper part of the shell body or on the cover.

According to the sludge drying device, the bottom plate is connected with the lower edge of the shell body, and two longitudinal side edges of the bottom plate extend obliquely inwards from the lower edge of the shell body in the transverse direction, so that the concave bottom of the drying chamber is formed.

According to the sludge drying apparatus described above, the at least one turning assembly has at least one blade or ratchet extending radially outwardly from the rotational shaft for shearing, crushing and turning the sludge.

According to the sludge drying device, the at least one sludge stirring device comprises two sludge stirring devices which are arranged in parallel, and the two sludge stirring devices are positioned at the same height in the vertical direction and are symmetrically arranged relative to the vertical axis passing through the axis of the axial air supply assembly.

According to the sludge drying apparatus described above, at least one of the two sludge turning devices includes a plurality of turning assemblies, each of the plurality of turning assemblies being spaced apart by a distance, wherein each turning assembly has one or more blades or ratchet teeth extending radially outwardly from the rotational axis.

The sludge drying device according to the above, further comprising a heating device for heating the drying gas, wherein the heating device is located upstream or downstream of the air supply device.

According to the sludge drying device, the sludge drying device further comprises an induced air device, wherein the induced air device is communicated with a drying chamber through an exhaust port.

According to the sludge drying device, the drying chamber is provided with the flat bottom, and the air supply assembly can be positioned at any position near the flat bottom.

The invention also provides a method for drying sludge by using the axial air supply type sludge drying device, which comprises the following steps:

The turning device arranged in the drying chamber of the sludge drying device is driven to enable the turning assembly of the turning device to rotate around the rotating shaft of the turning device, so that sludge entering and located in the drying chamber through the feeding hole of the drying chamber is turned, sheared and crushed. The air supply device is started to send the drying gas for the sludge to be dried into the air supply pipe of the air supply assembly arranged in the drying chamber and make the drying gas enter the drying chamber. And starting the induced air device to enable the drying gas of the dried sludge to be discharged through an exhaust port of the drying chamber. The air supply assembly is driven to rotate the rotating shaft of the air supply assembly, and the spiral piece which is sleeved on the air supply pipe and connected with the rotating shaft is driven to rotate relative to the air supply pipe, so that sludge attached to the pipe wall of the air supply pipe is scraped, turned or stirred and pushed to move towards a discharge hole for dried sludge, which is arranged on the end wall of the drying chamber and is positioned at a discharge hole between the turning device and the air supply assembly. And accelerating the drying of the sludge under the synergistic effect of the turning device and the air supply assembly, drying the sludge and discharging the dried sludge from a discharge hole of the drying chamber.

According to the method for drying sludge, the method further comprises the step of adjusting the rotation speed and the rotation direction of the rotating shaft of the turning device.

The method for drying sludge further comprises the step of adjusting the rotation speed and/or the rotation direction of the rotating shaft of the air supply assembly.

The method for drying sludge according to the above further comprises the step of heating the drying gas of the sludge to be dried before entering the drying chamber by means of a heating device.

Drawings

The construction, advantages, and technical effects of the embodiments of the present application will be described in detail with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic perspective view, partially in section, of a fluid delivery assembly for a sludge treatment device;

FIG. 2 is a transverse cross-sectional view of the fluid delivery assembly of FIG. 1 taken along line M-M;

FIG. 3 is a transverse cross-sectional view of the fluid delivery assembly of FIG. 1 taken along line N-N;

FIG. 4 is a longitudinal cross-sectional view of the fluid delivery assembly of FIG. 1;

FIG. 5 is an exploded perspective view of the fluid delivery assembly of FIG. 1;

FIG. 6 shows a longitudinal cross-sectional view of an axial air-fed sludge drying apparatus having an air-feeding assembly;

FIG. 7 is a transverse cross-sectional view of the sludge drying apparatus of FIG. 6;

FIG. 8 is a partially cut-away perspective view of the sludge drying apparatus of FIG. 6;

fig. 9 is a partially cut-away perspective view of the housing of the sludge drying apparatus of fig. 6; and

Fig. 10 is a flow chart of an axial blowing sludge drying method.

Detailed Description

Fig. 1 shows an embodiment of a fluid delivery assembly for a sludge treatment device of the present application in a partially cut-away perspective view. Fig. 2 shows a cross-sectional view of the structure of the fluid delivery assembly of fig. 1 at the M-M position, and fig. 3 shows a cross-sectional view of the structure of the fluid delivery assembly of fig. 1 at the N-N position provided with a rotation axis. As shown, fluid delivery assembly S includes a fluid delivery tube or feed barrel 801, a rotatable shaft 802, and a screw 803. The screw 803 may also be referred to as a screw or a screw blade, and one end of the screw 803 is fixedly connected to the rotation shaft 802 and is fitted over the delivery pipe 801 from the other end thereof, wherein a portion of the rotation shaft 802 to which the screw 803 is connected is located outside the fluid delivery pipe 801, and another portion of the rotation shaft 802 is rotatably provided inside the fluid delivery pipe 801 such that a large portion of the screw 803 is rotatable around the fluid delivery pipe. During operation, fluid delivery tube 801 may be stationary and rotational shaft 802 may be rotated by a drive means such that spiral 803 rotates with rotational shaft 802 relative to delivery tube 801.

