Multi-stage separation drying and dehydrating machine for granular materials

Abstract

The present invention discloses a multi-stage separation drying and dehydrating machine for particulate materials, which solves the technical problems of high energy consumption, poor operation stability and easy damage to materials in existing dehydrating machines. The technical scheme includes a vertical shell and a driving device, wherein the top of the shell is provided with a feed port and the bottom is provided with a discharge port and a drain port, the center of the shell is vertically provided with a rotating shaft connected to the driving device, and one or more stages of drying and dehydrating units connected in series are provided along the axial direction of the rotating shaft, the uppermost drying and dehydrating unit is connected to the feed port, and the lowermost drying and dehydrating unit is connected to the discharge port; the drying and dehydrating unit includes a distribution plate mounted on the rotating shaft and a lantern-shaped filter mounted on the outer periphery of the distribution plate, and the lantern-shaped filter is fixed in the shell via a fixing member. The present invention has a simple structure, low energy consumption, little material damage, a high product qualification rate, good dehydration effect and good operation stability.

Description

Technical Field

[0001] The invention relates to a drying and dehydrating machine, in particular to a multi-stage separation drying and dehydrating machine for granular materials. Background Art

[0002] At present, the equipment used for dehydration of chips and particles in the industrial and polyamide nylon 6 polymerization industries in my country is mainly for bottom feeding and top discharging. The scraper driven by electric machinery rotates and centrifuges the material for dehydration while lifting the material from bottom to top to the top discharge port for discharge. The water in the material is separated by one or more cylindrical filters outside the scraper and then collected and discharged. Foreign countries also use similar dehydration methods, and their technical level has not changed much in the past 25 years. There are mainly the following four problems:

[0003] 1. The motor drives the scraper to rotate and centrifuge for dehydration, which can easily cause the material to be squeezed and deformed by the scraper, or forcibly scratched, forming a large amount of powder and fine particles, affecting the product qualification rate;

[0004] 2. The filter screen of the dehydrator is made of punched stainless steel plate. Studies have shown that this porous structure will produce lateral cutting force when the material is in a centrifugal state, causing the material particles to produce powder and fine particles, further affecting the product qualification rate.

[0005] 3. The filter screen of the dehydrator is usually a straight circular single-stage or multi-stage. The corners where the stages are connected are welded at right angles, resulting in a large number of dead corners for dehydration. During centrifugal dehydration, the material is easily accumulated at the corners, causing some materials to lag in movement, oxidize, yellow, and have uneven molecular weight distribution.

[0006] 4. The feeding method of the dehydrator is to feed from the bottom, and the motor drives the scraper to lift the centrifugal dehydration. The mechanical equipment has a large load and high energy consumption, which can easily cause the equipment to get stuck and stop. In severe cases, a large amount of process water will enter the lower drying tower equipment, which can easily cause product quality problems and production safety accidents. Summary of the invention

[0007] The purpose of the present invention is to solve the above technical problems and to provide a multi-stage separation drying and dehydrating machine for granular materials with simple structure, low energy consumption, small material damage, high product qualification rate, good dehydration effect and good operation stability.

[0008] The technical solution includes a vertical shell and a driving device, wherein the top of the shell is provided with a feed port, and the bottom is provided with a discharge port and a drain port, a rotating shaft connected to the driving device is vertically provided at the center of the shell, and one or more drying and dehydration units are provided in series along the axial direction of the rotating shaft, the uppermost drying and dehydration unit is connected to the feed port, and the lowermost drying and dehydration unit is connected to the discharge port; the drying and dehydration unit includes a distribution plate mounted on the rotating shaft and a lantern-shaped filter mounted on the outer periphery of the distribution plate and having a top surface opening and a bottom surface opening, and the lantern-shaped filter is fixed in the shell via a fixing member.

[0009] The lantern-shaped filter is surrounded by a plurality of arc-shaped strips uniformly arranged in the radial direction, and a drainage gap is provided between two adjacent arc-shaped strips.

[0010] The ratio of the length of the short axis to the long axis of the lantern-shaped filter is 1:1.1-2.7, more preferably 1:1.7-2.0. The maximum width of the drainage gap between two adjacent arc-shaped strips is smaller than the minimum diameter of the material.

