Paper pulp drying system and fan device thereof

Abstract

The utility model provides a paper pulp drying system and a fan device thereof. The fan device comprises an air bellow, an impeller, a base and a driving assembly, the base is used for supporting a transmission shaft of the impeller, the impeller is arranged in the air bellow, the driving assembly is used for driving the impeller to rotate through the transmission shaft, and the impeller is made of stainless steel. According to the fan device provided by the embodiment of the invention, the impeller is made of a stainless steel material, so that the fan device has corrosion resistance, the problem of oxidation corrosion by wet slurry is solved, corrosion scrap iron is prevented from polluting the slurry, and the technological characteristic requirements of quick drying of chemimechanical slurry are met.

Description

Technical Field

[0001] The present application relates to the technical field of papermaking equipment, and in particular to a pulp drying system and a fan device thereof. Background Art

[0002] During the pulp drying process, the impeller needs to be in direct contact with the pulp. Since there are chemicals such as NaOH and H2O2 in the pulp, it is very easy to cause impeller corrosion. Utility Model Content

[0003] In a first aspect of an embodiment of the present application, a fan device for pulp drying is provided, which includes: a bellows, an impeller, a base and a drive assembly, wherein the base is used to support the transmission shaft of the impeller, the impeller is arranged in the bellows, and the drive assembly is used to drive the impeller to rotate through the transmission shaft, and the impeller is made of stainless steel.

[0004] In some embodiments, a fork hole is provided on the base.

[0005] In some embodiments, the base is made of steel plate.

[0006] In some embodiments, the base is made of a material with a thickness of 9 to 11 mm.

[0007] In some embodiments, the base is made of a material with a thickness of 10 mm.

[0008] In some embodiments, a plurality of reinforcing ribs are provided on the side of the base near the bottom.

[0009] In some embodiments, the plurality of reinforcing ribs are respectively located on opposite sides of the base.

[0010] In some embodiments, the impeller is made of 316L stainless steel.

[0011] In a second aspect, an embodiment of the present application provides a pulp drying system, which includes a first drying tower, a second drying tower and a cyclone separator arranged in series. The pulp drying system also includes the fan device described in the above embodiment, which is arranged between the first drying tower and the second drying tower.

[0012] In some embodiments, the pulp drying system includes multiple drying sections, each drying section includes the first drying tower, the second drying tower and the cyclone separator arranged in series, wherein at least the fan device located in the upstream drying section adopts the fan device structure described in the above embodiments.

[0013] The fan device provided in the embodiment of the present application has an impeller made of stainless steel, which is corrosion-resistant, solves the problem of oxidation corrosion by wet slurry, avoids corroded iron filings from contaminating the slurry, and meets the requirements of the chemical mechanical slurry flash drying process characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] Figure 1 This is a schematic structural diagram of an embodiment of the pulp drying system of the present application;

[0016] Figure 2 This is a structural diagram of an embodiment of the fan device of the present application;

[0017] Figure 3 yes Figure 2 A schematic structural diagram of the fan device from another perspective in the embodiment;

[0018] Figure 4 This is a schematic diagram of the structure of the drive assembly in an embodiment of the present application;

[0019] Figure 5 This is a schematic diagram of the process of an embodiment of the impeller of the present application;

[0020] Figure 6 yes Figure 5 A schematic cross-sectional view of the impeller in the embodiment;

[0021] Figure 7 This is a structural diagram of an embodiment of the base of the present application;

[0022] Figure 8 yes Figure 7 A structural schematic diagram of the base from another perspective in the embodiment. DETAILED DESCRIPTION

[0023] The present application will be further described in detail below in conjunction with the accompanying drawings and examples. It is particularly noted that the following examples are only intended to illustrate the present application and are not intended to limit the scope of the present application. Similarly, the following examples are only some examples of the present application and not all examples. All other examples obtained by those of ordinary skill in the art without creative work are intended to fall within the scope of protection of this application.

[0024] The terms "first", "second" and "third" in the embodiments of the present application are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second" and "third" may explicitly or implicitly include at least one of such features. In the description of the present application, "multiple" means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined. All directional indications in the embodiments of the present application (such as up, down, left, right, front, back...) are only used to explain the relative positional relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. The terms "including" and "having" in the embodiments of the present application and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or components inherent to these processes, methods, products or devices.

[0025] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] The chemical pulp flash drying line is to let flocculent pulp with a dryness of about 42% enter an air duct under the action of the drying fan suction. The outside air is heated to a certain temperature through the steam heat exchanger and then mixed with the pulp. The pulp enters a vertical drying tower. Under the action of hot air, the moisture in the pulp is continuously evaporated. At the top of the tower, the dried pulp and water vapor enter a cyclone separator. Under the action of centrifugal force, the pulp moves downward into the cooling tower, and the water vapor moves upward and is discharged. In order to ensure the drying effect and improve the utilization rate of thermal energy, this process will generally be repeated three times. The final pulp dryness can reach about 87%.