The fluid transfer tube 801 may be formed from a tubular member having an inner bore or axial bore, for example, the transfer tube may be a cylindrical tube having a central bore. One or more fluid delivery or feed holes 801b are formed in the wall of the delivery tube 801. The pipe wall penetrating delivery bore 801b is in fluid communication with the inner bore 801a of the delivery pipe 801 so that fluid can be delivered from one end of the delivery pipe 801 to the inner bore 801a and fluid entering the inner bore 801a flows out of the delivery pipe 801 through the pipe wall penetrating delivery bore 801b as shown by the arrows in fig. 2 and 3.

Fig. 4 and 5 illustrate the fluid delivery assembly of fig. 1 in a longitudinal cross-sectional view and an exploded perspective view, respectively. As shown, in the fluid delivery assembly S, a portion of the rotational shaft 802 is disposed in the inner bore 801a of the fluid delivery tube 801 and another portion thereof is located outside of the delivery tube 801, and thus, the entire length of the fluid delivery assembly S is substantially the sum of the length of the portion of the rotational shaft 802 located outside of the delivery tube and the length of the delivery tube 801. Referring to fig. 1 and 4, the second or right end of the rotational shaft 802 extends from the first or left end of the delivery tube 801 into its interior bore 801a distance, with the first or left end of the rotational shaft 802 and the second or right end of the delivery tube 801 serving as the two ends of the fluid delivery assembly S, respectively. Once the length of the rotational shaft 802 and the fluid delivery tube 801 is determined, the length of the rotational shaft 802 that extends into the bore 801a of the delivery tube 801 determines the overall length of the fluid delivery assembly S. In other words, by adjusting the length of the portion of the rotational shaft 802 that is located in the internal bore 801a of the delivery tube 801, the overall length of the fluid delivery assembly S can be varied.

In the embodiment shown in fig. 1-5, the inner bore or axial bore of the screw 803 has a different diameter, wherein a shorter portion with a small bore or first bore 803a, i.e. the small bore portion, is located at the first or left end of the screw 803, and a longer portion with a large bore or second bore 803b, i.e. the large bore portion is remote from the first end and extends from the small bore portion towards its second or right end. The small or first bore 803a of the screw 803 has an inner diameter corresponding to the diameter of the rotational shaft 802, while the large or second bore 803b has an inner diameter corresponding to the outer diameter of the delivery tube 801. The shorter or small hole portion at the first or left end of the spiral 803 may be fixed near the first or left end of the rotational shaft 802 by a known connection means such as welding or bonding. Since the aperture of the small hole portion of the screw 803 is substantially the same as the diameter of the rotation shaft 802, the screw 803 and the rotation shaft 802 can be connected by, for example, caulking, bolting, or the like by making a corresponding change in the structure of the connection portion thereof. The connection of the spiral 803 to the rotational shaft 802 is shown to cover the length of the spiral about two turns. It should be appreciated that the length of the small bore portion of the screw member may be designed as desired so that the length of the connection of the screw member 803 to the rotational shaft 802 is as short as possible, but the connection is secure. The diameter of the spiral 803 on the outer wall of the delivery tube 801 is greater than or slightly equal to the outer diameter of the delivery tube 801 so that the spiral 803 fits rotatably over the delivery tube 801. When the screw 803 is externally fitted over the delivery tube 801, a certain clearance should be maintained between the two so that the screw and the delivery tube do not interfere with each other when they are rotated relative to each other. In general, the length of the large hole portion of the spiral 803 is much longer than the length of the small hole portion thereof, and when the spiral 803 is overlapped on the conveying pipe 801, the large hole portion of the spiral 803 should cover the portion of the pipe wall of the conveying pipe 801 having the conveying hole 801b as much as possible. As shown, a substantial portion of the wall of the fluid transfer tube 801 is covered by the spiral 803, while at its second or right end only a small portion of the wall is exposed for use as a supported portion. Of course, it is also possible to attach another tube as the supported portion so that the spiral 803 can cover the entire wall of the fluid delivery tube 801. The transition or transition from the small hole portion of the spiral 803 having the first hole 803a to the large hole portion having the second hole 803b may be designed such that the transition of the spiral 803 (see the broken line portion in fig. 4) does not interfere with the first end portion or the left end portion of the conveying pipe 801 when the rotation shaft 802 is disposed in the conveying pipe 801. To help adjust the length of the shaft 802 extending into the bore 801a of the pipe 801, the transition between the first 803a and second 803b holes of the screw 803 may be separated from the first or left end of the pipe 801 by a distance. In another embodiment, the second bore of the screw may have a plurality of apertures.