[0011] The position of the material distribution plate on the rotating shaft is located at the upper section of the lantern-shaped filter.

[0012] The diameters of the top opening and the bottom opening of the lantern-shaped filter are both smaller than the diameter of the material distribution tray.

[0013] The lowest level drying and dehydration unit is connected with the discharge port via the discharge unit, and the discharge unit includes a discharge bin and a discharge distribution plate located in the discharge bin, the top surface opening of the discharge bin is connected with the bottom surface opening of the lantern-shaped filter of the lowest level drying and dehydration unit, the lower section or bottom surface of the discharge bin is connected with the discharge port, and the discharge distribution plate is fixedly mounted on the rotating shaft.

[0014] The lower part of the shell is also provided with a gas inlet, and the top or upper part is provided with a gas outlet. The gas inlet is connected with the gas outlet through the cavity between the shell and the lantern-shaped filter; the drain port is connected with the cavity.

[0015] A plurality of drying and dehydrating units are arranged in series along the axial direction of the rotating shaft, and the bottom opening of the lantern-shaped filter of the upper drying and dehydrating unit is directly connected to the top opening of the lantern-shaped filter of the lower drying and dehydrating unit.

[0016] In view of the problems existing in the background technology, the inventor has made the following improvements:

[0017] 1) A drying and dehydration unit is used to replace the existing scraper and filter structure, and a material dividing plate is used to receive the material and throw it to the inner wall of the lantern-shaped filter under the action of centrifugal force. On the one hand, the material dividing plate is different from the scraper. Under the rotation force, it will only have a centrifugal throwing effect on the material, and will not directly squeeze or scratch the material; on the other hand, the lantern-shaped filter is different from the vertical filter. When the material is centrifugally thrown and contacts the curved wall of the lantern-shaped filter, it is no longer a point contact, but an arc surface contact. While efficiently dehydrating, it can also make the local pressure more evenly dispersed, further reducing the damage to the material; and when the material rolls down along the curved surface of the lantern-shaped filter under the centrifugal force, the curved surface can extend the dehydration stroke of the material, improve the dehydration efficiency, and also play a role in shaping and maintaining the shape of the material particles, thereby improving the qualified rate of the product. The preferred ratio of the length of the short axis to the long axis of the lantern-shaped filter is 1: 1.1-2.7, and more preferably 1: 1.7-2.0. The curved wall formed in this way is more conducive to the dehydration and rolling state control of the material particles under the centrifugal action.

[0018] 2. The lantern-shaped filter of the present invention no longer uses a mesh structure, but is surrounded by a plurality of arc-shaped strips evenly arranged in the radial direction, forming a plurality of drainage gaps in the meridian direction, which increases the drainage area on the filter on the one hand, and avoids the influence of the lateral cutting force when the material is in the centrifugal state on the other hand, greatly reduces the generation of powder and fine particles caused by this, and improves the integrity rate of the product. Preferably, the maximum width of the drainage gap between the two adjacent arc-shaped strips is less than the minimum diameter of the material, thereby preventing the material from leaking into the housing through the drainage gap during centrifugation.

[0019] 3. The lantern-shaped filter can transport materials very well, there is no right-angle welding, and there is no dead corner of accumulation under the centrifugal effect, which completely solves various problems caused by material accumulation in dead corners.

[0020] 4. The structure of upper feeding and lower discharging is adopted, which makes full use of the natural downward gravity and centrifugal force of the material. There is no need to force scraping and rotating the granular material to lift and separate it. It has small operating resistance, small equipment load, low energy consumption and good operating stability.

[0021] 5. The shell is provided with a circulating gas inlet and a gas outlet. The gas is introduced to take away the moist gas and fine powder while the material is separated, dried and dehydrated, further improving the dehydration effect, reducing the moisture content of the material, reducing the mixing of powder in the product, and improving the product quality.

[0022] The present invention has a simple structure, and the multi-stage drying and dehydration steps can be completed in one device, which has good flexibility. Under the premise of the same dehydration efficiency, the device of the present invention has a smaller volume, low energy consumption, low equipment investment and low operating costs. The dehydrator of the present invention has little damage to the granular material, high product integrity rate, good dehydration effect, good operating stability, and is environmentally friendly. The present invention is not only suitable for the dehydration of chip particles in the polyamide nylon 6 polymerization industry, but also suitable for other granular materials that require centrifugal drying and dehydration, and has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention.

