Preheating feeder screw for steam rotary drier and steam rotary drier

Abstract

The utility model provides a kind of preheating feeding screw device and and steam rotary drier for steam rotary drier, and this preheating feeding screw device is by adopting hollow jacket screw shaft and hollow screw belt, hollow support rod, water baffle, swivel joint and its on water inlet and water outlet etc. constitute hot water distribution preheating system, adopt hot water to directly heat hollow jacket screw shaft and hollow screw belt, and screw belt integrates heating function, and directly contact between material, preheat material well, reduce the steam consumption of drier, while also reduce the corrosion of high moisture content material to drier front end heat exchange line pipe, so that equipment reduces energy consumption while drying efficiency is higher.

Description

Technical Field

[0001] This utility model relates to the field of dryer technology, and in particular to a preheating feeding screw device for a steam rotary dryer and a steam rotary dryer including the same. Background Technology

[0002] Rotary steam tube dryers are large-scale drying equipment widely used in petrochemical, food, and mining industries for drying powdery or granular materials. Their main working principle utilizes steam as a heat source. The steam circulates within the heat exchange tubes, transferring heat to the material inside the dryer. Specifically, the material enters through the feeding screw at the front of the dryer. As the dryer cylinder rotates, the material tumbles and moves inside, making full contact with the steam-filled heat exchange tubes. The high-temperature steam in the tubes transfers heat to the material, causing the moisture to gradually evaporate. Simultaneously, the internal air carrier system carries away the evaporated moisture through the feeding screw, thus completing the drying process. This drying method not only ensures uniform heating of the material but also effectively avoids material damage caused by localized overheating. Among them, the feeding screw is the most important component of the steam tube rotary dryer. It is the "throat" component connecting the upstream conveying system and the dryer cylinder. Its core function is not only to "feed the material in", but also to uniformly feed the material with high moisture content into the dryer cylinder under continuous, closed, controllable, low breakage and low adhesion conditions, and the carrier gas system carries away the water vapor from the dried material through the feeding screw.

[0003] However, traditional feeding screw devices have a single function, only used for mechanical conveying, and do not integrate preheating function. As a result, the material still has a high moisture content when it enters the front end of the dryer cylinder, and the dryer needs to consume more steam to heat the material. In addition, it is easy for the material to adhere, stick to the wall, and clump together on the inner wall of the front end of the dryer and the heat exchange tubes, which will significantly reduce the heat transfer efficiency, thereby causing the risk of blockage of the dryer cylinder, and even causing the dryer main motor to be overloaded.

[0004] To address the problems of traditional screw feeders, existing screw feeders are equipped with heating coils to preheat the material. However, the screw feeder and its supporting systems still have the following issues:

[0005] 1) The heat tracing coil has low thermal efficiency and cannot fully preheat the material.

[0006] 2) Material and liquid leakage often occurs at the end plate seal between the screw shaft and the feed screw housing, causing corrosion of the bearings and increasing safety hazards.

[0007] 3) Existing screw feeding methods cannot dynamically respond to the material state and adjust the screw speed to regulate the conveying volume, which easily leads to localized high humidity, clumping, blockage and other phenomena. Utility Model Content

[0008] To address the problems of existing feeding screw devices and their supporting systems used in steam rotary dryers, this invention provides a preheating feeding screw device (for the feed end of a steam tube rotary dryer). This design aims to pre-dry materials with high moisture content before they enter the steam tube rotary dryer by using a feeding screw with integrated preheating function, reducing the moisture content to a certain level before further drying. This two-stage drying method effectively solves the problems of material sticking to the walls and clogging at the front end of the heat exchange tubes in the steam tube rotary dryer, as well as overloading of the dryer's main motor, thus improving drying efficiency and product quality. Simultaneously, because the feeding screw with integrated preheating function has already removed some moisture from the high-moisture-content material, the drying capacity of the steam tube rotary dryer is more fully utilized, providing the possibility for expanding the capacity of subsequent equipment.

[0009] To achieve the above effects, the present invention adopts the following technical solution:

[0010] A preheating feeding screw device for a steam rotary dryer includes a feeding screw cavity and a hollow jacketed screw shaft;

[0011] The feeding screw cavity is composed of an end plate, a feeding screw shell, and a shell support frame. The end plate is fixed to one side of the feeding screw shell (the end plate and the feeding screw shell can be integrally formed or detachably fixed together). The shell support frame is used to support the feeding screw shell. A heat tracing coil is provided on the outer wall of the feeding screw shell by pipe clamps.

