A pressure screen

Abstract

The application discloses a pressure screen and belongs to the technical field of papermaking and pulping equipment, which comprises a shell, a screen drum fixedly installed on the inner wall of the shell and a rotor wing rotatably installed in the shell. The rotor wing comprises a columnar rotor body, the outer circumferential surface of the rotor body is provided with a plurality of wing seats, each wing seat is fixedly installed with a wing piece, the wing piece has an obtuse angle protrusion which is not isosceles, the obtuse angle protrusion comprises a front pulp surface and a rear pulp surface, an obtuse angle is formed between the front pulp surface and the rear pulp surface, the surface area of the front pulp surface is smaller than that of the rear pulp surface, a plurality of parallel flow guide grooves are formed in the wing piece, the flow guide grooves extend from the front pulp surface to the rear pulp surface, the both ends of the flow guide grooves are open, and the top of the flow guide groove is away from the rotor body and is open. The application solves the technical problems that the screen hole or screen gap is easy to be blocked and the screening efficiency is low, and is widely applied in papermaking and pulping.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of papermaking and pulping equipment, and particularly relates to a pressure screen. BACKGROUND

[0002] At present, in the papermaking and pulping industry, the wood-based panel manufacturing industry and other industries, in order to meet the requirements of their own processing technology, the purchased raw materials such as waste paper, wood chips and bamboo chips are usually processed into pulp by screening machines, and then the appropriate pulp is used for production. The pressure screen is one of the most commonly used screening equipment in the papermaking and pulping industry. At present, the pulping in paper mills is mostly completed through coarse screening and fine screening, which causes the defects of large power consumption and multiple process steps.

[0003] Due to the complex working condition of the pressure screen, many impurities enter the inlet, including coarse fiber bundles, plastic sheets, ropes and thread ends, which are easy to block the screen holes or screen gaps. In the prior art, although a rotor with rotary wings is used in the pressure screen, the rotor with rotary wings has a simple drum shape, although the radius is large and the fibers are not easy to wind, the screening efficiency is low, and the problem of easy blocking of the screen holes or screen gaps cannot be solved.

[0004] Therefore, in the technical field of papermaking and pulping equipment, there is still a need to research and improve the pressure screen, which is also a research hotspot and focus in the current technical field of papermaking and pulping equipment, and is also the starting point for the completion of the present application. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to provide a pressure screen to solve the technical problems of easy blocking of screen holes or screen gaps and low screening efficiency.

[0006] To solve the above technical problems, the technical scheme of the present application is as follows: a pressure screen, comprising a shell, a screen drum fixedly installed on the inner wall of the shell, a rotor with rotary wings rotatably installed in the shell and driven by a power device, the rotor with rotary wings comprising a columnar rotor body, a plurality of wing seats protruding from the outer circumferential surface of the rotor body, adjacent two wing seats being arranged in staggered positions in the axial direction of the rotor body, that is, the same positions of adjacent two wing seats are not located on the same circumference, a wing piece fixedly installed on each wing seat, the wing piece having a non-isosceles obtuse angle protrusion, the extension direction of the obtuse angle protrusion being consistent with the axial direction of the rotor body, the obtuse angle protrusion comprising a front pulp surface and a rear pulp surface, an obtuse angle being formed between the front pulp surface and the rear pulp surface, the surface area of the front pulp surface being smaller than the surface area of the rear pulp surface, a plurality of flow guide grooves being provided on the wing piece and arranged in parallel, the flow guide grooves extending from the front pulp surface to the rear pulp surface, the flow guide grooves being open at both ends, and the groove top of the flow guide groove being away from the rotor body and being open.

[0007] As an improvement, the groove bottom of the flow guide groove is close to the rotor body, and the groove bottom of the flow guide groove is an arc surface concentric with the rotor body.

[0008] As a further improvement, the rear pulp surface is an arc surface different from the rotor body.

[0009] As a further improvement, the ratio of the sum of the widths of all the flow guide grooves to the width of the wing is 2:3.

[0010] As a further improvement, the wing seat is provided with an anti-winding surface connected to the front pulp surface, the anti-winding surface is located on the same side as the front pulp surface, the extension direction of the anti-winding surface is consistent with the extension direction of the front pulp surface, and the surface shape of the anti-winding surface is a spherical surface extending obliquely from the rotor body surface to the front pulp surface.