[0027] See also Figure 1 , Figure 1This is a simplified structural diagram of an embodiment of the pulp drying system of the present application. The flash drying system in this embodiment is a three-stage drying scheme, comprising a first drying stage 10a, a second drying stage 10b, and a third drying stage 10c, which are arranged in series. Of course, in other embodiments, there may be only one, two, or more stages, and this is not specifically limited here. Each stage includes a first drying tower 100, a second drying tower 200, and a cyclone separator 300, which are arranged in series. A fan device 400 is located between the first drying tower 100 and the second drying tower 200. The thick black arrows in the figure indicate vapor discharge, and the dashed arrows indicate the flow direction of the pulp.

[0028] The fan device in the conventional solution mainly has the following technical problems.

[0029] The first choice is that since 42% of the pulp still has 58% moisture when it enters the first drying stage for drying, it contains chemicals such as NaOH and H2O2 (because the chemical pulp manufacturing method is alkaline hydrogen peroxide thermomechanical pulp, NaOH and H2O2 and other chemicals are added in the process to cause wood chip swelling pretreatment and pulp bleaching reaction), which has a certain corrosiveness; in the conventional scheme, the drying fan impeller is made of iron. The first stage drying fan impeller is easily oxidized and corroded by the pulp moistened with chemicals, falling off layer by layer, and finally perforated. The corroded iron chips contaminate the pulp and affect product quality. At the same time, the fan vibrates violently and the dynamic balance fails and cannot operate. Therefore, the iron impeller is not suitable for contacting chemical pulp with low dryness and high moisture content. There is a process defect in the first stage of chemical pulp flash drying.

[0030] In addition, 42% of the slurry enters the first drying stage. Due to the high moisture content of 58%, its weight is large. The fan device located in the first drying stage exerts a large force when transporting the slurry, which is several times that of the fan devices in the second and third drying stages. The fan itself is subjected to a reaction force; because the base of the first drying stage fan is subjected to a large force for a long time, metal fatigue occurs and cracks occur, while the bases of the second and third drying stages fan do not crack; it is concluded that the strength of the base of the first drying stage fan is insufficient in design.

[0031] Finally, the fan device was manufactured without consideration of the need for convenient maintenance. Currently, the replacement of the impeller, main shaft, etc. requires the use of a hoist for disassembly, a crane and a cart for transportation to the maintenance workshop, and then returning it for installation after maintenance. The operation is complicated and requires multiple relocations, which is time-consuming, labor-intensive and extremely inconvenient.

[0032] In view of the above problems, the present invention provides a fan device. Figure 2 and Figure 3 , Figure 2 This is a structural diagram of an embodiment of the fan device of the present application. Figure 3 yes Figure 2A structural diagram of the fan device from another perspective in the embodiment, wherein the fan device 400 in this embodiment includes: a bellows 410, an impeller 420, a base 430 and a drive assembly 440, the base 430 is used to support the drive shaft 4201 of the impeller 420, the impeller 420 is arranged in the bellows 410, and the air inlet 411 and the air outlet 412 of the bellows 410 are respectively connected to the first drying tower 100 and the second drying tower 200 (please refer to Figure 1 ).

[0033] The driving assembly 440 is used to drive the impeller 420 to rotate via the transmission shaft 4201. Figure 3 and Figure 4 , Figure 4 4 is a schematic diagram of the structure of the drive assembly in an embodiment of the present application, wherein the drive assembly 440 may include a drive motor 441, a drive shaft 442, and a transmission belt 443. The drive motor 441 and the base 430 are respectively fixed to the mounting platform 500. The drive motor 441 drives the impeller 420 to rotate via the drive shaft 442, the transmission belt 443, and the transmission shaft 4201. Of course, in some other embodiments, other transmission methods may be used, which will not be listed or described in detail here.

[0034] Please also refer to Figure 5 and Figure 6 , Figure 5 This is a flow chart of an embodiment of the impeller of the present application. Figure 6 yes Figure 5 The schematic diagram of the cross-sectional structure of the impeller in the embodiment, wherein the impeller 420 in this embodiment includes a rotating shaft 421 and a plurality of blades 422, wherein. The material of the impeller 420 in this embodiment is stainless steel. Specifically, it can be 316L stainless steel. 316L stainless steel has corrosion resistance, solves the problem of oxidation corrosion by wet slurry, avoids corrosion of iron filings and contamination of slurry, meets the requirements of the flash drying process characteristics of chemical pulp, and can also extend the service life of the impeller. The surface and interior of the iron impeller are corroded and uneven, and severe perforations occur. The stainless steel impeller is not corroded, and the surface is smooth and good without shedding.

