Rotary screen

Abstract

The utility model relates to screening equipment, and discloses a drum screen which comprises a screening drum set installed in a shell, the screening drum set is composed of a plurality of rotating screening drums, the axes of the screening drums are located on the same horizontal plane, or the positions of the screening drums are sequentially lowered from the feeding direction to the discharging direction. Each screening roller comprises a material guiding spiral on the inner side and a plurality of annular impeller blades which are located on the outer side of the circumferential direction of the material guiding spiral and are coaxially arranged with the material guiding spiral, the impeller blades are parallel to one another and are arranged at equal intervals, and the impeller blades between every two adjacent screening rollers are arranged in a staggered mode. The vibrating screen is small in abrasion, not prone to material adhesion, easy to maintain and particularly suitable for being used during raw coal screening.

Description

Technical Field

[0001] The utility model relates to a drum screen suitable for wet coal screening. Background Art

[0002] Material classification is widely used across various industrial production sectors, particularly for raw coal used in circulating fluidized bed boilers, where high demand and high particle size requirements necessitate grading and screening. Currently, vibrating screens and roller screens are the primary methods of screening. However, these devices have limited screening areas and low effective apertures, resulting in low screening efficiency. Furthermore, the high moisture content of the raw coal can easily clog the mesh after entering the screening equipment, significantly reducing screening efficiency. When the roller (screen) becomes blocked due to adhered material, the machine must be shut down for manual cleaning, impacting the operating efficiency of the circulating fluidized bed boiler. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a drum screen which has less wear and tear, is not prone to material adhesion, and has a longer normal operating cycle than that of a conventional drum screen.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a drum screen including a screening drum assembly mounted within a housing, the screening drum assembly comprising at least two rotating screening drums, each of the screening drums including an inner material guide spiral and a plurality of annular impeller blades located circumferentially outward of and coaxially arranged with the material guide spiral. The impeller blades are parallel to each other and spaced evenly apart, with the impeller blades between adjacent screening drums being staggered. The spacing between the impeller blades is generally selected and determined based on the particle size requirements of the screened material.

[0005] Furthermore, the screening drum group includes three or more screening drums, the axes of which are located on the same horizontal plane, or are positioned sequentially lowered from the feed direction to the discharge direction. This creates a wavy screen surface, which increases the aperture ratio of the screening device while maintaining the same screen frame projected area, thereby improving screening efficiency.

[0006] It is recommended that the axes of the screening drums share an inclined plane, and the acute angle between the inclined plane and the horizontal plane does not exceed 10°, so as to form a slowly descending wave-like screen surface, which has a better separation effect.

[0007] To facilitate the installation and fixation of the impeller blades, they are mounted on at least two equidistant rods, each of which is provided with regularly spaced impeller blade slots. The impeller blades are provided with inner ring bosses that mate with the impeller blade slots. The ends of the equidistant rods are fixed within the grooves of the end fixing discs. The end fixing discs can be connected to the drive device via a rotating shaft, thereby driving the screening drum to rotate.

[0008] It is recommended that the three equidistant rods be arranged in a centrally symmetrical manner, which can not only reliably fix the impeller blades but also relatively reduce the assembly workload.

[0009] A feed port is provided at one end of the top of the shell, a material buffer plate is provided in the feed port, a buffer distribution roller is provided between the lower edge of the material buffer plate and the first screening roller of the screening roller group, and the working surface of the buffer distribution roller is a cylindrical surface, which facilitates the more uniform delivery of materials to the screening roller group.

[0010] A divider plate is installed at the bottom end of the housing, away from the feed inlet. The top edge of the divider plate engages the last screening drum in the screening drum assembly. The outer side of the divider plate serves as a discharge port for oversize material, while the inner side serves as a discharge port for undersize material. The divider plate, similar to conventional drum screens, serves to divert and direct the material to be screened.

[0011] The beneficial effects of the utility model are as follows: the annular impellers on adjacent screening drums are partially staggered to achieve mutual self-cleaning of adhered materials, and the screen holes will not be blocked, so it has strong adaptability to high-moisture materials; the screening drum is a rotating moving component, and although the materials are in direct contact, it is mainly rolling friction, so the wear on the annular impeller is small, the service life of the equipment is long, and it is easy to maintain; the screen surface is in a wavy form, which increases the screening opening rate under the same screen frame area, and the design of the inner ring of the impeller blade as a cavity has little blocking effect on the material, and the material is not easily stuck in the screen gap, thereby improving the screening efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a diagram of the overall structure and working principle of the drum screen of the present invention.

[0013] Figure 2 yes Figure 1 Schematic diagram of the intermediate screening drum.

[0014] Figure 3 This is a partial enlarged view of the screening surface composed of two screening drums.

[0015] Figure 4 yes Figure 2 Schematic diagram of the isometric bars in .