The fluid delivery assembly S is typically disposed within a treatment chamber of a sludge treatment plant. In order to treat sludge in the sludge treatment chamber, fluid can be conveyed into the treatment chamber through the fluid conveying assembly S, and the sludge can be turned or moved at the right time. The fluid delivered by the fluid delivery assembly S may be a gas, a liquid, or other flowable substance. During the fluid transportation, the transportation hole 801b of the fluid transportation pipe 801 may be blocked due to the viscosity generated by the property of the fluid or the sludge or the interaction of the fluid and the sludge, and for this purpose, the sludge on the pipe wall of the transportation pipe 801 may be cleaned by the rotation of the screw 803 to smooth the flow of the fluid, and on the other hand, the frequency of the interaction of the sludge in the treatment chamber and the fluid entering the treatment chamber may be increased by the flipping or the movement, so that the uniformity, the fluidity, the viscosity, the cooling or the dryness of the sludge may be improved based on different needs. For example, when it is desired to dry the sludge in the treatment chamber, the drying gas may be delivered into the treatment chamber by the fluid delivery assembly S, that is, depending on the process requirements of the sludge to be treated in the treatment chamber. The fluid delivery assembly S may be disposed between opposing walls of the process chamber, such as opposing end walls or side walls, wherein one end of the rotatable shaft 802 extending out of the chamber, such as the left end, is coupled to the drive means, and one end of the fluid delivery tube 801, such as the right end, may be coupled to the fluid supply means so that fluid may be delivered by the fluid supply means to the internal bore 801a of the delivery tube 801. In operation, the driving device drives the rotation shaft 802 to rotate, so as to drive the spiral piece 803 sleeved outside the conveying pipe 801 to rotate relative to the conveying pipe, and fluid is supplied from the fluid supply device at the other end of the conveying pipe 801, so that the fluid is conveyed into the processing chamber from the outside through the fluid conveying assembly. As described above, the conveying unit S may be provided in the sludge treatment chamber in the longitudinal direction of the sludge treatment chamber or in the width direction thereof. Alternatively, one or more transport assemblies may be provided in one sludge treatment chamber. The spiral piece 803 of each conveying component S in the sludge treatment chamber can clean sludge on the pipe wall of the conveying pipe 801, can also generate turning and moving functions on the sludge, and can be independently provided with a driving device and a fluid supply device for each conveying component when a plurality of conveying components S are arranged, or can be connected with one or a plurality of driving devices or fluid supply devices through a connecting mechanism so as to realize independent or combined control on each conveying component. Of course, providing a transfer assembly along the longitudinal direction of the sludge treatment chamber helps to run the fluid into the interior bore 801a of the fluid transfer tube 801a longer distance along the length of the sludge treatment chamber, and thus can enter the sludge treatment chamber through transfer holes 801b distributed on the walls of the transfer tube 801, thereby facilitating interaction between the fluid and the sludge.

Referring to fig. 5, in the fluid delivery assembly S, in addition to reserving the necessary spatial positions for supporting the rotation shaft, passing through the wall of the hollow chamber, and/or installing the driving part, etc., the left end or first end of the screw 803 may be as close as possible to the left end or first end of the rotation shaft 802, and fixedly attached to the rotation shaft 802, and ensure that the rotation shaft 802 coincides with the axis of the inner hole of the screw 803, so that when the rotation shaft 802 and the screw 803 are attached and fitted to the fluid delivery tube 801, the rotation shaft 802, the large hole 803b of the screw 803 and the inner hole 801a of the delivery tube 801 remain substantially on the same axis, that is, during operation of the fluid delivery assembly S, the gap between the inner walls of the large holes 803b of the spiral 803 and the wall of the delivery tube 801 is sufficient to both scrape off sludge adhering to the wall and to avoid contact of the spiral with the wall. Since the longitudinal dimension of the screw member is much larger than the rotational axis, when the rotational axis rotates the screw member, the right or second end of the screw member 803 may swing laterally or radially relative to the left or first end thereof, and thus may scrape against the wall of the pipe 801. In order to substantially coincide or align the axes of the rotating shaft and the screw member as they rotate relative to the fluid transfer tube, two spaced apart large diameter sections 804 may be provided adjacent to the left or first end of the rotating shaft 802 that extends into the bore 801a of the transfer tube 801. The large diameter section 804 has a diameter slightly smaller than or close to the diameter of the inner bore 801a of the pipe 801 so as to be corrected when the spiral 803 is oscillated radially as described above, thereby achieving centering so that the spiral 803 can smoothly scrape the sludge on the pipe wall of the pipe 801 during operation. As shown, each large diameter section 804 may be a separate component and fixedly mounted on the rotating shaft 802. In yet another embodiment, the number of large diameter sections 804 may be one or more than two. In addition, the diameter of the rotating shaft 802 may be designed as desired, for example, the diameter of the rotating shaft 802 may be equal to the outer diameter of the delivery tube 801 or slightly smaller than the inner diameter of the inner bore 801a of the delivery tube 801, and the diameter of the small hole 803a of the screw 803 connected thereto and the diameter of the portion of the rotating shaft 802 protruding into the inner bore 801a of the delivery tube 801 may be adjusted accordingly, thereby assembling the fluid delivery assembly S according to the disclosure herein. Of course, the use of a small diameter shaft 802 with a large diameter section 804 as shown is advantageous for reducing the weight of the shaft and for maintaining the alignment of the tube 801 with the shaft 802 on the same axis by the large diameter section 804, thereby preventing the shaft from swinging laterally or radially and thereby avoiding scraping the wall of the tube 801. In another embodiment, the large diameter section 804 may be a sliding bearing or rolling bearing fitted within the delivery tube. Typically, the plurality of delivery holes 801b may be arranged or aligned in a regular or irregular manner on the wall of the delivery tube 801 to provide a more uniform distribution of fluid to the area surrounding the delivery tube. In yet another embodiment, directional distribution of fluid into the sludge treatment chamber may be achieved by providing different numbers or different apertures of the transfer holes 801b at different locations on the wall of the transfer tube. For example, the number of delivery holes may be gradually increased or decreased from one end of the delivery tube to the other end along the axis of the delivery tube, or the aperture of the delivery holes may be gradually increased or decreased. In addition, the shape and size of the delivery orifice may be arbitrarily determined based on the need.

