CN112479540A

CN112479540A - Sludge drying device and using method thereof

Info

Publication number: CN112479540A
Application number: CN201910864478.1A
Authority: CN
Inventors: 谭玮
Original assignee: Swison Creative Environmental Solutions Co ltd
Current assignee: Guangzhou Zhengsheng Technology Co ltd
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2021-03-12
Anticipated expiration: 2039-09-12
Also published as: CN112479540B

Abstract

The invention provides an axial air supply type sludge drying device which comprises a shell, wherein a drying chamber is formed in the shell, and the drying chamber is provided with a sludge feeding hole, a tail gas exhaust hole and a sludge discharge hole. A flipping device having a flipping assembly. The axial air supply assembly comprises an air supply pipe and a spiral part, wherein the air supply pipe is provided with an axial hole and a vent hole which is communicated with the axial hole in a fluid manner and is formed on the pipe wall, and the spiral part is sleeved and fixed on the pipe wall of the air supply pipe through a shaft hole and comprises a positive spiral part or an inclined spiral part. The axial air supply assembly is arranged at the lower part of the drying chamber, the turning device is positioned above the axial air supply assembly, and the discharge port on the end wall of the drying chamber is positioned 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 using 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, the common sludge treatment devices are indirect type and direct type drying equipment. The indirect drying equipment is to convey steam, hot oil or hot water into the hollow shaft and the stirring blades running in the drying chamber to heat the shaft and the stirring blades, and then to transfer the heat to wet sludge in the drying chamber by using the heat-conducting hollow shaft and the stirring blades, so as to evaporate the moisture in the sludge and gradually dry the sludge. However, since heat is transferred by the flow of high-temperature hot oil or steam in the hollow shaft and the stirring vanes, the stirring vanes are easily worn and broken, and the treated sludge has a high water content and a high viscosity. The method not only causes high failure rate and large energy consumption of the sludge treatment equipment, but also has very low sludge drying efficiency. The direct drying apparatus directly applies hot air to sludge to evaporate water in the sludge, and thus improves heat transfer efficiency, but because the sludge has high viscosity and is easy to block air holes, the drying apparatus not only affects the stability of the drying process, but also is difficult to reduce the sludge due to uneven drying of the sludge, and the drying apparatus cannot dry a large amount of sludge due to low drying efficiency of the sludge.

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

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides an axial air supply type sludge drying device, such as a single axial air supply type sludge drying device. The axial air supply type sludge drying device comprises a shell with a drying chamber, a feed inlet which is arranged at the upper part of the drying chamber and used for drying sludge, an exhaust port which is used for exhausting dried gas after drying the sludge, and a discharge outlet which is far away from the feed inlet and arranged on the end wall of the drying chamber and used for dried sludge; a flipping mechanism having at least one flipping assembly; and an axial blower 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 port is positioned between the turning device and the axial air supply assembly. The sludge is frequently contacted with the dry gas through the direct action of the dry gas from the axial air supply component on the sludge at the lower part of the drying chamber, the turning and pushing of the axial air supply component on the sludge and the continuous shearing, crushing and turning of the turning component of the turning device on the sludge, thereby solving the problem of uneven drying degree of the inner part and the outer part in the sludge drying process.

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 the turning device positioned in the drying chamber, and turning, crushing and shearing the sludge by using a turning component of the turning device. The air supply device is started to send the dry air into the air supply component arranged in the drying chamber and make the dry air enter the drying chamber. And starting the air inducing device to discharge the dried gas of the dried sludge through the exhaust port. The air supply assembly is driven to make the spiral piece turn and push the sludge. In addition, the hot drying gas may be obtained by introduction from a heat source or heating by a heating device, and the above operations may be performed sequentially, simultaneously or separately as required, thereby increasing the temperature of the drying gas, accelerating the flow rate of the drying gas, and further promoting the contact of the drying gas with the sludge. Then, under the synergistic action of the turning device and the air supply assembly, the drying of the sludge is accelerated, and the dried sludge is discharged from the discharge hole. The method for drying the sludge by the axial air supply type conveys the drying gas into the drying chamber through the air supply assembly, so that the drying gas directly acts on the sludge, and the sludge is continuously crushed and loosened in the operation process along with the turning, shearing and crushing of the turning assembly of the turning device and the turning and pushing of the air supply assembly, thereby being beneficial to increasing the area of direct contact between the drying gas and the sludge and improving the drying efficiency.

In the axial air supply type sludge drying device, the rotation of the air supply assembly can effectively prevent the sludge from being attached to the pipe wall of the air supply pipe of the air supply assembly, so that the air vent of the air supply pipe can be prevented from being blocked, the frequency of contact between the sludge and drying gas can be increased by the turning and the pushing of the spiral piece of the air supply assembly on the sludge, the drying efficiency is improved, the bottom of the drying chamber is used for configuring the arc-shaped channel of the axial air supply assembly, and the position of the discharge port is arranged, so that the sludge can run along the longitudinal direction of the shell or the drying chamber, the dried sludge can be continuously turned over in continuous accumulation, 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 body form, thereby obtaining the sludge drying device with low energy consumption, small volume, compact structure and high drying efficiency, and can be combined with other sludge treatment equipment. In the method for drying the sludge by the axial air supply, the drying air is continuously input into the drying chamber through the air supply assembly, and the sludge is turned, sheared and crushed, so that the moisture in the sludge is continuously evaporated, further, the sludge drying time is shortened, and the sludge reduction ratio is also improved.

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

a housing forming a drying chamber therein; a feed inlet for sludge to be dried and an exhaust outlet for discharging dried gas after drying the sludge, which are arranged on the upper part or the top of the drying chamber, and a discharge outlet for dried sludge, which is far away from the feed inlet and is arranged on the end wall of the drying chamber; at least one flipping unit, wherein the at least one flipping unit has at least one flipping assembly; an axial air supply assembly, comprising: the air supply pipe is used for conveying air and provided with an axial hole, and at least one vent hole is formed in the pipe wall of the air supply pipe, wherein the at least one vent hole is in fluid communication with the axial hole; the spiral piece is provided with a shaft hole, wherein the spiral piece is sleeved on the pipe wall of the blast pipe through the shaft hole and is fixedly connected with the blast pipe; and the axial air supply assembly is arranged at the lower part of the drying chamber, the at least one turning device is positioned above the axial air supply assembly, and the discharge port on the end wall is positioned between the at least one turning device and the axial air supply assembly.