[0011] As a further improvement, the wing seat is provided with a vacuum surface connected to the rear pulp surface, the vacuum surface is located on the same side as the rear pulp surface, the vacuum surface extends along the radial direction of the rotor body, and the vacuum surface extends from the rotor body surface to the rear pulp surface.

[0012] As a further improvement, the wing seat is provided with an anti-blocking surface for separating impurities from the screening area, the anti-blocking surface is located on the lower side of the wing seat between the anti-winding surface and the vacuum surface, and the surface shape of the anti-blocking surface is a spherical surface extending obliquely from the upper wing position of the wing seat to the rotor body surface.

[0013] As a further improvement, the wing seat is provided with a tailings boosting surface for excluding residual tailings, the tailings boosting surface is located on the upper side of the wing seat between the anti-winding surface and the vacuum surface, and the tailings boosting surface extends from the front pulp surface to the rear pulp surface and gradually rises in the axial direction of the rotor body.

[0014] After adopting the above technical scheme, the application has the following advantages:

[0015] In the embodiment of the application, the wing is provided with a front pulp surface and a rear pulp surface, the front pulp surface plays a pushing role on the pulp, accelerates the passage of the pulp through the screen drum, and improves the screening efficiency, and the rear pulp surface plays a suction role on the pulp, so that the screen drum is self-cleaning, the screen holes (screen seams) are unobstructed, and the screening efficiency is improved; and since the flow guide grooves are provided on the wing, the accumulation of pulp and slag is reduced, the wear of the screen drum is reduced, the fiber rope is prevented, the entanglement of impurities and fibers is effectively prevented, and the service life of the screen drum is prolonged.

[0016] Since the anti-winding surface is provided on the wing seat and forms a spherical surface structure, the structure has a large radius and no dead angle, and smoothly transitions with the front pulp surface, so that the pulp in the horizontal direction is guided and accelerated, the fiber entanglement is reduced, and the fiber mixture is adapted.

[0017] Because the wing seat is provided with a vacuum surface, its structure is trapezoidal section, that is, it conforms to the production requirement of slurry to be mixed and the natural law that vortex is generated when the carrier suddenly widens in the flow process of fluid, its formation is beneficial to the mixing of slurry, improves the screening efficiency, strengthens the self-cleaning ability of the screen drum, reduces the damage of the screen drum, and prolongs the service life of the screen drum.

[0018] Because the wing seat is provided with an anti-blocking surface, it is a spherical surface structure, which is designed according to the principle of suspended matter fluid mechanics, that is, the acceleration phenomenon of liquid from low to high is utilized, and the characteristics that fluid does not adhere to smooth surface are utilized, so that impurities are separated from the screening area in a very short time. The unique streamline design and seamless connection with other components avoid the occurrence of blocking accidents.

[0019] Because the wing seat is provided with a tail slag boost surface, the tail slag boost surface extends from the front slurry surface to the rear slurry surface and gradually rises in the direction of the rotor body axis, so as to overcome the defect that the slurry mixture flow is difficult due to the increase of slurry concentration. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0021] The structures, proportions, sizes, etc. shown in the specification are only used to cooperate with the content disclosed in the specification, to be understood and read by those skilled in the art, and do not define the limiting conditions for the implementation of the present application, so they do not have technical significance. Any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application.

[0022] Figure 1 is a structural schematic diagram of an embodiment of the present application;

[0023] Figure 2 is a structural schematic diagram of a rotor structure in an embodiment of the present application;

[0024] Figure 3 is a structural schematic diagram of a wing structure in an embodiment of the present application;

[0025] Figure 4 is Figure 3 is a structural schematic diagram of the bottom view of

[0026] Figure 5This is a schematic diagram of the wing mount structure in an embodiment of the present invention;

[0027] Figure 6 yes Figure 5 Schematic diagram of the cross-sectional structure of AA;

[0028] Figure 7 This is a three-dimensional structural diagram of the wing mount in an embodiment of the present invention;

[0029] In the figure: 1. Rotor body, 2. Wing seat, 201. Anti-winding surface, 202. Vacuum surface, 203. Anti-clogging surface, 204. Tail slag boosting surface, 3. Blade, 301. Front slurry surface, 302. Rear slurry surface, 303. Guide groove, 4. Shell, 5. Screen drum. Detailed Implementation

[0030] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The terms used in this specification, such as "front," "back," "left," "right," "inner," "outer," and "middle," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of the invention.