Fig. 6 shows an embodiment of a axially air-fed sludge drying apparatus with an air-feeding assembly in a longitudinal section, while fig. 7 shows the sludge drying apparatus shown in fig. 6 in a transverse section. As described above, the fluid delivery assembly S may deliver both liquid and gas, and thus, as an example, is used to deliver gas in the sludge drying apparatus 1, and thus, may be referred to as a blower assembly or a ventilation assembly 8.

As shown, the axial blowing sludge drying apparatus 1 has a housing, which includes, for example, a body 2, a cover 3, and a bottom plate 4, and a space inside the housing constitutes a drying chamber 6 for drying sludge. In addition, the housing may be constructed from multiple components or in a variety of ways, for example, the body 2 may be integrally formed with the base plate 4, or the like. The upper portion of the housing is rectangular in shape, but may be square, polygonal, oval or other shape. A feed port 11 for feeding sludge to be dried or dried into the drying chamber and an exhaust port 13 for exhausting tail gas or dry gas after drying the sludge are provided on the cover 3, respectively, and a discharge port 12 for discharging the dried sludge is provided on the end wall of the body 2 at a position approximately midway away from the feed port 11. In another embodiment, the inlet 11 and the outlet 13 may be provided at desired positions on the cover 3 or the body 2, respectively, as needed, in other words, they may be located at arbitrary positions on the upper portion of the drying chamber 6, while the outlet 12 may be provided on the side wall, or near the bottom portion of the drying chamber, etc. The body 2 may be secured to the base plate 4 by a common connection such as welding, riveting or bolting.

The sludge drying apparatus 1 further comprises two turning devices 7a, 7b and an air supply assembly 8 arranged in the housing for turning, crushing and shearing sludge, wherein the air supply assembly 8 may be arranged in the middle or near the bottom of the drying chamber 6, and the turning devices 7a, 7b are arranged above and parallel to the air supply assembly 8. In order to deliver as much drying gas as possible into the drying chamber 6 of the sludge drying apparatus, the air supply assembly 8 is usually arranged in the longitudinal direction of the drying chamber 6, for example substantially horizontally or parallel to the floor 4 of the drying chamber. During the drying gas entering the drying chamber through the air supply assembly 8, the spiral 803 rotates relative to the air supply pipe 801 as the rotating shaft 802 rotates, so that the spiral 803 can scrape the sludge adhered to the pipe wall of the air supply pipe 801 to keep the vent hole 801b smooth, and can push the sludge to move towards one end of the drying chamber 6, for example, to move towards the end wall with the discharge port 12. One end of the air blowing assembly 8, that is, an end of the rotation shaft 802 thereof is rotatably supported in a shaft hole 5c formed on one end wall of the drying chamber 6, and the other end thereof, that is, an end of the air blowing pipe 801 thereof is fixedly supported in a shaft hole 5d formed on the other end wall of the drying chamber 6. In another embodiment it is also possible to have both ends of the air supply assembly 8 extend through the shaft holes 5c and 5d, respectively, beyond the opposite end walls, wherein the end, e.g. the right end, of the rotation shaft of the air supply assembly 8 is rotatably supported on an external bearing means, and in turn the rotation shaft 802 is connected to the driving means, while the end, e.g. the left end, of its air supply duct 801 is connected to the air supply means 10 by means of the connecting means 9. Since the drying gas is transported along the length or longitudinal direction of the housing of the sludge drying apparatus 1 by the inner hole or axial hole 801a of the blast pipe 801 of the blast module 8, the blast module 8 may also be referred to as an axial blast module. Since the air blowing assembly 8 is substantially the same as the fluid delivery assembly S described above, the construction of the air blowing assembly 8 is not repeated.

The bottom plate 4 of the housing is a curved plate having an arc shape, wherein the curved plate is fixedly connected with the lower end of the side wall of the rectangular body 2, and the middle of the curved plate is concave downward as seen from the transverse direction, i.e. the two side edges of the body are respectively inclined downward toward the middle and converged in the arc shape. In the cross section of the housing, the two longitudinal sides of the housing taper diagonally inward and transition to an arcuate bottom at the junction of the body 2 and the floor 4 generally above the air moving assembly. The bottom region of the drying chamber 6 is recessed laterally as seen from the inside of the housing, so that a longitudinal arc-shaped channel is formed in the longitudinal direction, in which the air supply assembly 8 is arranged. For example, the bottom of the drying chamber 6 may be formed in a circular arc shape, and the radius of the circular arc may be slightly larger than the radius of the spiral 803 of the air blowing assembly so that a uniform interval or gap is maintained between the spiral 803 and the bottom of the drying chamber. The air supply assembly 8 is rotatably disposed in shaft holes 5c and 5d formed in two opposite end walls of the drying chamber and corresponding to the longitudinal arc-shaped passages, respectively, wherein an end portion, e.g., a right end, of the rotation shaft 802 of the air supply assembly 8 extends outwardly from the hole 5c in the right end wall of the drying chamber 6 and is connectable to the driving means by means of a power input 14c provided thereon, and an end portion, e.g., a left end, of the air supply pipe 801 thereof extends outwardly from the hole 5d in the left end wall of the drying chamber 6 and is connected to and in fluid communication with the air supply means 10 by means of the connecting means 9. The air supply device may be a blower, a fan, a gas pressurizing device, or the like. Similar to the fluid delivery assembly S described above, in the air blowing assembly 8, the right end portion of the spiral 803 is mounted near and fixedly connected to the right end portion of the rotating shaft 802 by its small hole, and most of the left end portion of the spiral 803 is overlapped on the air blowing pipe 801 through the large hole and covers the pipe wall thereof and is rotatable with respect to the air blowing pipe. The left end of the rotation shaft 802 and two large-diameter sections 804 mounted thereon are disposed in the inner hole 801a of the air supply duct 801, and the two large-diameter sections 804 are separated from each other by a certain distance. The drying gas is fed into the inner hole 801a of the blast pipe 801 by the blast apparatus 10 and runs from left to right toward the power input member 14c along the axial direction of the blast pipe, during which the drying gas can flow out through the blast holes 801b formed on the pipe wall of the blast pipe and into the sludge drying chamber 6, respectively.