According to the above fluid delivery assembly, the helical element comprises a forward helical element or an inclined helical element, wherein the forward helical element is perpendicular to the axis of the blower tube or the wall of the blower tube, and the inclined helical element is inclined at an angle to the wall of the blower tube along the axis of the blower tube, and the inclined helical element comprises a right-inclined helical element or a left-inclined helical element.

According to the above fluid conveying assembly, the screw member includes a plurality of screw sections, and the plurality of screw sections include a regular screw section, a right-inclined screw section and a left-inclined screw section, wherein the regular screw section is perpendicular to the axis or wall of the blast pipe, the right-inclined screw section is inclined at a certain angle to the right with respect to the axis or wall of the blast pipe, and the left-inclined screw section is inclined at a certain angle to the left with respect to the axis or wall of the blast pipe.

According to the above fluid transport assembly, any two of the right-handed helical section, the left-handed helical section and the right-handed helical section may be alternately arranged in the axial direction of the blast pipe, and each inclined helical section may have the same or different inclination angle.

According to the sludge drying device, the right-inclined spiral section and the left-inclined spiral section in the plurality of spiral sections can be arranged in pair in the axial direction of the air supply pipe, and every two pairs of the right-inclined spiral section and the left-inclined spiral section are spaced from each other, wherein each spiral section can have the same or different inclination angles.

According to the sludge drying device, the at least one vent hole comprises a plurality of vent holes, wherein the plurality of vent holes are distributed on the pipe wall of the blast pipe, and the spiral piece or the spiral section can axially cover at least one part of the plurality of vent holes.

According to the sludge drying device, the plurality of vent holes can be positioned below the inclined spiral piece or the inclined spiral section as much as possible in a regular or irregular mode.

According to the sludge drying device, the plurality of vent holes can be arranged along the length direction of the air supply pipe from one end of the air supply pipe to the other end of the air supply pipe, so that the number of the vent holes is gradually increased, and/or the aperture of the vent holes is gradually increased.

According to the sludge drying device, one end of the air supply component can be connected with the driving device, the other end of the air supply component can be connected with the air supply device and is communicated with the air supply device in a fluid mode, and the driving device can drive the air supply pipe of the air supply component to rotate.

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, the shell comprises a shell body, a bottom plate and a cover, wherein the feeding hole and the exhaust hole can be arranged on the upper part of the shell body or the cover.

According to the sludge drying device, the bottom plate is connected with the lower end of the side wall of the shell body, and two longitudinal side edges of the bottom plate in the transverse direction extend from the lower edge of the shell body in an inward inclining mode, so that a concave bottom of the drying chamber is formed.

According to the sludge drying device, the concave bottom of the drying chamber forms a longitudinal arc-shaped channel 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 drying chamber is provided with the flat bottom, and the air supply assembly can be positioned at any position near the flat bottom.

According to the sludge drying apparatus, at least one of the tumbling assemblies has at least one blade or ratchet extending radially outward from the rotating shaft for shearing, crushing and tumbling the sludge.

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

According to the sludge drying device, at least one of the two sludge turning devices comprises a plurality of turning assemblies, and each two turning assemblies in the plurality of turning assemblies are spaced at a certain distance, wherein each turning assembly is provided with one or more blades or ratchets which extend outwards from the rotating shaft in the radial direction.

According to the sludge drying device, the sludge drying device further comprises a heating device for heating the drying gas, wherein the heating device is positioned at the upstream or the downstream of the air supply device.

According to the sludge drying device, the sludge drying device further comprises an air inducing device, wherein the air inducing device is connected with the air outlet and is in fluid communication with the drying chamber.

According to the sludge drying device, at least one turning device comprises two turning devices, wherein the rotating shaft of each turning device is arranged in parallel with the longitudinal direction of the drying chamber, and a connecting line between the axes of the rotating shafts of the two turning devices and the axis of the air supply pipe of the axial air supply assembly is in an inverted triangle shape in the transverse direction.

The invention also provides a method for drying sludge by using the axial air supply type sludge drying device, which comprises the following steps of driving the turning device arranged in the drying chamber of the sludge drying device so as to enable the turning component of the turning device to rotate around the rotating shaft of the turning component, thereby turning, shearing and crushing the sludge entering the drying chamber through the feeding hole of the drying chamber and positioned in the drying chamber; starting an air supply device to send dry gas for sludge to be dried into an air supply pipe of an air supply assembly arranged in the drying chamber and make the dry gas enter the drying chamber; starting an air inducing device to enable dry gas after the sludge is dried to be discharged through an air outlet of the drying chamber; driving the air supply assembly to rotate the air supply pipe and drive the spiral piece on the air supply assembly to push the sludge; and under the synergistic action of the turning device and the air supply assembly, the drying of the sludge is accelerated, and the dried sludge is discharged from the discharge hole.

The method for drying the sludge further comprises the step of adjusting the rotating speed and/or the rotating direction of the rotating shaft of the turning device.

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

The method for drying the sludge further comprises the step of heating the drying gas of the sludge to be dried before the sludge enters the drying chamber by using a heating device.

Drawings

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

FIG. 1 is a schematic perspective view of a fluid delivery assembly for a sludge treatment plant;

FIG. 2 is a longitudinal cross-sectional view of the fluid delivery assembly shown in FIG. 1;

FIG. 3 is a transverse cross-sectional view of the fluid delivery assembly shown in FIG. 1;

FIG. 4 is a schematic perspective view of another embodiment of a fluid delivery assembly;

FIG. 5 is a longitudinal cross-sectional view of the fluid delivery assembly of FIG. 4;

FIG. 6 is a schematic perspective view of yet another embodiment of a fluid delivery assembly;

FIG. 7 is a longitudinal cross-sectional view of the fluid delivery assembly of FIG. 6;

FIG. 8 is a longitudinal sectional view of an axial air supply type sludge drying device with an axial air supply assembly;

FIG. 9 is a cross-sectional view of the axial-blowing sludge drying apparatus of FIG. 8;

FIG. 10 is a schematic partially cut-away perspective view of the sludge drying apparatus of FIG. 8;

FIG. 11 is a partially cut-away perspective view of a housing of the sludge drying apparatus of FIG. 8; and

FIG. 12 is a flow chart of an axial-blowing sludge drying method.