[0012] The upper part of the feeding screw shell is provided with a material inlet, and the interior is provided with a material outlet that communicates with the dryer cylinder.

[0013] The hollow jacketed spiral shaft is sealed to the end plate via a shaft end sealing assembly;

[0014] The hollow jacketed spiral shaft passes through the feeding spiral housing, and one end of the hollow jacketed spiral shaft located on the end plate protrudes from the feeding spiral housing. A rotary joint is provided at the end of the protruding section, and the rotary joint is respectively provided with an inlet and an outlet. The inlet is connected to the outer tube in the hollow jacketed spiral shaft, and the inner tube in the hollow jacketed spiral shaft is connected to the outlet. A transmission system is provided on the protruding section.

[0015] The hollow jacketed spiral shaft is provided with an annular water-blocking baffle in the annular jacket formed by the outer pipe section and the inner pipe section near the end plate (the outer periphery of the annular water-blocking baffle is fixed to the inner wall of the outer pipe, and the inner periphery is fixed to the outer wall of the inner pipe). The annular water-blocking baffle is arranged along the radial plane.

[0016] Multiple hollow support rods, which communicate with the outer tube, are vertically arranged on the outer wall of the hollow jacketed spiral shaft section located in the feeding spiral cavity;

[0017] Each of the hollow support rods is distributed circumferentially along the outer side of the hollow jacket spiral shaft section, and is used to support and connect the hollow spiral ribbon;

[0018] One end of the hollow spiral ribbon is connected to the outer pipe section between the water inlet and the annular water-blocking baffle, and the other end is connected to the inner pipe section at the outlet of the feeding spiral shell.

[0019] To prevent material leakage, multiple reverse spiral blades (opposite to the material running direction) are provided on the outer wall of the hollow jacketed spiral shaft section located in the feeding spiral cavity near the end plate, such as 4-6.

[0020] Existing preheating feeding screw devices often suffer from material and liquid leakage at the end plate seal between the screw shaft and the feeding screw housing, leading to bearing corrosion and increased safety hazards. Current technology uses a packing seal structure with gas backflushing to improve sealing. The shaft end sealing assembly of this invention adds an oil seal to the existing packing seal structure with gas backflushing and modifies the structure of the sealing ring. It includes packing, a sealing ring, and an oil seal arranged sequentially along the axial direction. The sealing ring has a groove in its circumferential center with numerous evenly distributed holes (e.g., 32 holes evenly distributed around the center of the sealing ring). This design aims to improve the gas backflushing effect while effectively preventing material and water leakage, significantly enhancing the sealing performance.

[0021] To improve the stability of the preheating feeding screw device, the housing support frame is fixedly connected to the feeding screw housing.

[0022] To improve the preheating effect on the hollow jacketed spiral shaft, and thus improve the preheating effect on the material, a hot water inlet pipe is provided on the outer pipe section between the water inlet and the annular water-blocking baffle, and one end of the hollow spiral ribbon is connected to the outer pipe through the hot water inlet pipe.

[0023] A hot water drain pipe is provided on the inner pipe section at the outlet of the feeding screw housing, and the other end of the hollow screw ribbon is connected to the inner pipe via the hot water drain pipe. The hot water inlet pipe and the hot water drain pipe can also be replaced by hollow support rods at corresponding positions.

[0024] To improve the stability and preheating effect of the preheating feeding screw device, each of the hollow support rods is welded to the hollow spiral ribbon and the hollow jacketed screw shaft as a whole (or each of the hollow support rods, the hot water inlet pipe, the hot water outlet pipe, and the hollow spiral ribbon and the hollow jacketed screw shaft section are welded to the whole).

[0025] To further improve the stability and preheating effect of the preheating feeding screw device, reinforcing rings are provided at the welded parts of the hollow support rod, the hollow spiral ribbon, and the hollow jacketed screw shaft (or reinforcing rings are provided at the welded parts of the hollow support rod, the hot water inlet pipe, the hot water outlet pipe, and the hollow spiral ribbon and the hollow jacketed screw shaft).

[0026] The hollow jacketed spiral shaft, the hollow spiral ribbon, each of the hollow support rods, the annular water baffle, the hot water inlet pipe, the hot water outlet pipe, the rotary joint and its inlet and outlet, etc., constitute a hot water distribution and preheating system for preheating and drying materials.

[0027] To improve the stability of the preheating feeding screw device during operation, the transmission system, the bearing housing, and the hollow jacketed screw shaft are supported by a support frame. As a specific example, the transmission system includes a variable frequency motor, a coupling, a reducer, a transmission sprocket, and a chain.