The two flipping means 7a, 7b have a rotation shaft 701a, 701b and a plurality of flipping assemblies 702a, 702b mounted thereon, respectively. Since both have the same or similar structure or configuration, only one of the flipping means 7a will be described herein. As shown, a plurality of turning assemblies 702a for turning, crushing and shearing sludge are fixedly installed on the rotating shaft 701a at a certain interval along the axis of the rotating shaft, respectively, and each turning assembly 702a is provided with one or more blades or ratchets, for example, blades or ratchets 703a. The rotary shafts 701a are respectively provided in shaft holes 5a on two opposite end walls of the housing 2 in the longitudinal direction of the housing, and a power input member 14a for connection with a driving device is provided at one end of the rotary shafts 701 a. In addition, the turning device can be made to displace the sludge in the longitudinal direction of the drying chamber by the shape of the blades or ratchet teeth of the turning assembly designed to turn, break and shear the sludge.

Fig. 8 shows the sludge drying apparatus of fig. 6 in a partial perspective view. As shown, two flipping means 7a, 7b are arranged in parallel in the longitudinal direction a of the housing in the upper part of the drying chamber. Similarly, each flipping means 7a, 7b may be rotatably supported at both ends thereof in shaft holes 5a, 5b formed in opposite end walls of the drying chamber 6, respectively, and may also extend beyond the opposite end walls through the respective shaft holes 5a, 5b and be rotatably supported on external bearing means. Although the two flipping means 7a, 7b are substantially identical and arranged at the same height in the vertical direction, the person skilled in the art may have different configurations for the two flipping means 7a, 7b depending on the process requirements for drying sludge or the internal structure of the housing. For example, a plurality of flipping assemblies 702a, 702b on two flipping devices 7a, 7b are disposed on the respective rotation shafts 701a, 701b at different pitches, respectively. For example, one or several of the plurality of flip assemblies 702a, 702b have blades or ratchet teeth 703a, 703b, respectively, of different lengths. For example, the plurality of flipping assemblies 702a of the flipping unit 7a and the plurality of flipping assemblies 702b of the flipping unit 7b may be disposed to cross each other. In a further embodiment, the two flipping means 7a, 7b may be arranged at different heights, respectively. In other words, the number of flipping assemblies, the spacing between adjacent flipping assemblies, the number, shape or size of the blades or ratchets, and the positions between the plurality of flipping devices may be arbitrarily arranged by those skilled in the art in accordance with the concept of the present invention.

Fig. 9 shows a housing for the sludge drying apparatus of fig. 6 in a partial perspective view. As shown in the drawing, shaft holes 5a, 5b are formed in the longitudinal direction of the housing on two opposite end walls of the housing, respectively, to provide rotation shafts 701a, 701b of two turning devices 7a, 7b for turning, crushing, shearing sludge, and shaft holes 5c, 5d of different diameters, wherein the shaft hole 5c of a small diameter is used to provide a rotation shaft 802 of the air blowing assembly 8, and the shaft hole 5d of a large diameter is used to provide an air blowing pipe 801 of the air blowing assembly 8. Since the shaft holes 5a, 5b for the two flipping means 7a, 7b provided above the air blowing module 8 are at the same height, the shaft holes 5c and 5d for the air blowing module 8 are concentric in the longitudinal direction and are located between the shaft holes 5a, 5 b. On the end wall, the shaft hole 5c or 5d is at a different height from the shaft holes 5a, 5b, so that the line between the shaft holes 5a, 5b and the center of the shaft hole 5c or 5d forms a triangle. For example, it can be seen on the end wall provided with the discharge opening 12 for discharging dried sludge that the shaft hole 5d or 5c is located at the apex of the inverted triangle, and the shaft holes 5a, 5b are located at the two points of the base of the inverted triangle, respectively. The shaft holes 5a, 5b for the two flipping means 7a, 7b are arranged symmetrically with respect to a vertical line passing through the center of the shaft hole 5d or 5c for the blower assembly 8 in the lateral direction, while the discharge opening 12 is arranged near the vertical line in the middle of the triangle. This design allows the dried sludge to be subjected to continuous tumbling or stirring and pushing under the cooperation of the two tumbling means 7a, 7b located above and the screw 803 of the air-blowing assembly 8 located below, while being pushed to the discharge opening 12 located between the tumbling means 7 and the air-blowing assembly 8.