Detailed Description

Fig. 1 shows an embodiment of the fluid transfer assembly for a sludge treatment apparatus of the present application in perspective view, while fig. 2 and 3 illustrate the fluid transfer assembly of fig. 1 in longitudinal and transverse cross-sectional views, respectively. As shown, the fluid delivery assembly S includes a fluid delivery tube or feed barrel 801 and a screw 802. The helix 802 may also be referred to as a helix or helical blade. The screw 802 may be fitted over and fixedly connected to the pipe 801 through its inner or axial bore, or both. The fluid delivery assembly S may be generally disposed in a sludge treatment chamber or chamber of a sludge treatment apparatus, wherein both ends of the fluid delivery assembly S are rotatably supported on, for example, opposite walls of the sludge treatment chamber, and the fluid delivery assembly S may be rotated by a driving means connected to one end of the fluid delivery assembly S, and may be delivered into the sludge treatment chamber through the delivery pipe 801 by a fluid supply means disposed at the other end of the fluid delivery assembly S.

The fluid delivery tube 801 may be formed from a tubular member having an internal or axial bore, for example, the delivery tube may be a cylindrical tube having a central bore. One or more fluid transfer apertures 804 are formed in the wall of the transfer tube 801, and the fluid transfer apertures 804 penetrate the wall of the tube to fluidly communicate with the internal or axial bore 803 of the transfer tube 801. Fluid can be fed into the bore 803 from one end of the pipe 801 by a fluid feed means, and fluid entering the bore 803 can exit the pipe 801 through the feed holes 804 in the pipe wall, as shown by the arrows in fig. 3, for example into a sludge treatment chamber.

Referring to fig. 1, the diameter of the internal bore or axial bore of the screw 802 may be designed to be approximately equal to or close to the outer diameter of the delivery tube 801 so that the screw 802 fits over the wall of the delivery tube 801 and is fixedly attached thereto by conventional means such as welding, bolting, riveting or gluing, or both the screw and the delivery tube are integrally formed. The screw 802 is fixedly mounted on the wall of the duct 801 and forms a helically wound and radially outwardly extending fin on the wall. If the screw is cut transversely along the outer peripheral surface of the conveying pipe through 360 degrees of revolution, a plurality of substantially truncated cones may be cut in the longitudinal direction of the screw. As best seen in the longitudinal cross-sectional view of fig. 2, the cross-section of the screw 802 appears as a plurality of shaded strip portions distributed over and under the delivery tube 801, wherein each strip portion has one end connected to the wall of the delivery tube 801 and another end extending radially outwardly at an angle α relative to the axis of the delivery tube 801 or from the wall. Each frustoconical body generally assumes a trapezoidal shape, although the upper and lower narrow strip portions are slightly staggered with respect to the longitudinal axis.

In fig. 2, the strip portion representing the helix or helical fin is inclined relative to the wall of the duct, whereas normally the strip portion is disposed perpendicular to the longitudinal axis or duct wall of the duct (see also helical section 802b1 in fig. 7) and appears generally disc-like if the helix is taken through 360 degrees of revolution. In this context, a helix or helical flight that is substantially perpendicular to the longitudinal axis or wall of the transport tube is referred to as a positive helix or positive helical flight, while a helix or helical flight that is at an oblique angle to the longitudinal axis or wall of the transport tube is defined as an oblique helix or oblique helical flight. When the viewer is facing the split helix, the helix that is angled to the right relative to the longitudinal axis or wall of the duct is considered a right-handed helix, and the helix that is angled to the left is considered a left-handed helix. That is, the screw 802 of the fluid transport assembly S in fig. 2 is a right-handed screw. If a section of the screw is cut out 360 degrees around the outer peripheral surface of the delivery tube, the cut section of the screw will appear generally frusto-conical or flared, with the forward end of the cone abutting the wall of the delivery tube 801 and the rearward end of the cone extending obliquely to the right and radially outward along the longitudinal axis of the fluid delivery assembly S.

As described above, the fluid transfer assembly S is provided in the sludge treatment chamber generally in order to treat the sludge in the sludge treatment chamber, wherein the fluid is transferred into the sludge treatment chamber from the outside through the fluid transfer assembly S. The fluid may include, for example, a gas, liquid, or other flowable substance. As described above, the transfer module 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 modules may be provided in a sludge treatment chamber. The longitudinal blade 802 of each conveying assembly S in the sludge treatment chamber can shield sludge to be attached to the pipe wall of the conveying pipe 801 and can also generate the functions of stirring and moving the sludge, and when a plurality of conveying assemblies S are arranged, a driving device and a fluid supply device can be independently configured for each conveying assembly, or the plurality of conveying assemblies can be connected with one or more driving devices or fluid supply devices through a connecting mechanism, so that the independent or combined control of each conveying assembly is realized. Of course, the arrangement of the transfer assembly along the longitudinal direction of the sludge treatment chamber helps to make the fluid entering the inner bore 803 of the fluid transfer pipe 801 travel a long distance along the length direction of the sludge treatment chamber, and then can enter the sludge treatment chamber through the fluid transfer holes 804 distributed on the pipe wall of the transfer pipe 801, thereby benefiting the interaction between the fluid and the sludge. The conveying holes 804 of the conveying pipe 801 may be blocked due to the nature of the fluid or sludge or the viscosity generated by the interaction of the fluid and the sludge, so that the conveying holes 804 may be blocked by the screw 802 longitudinally inclining at a certain angle to the right or left relative to the pipe wall of the conveying pipe 801, thereby reducing the probability that the sludge in the sludge treatment chamber adheres to the conveying pipe, and further reducing the obstruction of the fluid flowing out of the conveying holes 804 during the fluid conveying process.