[0016] Figure 5 yes Figure 2 Schematic diagram of the impeller blades.

[0017] Figure 6 yes Figure 2 Schematic diagram of the end-fixed disk in .

[0018] Figure 7 yes Figure 6 Left view of .

[0019] Markings in the figure are: 1-shell, 2-feed port, 3-material buffer plate, 4-buffer distribution drum, 5-screening drum, 6-drum interior, 7-screen undersize material discharge port, 8-distribution partition, 9-screen oversize material discharge port, 10-inclined dynamic screen surface, 11-equidistant rods, 12-impeller blades, 13-screen gaps, 14-material guide spirals, 15-end fixed discs, 16-drum outlets at both ends, 17-intersection gaps, 18-arc-shaped dynamic screen holes, 19-impeller blade slots, 20-inner ring bosses, 21-hollow inside the impeller blades, 22-groove openings, 23-key slots, 24-inclined planes. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Example:

[0022] like Figures 1 to 7 As shown, the drum screen of the present invention includes a screening drum group installed in a shell 1, and the screening drum group consists of a plurality of rotating screening drums 5. A feed port 2 is provided at one end of the top of the shell 1, and a material buffer plate 3 is provided in the feed port 2. A buffer dividing drum 4 is provided between the lower edge of the material buffer plate 3 and the first screening drum of the screening drum group. The working surface of the buffer dividing drum 4 is a cylindrical surface, and a dividing partition 8 is provided at one end of the bottom of the shell 1 away from the feed port 2. The upper edge of the dividing partition 8 is matched with the last screening drum of the screening drum group. The outer side of the dividing partition 8 is the screened material discharge port 9, and the inner side of the dividing partition 8 is the screened material discharge port 7. The material entering the shell 1 from the feed port 2 is guided to the buffer distribution drum 4 through the material buffer plate 3 arranged obliquely relative to the horizontal plane. The buffer distribution drum 4 rotates to evenly transport the material to the screening drum group. At the end of the screening drum group, the distribution partition 8 separates the upper material discharge port 9 and the screened material discharge port 7, and the material is screened.

[0023] like Figure 1 、 Figure 2 and Figure 3As shown, a single screening drum 5 includes an inner material guide spiral 14 and a plurality of annular impeller blades 12 located on the outer side of the material guide spiral 14 and coaxially arranged therewith. The impeller blades 12 are parallel to each other and are equally spaced apart. The impeller blades 12 between adjacent screening drums 5 are staggered. The plane where the axes of the various screening drums 5 constituting the screening drum group are located is a plane inclined relative to the horizontal plane, and is inclined downward from the feed direction to the discharge direction. Multiple rotating screening drums 5 form an inclined dynamic screen surface 10. During the screening process, the material is in direct contact with the screening drum 5. As the screening drum 5 rotates, the material forms a wave-like forward motion on the screen surface for screening, transportation and distribution. The working surface of the screening drum 5 is composed of multiple annular impeller blades 12. Adjacent impeller blades 12 on the same drum are spaced a certain distance apart according to the particle size requirements of the screening to form an arc-shaped screen gap 13. Multiple screening drums 5 rotate simultaneously to form an arc-shaped dynamic screen hole 18. The impeller blades on adjacent screening drums 5 are staggered. The depth of the staggered part is limited to the fact that adjacent screening drums 5 do not interfere with each other. After staggering, there is a gap between the corresponding impeller blades 12 of adjacent screening drums 5, that is, the staggered gap 17. The staggered gap 17 is smaller than the width of the screen gap 13, which can realize the mutual self-cleaning of materials adhering to adjacent drums. Therefore, it has a strong adaptability to the moisture content of the material. The material mainly rolls on the screen surface, so the wear on the impeller blades is small and the service life of the equipment can be longer.

[0024] Part of the qualified material passes through the arc-shaped dynamic sieve hole 18 and falls into the undersize material discharge port 7 at the lower part of the shell, and the other part falls into the drum interior 6 through the arc-shaped dynamic sieve hole 18, and is then transported to the outlets 16 at both ends of the drum through the guide screw 14, and then falls into the undersize material discharge port 7 and is discharged outside the machine; the coarse particle material on the screen surface moves forward continuously with the rotation of the screening drum until it falls into the oversize material discharge port 9 and is discharged outside the machine; thus, the dynamic screening, grading and distribution of the material are realized.