[0028] The hollow jacketed spiral shaft has, in sequence, the end cap, the drive sprocket and chain, and at least two bearing seats on its protruding section; the variable frequency motor is connected to the drive sprocket and chain in sequence via the coupling and the reducer. The transmission system drives the drive sprocket and chain to rotate the hollow jacketed spiral shaft through the variable frequency motor, coupling, and reducer.

[0029] As a more specific example, the hollow jacketed spiral shaft is supported on the end plate of the feed spiral housing by a pair of bearing seats.

[0030] For ease of maintenance and relocation, the support frame is placed on the guide rail.

[0031] To increase the material preheating time and improve the preheating effect, a shell block plate is provided at the material outlet of the feeding screw shell to act as an overflow weir.

[0032] To address the problems of existing screw feeding methods, which cannot dynamically respond to material conditions and adjust the screw speed to regulate the conveying capacity, thus easily causing localized high humidity, clumping, and blockage, two openings are provided at the lower front end of the feeding screw housing (see...). Figure 1This device serves as an interface with multispectral moisture sensors and distributed thermocouples. By adding multispectral moisture sensors and distributed thermocouples to the feeding screw shell, the temperature and humidity monitoring module and intelligent control system can accurately detect the moisture content and temperature of the material, effectively providing feedback on the moisture content and temperature of the preheated material. This allows the variable frequency motor to be adjusted to change the screw speed, ensuring the stability of material conveying.

[0033] This utility model also provides a steam rotary dryer including the aforementioned preheating feeding screw device for a steam rotary dryer.

[0034] 1. The preheating feeding screw device for a steam rotary dryer provided by this utility model constitutes a hot water distribution preheating system by using a hollow jacketed screw shaft, hollow screw ribbon, hollow support rod, annular water baffle, rotary joint, and its inlet and outlet. Hot water is used to directly heat the hollow screw ribbon, which integrates the heating function. Combined with the hollow support rod and hollow jacketed screw shaft, it is in direct contact with the material, which can effectively preheat the material, reduce the steam consumption of the dryer, and also reduce the corrosion of the heat exchange tubes at the front end of the dryer by materials with high moisture content, resulting in higher drying efficiency of the equipment.

[0035] 2. The preheating feeding screw device for a steam rotary dryer provided by this utility model has 4 to 6 reverse spiral blades set near the end plate of the feeding screw in the hollow jacketed screw shaft section located in the feeding screw cavity, so as to promote the material to move into the dryer cylinder and prevent leakage from the end plate and shaft end seal in the reverse direction.

[0036] 3. The preheating feeding screw device for a steam rotary dryer provided by this utility model, by adopting a packing seal structure with gas backflushing between the hollow jacketed screw shaft and the end plate, and by adding an oil seal and upgrading the internal sealing ring structure, can effectively prevent the overflow of materials and water vapor, prevent corrosion of bearings, and reduce safety hazards.

[0037] 4. The preheating feeding screw device for a steam rotary dryer provided by this utility model continuously stirs, mixes, preheats, and dries the material during the feeding process through a hollow screw ribbon and hollow support rod circulated with hot water. This improves heat transfer efficiency, reduces the heat load on the dryer cylinder, and, combined with upgraded nitrogen gas seals and oil seals, prevents material leakage and adhesion. Simultaneously, a temperature and humidity monitoring module and intelligent control system accurately detect the material's moisture content and temperature, dynamically adjusting the variable frequency motor in real time to change the screw speed, ensuring stable material conveying. This significantly reduces drying energy consumption and blockage rate for easily agglomerated materials such as PTA, POM, PPE, and HDPE. It is suitable for energy-saving pretreatment of high-humidity powder materials in petrochemical and coal chemical industries, fundamentally eliminating the possibility of the hollow jacketed screw shaft jamming. It also eliminates losses caused by material blockage at the front end of the dryer leading to equipment shutdown, greatly reducing operating costs and significantly improving the overall performance and operational stability of the steam rotary dryer. Attached Figure Description

[0038] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the preheating feeding screw device for a steam rotary dryer provided by this utility model;

[0040] Figure 2 for Figure 1 Schematic diagram of the hollow jacketed spiral shaft;

[0041] Figure 3 for Figure 1 Right view of the hollow jacketed spiral shaft;

[0042] Figure 4 for Figure 1 A schematic diagram of the central shaft end sealing assembly.