In fig. 1-3, a delivery tube 801 may be provided with one or more fluid delivery apertures 804, with the right-handed helix 802 occluding the fluid delivery apertures 804 in the wall of the delivery tube 801. The plurality of delivery holes 804 may be arranged or arrayed in a regular or irregular manner and as much as possible below the inclined screw 802. The degree to which the inclined screw 802 obstructs the delivery hole 804 depends on the angle α at which the screw 802 is inclined with respect to the wall of the delivery tube 801, for example the angle α may have a value between 1 ° and 90 °, between 10 ° and 70 °, or between 20 ° and 60 °. The value of the angle of inclination a can be determined by a person skilled in the art on the basis of the properties of the sludge and the fluid to be conveyed. As described above, the fluid delivery assembly S is rotatably disposed within the sludge treatment chamber and the screw 802 is fixedly integrally connected to the delivery pipe 801, and thus, both rotate together during operation of the fluid delivery assembly S. By means of the rotation, on the one hand, the sludge is prevented from adhering to the wall of the transport pipe 801, and on the other hand, the fluid is distributed more evenly to the area around the transport pipe. The screw 802 not only can shield the delivery hole to ensure the smooth flow of the fluid, but also can move or run the sludge in the sludge treatment chamber along the longitudinal direction along with the rotation, so that the properties of the sludge, such as uniformity, fluidity, viscosity, cooling and/or dryness, can be improved based on different requirements. In addition, the directional distribution of the fluid entering the sludge treatment chamber can be realized by arranging different numbers or different hole diameters of the conveying holes 804 at different positions on the pipe wall of the conveying pipe. For example, the number of the delivery holes may be increased gradually from one end of the delivery pipe to the other end thereof along the axis of the delivery pipe, or the diameter of the delivery holes may be increased gradually. The fluid delivery assembly S may be rotated in different directions as desired by means of a drive device connected to one of the ends of the delivery tube 801.

Fig. 4 illustrates another embodiment of the fluid delivery assembly of the present application in perspective view, while fig. 5 illustrates the fluid delivery assembly of fig. 4 in longitudinal cross-section. As shown, the fluid delivery assembly Sa includes a fluid delivery tube 801a and a helix 802 a. The fluid delivery tube 801a is of substantially the same construction as the fluid delivery tube 801 shown in FIG. 1, but the helix 802a includes a plurality of helical segments or portions 802a1-802a6, and each helical segment may include a plurality of substantially frustoconical bodies such as described above. The multiple spiral sections 802a1-802a6 have the same inner hole or shaft hole respectively, and each spiral section is sleeved on the conveying pipe 801a through the inner hole and fixedly connected with the conveying pipe into a whole. Three helical sections 802a1, 802a3, 802a5 of the plurality of helical sections 802a1-802a6 are left-inclined helical sections, i.e., a first left-inclined helical fin, a second left-inclined helical fin, and a third left-inclined helical fin, which are inclined at a certain angle α to the left with respect to the tube wall of the transport tube 801a, respectively, and the other three helical sections 802a2, 802a4, 802a6 are right-inclined helical sections, i.e., a first right-inclined helical fin, a second right-inclined helical fin, and a third right-inclined helical fin, which are inclined at a certain angle α to the right with respect to the tube wall of the transport tube 801, respectively. As mentioned above, if a transverse cut is made for each inclined helical section for each revolution about the axis of the pipe, as seen in a longitudinal section taken along the longitudinal axis of the helical element 802a, a plurality of substantially frustoconical or flared portions can be obtained, wherein the small openings of the flared portions are connected to the wall of the pipe 801 and the large openings of the flared portions are directed towards the right or left end of the pipe along the axis of the helical element 802a or the pipe 801. In the screw 802a, three left-inclined screw sections 802a1, 802a3, 802a5 and three right-inclined screw sections 802a2, 802a4, 802a6 are alternately arranged in turn at regular intervals on the wall of the conveying pipe 801a, and each two of the left-inclined screw sections 802a1 and 802a2, 802a3 and 802a4, 802a5 and 802a6 are arranged opposite to each other. The frusto-conical tips of each pair of inclined helical segments are adjacent one another with their bases facing away from one another and in opposite directions, e.g. the small openings of the horns of the second left-inclined helical segment 802a3 and the second right-inclined helical segment 802a4 face one another, while the large openings of their horns face the left and right ends, respectively, of the conveying pipe 801a and face the first right-inclined helical segment 802a2 and the third left-inclined helical segment 802a5, respectively, of the other pair. The spacing between the first pair of canted helix segments 802a1, 802a2 and the second pair of canted helix segments 802a3, 802a4, and between the second pair of canted helix segments 802a3, 802a4 and the third pair of canted helix segments 802a5, 802a6 may be greater than the distance between the pairs of canted helix segments. Most of the fluid transfer holes 804a are located as far below the inclined spiral section as possible so that the fluid in the inner bore or axial hole 803a of the transfer pipe 801a smoothly flows out of the transfer holes 804a and into the sludge treatment chamber. Although each inclined helical section is shown as being inclined at the same angle a, it will be appreciated that each of the plurality of helical sections may have a different angle of inclination relative to the wall of the duct, and may be inclined in different directions, and may be paired in any combination. In other words, one skilled in the art can select and arrange a plurality of inclined spiral sections, including their number, inclination direction, spiral direction, arrangement, etc., according to the requirements of the processing sludge. For example, the paired oblique spiral sections in this embodiment are designed such that when the fluid conveying pipe 801a rotates, one of the oblique spiral sections 802a1, 802a3, 802a5 and the right oblique spiral sections 802a2, 802a4, 802a6 pushes the sludge to move in one direction along the axial direction, while the other oblique spiral section retards the movement of the sludge, one of which is beneficial to the up-and-down movement of the sludge, so as to turn or stir the sludge, and prevent the sludge from blocking the conveying hole 804 a.

