High-efficiency fly ash classification device and method with electric and magnetic field coupling

Abstract

This invention provides a high-efficiency fly ash grading device and method using electric and magnetic field coupling, relating to the field of fly ash grading technology. It includes: a main support; a first separation chamber fixedly installed above the main support, a feed pipe located at the top front of the first separation chamber, and a motor A fixedly installed at the top center of the first separation chamber. Inside the first separation chamber, motor A drives the separation cylinder A to rotate, generating airflow disturbance. Combined with the negative pressure of the cyclone separator, this accelerates the entry of fine particles into the separation cylinder, improving the first-stage grading efficiency. Inside the second separation chamber, motor B drives the lifting plate and separation cylinder B to move up and down via a U-shaped frame and transmission arm. Simultaneously, motor C drives the separation cylinder B to rotate, preventing particle agglomeration and significantly improving the second-stage grading efficiency. This invention solves the problems of existing devices where the single separation structure cannot adequately disturb the fly ash, resulting in uneven particle dispersion, easy mixing of some fine particles with coarse particles, and the need for multiple grading cycles, thus extending the processing cycle.

Description

Technical Field

[0001] This invention relates to the field of fly ash classification technology, and in particular to a high-efficiency fly ash classification device and method using electric and magnetic field coupling. Background Technology

[0002] Application number CN202221492564.8 discloses a fly ash grading device, including a sorting box. A filter screen is slidably connected to the upper end of the inner cavity of the sorting box, and a fine ash collection plate is fixedly connected to the lower end of the inner cavity. A connecting rod is fixedly connected to the lower end of the filter screen, passing through the fine ash collection plate. A vertical vibrator is fixedly connected to the bottom of the inner cavity of the sorting box, and the vibrating end of the vertical vibrator is fixedly connected to the connecting rod. The outer surface of the sorting box is provided with coarse ash outlet pipes and fine ash outlet pipes. Coarse ash will continue to remain at the upper end of the filter screen until the upper end of the inner cavity of the sorting box is filled with fly ash, thereby increasing the output of fine ash and increasing the filtration time of the equipment, allowing the equipment to work continuously, increasing the output and working efficiency of the equipment. At the same time, the setting of the vertical vibrator can prevent the filter screen from clogging, which would lead to poor separation effect and reduce the output of fine ash.

[0003] Based on the above patent searches and understanding of the application of existing fly ash grading devices: Current fly ash grading devices only achieve the separation of coarse and fine particles through filter screens and vertical vibrators. They cannot specifically treat magnetic impurities or magnetic components contained in fly ash, resulting in insufficient purity of the graded product and affecting subsequent resource utilization.

[0004] On the one hand, existing equipment is prone to clogging of separation components by fly ash particles during long-term use. Although some equipment is equipped with vibrators to prevent clogging, the vibration amplitude and frequency are fixed and it is difficult to adapt to fly ash of different particle sizes and moisture content, which still leads to a decrease in separation efficiency. On the other hand, a single separation structure cannot fully turbulent the fly ash, resulting in uneven particle dispersion. Some fine particles are easy to mix with coarse particles, requiring repeated grading and extending the processing cycle.

[0005] Therefore, in view of this, we will study and improve the existing structure and its shortcomings, and provide a high-efficiency fly ash classification device and method with electric and magnetic field coupling, in order to achieve a more practical purpose. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a high-efficiency fly ash grading device and method using electric and magnetic field coupling. This solves the problems of existing fly ash grading devices, which rely solely on filters and vertical vibrators to separate coarse and fine particles. These devices cannot effectively handle magnetic impurities or components in fly ash, resulting in insufficient purity of the graded product and hindering subsequent resource utilization. Furthermore, existing devices suffer from several drawbacks: firstly, the separation components are prone to clogging by fly ash particles during long-term use, leading to reduced separation efficiency; secondly, the single separation structure cannot adequately turbulent the fly ash, resulting in uneven particle dispersion and the mixing of fine particles with coarse particles, necessitating repeated grading and extending the processing cycle.