[0043] Among them, 1-rotary joint; 2-metal hose; 3-drive sprocket and chain; 4-bearing seat; 5-hollow jacketed spiral shaft; 6-shaft end sealing assembly; 7-end plate; 8-feeding spiral shell; 9-hollow helical ribbon; 10-shell blocking plate; 11-hollow support rod; 12-shell support frame; 13-heat tracing coil; 14-outrigger; 15-support frame; 16-variable frequency motor; 17-coupling; 18-reducer; 19-maintenance guide rail; 20-spiral blade; 21-water baffle; 22-hot water inlet pipe; 23-hot water drain pipe; 24-packing; 25-sealing air ring; 26-oil seal. Detailed Implementation

[0044] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the content of the present invention.

[0045] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting unless the context clearly indicates otherwise. The terms “comprising,” “including,” and “having” are inclusive and therefore indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0046] Furthermore, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0047] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "upper," "lower," "inner," "outer," "end," "side," etc. Such spatial relative terms are intended to include different orientations of the mechanism in use or operation, in addition to those depicted in the figure. For example, if the mechanism in the figure is flipped, then an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The mechanism may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0048] The preheating feeding screw device for a steam rotary dryer provided by this utility model includes a rotary joint 1, a metal hose 2, a transmission sprocket and chain 3, a bearing seat 4, a hollow jacketed screw shaft 5, a shaft end sealing assembly 6, an end plate 7, a feeding screw shell 8, a hollow screw ribbon 9, a shell blocking plate 10, a hollow support rod 11, a shell support frame 12, a heat tracing coil 13, a support leg 14, a support frame 15, a variable frequency motor 16, a coupling 17, a reducer 18, a maintenance guide rail 19, a screw blade 20, a water baffle 21, a hot water inlet pipe 22, a hot water drain pipe 23, a packing 24, a sealing ring 25, and an oil seal 26.

[0049] like Figure 1 As shown, the end plate 7, the feeding screw shell 8, and the shell support frame 12 constitute the feeding screw cavity. The end plate 7 is fixed to one side of the feeding screw shell 8 (the end plate 7 and the feeding screw shell 8 can be an integrally formed structure or a structure that can be detachably fixed together). A heat tracing coil 13, fixed by pipe clamps, is provided on the outer wall of the feeding screw shell 8. The upper part of the feeding screw shell 8 has a material inlet, and the interior has a material outlet communicating with the dryer cylinder, supported by the shell support frame 12 (the shell support frame 12 is fixedly connected to the feeding screw shell 8). A shell plug 10 is provided at the material outlet position of the feeding screw shell 8 to act as an overflow weir, used to increase the material preheating time. An opening is also provided at the lower front end of the feeding screw shell 8. Figure 1(Enlarged view) This opening serves as a connection interface with a multispectral moisture sensor and a distributed thermocouple, effectively providing feedback on the moisture content and temperature of the preheated material. The hollow jacketed spiral shaft 5 penetrates the feeding spiral housing 8, and one end of it protrudes from the feeding spiral housing 8 at the end plate 7. A rotary joint 1 is provided at the end of the protruding section, connected to metal hoses 2 (i.e., inlet and outlet) for water inlet and outlet. The inlet is connected to the outer tube in the hollow jacketed spiral shaft 5, and the inner tube in the hollow jacketed spiral shaft 5 is connected to the outlet. A transmission system is provided on the protruding section, comprising a variable frequency motor 16, a coupling 17, a reducer 18, a transmission sprocket, and a chain 3. The protruding section of the hollow jacketed spiral shaft 8 is sequentially equipped with the rotary joint 1, the transmission sprocket and chain 3, and two bearing seats 4 (or multiple bearing seats). The variable frequency motor 16 is sequentially connected to the transmission sprocket and chain 3 via the coupling 17 and the reducer 18. The hollow jacketed spiral shaft 5 is supported by two sets of bearing seats 4 and connected to the front rotary joint 1. The sprocket at the output end of the reducer 18 drives the sprocket on the hollow jacketed spiral shaft 5 to rotate through the transmission chain. For easy maintenance and movement, the entire transmission system is supported by the support frame 15 and placed on the maintenance guide rail 19 and fixed by four sets of support legs 14. The hollow jacketed spiral shaft 5 adopts a cantilever structure, which makes the operation more stable and reliable.