In another embodiment, the bottom of the drying chamber 6 of the sludge drying apparatus 1 may be flat, i.e. the bottom plate 4 is a flat plate or a curved plate, so that the air blowing assembly 8 may be arranged in the middle of the drying chamber 6 or at any position adjacent to the bottom, so that an asymmetric inverted triangle may be formed between the central lines of the shaft holes 5a, 5b for the two flipping means 7a, 7b and the shaft holes 5d or 5c for the air blowing assembly 8 in the lateral direction. In addition, one or more air blowing assemblies and one or more flipping devices may be provided in the drying chamber as needed. For example, one end of the air pipe 801 of the air blowing unit 8 may be connected to both the driving device and the air blowing device 10. In addition, in order to accelerate the flow of dried gas or off-gas out of the drying chamber, a draught device (not shown) may be connected via a pipe to the exhaust opening 13 on the cover 3 in fluid communication with the drying chamber 6. For example, if hot gas is used as the drying gas, a heating device (not shown) may be provided to heat the gas entering the blower assembly 8, and the heating device may be provided before or after the blower assembly 10. In another embodiment, the heating means may be removed, hot gas or steam may be directly introduced as a drying gas into the drying chamber to be in direct contact with the sludge, and the sludge may be dried.

Although only a single housing or a unitary sludge drying apparatus is shown and described herein, it will be appreciated that one skilled in the art may utilize the above described apparatus or components in a sludge drying chamber in other sludge treatment facilities and perform similar arrangements based thereon.

Fig. 10 is a flow chart showing an embodiment of the sludge drying method using the axial air supply method according to the present application. The axial air-supply type sludge drying method of the application can utilize the axial air-supply type sludge drying device similar to that shown in fig. 6 and 7 to dry the sludge. Referring to fig. 6-8, the process of treating sludge may be performed, for example, as sludge to be dried is fed into the drying chamber through a feed port by a not-shown conveyor, for example, into the drying chamber 6 through the feed port 11, at step 1, a driving means first drives a turning means, for example, by driving rotation shafts 701a, 701b to rotate by power input 14a, so as to rotate a plurality of turning assemblies 702a, 702b, whereby blades or ratchet teeth 703a, 703b on each turning assembly constantly turn, break and shear the sludge, and at step 2, a blowing means, for example, blowing means 10, is activated to deliver drying gas to a blast pipe of the blowing assembly, for example, the inner hole 801a of the air supply pipe 801, and the drying gas flows out through the vent hole 801b on the pipe wall of the air supply pipe and into the drying chamber, for example, the drying chamber 6. Next, in order to accelerate the flow of the dried gas or exhaust gas, in step 3, the induced draft device is activated so that the exhaust gas rapidly flows out of the drying chamber through an exhaust port, e.g. the exhaust port 13. Typically, the air supply means may be a blower means such as a blower or fan, and the air inducing means may be an induced draft fan. Alternatively, the air pressurizing device may be used instead of the air blowing device to convey the drying air into the drying chamber at a certain pressure, thereby accelerating the flow of the drying air into the drying chamber. The pressure reducing device can be used for replacing the induced air device to accelerate the flow velocity of the tail gas, so that the sludge drying efficiency is improved. In another embodiment, the step of adjusting the turning direction and/or the rotation speed of the rotation shaft of the turning device may be added as needed after the step 1 driving device drives the turning device, for example, step 1a, and then the blower device is restarted. After the air inducing device is started, in step 4, the air supply assembly is driven, the driving device rotates the rotating shaft of the air supply assembly and drives the spiral piece to turn over and push the sludge, for example, the rotating shaft 802 of the air supply assembly and the spiral piece 803 are driven by the power input piece 14c to rotate together relative to the air supply pipe 801, wherein the spiral piece can also play a role of turning over or stirring and pushing the sludge while scraping the sludge attached to the air supply pipe. Subsequently, in step 5, the drying of the sludge is accelerated by the cooperation of the turning assembly of the turning device and the screw of the air supply assembly, and the dried sludge is discharged out of a discharge opening, such as the discharge opening 12. In yet another aspect, after step 4, the rotation shaft of the air supply assembly is driven to rotate, and then, a step of adjusting the rotation direction and/or rotation speed of the air supply assembly is added as required, for example, step 4a, so that the dried sludge is in a better drying state, and the dried sludge is discharged from the drying chamber after the desired dried sludge is obtained. In another embodiment, if it is desired to dry the sludge with hot drying gas, the drying gas to be introduced into the drying chamber may be heated by means of a heating device provided additionally. The heating step may be arranged after driving the flipping means, e.g. step 1b. In another variant, not shown, a plurality of flipping means, for example the rotating shafts 701a, 701b of the flipping means 7a, 7b, can be controlled to rotate or to keep the blower assembly stationary, respectively. In yet another arrangement, not shown, a heat source with hot drying gas may be in fluid communication with the piping before or after the blower means to feed the hot drying gas into the blower pipes of the blower assembly. In a further solution, not shown, the heating means may be activated after activating the air supply means and the air inducing means separately or simultaneously, or after driving the rotation shaft of the air supply assembly. In a further variant, which is not shown, the turning direction and/or the rotational speed of the rotational shaft of the turning device can be adjusted after the heating device, the air supply device and/or the air induction device have been activated. In a further solution, not shown, the rotation direction of the rotation shaft of the air supply assembly may be adjusted before the heating means, the air supply means and/or the air inducing means are activated. In a further version, not shown, the turning device's axis of rotation and the blower assembly may also be adjusted such that the turning device's axes of rotation, e.g. axis of rotation 701a and axis of rotation 701b, may rotate in the same or opposite direction to each other, while the blower assembly's axis of rotation and the turning device's axis of rotation rotate together or with one or more of them, e.g. one of axes of rotation 701a, 701b, in the same direction. In a further alternative not shown, the rotation shaft 802 and the screw 803 of the blower assembly 8 may be kept stationary and the blower pipe 801 may be rotated by another arrangement, if desired.