[0025] like Figure 1 、 Figure 5 、 Figure 6 and Figure 7As shown, a single screening drum 5 is composed of multiple annular impeller blades 12, multiple equidistant rods 11, a material guide spiral 14, and an end fixed disc 15. The impeller blades 12 have a certain thickness, are circular on the outside, and are hollow on the inside. A plurality of inner ring bosses 20 are provided on the inner ring, and the number of bosses is three. There are also three equidistant rods 11 that are assembled with the impeller blades 12. The inner ring bosses 20 cooperate with the impeller blade slots 19 to complete the assembly of the impeller blades 12 on the equidistant rods 11. The equidistant rods 11 can be made of rods with circular, square or polygonal cross-sections, and are provided with numerous equidistantly distributed impeller blade slots 19. The spacing between the slots is 1 / 4. Determined according to the screening particle size; the outer portion of the end fixed disc 15 is circular, and a plurality of groove openings 22 are opened on it. The number and shape of the groove openings 22 are adapted to the equidistant rods 11. The end ends of the equidistant rods 11 are fixed in the groove openings 22 of the end fixed disc 15. The inner portion of the end fixed disc 15 is cylindrical, and a key groove 23 is opened in the inner hole of the cylinder to facilitate the connection and fixation with the rotating shaft, and is connected to the driving device through the rotating shaft. The rotary drive is a well-known structure that can adopt the existing technology and will not be described in detail.

[0026] When assembling the screening drum 5, first install the multiple impeller blades 12 on the equidistant rods 11, with the inner ring bosses 20 mating with the impeller blade slots 19 to form the arcuate screening slots 13. Then, install the internal material guide screws 14. Finally, install the end fixing discs 15, with the grooves 22 mating with the equidistant rods 11. In this embodiment, a single screening drum 5 uses three equidistant rods 11. At least two equidistant rods 11 are sufficient to secure the impeller blades 11, and four or more equidistant rods 11 can also be used to secure the impeller blades 11. However, they should not be too closely spaced to prevent the screening slots 13 from being of inappropriate size.

[0027] When each screening drum 5 is installed one by one inside the housing 1, the axis position of the screening drum 5 decreases from the feed direction to the discharge direction, and the height difference of the axis positions of adjacent screening drums is equal. The axes of each screening drum 5 are coplanar and lie on an inclined plane 24 that is tilted relative to the horizontal plane. The acute angle between the inclined plane 24 and the horizontal plane is 10°. The annular impellers on adjacent screening drums are partially staggered 17, and the drums rotate to form arc-shaped dynamic screen holes 18. Under the same screen frame area, the screening drum group with the above arrangement is equivalent to increasing the screening opening rate, thereby improving screening efficiency.

[0028] The axes of the screening drums 5 in the screening drum group of the utility model can also be placed on the same horizontal plane, which can also achieve mutual self-cleaning and reduce the adhesion of materials. Therefore, the drum screen of the utility model is particularly suitable for wet coal screening.

Claims

1. A drum screen, comprising a screening drum group installed in a housing (1), wherein the screening drum group consists of at least two rotating screening drums (5), and is characterized by: The screening drum (5) comprises an inner material guide spiral (14) and a plurality of annular impeller blades (12) located on the outer side of the material guide spiral (14) in a circumferential direction and arranged coaxially therewith. The impeller blades (12) are parallel to each other and are spaced at equal intervals. The impeller blades (12) between adjacent screening drums (5) are arranged in a staggered manner.

2. A drum screen according to claim 1, characterized in that: The screening drum group comprises more than three screening drums (5), and the axes of the screening drums (5) are located on the same horizontal plane, or are positioned successively lowered from the feeding direction to the discharging direction.

3. A drum screen according to claim 2, characterized in that: The axes of the screening drums (5) share an inclined plane, and the acute angle between the inclined plane and the horizontal plane does not exceed 10°.

4. A drum screen according to claim 1 or 2, characterized in that: The impeller blade (12) is mounted on at least two equidistant rods (11), the equidistant rods (11) are provided with impeller blade slots (19) distributed at a fixed distance, the impeller blade (12) is provided with an inner ring boss (20) that cooperates with the impeller blade slot (19), and the end portions of the equidistant rods (11) are fixed in groove openings (22) of the end fixing discs (15).

5. A drum screen according to claim 4, characterized in that: The equidistant rods (11) are three in a centrally symmetrical arrangement.

6. A drum screen according to claim 1 or 2, characterized in that: A feed port (2) is provided at one end of the top of the shell (1), a material buffer plate (3) is provided in the feed port (2), a buffer material distribution roller (4) is provided between the lower edge of the material buffer plate (3) and the first screening roller of the screening roller group, and the working surface of the buffer material distribution roller (4) is a cylindrical surface.

7. A drum screen according to claim 1 or 2, characterized in that: A material dividing plate (8) is provided at one end of the bottom of the shell (1) away from the feed port (2), and the upper edge of the material dividing plate (8) is engaged with the last screening drum of the screening drum group. The outer side of the material dividing plate (8) is the screen-surface material discharge port (9), and the inner side of the material dividing plate (8) is the screen-surface material discharge port (7).

Images