[0050] Multiple hollow support rods 11, connected to the outer pipe, are vertically installed on the outer wall of the hollow jacketed spiral shaft section located within the feeding spiral cavity. The ends of each hollow support rod 11 away from the hollow jacketed spiral shaft 5 are interconnected to form a hollow spiral ribbon 9. The hollow support rods 11 are distributed circumferentially along the outer side of the hollow jacketed spiral shaft section within the feeding spiral cavity, serving to support and connect the hollow spiral ribbon 9. One end of the hollow spiral ribbon 9 connects to the outer pipe section between the water inlet and the annular water-blocking baffle, and the other end connects to the inner pipe section at the outlet of the feeding spiral shell 8. The hollow support rods 11, the hollow spiral ribbon 9, and the hollow jacketed spiral shaft 5 are welded together as a single unit, and a reinforcing ring is provided at the welded area.

[0051] like Figure 2 As shown, the annular jacket formed by the outer pipe section and the inner pipe section near the end plate 7 inside the hollow jacketed spiral shaft 5 is provided with an annular water-blocking baffle 21 for separating water inlet and water outlet. The annular water-blocking baffle 21 is arranged along the radial plane. Multiple spiral blades 20 (such as 4-6) are arranged on the outer wall of the hollow jacketed spiral shaft section located in the feeding spiral cavity near the end plate 7, which are opposite to the material running direction.

[0052] like Figure 3 As shown, a hot water inlet pipe 22 is provided on the outer pipe section between the water inlet and the annular water baffle 21, and a hot water drain pipe 23 is provided on the inner pipe section at the outlet of the feeding screw shell 8. One end of the hollow screw ribbon 9 is connected to the outer pipe via the hot water inlet pipe 22, and the other end of the hollow screw ribbon 9 is connected to the inner pipe via the hot water drain pipe 23.

[0053] The hollow jacketed spiral shaft 5 is sealed and fixedly connected to the end plate 7 via the shaft end sealing assembly 6; the shaft end sealing assembly 6 is an improved packing seal structure with gas backflushing, such as... Figure 4 As shown, the device includes packing 24, sealing ring 25 and oil seal 26 arranged sequentially along the axial direction. The sealing ring 25 has a groove in the center of its circumference, and the groove has a number of evenly distributed holes (the sealing ring has a groove in the middle, and 32 holes are evenly distributed around it), which is intended to improve the effect of gas backflushing and can effectively prevent material leakage.

[0054] During the preheating process, hot water enters the outer tube of the hollow jacketed spiral shaft from the metal hose for water inlet on the rotary joint at the front end of the hollow jacketed spiral shaft. The hot water is isolated by an annular water-blocking baffle. It then enters the hollow spiral ribbon and hollow support rod through the hot water inlet pipe to preheat them. After the hollow spiral ribbon and hollow support rod are filled, they enter the inner tube of the hollow jacketed spiral shaft through the hot water drain pipe at the tail of the hollow spiral ribbon and return to the metal hose for drainage at the rotary joint at the front end for discharge. After the entire hollow jacketed spiral shaft is heated, the transmission system drives the transmission sprocket and chain to rotate the hollow jacketed spiral shaft through a variable frequency motor, coupling, and reducer. The material is then fed into the feeding spiral cavity from the material inlet at the top of the feeding spiral shell. During the feeding process, the material is continuously stirred, mixed, preheated, and dried by the preheated hollow jacketed spiral shaft, hollow spiral ribbon, and hollow support rod within the feeding spiral cavity. After drying, the material is pushed into the dryer cylinder through the material outlet, which connects the inside of the feeding spiral shell to the dryer cylinder. This prevents material agglomeration. Simultaneously, the multi-spectral feed connected at the opening of the feeding spiral shell... Moisture sensors and distributed thermocouples, along with a temperature and humidity monitoring module and intelligent control system, accurately detect the moisture content and temperature of the dried material and provide real-time feedback to the control system. Based on the real-time feedback data, the variable frequency motor is adjusted to change the speed of the hollow jacketed screw shaft and control the time the material spends in the feeding screw shell (achieving dynamic adjustment of the hollow jacketed screw shaft speed and avoiding phenomena such as agglomeration and blockage caused by excessive local humidity of the material). At the same time, the shaft end sealing assembly can effectively prevent the leakage of material and moisture, prevent corrosion of the bearings, reduce safety hazards, and ensure the stability of material conveying.

[0055] Of course, there may be other embodiments of this utility model. Without departing from the spirit and essence of this utility model, those skilled in the art can make various corresponding changes and modifications based on this utility model, but these corresponding changes and modifications should all fall within the protection scope of the claims of this utility model.