Fig. 6 illustrates a further embodiment of the fluid delivery assembly of the present application in perspective view, while fig. 7 is the fluid delivery assembly of fig. 6 shown in longitudinal cross-section. As shown, the fluid delivery assembly Sb includes a fluid delivery tube 801b and a helix 802 b. The fluid delivery tube 801b is substantially identical in construction to the fluid delivery tube 801 shown in FIG. 1, but the helix 802b includes a plurality of helical segments 802b1-802b 6. The multiple spiral sections 802b1-802b6 each have the same internal bore or shaft hole, and each spiral section is sleeved on and fixedly connected with the conveying pipe 801b through the internal bore of each spiral section. Three helical sections 802a1, 802a3, 802a5 of the plurality of helical sections 802b1-802b6 are respectively positive helical sections, i.e., a first positive helical fin, a second positive helical fin, and a third positive helical fin, i.e., fin or strip portions of the positive helical sections are respectively substantially perpendicular to the axis or pipe wall of the conveying pipe 801b, as described above, while the other three helical sections 802a2, 802a4, 802a6 are respectively right-inclined helical sections, i.e., a first right-inclined helical fin, a second right-inclined helical fin, and a third right-inclined helical fin, and the fin or strip portions of the right-inclined helical sections are respectively inclined at an angle α to the right with respect to the pipe wall of the conveying pipe 801 b. If each right-inclined helical section is cut in one revolution transverse to the longitudinal axis of the delivery tube 801b, the resulting generally frustoconical portion has its base facing the right end of the delivery tube. In the helix 802b, three positive helical sections 802b1, 802b3, 802b5 alternate with three right-inclined helical sections 802b2, 802b4, 802b6 in sequence at intervals along the longitudinal axis of the delivery tube on the wall of the delivery tube 801 b. Most of the fluid transfer holes 804a are located below the right-handed helical segments 802a2, 802a4, 802a6 to help facilitate the fluid in the inner bore or axial bore 803b of the transfer tube 801b to flow smoothly out of the transfer holes 804b and into the sludge treatment chamber. In the helix 802b, the helical directions of the positive helical segments 802b1, 802b3, 802b5 and the right-handed helical segments 802b2, 802b4, 802b6 are the same. The combination of helical sections is such that when the fluid transfer tube 801b is rotated in one direction, all helical sections will push the sludge axially in one direction, and in comparison, the positive helical section will tend to move the sludge more, while the right-angled helical section will tend to promote smooth fluid flow out of the transfer holes 804b and partially push the sludge. Also, although the right-handed helical segments are shown as being inclined at the same angle α, it will be appreciated that a person skilled in the art may select and arrange a plurality of inclined helical segments, including their type, number, direction of inclination, angle of inclination, helical orientation, arrangement, etc., as desired for processing the sludge. Either the single screw or the multiple screw sections are typically arranged in the middle of the transport pipe so that when the fluid transport assemblies, such as S, Sa and Sb, are installed, the single screw or the multiple screw sections are located within the sludge treatment chamber.

As noted above, the fluid transport assembly of the present application may have a single positive helix, left-leaning or right-leaning helix, or may have a helix that includes a plurality of differently oriented helical segments, e.g., the plurality of helical segments may include one or more positive helical segments, one or more left-leaning helical segments, and/or one or more right-leaning helical segments. It will be appreciated that the fin or strip portion of each inclined helical section of the helix may be curved or arcuate, for example, and the angle between it and the wall of the duct 801 may be determined by the angle between a line passing through two points of the centre line of the curved strip portion in the thickness direction, at the front and rear ends, and the wall of the duct 801. The strip portion of each inclined helical segment may for example have a different degree of curvature or pitch. When the conveying hole 804 is not required to be shielded, a positive spiral piece or a plurality of positive spiral sections can be arranged on the conveying pipe.

Fig. 8 illustrates an embodiment of an axial-blowing sludge drying apparatus having an air-blowing assembly in a longitudinal sectional view, and fig. 9 illustrates the sludge drying apparatus shown in fig. 8 in a transverse sectional view. As described above, the fluid delivery assemblies S, Sa and Sb of the present application can deliver both liquid and gas, and thus, as an example, in the sludge drying apparatus 1, they are used to deliver gas, and thus, may be referred to as air supply assemblies or air vent assemblies 8.

As shown in the figure, the axial-blowing sludge drying apparatus 1 has a housing including, 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 of multiple parts or in various ways, for example, the body 2 may be integrally formed with the bottom 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 opening 11 for feeding sludge to be dried or dried into the drying chamber and an exhaust opening 13 for exhausting tail gas or drying gas after drying the sludge are provided in the cover 3, respectively, and a discharge opening 12 for dried sludge is provided in the end wall of the body 2 at a position approximately in the middle of the feed opening 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 provided at any position of the upper portion of the drying chamber 6, and the outlet 12 may be provided on the side wall or near the bottom of the drying chamber, etc. The body 2 and the base plate 4 may be secured together by conventional attachment means such as welding, riveting or bolting.

The sludge drying apparatus 1 further comprises two flipping

devices

7a, 7b for flipping, crushing and shearing the sludge and an air blowing assembly 8 disposed in the housing, wherein the fluid delivery assembly Sb of the above fluid delivery assemblies S, Sa and Sb is selected as the air blowing assembly 8 for the sake of illustration. The air supply assembly 8 may be located in the middle or near the bottom of the drying chamber 6 with the flipping

devices

7a, 7b located above and parallel to the air supply assembly 8. In order to supply as much drying gas as possible into the drying chamber 6 of the sludge drying apparatus, the air supply assembly 8 is typically arranged along the longitudinal direction of the drying chamber 6, e.g. substantially horizontally or parallel to the bottom plate 4 of the drying chamber. In the process of the dry air entering the drying chamber through the blowing assembly 8, the screw 802b can shield the vent hole 804b formed on the wall of the blowing pipe 801b below the blowing assembly 8 to ensure smooth outflow of the air, or can push the sludge to move toward one end of the drying chamber 6, for example, the sludge moves toward the end wall with the discharge port 12, along with the rotation of the blowing assembly 8. Both ends of the blowing duct 801b of the blowing module 8 are rotatably supported in shaft holes 5c formed in opposite end walls of the drying chamber 6, respectively. In another embodiment, both ends of the blowing module 8 may extend through the respective shaft holes 5c to the outside of the opposite end walls, wherein both ends of the blowing pipe 801b of the blowing module 8 are rotatably supported on the external supporting device, and further, both ends of the blowing pipe 801b may be connected to the driving device and the blowing device 10, respectively. Since the dry gas is sent along the axial direction or the longitudinal direction of the housing of the sludge drying apparatus 1 by the inner hole or the axial hole 803b of the air supply pipe 801b of the air supply unit 8, the air supply unit 8 may also be referred to as an axial air supply unit.