[0032] The arrows in the diagram indicate the direction of rotation of the rotor. The direction of rotation of the rotor is defined as forward, and the direction toward the top of the pressure screen is defined as upward.

[0033] like Figure 1 As shown, the present invention provides a rotor, including a housing 4, a screen drum 5 fixedly installed on the inner wall of the housing 4, and a rotor driven by a power device rotatably installed inside the housing 4. The power device is typically a belt drive device driven by an electric motor, which is a common technology in the field and will not be described in detail here. Figure 2 As shown, the rotor includes a cylindrical rotor body 1. The outer circumferential surface of the rotor body 1 has several protruding flanges 2. Adjacent flanges 2 are staggered in the axial direction of the rotor body 1. Each flange 2 is fixedly mounted with a blade 3. The blades 3 are typically fixed to the flange 2 using fasteners such as screws or welded to it. Figure 3 and Figure 4As shown, the fin 3 has an obtuse angle protrusion with non-isosceles, the extension direction of the obtuse angle protrusion is consistent with the axial direction of the rotor body 1, the obtuse angle protrusion includes a front blade surface 301 and a rear blade surface 302, the front blade surface 301 meets the pulp when the rotor body 1 rotates, an obtuse angle is formed between the front blade surface 301 and the rear blade surface 302, the surface area of the front blade surface 301 is smaller than that of the rear blade surface 302, the rear blade surface 302 is an arc surface different from the rotor body 1, the front blade surface 301 is also designed as an arc surface different from the rotor body 1, and the arc diameter of the front blade surface 301 is smaller than that of the rear blade surface 302, the front blade surface 301 is designed as a small arc surface (the radius and the center are determined according to the rotating direction), which has a pushing force from small to large on the mixed pulp during operation, so that the pulp fibers enter the screen hole (screen gap) and pass through quickly, if there is no arc, it is a straight surface or a plane, under the same pushing force, the fibers are pushed away before entering the screen hole (screen gap), and the working efficiency will be reduced, the rear blade surface 302 is designed as a large arc (the radius and the center are opposite to those of the front blade surface 301), according to the principle of fluid mechanics, the pressure reduction forms a vacuum, that is, backwashing, therefore, the front blade surface 301 plays a pushing role on the pulp, accelerates the pulp passing through the screen drum and improves the screening efficiency, the rear blade surface 302 plays a suction role on the pulp, so that the screen drum is self-cleaning, the screen hole (screen gap) is unobstructed, and the screening efficiency is improved. A plurality of guide grooves 303 are arranged on the fin 3 and are parallel to each other, the guide grooves 303 extend from the front blade surface 301 to the rear blade surface 302, the two ends of the guide grooves 303 are open, the top of the guide grooves 303 is away from the rotor body 1 and is open, the bottom of the guide grooves 303 is close to the rotor body 1, the bottom of the guide grooves 303 is an arc surface concentric with the rotor body 1, the sum of the widths of all the guide grooves 303 and the width of the fin 3 are in a ratio of 2:3, the guide grooves 303 are a powerful measure to prevent the front blade surface 301 of the fin 3 from rubbing the screen drum of the pressure screen, because there is only a distance of 2-2.5 mm between the screen drum of the pressure screen and the front blade surface 301 of the fin 3, the width of 130 mm of the existing fin is the most prone to rubbing, and the distance of 2-2.5 mm cannot be changed, changing will affect the screening efficiency, therefore, only the width of 130 mm can be changed, the smaller the width, the lower the probability of rubbing, the applicant's technical personnel obtain that the height of the fin 3 is less than 30 mm, and the sum of the widths of all the guide grooves 303 and the width of the fin 3 are in a ratio of 2:3, which is the best effect, here the width of the fin 3 refers to the sum of the widths of the remaining part of the fin 3 after deducting the guide grooves 303, the guide grooves 303 are also a large arc, which is concentric with the highest part of the fin 3, the depth is 12 mm, and the length extends to the rear blade surface 302 and ends. The guide grooves 303 reduce the accumulation of pulp residue, reduce the wear of the screen drum, prevent the fibers from rubbing, effectively prevent the entanglement of impurities and fibers, and prolong the service life of the screen drum.The distance between the screen drum 5 and the highest point of the front pulp surface 301 of the wing 3 is 2-2.5 mm, which solves the problems of traditional screening equipment, such as low screening concentration, poor screening efficiency, serious blocking, winding rotor, difficult discharge of pulp, serious damage of the screen drum 5, short service life, etc.