Claims

1. A preheating feeding screw device for a steam rotary dryer, characterized in that, Includes a feeding spiral cavity and a hollow jacketed spiral shaft; The feeding screw cavity is composed of an end plate, a feeding screw shell, and a shell support frame; the end plate is fixed to one side of the feeding screw shell, and the shell support frame is used to support the feeding screw shell; a heat tracing coil is provided on the outer wall of the feeding screw shell and fixed by a pipe clamp; The upper part of the feeding screw shell is provided with a material inlet, and the interior is provided with a material outlet that communicates with the dryer cylinder. The hollow jacketed spiral shaft is sealed to the end plate via a shaft end sealing assembly; The hollow jacketed spiral shaft passes through the feeding spiral housing, and one end of the shaft located on the end plate protrudes from the feeding spiral housing. A rotary joint is provided at the end of the protruding section. The rotary joint is provided with an inlet and an outlet. The inlet is connected to the outer tube in the hollow jacketed spiral shaft, and the inner tube in the hollow jacketed spiral shaft is connected to the outlet. A transmission system is provided on the protruding section. An annular water-proof baffle is provided inside the annular jacket formed by the outer pipe section and the inner pipe section near the end plate inside the hollow jacket spiral shaft. The annular water-proof baffle is arranged along the radial plane. Multiple hollow support rods, which communicate with the outer tube, are vertically arranged on the outer wall of the hollow jacketed spiral shaft section located in the feeding spiral cavity; Each of the hollow support rods is distributed circumferentially along the outer side of the hollow jacket spiral shaft section, and is used to support and connect the hollow spiral ribbon; One end of the hollow spiral ribbon is connected to the outer pipe section between the water inlet and the annular water-proof baffle, and the other end is connected to the inner pipe section at the outlet of the feeding spiral shell. Multiple reverse spiral blades are provided on the outer wall of the hollow jacketed spiral shaft section located in the feeding spiral cavity near the end plate; The shaft end sealing assembly is selected from packing, sealing ring and oil seal arranged sequentially along the axial direction. The sealing ring has a groove in the circumferential center and a plurality of evenly distributed holes in the groove. A casing block is provided at the material outlet of the feeding screw casing.

2. The preheating feeding screw device for a steam rotary dryer as described in claim 1, characterized in that, The housing support frame is fixedly connected to the feeding screw housing.

3. The preheating feeding screw device for a steam rotary dryer as described in claim 1, characterized in that, A hot water inlet pipe is provided on the outer pipe section between the water inlet and the annular water-blocking baffle, and one end of the hollow spiral ribbon is connected to the outer pipe through the hot water inlet pipe; A hot water drain pipe is provided on the inner pipe section at the outlet of the feeding screw shell, and the other end of the hollow screw ribbon is connected to the inner pipe through the hot water drain pipe.

4. The preheating feeding screw device for a steam rotary dryer as described in claim 3, characterized in that, The hollow support rods, the hot water inlet pipe, the hot water drain pipe, the hollow threaded ribbon, and the hollow jacketed spiral shaft section are welded together as a whole.

5. The preheating feeding screw device for a steam rotary dryer as described in claim 4, characterized in that, Reinforcing rings are provided at the welded joints of the hollow support rod, the hot water inlet pipe, the hot water outlet pipe, the hollow threaded ribbon, and the hollow jacket spiral shaft section.

6. The preheating feeding screw device for a steam rotary dryer as described in claim 1, characterized in that, The transmission system, bearing housing, and hollow jacketed spiral shaft are supported by a support frame.

7. The preheating feeding screw device for a steam rotary dryer as described in claim 1, characterized in that, The transmission system includes a variable frequency motor, a coupling, a reducer, a transmission sprocket, and a chain; The hollow jacketed spiral shaft has a convex section on which the rotary joint, the transmission sprocket and chain, and at least two bearing seats are arranged in sequence; the variable frequency motor is connected to the transmission sprocket and chain in sequence via the coupling and the reducer.

8. The preheating feeding screw device for a steam rotary dryer as described in claim 1, characterized in that, The material outlet of the feeding screw casing is provided with a casing block plate.

9. The preheating feeding screw device for a steam rotary dryer as described in any one of claims 1-8, characterized in that, The lower part of the feeding screw housing is also provided with an opening for connecting to the interface of the multispectral moisture sensor and the distributed thermocouple.

10. A steam rotary dryer, characterized in that, Includes the preheating feed screw device for a steam rotary dryer as described in any one of claims 1-9.

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