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 downward concave when viewed from the transverse direction, i.e., the curved plate extends from the two side edges of the body 2 to the middle in a downward inclined manner and converges to an arc shape. In the cross section of the casing, two longitudinal sides of the casing are gradually narrowed in a diagonal manner inwards at the joint of the body 2 and the bottom plate 4 approximately at the position above the air supply assembly and transition to an arc-shaped bottom. The bottom area of the drying chamber 6 is laterally recessed, viewed from the interior of the housing, so that a longitudinal curved 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 screw 802b of the blowing assembly, so that a uniform interval or gap is maintained between the screw 802b and the bottom of the drying chamber. The end of the blower tube 801b of the blower assembly 8, e.g. the right end, is provided with a power input 14c for connection to the drive means, while its other end, e.g. the left end, is connected to and in fluid communication with the blower means 10 via a connection means 9. The air supply device can be a blower, a fan, a gas pressurizing device or the like. Since the air blowing assembly 8 is substantially the same as the fluid conveying assembly Sb, the structure of the air blowing assembly 8 can be referred to the description of the fluid conveying assembly Sb, and will not be described again.

Blower modules 8 are rotatably disposed in holes 5c formed in two opposite end walls of the drying chamber, respectively, and corresponding to the longitudinal arc-shaped passages, and screws 802b of three right-angled screw sections 802a1, 802a3, 802a5 and three right-angled screw sections 802b2, 802b4, 802b6 alternately disposed on blower pipe 801b are located in drying chamber 6, wherein each right-angled screw section is inclined toward the power input 14 c. One end, e.g., the right end, of the blower pipe 801b extends outward from the hole 5c in the right end wall of the drying chamber 6, and is connectable to the driving device via the power input member 14c provided thereon. Similarly, the other end, e.g., the left end, of the air blowing duct 801b extends outward from the hole 5c in the left end wall of the drying chamber 6, and is connected to the air blowing device 10 by the connecting device 9, and allows fluid communication therebetween. It should be understood that whatever connection method is adopted, it is ensured that the dry air is delivered into the inner hole 803b of the blast pipe 801b by the air blowing device 10 and travels from one end to the other end, for example, from left to right, along the axial direction of the blast pipe toward the power input member 14c, so that the dry air can flow out through the vent holes 804b formed in the pipe wall of the blast pipe and enter the sludge drying chamber 6, respectively.

The two flipping

mechanisms

7a, 7b have

rotating shafts

701a, 701b, respectively, and a plurality of flipping

assemblies

702a, 702b mounted thereon. Since both have the same or similar structure or configuration, only one of the flipping mechanisms 7a will be described herein. As shown, a plurality of flipping units 702a for flipping, crushing and shearing sludge are fixedly installed on a rotating shaft 701a at regular intervals along the axis of the rotating shaft, respectively, and each flipping unit 702a is provided with one or more blades or ratchets, such as blades or ratchets 703 a. 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 blade or ratchet shape of the stirring component designed to stir, break and shear the sludge can make the stirring device move the sludge along the longitudinal direction of the drying chamber.

Fig. 10 shows the sludge drying apparatus of fig. 8 in a partial perspective view. As shown in the figure, 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, the two ends of each flipping means 7a, 7b may be rotatably supported in the

shaft holes

5a, 5b formed on the opposite end walls of the drying chamber 6, respectively, and may also extend through the

respective shaft holes

5a, 5b to the outside of the opposite end walls and be rotatably supported on the external supporting means. Although the two flipping

units

7a, 7b are essentially identical and are arranged at the same height in the vertical direction, the skilled person can have different configurations for the two flipping

units

7a, 7b depending on the process requirements of the dried sludge or the internal structure of the housing. For example, the plurality of flipping

units

702a, 702b of the two flipping

units

7a, 7b are disposed on the respective

rotating shafts

701a, 701b at different pitches. For example, one or more of the plurality of

flip assemblies

702a, 702b may have different length blades or ratchet

teeth

703a, 703b, respectively. For example, the plurality of flipping

units

702a, 702b of the two flipping

units

7a, 7b are disposed on the respective

rotating shafts

701a, 701b at different pitches. For example, the plurality of flip assemblies 702a of the flip device 7a and the plurality of flip assemblies 702b of the flip device 7b may be arranged to cross each other. In a further embodiment, the two flipping

means

7a, 7b can be arranged at different heights, respectively. In other words, the number of flip assemblies, the spacing between adjacent flip assemblies, the number, shape or size of the blades or ratchets, and the positions between the plurality of flip assemblies can be arbitrarily arranged by those skilled in the art according to the concept of the present invention.

Fig. 11 illustrates in partial perspective view a housing for the sludge drying apparatus of fig. 8. As shown in the figure,

shaft holes

5a, 5b for arranging the

rotation shafts

701a, 701b of the two

stirring devices

7a, 7b for stirring, crushing, and shearing sludge, and a shaft hole 5c for arranging the blast pipe 801b of the blast assembly 8 are formed on the two opposite end walls of the housing in the longitudinal direction of the housing, respectively. Since the shaft holes 5a and 5b for the two

flipping devices

7a and 7b disposed above the blowing assembly 8 are at the same height, and the shaft hole 5c is located between the shaft holes 5a and 5b and at a position below the shaft holes, i.e., at different heights, the connecting line of the centers of the shaft holes 5a and 5b and the shaft hole 5c forms a triangle. For example, on the end wall provided with the discharge port 12 for discharging dried sludge, it can be seen that the shaft hole 5c is located at the apex of the inverted triangle, and the

shaft holes

5a, 5b are located at two points of the base of the inverted triangle, respectively. The shaft holes 5a, 5b for the two

flap devices

7a, 7b are arranged symmetrically with respect to a vertical line passing through the center of the shaft hole 5c for the air blowing assembly 8 in the lateral direction, and the discharge port 12 is provided in the vicinity of the vertical line in the middle of the inverted triangle. This design allows the dried sludge to undergo continuous tumbling or agitation and displacement under the synergistic action of the two upper tumbling

devices

7a, 7b and the lower air supply assembly 8, while being pushed toward the discharge port 12 between the tumbling devices 7 and the air supply assembly 8.