[0034] It is well known that the winding problem of pressure screen is a big problem in the production process, mainly including two points: firstly, the existing wing is not smooth enough, and there are gaps when connected with other parts; secondly, the radius of the streamline design is too small. In view of the two defects, as shown in Figure 5 、 Figure 6 and Figure 7 , the wing seat 2 is provided with an anti-winding surface 201 connected with the front pulp surface 301, the anti-winding surface 201 and the front pulp surface 301 are located on the same side, the extension direction of the anti-winding surface 201 is consistent with the extension direction of the front pulp surface 301, and the surface shape of the anti-winding surface 201 is a spherical surface extending from the surface of the rotor body 1 to the front pulp surface 301. The applicant adds the spherical anti-winding surface 201 in the forward direction of the wing seat 2, the radius at the highest point is 358 mm, the radius at the lowest point is 300 mm, and the width is 240 mm, forming a spherical structure. The radius of this structure is large and has no dead angle, and it smoothly transitions with the front pulp surface 301, so that the pulp in the horizontal direction is accelerated and guided, reducing fiber winding and adapting to fiber mixtures.

[0035] The wing seat 2 is provided with a vacuum surface 202 connected with the rear pulp surface 302, the vacuum surface 202 and the rear pulp surface 302 are located on the same side, the vacuum surface 202 extends along the radial direction of the rotor body 1, and the vacuum surface 202 extends from the surface of the rotor body 1 to the rear pulp surface 302. During operation of the rotor body 1, the running speed is always ahead of the running speed of the mixed pulp, therefore, a vacuum area is formed between the rear of the wing seat 2 and the mixed pulp. From the perspective of fluid mechanics, fluid will generate vortex flow when the carrier suddenly widens or narrows during flow, also called vortex area (sudden widening produces a vacuum area, and sudden narrowing produces a positive pressure area, collectively called vortex area). Its role is to increase the mixing of fluid, which is caused by different forces. Since the pulp needs to be mixed behind the wing seat 2, the applicant designs the vacuum surface 202, which has a trapezoidal cross section with a height of 58 mm, an upper base length of 116 mm, and a lower base length of 280 mm. That is, it meets the production requirements of pulp mixing and the natural law of vortex flow when the carrier suddenly widens during fluid flow. The formation of the vacuum surface 202 is beneficial to the mixing of the pulp, improves the screening efficiency, strengthens the self-cleaning ability of the screen drum, reduces the damage of the screen drum, and prolongs the service life of the screen drum.

[0036] In order to prevent the clogging accident, the wing seat 2 is provided with the anti-clogging surface 203 for making the impurities separate from the screening area. The anti-clogging surface 203 is located at the lower side of the wing seat 2 between the anti-winding surface 201 and the vacuum surface 202. The surface shape of the anti-clogging surface 203 is a spherical shape extending from the position of the wing piece 3 on the wing seat 2 to the surface of the rotor body 1. There are multiple wing pieces 3 and wing seats 2 on the rotor body 1. The lower part of each wing seat 2 plays a role of hindering the pulp to rise. The greater the role is, the greater the power consumption is. If not handled properly, the screen plate will be clogged to cause an accident. In order to avoid the accident, the anti-clogging surface 203 is designed by the applicant. The anti-clogging surface 203 is a spherical structure with the highest position of 58 mm and the lowest position of zero. The inclined surface is 116 mm long, the upper top is 108 mm wide, and the lower bottom is 116 mm long. The structure is designed according to the principle of suspended matter fluid mechanics, that is, the acceleration phenomenon of liquid from low to high is utilized, and the characteristics of smooth surface without fluid adhesion are utilized. The impurities separate from the screening area in a very short time. The unique spherical design and seamless connection with other components avoid the clogging accident.