The sludge is continuously sheared, crushed and turned through the turning component, the spiral piece of the air supply component and the granularity of the sludge becomes small gradually to become particles and then becomes partial particles under the action of the drying gas entering the drying chamber, so that the drying degree of the sludge is continuously improved. For example, when the rotation shaft 802 of the air supply assembly and the rotation shafts of the turning device are rotated together in the same direction, the spiral members of the turning assembly and the air supply assembly that help the turning device accelerate the movement of sludge toward the end wall having the discharge port, and when the rotation directions of the two are different, the movement of sludge is slowed down. Therefore, the rotating shaft of each turning device or the rotating speed and/or the rotating direction of the air supply assembly, the feeding speed of the drying gas, the gas temperature and the like are/is adjusted timely according to the drying degree of the sludge, so that the sludge drying efficiency is improved. It should be noted that the effect of the blower assembly, i.e. the screw, is described herein with an excessive emphasis on the effect of pushing the sludge, however, the screw also has the effect of stirring or agitating the sludge, in particular with a conveyor assembly having screws of different layout or shape, with a slightly different force or force. As described above, the air blowing unit 8 is disposed at a position adjacent to the bottom of the drying chamber 6, and the drying gas first acts on the sludge located at the bottom of the drying chamber, so that the sludge is continuously dried as the dried sludge is moved toward one end of the drying chamber by the screw 803 along the longitudinal passage, and in particular, the sludge is continuously stacked, turned or stirred, moved upward by the pushing of the screw 803 by the combined action of the screw of the air blowing unit and the turning unit of the turning device, and gradually moved out of the discharge port. It is obvious to the person skilled in the art that when a turning device is not used which pushes the sludge in the axial direction, the dried sludge can be discharged through a discharge opening provided at a suitable position of the drying chamber. Although the axial-blowing sludge drying apparatus is shown in a single unit, the axial-blowing sludge drying apparatus of the present application may be part of other sludge treatment apparatuses. It will be appreciated that in the method of the application, the heating means may be removed when using e.g. a chemical-containing, ambient or cooled gas or a gas with a specific composition, based on the different treatment requirements of the sludge. Of course, the dry gas referred to in the present application includes, but is not limited to, a gas containing a chemical substance, a gas at normal temperature or cooled, a hot gas, or a gas having a specific composition, and the like.

While various embodiments are exemplified in the present invention, the present invention is not limited to the description, and one skilled in the art can make variations and modifications of the respective parts, components or devices in the sludge drying apparatus of the present invention by fully using the above-described design ideas of the present invention, and such variations and modifications are within the scope of the idea of the present invention.

Claims

1. An axial air-supply type sludge drying device, the sludge drying device comprising:

A housing in which a drying chamber is formed;

A feed inlet for sludge to be dried and an exhaust outlet for drying gas after drying the sludge are provided on the upper part or the top of the drying chamber, and a discharge outlet for the dried sludge is provided on the end wall of the drying chamber away from the feed inlet;

at least one flipping device, wherein the at least one flipping device has at least one flipping assembly;

an axial air supply assembly, the axial air supply assembly comprising:

An air supply tube for delivering a gas, the air supply tube having an axial bore and first and second ends and forming at least one vent hole in a tube wall thereof, wherein the at least one vent hole is in fluid communication with the axial bore;

A screw having shaft holes of different inner diameters and first and second ends, wherein a first portion of the screw having the shaft hole of a first inner diameter is located at the first end, and a second portion including the shaft hole of a second inner diameter extends from the first portion to the second end, the second inner diameter of the shaft hole of the second portion being greater than an outer diameter of the air supply duct;

A rotating shaft having a first end and a second end, wherein a first portion of the rotating shaft is disposed in the shaft bore of the first portion of the screw having the first inner diameter near the first end and fixedly coupled together, and a second portion of the rotating shaft extends from the first portion to the second end and is positioned within the shaft bore of the second portion of the screw having the second inner diameter; the rotating shaft and the screw are fitted to the air supply pipe from the first end of the air supply pipe, wherein the second part of the rotating shaft is rotatably arranged in the axial hole of the air supply pipe, and the second part of the screw is rotatably nested on the air supply pipe;

the axial air supply assembly is arranged at the lower part of the drying chamber, the at least one turning device is arranged above the axial air supply assembly, and the discharge hole on the end wall is arranged between the at least one turning device and the axial air supply assembly.