In another embodiment, the bottom of the drying chamber 6 of the sludge drying apparatus 1 may be flat, that is, the bottom plate 4 may be a flat plate or a curved plate, so that the air supply assembly 8 may be disposed at any position in the middle of the drying chamber 6 or adjacent to the bottom, and thus, an asymmetric inverted triangle may be formed between the central connecting lines of the

axle holes

5a, 5b for the two

turning devices

7a, 7b and the axle hole 5c for the air supply assembly 8 in the transverse direction. In addition, more than one air supply assembly and one or more than two turning devices can be arranged in the drying chamber according to requirements. For example, one end of the air supply duct 801b of the air supply unit 8 may be connected to the driving device and the air supply device 10. Furthermore, in order to accelerate the flow of the dried gas or off-gas out of the drying chamber, an air-inducing device (not shown) may also be connected in fluid communication with the drying chamber 6 via a pipe to an exhaust 13 located on the lid 3. For example, if hot gas is used as the drying gas, a heating device (not shown) may be further provided to heat the drying gas entering the blowing assembly 8, and the heating device may be provided before or after the blowing device 10. In another embodiment, the heating device may be removed, hot gas or steam may be directly passed into the drying chamber as a drying gas to directly contact the sludge, and the sludge is dried.

Although only the sludge drying apparatus shown and described herein may have a single housing or be a unitary sludge drying apparatus, it will be appreciated by those skilled in the art that the apparatus or assembly described above may be employed in sludge drying chambers in other sludge treatment plants and similarly configured based thereon.

FIG. 12 is a flow chart illustrating an embodiment of the method for drying sludge by axial air blowing according to the present application. The axial air supply type sludge drying method can be used for drying sludge by using an axial air supply type sludge drying device similar to that shown in figures 8 and 9. Referring to fig. 8-11, the process of treating the sludge may be performed, for example, as the sludge to be dried is fed into the drying chamber through the feed inlet by a not-shown conveying device, for example, into the drying chamber through the feed inlet 11, at step 1, the driving device first drives the flipping devices, for example, the rotating

shafts

701a, 701b via the power input 14a, to rotate the plurality of flipping

units

702a, 702b, so that the blades or ratchets 703a, 703b on each flipping unit continuously flip, break and shear the sludge. In step 2, an air supply device, such as air supply device 10, is activated to deliver dry air to an air supply duct of an air supply assembly, such as inner hole 803b of air supply duct 801, and the dry air flows out through vent hole 804b on the wall of the air supply duct and into a drying chamber, such as drying chamber 6. Next, to accelerate the flow of the dried gas or exhaust gas, in step 3, the air inducing device is activated to rapidly flow the exhaust gas out of the drying chamber through an exhaust port, such as exhaust port 13. Typically, the air-blowing device may be an air-blowing device such as a blower or a fan, and the air-inducing device may be an induced draft fan. Alternatively, the blower may be replaced by a gas pressurizing device to deliver the drying gas into the drying chamber at a constant pressure to accelerate the flow of the drying gas into the drying chamber. The pressure reducing device can also be used for replacing an induced draft device to accelerate the flow rate of tail gas, so that the sludge drying efficiency is improved. In another scheme, after the driving device drives the turning device in the step 1, a step of adjusting the rotation direction and/or the rotation speed of the rotating shaft of the turning device, such as the step 1a, can be added according to needs, and then the air supply device is started. After the air inducing device is started, in step 4, the air supply assembly is driven, and the air supply assembly, i.e., the air supply pipe, is rotated by the driving device and drives the screw to turn or stir and push the sludge, for example, the air supply pipe 801b is rotated together with the screw 802 under the driving of the power input part 14c, wherein the screw can also play a role in moving the sludge while shielding the sludge. Then, in step 5, the drying of the sludge is accelerated by the synergistic action of the turning component of the turning device and the screw of the air supply component, and the dried sludge is discharged out of a discharge port, such as the discharge port 12. In another scheme, after the air supply assembly is driven to rotate in step 4, a step of adjusting the rotation direction and/or the rotation speed of the air supply assembly, for example, step 4a, can be added as required to make the dried sludge in a better drying state and discharge the dried sludge after obtaining the expected dried sludge. In another embodiment, if it is desired to dry the sludge with hot drying gas, the drying gas to be fed into the drying chamber may be heated by an additional heating device. The heating step may be arranged after driving the flipping means, e.g. step 1 b. In another solution, not shown, it is possible to control a plurality of flipping devices, respectively, such as the rotation of the

rotating shafts

701a, 701b of the flipping

devices

7a, 7b or to keep the air blowing assembly 8 still. In yet another arrangement, not shown, a heat source with hot dry air may be in fluid communication with a conduit before or after the air supply means to feed the hot dry air into the air supply duct of the air supply assembly. In a further not shown solution, the heating means may be activated after the air supply means and the air inducing means are activated separately or simultaneously, or after the air supply assembly is driven. In a further embodiment, which is not shown, the rotational direction and/or the rotational speed of the rotational shaft of the turning device can be adjusted after the heating device, the air blowing device and/or the air inducing device are/is activated. In a further embodiment, which is not shown, the direction of rotation and/or the rotational speed of the air supply assembly can be adjusted before the heating device, the air supply device and/or the air induction device are/is activated. In a further not shown solution, the air supply assembly is rotated before the driving means drive the flipping means, after which the heating means, the air supply means and/or the air inducing means are activated, respectively. In a further not shown solution, the turning axis of the flipping unit and the air supply assembly may also be adjusted such that a plurality of turning axes of the flipping unit, for example, the turning

axes

701a, 701b, may be rotated in the same or opposite directions to each other, while the air supply assembly and the turning axes 701a, 701b are rotated together or in the same or opposite directions to one another.