[0024] Figure 2 Schematic diagram of a lantern-shaped filter 10 .

[0025] Among them, 1-shell, 2-driving device, 3-feeding port, 4-discharging port, 5-draining port, 6-gas inlet, 7-gas outlet, 8-rotating shaft, 9-distributing plate, 10-lantern-shaped filter, 10.1-arc-shaped strip plate, 10.2-draining gap, 10.3-top opening, 10.4-bottom opening, 11-discharging bin, 12-discharging distributing plate, 13-fixing part, 14-cavity. DETAILED DESCRIPTION

[0026] The present invention will be further explained below in conjunction with the accompanying drawings:

[0027] See also Figure 1 The shell 1 is provided with a feed inlet 3 and a gas outlet 7 at the top, a gas inlet 6 at the bottom, a discharge port 4 and a drain port 5 at the bottom, and a rotating shaft 8 is vertically provided at the center of the shell 1. The rotating shaft is driven to rotate by a driving device 2, and the driving device 2 can be a motor or other power equipment.

[0028] At least one drying and dehydration unit is arranged along the axial direction of the rotating shaft 8. Figure 1 In the embodiment, multiple stages of drying and dehydration units are connected in series from top to bottom.

[0029] The drying and dehydration unit includes a distribution plate 9 mounted on a rotating shaft 8 and a lantern-shaped filter 10 mounted on the outer periphery of the distribution plate 8. The distribution plate 9 rotates driven by the rotating shaft 8 to generate centrifugal force on the material; the lantern-shaped filter 10 is fixed to the housing 1 via a fixing member 13, maintains a certain distance from the distribution plate 9, and does not rotate therewith.

[0030] When only one primary drying and dehydration unit is provided, the top opening 10.3 of the lantern-shaped filter 10 is connected to the feed port 3, the bottom opening 10.4 is connected to the top opening of the discharge bin 11, the discharge bin 11 is connected to the discharge port 4, and the material passes through the discharge bin 11 and is discharged from the discharge port 4;

[0031] When multiple drying and dehydrating units are connected in series, except that the top opening 10.3 of the lantern-shaped filter 10 of the uppermost drying and dehydrating unit is connected to the feed port 3, and the bottom opening 10.4 of the lantern-shaped filter 10 of the lowermost drying and dehydrating unit is connected to the discharge port 4 via the discharge unit, the top openings 10.3 of the remaining lantern-shaped filters 10 are connected to the bottom openings 10.4 of the lantern-shaped filter 10 of the upper drying and dehydrating unit, and the bottom openings 10.4 are connected to the top openings 10.3 of the lantern-shaped filter 10 of the lower drying and dehydrating unit. In this way, a process of continuous centrifugal dehydration of materials from top to bottom is formed in sequence through the multiple drying and dehydrating units.

[0032] The discharging unit includes a discharging bin 11 and a discharging distribution plate 12 located in the discharging bin 11. The top opening of the discharging bin 11 is connected to the bottom opening of the lantern-shaped filter 10 of the lowest drying and dehydration unit. The lower section or bottom surface of the discharging bin 11 is connected to the discharging port 4. The discharging distribution plate 12 is fixedly mounted on the rotating shaft 8. The material from the lowest drying and dehydration unit falls from the bottom opening of the lantern-shaped filter 10 onto the rotating discharging distribution plate 12, and is then centrifugally transported to the discharging port 4, and the material is discharged from the discharging port 4.