2. The sludge drying apparatus of claim 1 wherein said one end of said axial air supply assembly is connectable to a drive means by means of said first end of said rotatable shaft and the other end of said axial air supply assembly is fixedly connectable to and in fluid communication with said air supply assembly by means of said second end of said air supply tube so that said rotatable shaft and said screw member are rotated relative to said air supply tube.

3. The sludge drying apparatus of claim 1 wherein said first portion of said rotatable shaft has a first diameter and said second portion has said second diameter.

4. A sludge drying apparatus according to any one of claims 1 to 3 wherein said first diameter of said first portion of said rotary shaft is greater than or less than said second diameter of said second portion thereof and said first inner diameter of said shaft bore of said first portion of said screw is less than or greater than said second inner diameter of said shaft bore of said second portion thereof.

5. A sludge drying apparatus as claimed in any one of claims 1-3, wherein at least one large diameter section is provided on said at least part of said rotary shaft at said second end, wherein said at least one large diameter section is provided in said axial bore of said blast pipe and has a diameter slightly smaller than the diameter of said axial bore.

6. A sludge drying apparatus according to any one of claims 1 to 3 wherein the at least one large diameter section is two spaced cylinders fixedly mounted on the rotatable shaft.

7. A sludge drying apparatus as claimed in any one of claims 1 to 3 wherein the air supply means is a blower, fan or gas pressurizing means.

8. A sludge drying apparatus as claimed in any one of claims 1 to 3 wherein the at least one large diameter section may be a plain bearing or a rolling bearing.

9. A sludge drying apparatus according to any one of claims 1 to 3 wherein the drying chamber has a concave bottom so as to form a longitudinal arcuate path in the longitudinal direction of the housing, and the axial air supply assembly is located within the longitudinal arcuate path.

10. A sludge drying apparatus according to any one of claims 1 to 3 wherein the housing comprises a housing body, a floor and a cover, wherein the inlet and the outlet may be provided on an upper portion of the housing body or on the cover.

11. A sludge drying apparatus according to any one of claims 1 to 3 wherein the floor is connected to the lower edge of the housing body and the two longitudinal sides of the floor extend obliquely inwardly from the lower edge of the housing body in a transverse direction so as to form a concave bottom of the drying chamber.

12. A sludge drying apparatus according to any one of claims 1 to 3 wherein the at least one turning assembly has at least one blade or ratchet extending radially outwardly from the rotational axis for shearing, crushing and turning the sludge.

13. A sludge drying apparatus according to any one of claims 1 to 3 wherein the at least one sludge turning device comprises two sludge turning devices arranged in parallel, the two sludge turning devices being located at the same height in a vertical direction and being symmetrically arranged with respect to a vertical axis passing through the axis of the axial air supply assembly.

14. A sludge drying apparatus according to any one of claims 1 to 3 wherein at least one of the two sludge turning assemblies comprises a plurality of turning assemblies, each two of the plurality of turning assemblies being spaced apart by a distance, wherein each turning assembly has one or more blades or ratchet teeth extending radially outwardly from the rotational axis.

15. A sludge drying apparatus as claimed in any one of claims 1 to 3, further comprising heating means for heating the drying gas, wherein the heating means is located upstream or downstream of the air supply means.

16. A sludge drying apparatus as claimed in any one of claims 1 to 3, further comprising an air inducing means, wherein the air inducing means communicates with the drying chamber via an air outlet.

17. A sludge drying apparatus according to any one of claims 1 to 3 wherein the drying chamber has a flat bottom and the air supply assembly is positionable at any location adjacent the flat bottom.

18. A method of drying sludge using a sludge drying apparatus according to any one of claims 1 to 17, the method comprising the steps of:

driving a turning device arranged in a drying chamber of the sludge drying device to enable a turning assembly of the turning device to rotate around a rotating shaft of the turning device, so as to turn, shear and crush sludge entering through a feed inlet of the drying chamber and positioned in the drying chamber;

Starting an air supply device to send dry air for sludge to be dried into an air supply pipe of an air supply assembly arranged in the drying chamber and enable the dry air to enter the drying chamber;

starting an induced draft device to enable drying gas of the dried sludge to be discharged through an exhaust port of the drying chamber;

The air supply assembly is driven to rotate so as to enable the rotating shaft to rotate, and the spiral piece which is sleeved on the air supply pipe and connected with the rotating shaft is driven to rotate relative to the air supply pipe, so that sludge attached to the pipe wall of the air supply pipe is scraped, turned or stirred and pushed to move towards a discharge hole for dried sludge, which is arranged on the end wall of the drying chamber and is positioned at a discharge hole between the turning device and the air supply assembly; and

Under the synergistic effect of the turning device and the air supply assembly, the drying of the sludge is quickened, and the dried sludge is discharged from the discharge hole of the drying chamber.

19. The method of drying sludge according to claim 18, further comprising the step of adjusting a rotational speed and a rotational direction of a rotating shaft of the flipping means.

20. The method of drying sludge of claim 18, further comprising adjusting a rotational speed and/or a rotational direction of a rotational shaft of the air moving assembly.

21. The method of drying sludge according to any one of claims 18 to 20, further comprising the step of heating the drying gas of the sludge to be dried before entering the drying chamber by means of a heating device.