Through the continuous shearing, crushing and turning of the turning assembly, the pushing of the air supply assembly and the action of the drying gas entering the drying chamber, the granularity of the sludge is gradually reduced to become particles, and then the particles are partially formed, so that the drying degree of the sludge is continuously improved. For example, when the air supply assembly and the plurality of rotating shafts of the turning device rotate together in the same direction, the turning assembly of the turning device and the screw of the air supply assembly help to accelerate the sludge toward the end wall having the discharge port, and when the rotating directions of the turning assembly and the air supply assembly are different, the sludge movement is slowed down. Therefore, the rotating speed and/or the rotating direction of the rotating shaft or the air supply assembly of each turning device, the feeding speed of the drying gas, the gas temperature and the like are adjusted in time according to the drying degree of the sludge, and the sludge drying efficiency is improved. It should be noted that the function of the air blowing assembly, i.e. the screw, is described herein to emphasize the function of pushing the sludge, however, the screw also has the function of stirring or agitating the sludge, especially when the conveying assembly with different layout or shape of the screw or screw segment structure, such as S, Sa, Sb, is adopted, the force of stirring or agitating the sludge is slightly different. For example, when the screw member has both the positive screw section and the inclined screw section, although both the positive screw section and the inclined screw section can push the sludge to move in the longitudinal direction of the drying chamber, the force is strong and weak, the sludge which is not pushed is turned up and down, and the inclined screw section or the inclined screw wing can also shield the vent hole which is formed on the blast pipe and is positioned below the inclined screw section or the inclined screw wing. As described above, the air blowing assembly is disposed at a position adjacent to the bottom of the drying chamber, the drying gas first acts on the sludge located at the bottom of the drying chamber, and thus the sludge is continuously dried as the dried sludge is moved by the screw along the longitudinal passage toward one end of the drying chamber, and particularly, the sludge screw is pushed down to be continuously stacked, flipped or stirred, moved upward, and gradually moved out of the discharge port by the combined action of the screw of the air blowing assembly and the flipping assembly of the flipping unit. It is obvious to a person skilled in the art that when a stirring device having the function of moving the sludge in an axial direction is not used, the dried sludge can be discharged through a discharge port provided at a suitable position of the drying chamber.

Although the axial-blowing sludge drying device is shown in a single body form, the axial-blowing sludge drying device of the present application may be a part of other sludge treatment devices. It will be appreciated that in the method of the present application, the heating means may be removed when using, for example, 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 this application includes, but is not limited to, a chemical-containing gas, an ambient or cooled gas, a hot gas, or a gas having a particular composition, and the like.

Although various embodiments have been described in the present invention, the present invention is not limited to the embodiments described in the specification, and those skilled in the art can make various changes and modifications to the components, assemblies or devices of the sludge drying apparatus and the axial-blowing sludge drying method of the present invention, which are within the scope of the concept of the present invention, by the above-described design concept of the present invention.

Claims

1. The utility model provides an axial air supply formula sludge drying device, sludge drying device includes:

a housing forming a drying chamber therein;

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

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

an axial air supply assembly, comprising:

the air supply pipe is used for conveying air, is provided with an axial hole, and is provided with at least one vent hole on the pipe wall, wherein the at least one vent hole is communicated with the axial hole in a fluid manner;

the spiral piece is provided with a shaft hole, and the spiral piece is sleeved on the pipe wall of the blast pipe through the shaft hole and is fixedly connected with the pipe wall; and

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

2. A fluid delivery assembly according to claim 1, wherein the helical elements comprise a forward helical element or an inclined helical element, wherein the forward helical element is perpendicular to the axis of the blower tube or the wall of the tube, and the inclined helical element is inclined at an angle to the wall of the tube along the axis of the blower tube, and the inclined helical element comprises a right-inclined helical element or a left-inclined helical element.

3. A fluid delivery assembly according to claim 1 or claim 2, wherein the screw comprises a plurality of screw sections, and the plurality of screw sections comprises a positive screw section, a right-handed screw section and a left-handed screw section, wherein the positive screw section is perpendicular to the axis or wall of the supply duct, the right-handed screw section is angled to the right relative to the axis or wall of the supply duct, and the left-handed screw section is angled to the left relative to the axis or wall of the supply duct.

4. A fluid delivery assembly according to any of claims 1 to 3, wherein any two of the positive helical section, the right-handed helical section and the left-handed helical section are arranged alternately in the direction of the axis of the blower tube, and each inclined helical section may have the same or different inclination angle.

5. The sludge drying apparatus as claimed in any one of claims 1 to 4, wherein the right-inclined screw section and the left-inclined screw section of the plurality of screw sections are provided in pairs in the axial direction of the blast pipe, and each two pairs of the right-inclined screw section and the left-inclined screw section are spaced apart from each other, wherein each screw section may have the same or different inclination angle.

6. The sludge drying apparatus as claimed in any one of claims 1 to 5, wherein the at least one air vent comprises a plurality of air vents, wherein the plurality of air vents are distributed on the wall of the air supply pipe, and the screw member or the screw section axially covers at least a part of the plurality of air vents.

7. The sludge drying apparatus of any one of claims 1 to 6, wherein the plurality of ventilation holes are positioned as far as possible below the inclined screw member or the inclined screw section in a regular or irregular manner.

8. The sludge drying device as claimed in any one of claims 1 to 7, wherein the plurality of vent holes are arranged along the length direction of the air supply pipe from one end of the air supply pipe to the other end thereof in such a way that the number of the vent holes is gradually increased and/or the aperture of the vent holes is gradually increased.

9. The sludge drying apparatus as claimed in any one of claims 1 to 8, wherein said one end of said air supply assembly is connectable to a driving device, and the other end of said air supply assembly is connectable to and in fluid communication with an air supply device, said driving device being capable of driving said air supply pipe of said air supply assembly to rotate.

10. A method for drying sludge by using an axial air supply type sludge drying device comprises the following steps:

driving a turning device arranged in a drying chamber of a 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 the drying chamber through a feed inlet of the drying chamber and located in the drying chamber;

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

starting an air inducing device to enable the dried gas after the sludge is dried to be discharged through an exhaust port of the drying chamber;

driving the air supply assembly to enable the air supply pipe to rotate and drive the spiral piece on the air supply assembly to push sludge; and

under the synergistic action of the turning device and the air supply assembly, the drying of the sludge is accelerated, and the dried sludge is discharged from the discharge port.