[0035] Optionally, please also refer to Figure 7 and Figure 8 , Figure 7 This is a structural diagram of an embodiment of the base of the present application. Figure 8 yes Figure 7A schematic diagram of the base structure from another perspective in an embodiment shows a central portion of base 430, wherein a shaft hole 4301 is provided for inserting and supporting the drive shaft 4201 of impeller 420. A fork hole 431 is provided on the side of base 430. Two fork holes 431 can be provided to facilitate insertion of a forklift for transporting base 430. When maintenance is required, a forklift can be used to align the fork holes 431 for direct disassembly and transportation, simplifying previously complex operations and providing a convenient and time-saving solution.

[0036] Optionally, the base 430 may be made of a steel plate, specifically a 9 to 11 mm thick steel plate, and in this embodiment, a 10 mm thick steel plate. By increasing the thickness of the steel plate, the overall strength of the base 430 can be improved.

[0037] Optionally, the base 430 in the embodiment of the present application further includes a plurality of reinforcing ribs 432, which are disposed near the bottom. The plurality of reinforcing ribs 432 may be disposed on opposite sides of the base 430. By providing the reinforcing ribs 432 at multiple locations on the side panels of the base, the support strength and intensity can be increased, providing high-strength fatigue resistance and compensating for deficiencies in the original design.

[0038] The fan device in the embodiment of the present application first improves the material of the impeller, which is made of 316L stainless steel, which has corrosion resistance, solves the problem of oxidation corrosion by wet slurry, avoids iron filings from contaminating the slurry quality, and meets the requirements of the chemical pulp flash drying process characteristics; the fan runs stably with low vibration, extends its service life, and saves spare parts replacement and maintenance time. In addition, the strength of the base is improved: the thickness of the plate is increased from 8MM to 10MM, and strong plate ribs are set in multiple places on the front and back of the side plate to improve the support strength and strength, with high strength and fatigue resistance, making up for the shortcomings of the original design; avoiding cracking and fault shutdown and repair welding to increase maintenance time. Two fork holes are also added to the base of the fan device. During maintenance, a forklift is used to align with the fork holes for direct disassembly, assembly and transportation, simplifying the original complex operation, making it convenient and quick, and saving routine maintenance time. Combined with the above multiple improvements, the chemical pulp flash drying process is improved and perfected, product quality is excellent, equipment performance is improved, downtime and spare parts purchase are reduced, and great economic benefits are achieved.

[0039] Please continue reading Figure 1 It should be noted here that, among the multiple drying sections of the pulp drying system in the embodiment of the present application, at least the fan device 400 located in the upstream drying section (for example, the first drying section) adopts the fan device structure in the aforementioned embodiment. Of course, all drying sections may also adopt the fan device structure in the aforementioned embodiment, which is not specifically limited here.

[0040] The above descriptions are only some embodiments of the present application and do not limit the scope of protection of the present application. Any equivalent device or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of this application.

Claims

1. A fan device for pulp drying, characterized in that: The fan device includes: a bellows, an impeller, a base and a drive assembly. The base is used to support the transmission shaft of the impeller. The impeller is arranged in the bellows. The drive assembly is used to drive the impeller to rotate through the transmission shaft. The impeller is made of stainless steel.

2. The fan device according to claim 1, characterized in that A fork hole is provided on the base.

3. The fan device according to claim 1, characterized in that: The base is made of steel plate.

4. The fan device according to claim 3, characterized in that: The material thickness of the base is 9 to 11 mm.

5. The fan device according to claim 4, characterized in that: The base is made of a material with a thickness of 10 mm.

6. The fan device according to claim 4, characterized in that: A plurality of reinforcing ribs are provided on the side of the base near the bottom.

7. The fan device according to claim 6, characterized in that: The plurality of reinforcing ribs are respectively located on two opposite sides of the base.

8. The fan device according to claim 1, characterized in that: The material of the impeller is 316L stainless steel.

9. A pulp drying system, characterized in that: The pulp drying system includes a first drying tower, a second drying tower and a cyclone separator arranged in series, and the pulp drying system also includes a fan device according to any one of claims 1 to 8, wherein the fan device is arranged between the first drying tower and the second drying tower.

10. The pulp drying system according to claim 9, characterized in that: The pulp drying system includes multiple drying sections, each drying section includes the first drying tower, the second drying tower and the cyclone separator arranged in series, wherein at least the fan device located in the upstream drying section adopts the fan device structure according to any one of claims 1 to 8.

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