[0033] See also Figure 2 The lantern-shaped filter 10 is surrounded by a plurality of arc-shaped strips 10.1 evenly arranged in the radial direction, and a drainage gap 10.2 is provided between two adjacent arc-shaped strips. Figure 2Since the arc strip 10.1 has the same width at the top and bottom, the drainage gap 10.2 is narrow at both ends and wide in the middle. Those skilled in the art can also obtain drainage gaps 10.2 of other shapes by controlling the shape of the arc strips as needed. For example, if the arc strip 10.1 is a shuttle shape, a drainage gap 10.2 similar to a strip with the same width at the top and bottom can be formed. The length ratio L1:L2 of the short axis and the long axis of the lantern-shaped filter surrounded by the arc-shaped strips 10.1 is 1:1.1-2.7, and more preferably 1:1.7-2.0. The arc-shaped wall formed in this way is more conducive to the control of the dehydration and rolling state of the material particles under the centrifugal action. If the ratio of the short axis to the long axis is too large, the arc rotation angle will be too small, the material dehydration path will be shortened, the dehydration effect will be reduced, and it is easy to form a corner stagnation area, causing the materials to collide with each other and produce fine powder particles, affecting the product quality. If the ratio is too small, the arc rotation angle will be too large, the material dehydration path will be shortened, and it is easy to cause the materials to collide with each other and produce fine powder particles, reducing the dehydration effect and affecting the product quality. The maximum width H of the drainage gap 10.2 between two adjacent arc-shaped strips 10.1 is less than the minimum diameter of the material particles to prevent the material from leaking out of the filter. The position of the distribution plate 9 on the rotating shaft 8 is located at the upper section of the lantern-shaped filter 10 where it is located. In this way, on the one hand, the material falling from the upper-level lantern filter 10 can be quickly and fully received, and on the other hand, it is also beneficial for the material in the distribution plate 9 to obtain a greater centrifugal force and obtain a longer dehydration stroke on the wall of the lantern-shaped filter 10; the diameters of the top surface opening 10.3 and the bottom surface opening 10.4 of the lantern-shaped filter 10 are both smaller than the diameter of the distribution plate 9 and larger than the diameter of the rotating shaft 8, so as to ensure that the material can smoothly fall onto the distribution plate 9 when entering the drying and dehydration unit.

[0034] The gas inlet 6 is connected with the gas outlet 7 through the cavity 14 between the shell 1 and the lantern-shaped filter 10, and the drain port is connected with the cavity 14. The introduced gas is used to take away the moisture and dust in the shell 1, further reducing the moisture content of the material and reducing the mixing of dust in the material. The material after dehydration from the dehydrator does not need to be separately dust recovered; the dust and moisture gas discharged from the gas outlet 7 is separated, dehumidified and dusted, and the gas is returned to the equipment for recycling. The separated dust and small particles can be granulated and reused, reducing production costs and improving product quality.

[0035] Working principle:

[0036] The water-containing granular material falls through the top feed port 3, is dehydrated in the multi-stage drying and dehydration unit, and then is discharged from the discharge port after passing through the circular discharge unit. The driving device 2 drives the rotating shaft 8, the distribution plate 9, and the discharge distribution plate 12 to rotate at high speed in turn. In a certain drying and dehydration unit, the water-containing granular material first falls into the rotating material distribution plate 9, and then is quickly thrown to the arc-shaped inner wall surface of the lantern-shaped filter 10 under the action of centrifugal force, rotates and falls along the arc-shaped wall surface, and the water in the water-containing granular material is removed under the action of centrifugal force, most of which is thrown to the inner wall surface of the shell 1 through the drainage gap 10.2 and the cavity 14, and a small part flows down along the outer wall surface of the spherical filter 10. The removed water is concentrated at the bottom of the cavity 14 of the shell 1 and discharged from the drain port 5; the dehydrated granular material falls into the material distribution plate 9 of the next-level drying and dehydration unit through the bottom opening 10.4 for centrifugal dehydration again, and finally enters the discharge bin 11 and is centrifugally transported to the discharge port 4 by the discharge material distribution plate 12, and the material is discharged from the discharge port 4; the whole process is continuous without dead angles, the dehydration is thorough, and the material damage is small. The number of the drying and dehydration units can be reasonably set according to the water content and output size of the material.

[0037] Comparative Example 1: The lantern-shaped filter 11 of the present invention is replaced by a lantern-shaped filter plate with a plurality of uniformly punched holes, and the rest is the same as the present invention.