[0037] The screening process of the pressure screen is also a concentration process and a pulp residue gathering process. With the increase of the pulp residue, the concentration increases, and the flow rate slows down, which causes the tail residue to be difficult to flow and discharge. In order to overcome these problems, the wing seat 2 is provided with the tail residue boosting surface 204 for discharging the tail residue. The tail residue boosting surface 204 is located at the upper side of the wing seat 2 between the anti-winding surface 201 and the vacuum surface 202. The tail residue boosting surface 204 extends from the front pulp surface 301 to the rear pulp surface 302 and gradually rises in the axial direction of the rotor body 1. The front advances from zero to 30 mm when the pulp residue leaves. In the distance of 108 mm, the tail residue boosting surface 204 rises by 30 mm, and the rising rate is 27.8%. The parameter is calculated and designed according to the linear velocity of the pressure screen, the fluid rising velocity, and the fluid friction coefficient, which overcomes the defect of the difficulty of the pulp mixture flow caused by the increase of the pulp residue concentration.

[0038] The pressure screen can be provided with multiple stages according to the screening needs. The integrated multi-stage pressure screen is the prior art in the field, and will not be described here.

[0039] Although the present application has been described in detail by the general description and specific embodiments above, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application are within the scope of the present application.

Claims

1. A pressure screen comprising a housing, a screen drum being fixedly mounted on the inner wall of the housing, a rotor of a rotor wing being rotatably mounted in the housing and being driven by a drive device, the rotor of the rotor wing comprising a cylindrical rotor body, characterized in that The outer circumferential surface of the rotor body is provided with a plurality of wing seats protruding from the rotor body, two adjacent wing seats are arranged staggeredly in the axial direction of the rotor body, a wing piece is fixedly installed on each wing seat, the wing piece has an obtuse angle protrusion which is not isosceles, the extension direction of the obtuse angle protrusion is consistent with the axial direction of the rotor body, the obtuse angle protrusion includes a front surface and a rear surface, an obtuse angle is formed between the front surface and the rear surface, the surface area of the front surface is smaller than that of the rear surface, a plurality of flow guide grooves are arranged in parallel on the wing piece, the flow guide grooves extend from the front surface to the rear surface, the flow guide grooves are open at both ends, the groove top of the flow guide groove is away from the rotor body and is open, the distance between the screen drum and the highest part of the front surface of the wing piece is 2-2.5 mm, the wing seat is provided with an anti-winding surface connected with the front surface, the anti-winding surface and the front surface are located on the same side, the extension direction of the anti-winding surface is consistent with that of the front surface, the surface shape of the anti-winding surface is a spherical surface extending from the surface of the rotor body to the front surface, the wing seat is provided with a vacuum surface connected with the rear surface, the vacuum surface and the rear surface are located on the same side, the vacuum surface extends along the radial direction of the rotor body, the vacuum surface extends from the surface of the rotor body to the rear surface, the wing seat is provided with an anti-blocking surface for separating impurities from the screening area, the anti-blocking surface is located on the lower side of the wing seat between the anti-winding surface and the vacuum surface, the surface shape of the anti-blocking surface is a spherical surface extending from the wing piece position on the wing seat to the surface of the rotor body, the wing seat is provided with a tail slag boosting surface for excluding tail slag, the tail slag boosting surface is located on the upper side of the wing seat between the anti-winding surface and the vacuum surface, the tail slag boosting surface extends from the front surface to the rear surface and gradually rises in the axial direction of the rotor body.

2. The pressure screen according to claim 1, characterized in that The groove bottom of the flow guide groove is close to the rotor body, and the groove bottom of the flow guide groove is an arc surface concentric with the rotor body.

3. The pressure screen of claim 1, wherein, The rear surface is an arc surface different from the rotor body.

4. The pressure screen of claim 1, wherein, The sum of the widths of all the flow guide grooves is 2:3 compared with the width of the wing piece.

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