[0038] The embodiment of the present invention is compared with the traditional dehydrator and comparative example 1. Under the premise that the number of drying and dehydration units and materials are the same, the comparison results are as follows:

[0039] After dehydration, the granular material of the dehydrator of the present invention contains almost no dust, and the granular material is less damaged. Comparative experiments show that the product qualification rate (completeness rate) of the traditional dehydrator is 96%, the product qualification rate (completeness rate) of the comparative example 1 is 98%, and the product qualification rate (completeness rate) of the dehydrator of the embodiment of the present invention can reach nearly 100%, almost no fine particles are generated, and a very small amount of dust is also taken away and recovered by the gas, and the product contains almost no dust and fine particles; the moisture content of the product can be further reduced from 11wt% in the past (traditional dehydrator) to more than 6.5wt%; from the perspective of energy consumption: the power configuration power of the traditional dehydrator with the same efficiency is 11KW, and the dehydration power configuration power of the dehydrator of the present invention is 7.5KW, and the energy consumption can be saved by more than 30%.

Claims

1. A multi-stage separation drying and dehydrating machine for particulate materials, comprising a vertical shell and a driving device, wherein the top of the shell is provided with a feed inlet, the bottom is provided with a discharge port and a drain port, and the center of the shell is vertically provided with a rotating shaft connected to the driving device, characterized in that: One or more drying and dehydration units are arranged in series along the axial direction of the rotating shaft, the uppermost drying and dehydration unit is connected to the feed port, and the lowermost drying and dehydration unit is connected to the discharge port; the drying and dehydration unit comprises a material distribution plate mounted on the rotating shaft and a lantern-shaped filter mounted on the outer periphery of the material distribution plate and having a top opening and a bottom opening, wherein the lantern-shaped filter is fixed in the shell via a fixing member.

2. The multi-stage separation drying and dehydrating machine for particulate materials according to claim 1, characterized in that: The lantern-shaped filter is surrounded by a plurality of arc-shaped strips uniformly arranged in the radial direction, and a drainage gap is provided between two adjacent arc-shaped strips.

3. The multi-stage separation drying and dehydrating machine for particulate materials according to claim 2, characterized in that: The maximum width of the drainage gap between two adjacent arc-shaped strips is smaller than the minimum diameter of the material.

4. The multi-stage separation drying and dehydrating machine for particulate materials according to claim 1, characterized in that: The length ratio of the short axis to the long axis of the lantern-shaped filter is 1:1.1-2.

7.

5. The multi-stage separation drying and dehydrating machine for particulate materials as claimed in claim 4, characterized in that: The length ratio of the short axis to the long axis of the lantern-shaped filter is 1:1.7-2.

0.

6. The multi-stage separation drying and dehydrating machine for particulate materials according to claim 1, characterized in that: The position of the material distribution plate on the rotating shaft is located at the upper section of the lantern-shaped filter.

7. The multi-stage separation drying and dehydrating machine for particulate materials according to claim 1, characterized in that: The diameters of the top opening and the bottom opening of the lantern-shaped filter are both smaller than the diameter of the material distribution tray.

8. The multi-stage separation drying and dehydrating machine for particulate materials according to any one of claims 1 to 7, characterized in that: The lowest level drying and dehydration unit is connected with the discharge port via the discharge unit, and the discharge unit includes a discharge bin and a discharge distribution plate located in the discharge bin, the top surface opening of the discharge bin is connected with the bottom surface opening of the lantern-shaped filter of the lowest level drying and dehydration unit, the lower section or bottom surface of the discharge bin is connected with the discharge port, and the discharge distribution plate is fixedly mounted on the rotating shaft.

9. The multi-stage separation drying and dehydrating machine for particulate materials according to any one of claims 1 to 7, characterized in that: The lower part of the shell is also provided with a gas inlet, and the top or upper part is provided with a gas outlet. The gas inlet is connected with the gas outlet through the cavity between the shell and the lantern-shaped filter; the drain port is connected with the cavity.

10. The multi-stage separation drying and dehydrating machine for particulate materials according to claim 1, characterized in that: A plurality of drying and dehydrating units are arranged in series along the axial direction of the rotating shaft, and the bottom opening of the lantern-shaped filter of the upper drying and dehydrating unit is directly connected to the top opening of the lantern-shaped filter of the lower drying and dehydrating unit.

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