[0007] This invention provides a high-efficiency fly ash grading device and method using electric and magnetic field coupling, specifically including: a main support; a first separation chamber fixedly installed above the main support, a feed pipe provided at the front top of the first separation chamber, a motor A fixedly installed at the middle top of the first separation chamber, the shaft of motor A fixedly connected to the middle top of the separation cylinder A, the separation cylinder A located in the middle of the first separation chamber, a through groove opened at the middle bottom of the separation cylinder A, a cyclone separator fixedly installed at the lower interior of the first separation chamber, the top inlet of the cyclone separator located at the through groove at the bottom of the separation cylinder A, the bottom of the cyclone separator connected to the rear top of the screw conveyor, a three-stage discharge port provided at the rear bottom of the first separation chamber, a three-stage ash silo fixedly installed at the rear interior of the main support, the top of the three-stage ash silo connected to the three-stage discharge port of the first separation chamber, an electromagnetic motor provided at the rear middle interior of the first separation chamber, a scraper provided at the front end of the electromagnetic motor, the scraper at the front end of the electromagnetic motor being in contact with the rear of the separation cylinder A.

[0008] Furthermore, the front end of the main support is fixedly connected to the rear end of the auxiliary support, a second separation chamber is fixedly installed at the top of the auxiliary support, an adjustment frame is fixedly installed at the upper middle position inside the second separation chamber, a motor B is fixedly installed at the front middle position of the adjustment frame, the rear end of the second separation chamber is fixedly connected to the front end of the screw conveyor, and a secondary ash silo is connected at the lower front end of the second separation chamber.

[0009] Furthermore, the rotating shaft of motor B is fixedly connected to the front end of the U-shaped frame, the U-shaped frame is rotatably connected to the middle position inside the adjusting frame, and the middle protrusion of the U-shaped frame is rotatably connected to the top position of the transmission arm.

[0010] Furthermore, the bottom position of the transmission arm is rotatably connected to the top position of the sliding member, the sliding member is slidably connected to the lower middle position inside the adjusting frame, and the bottom middle position of the sliding member is fixedly connected to the top middle position of the lifting plate.

[0011] Furthermore, the lifting plate is slidably connected to the upper part of the second separation chamber, the bottom middle position of the lifting plate is fixedly connected to the top position of the motor C, the bottom shaft of the motor C is fixedly connected to the top middle position of the separation cylinder B, the separation cylinder B is located in the lower part of the second separation chamber, and a through groove is opened at the bottom middle position of the second separation chamber.

[0012] Furthermore, a cylinder is fixedly installed at the bottom rear position of the lifting plate, and the cylinder is located directly behind the motor C.

[0013] Furthermore, the rear telescopic rod of the cylinder component is fixedly connected to the upper front position of the scraper, and the scraper is located directly behind the second separation chamber. When the cylinder component is in the retracted state, the front end of the scraper is in contact with the rear position of the second separation chamber.

[0014] Furthermore, a transfer frame is fixedly installed at the bottom of the second separation chamber, with the upper middle part of the transfer frame passing through a groove at the bottom of the second separation chamber, and a motor D is fixedly installed at the bottom of the transfer frame.

[0015] Furthermore, the upper part of the rotating shaft of the motor D is fixedly connected to the bottom part of the spiral fan blade, the spiral fan blade is located in the middle of the groove inside the second separation chamber, and a primary ash hopper is set at the bottom front part of the transfer frame.

[0016] This invention also discloses a method for efficient classification of fly ash using electric and magnetic field coupling, comprising the following steps: 1) First, fly ash is introduced into the first separation chamber through the feed pipe. Then, motor A is started to drive separation cylinder A to rotate, which disturbs the airflow of fly ash inside the first separation chamber. At the same time, the cyclone separator is started to generate negative pressure, allowing smaller particles to enter the interior of separation cylinder A for separation. Meanwhile, the magnetic field strength of the electromagnetic motor is set to ensure that it can effectively adsorb magnetic particles without affecting the normal separation of non-magnetic particles. Magnetic particles and larger fly ash particles are isolated to the outside of separation cylinder A. Magnetic particles and larger fly ash particles are then collected and stored in the third-stage ash silo. During the rotation of separation cylinder A, the scraper of the electromagnetic motor can scrape and clean the outer circumference of separation cylinder A to avoid blockage. 2) After primary screening in separator A, the fly ash from primary screening in separator A is transferred to the interior of the second separation chamber via a screw conveyor. Next, motor B is started, which drives the U-shaped frame to rotate within the adjusting frame. The U-shaped frame, through the transmission arm, drives the sliding parts to slide up and down within the adjusting frame, thereby moving the lifting plate and separator B up and down. The lifting plate and separator B turbulent the fly ash inside the second separation chamber, allowing the fly ash in the second separation chamber to enter the interior of separator B, completing the secondary screening process. At the same time, motor C is started, driving separator B to rotate, creating negative pressure inside separator B, accelerating the grading efficiency of the secondary screening process. Fly ash that cannot enter separator B from the second separation chamber is subsequently transferred to the secondary ash silo for temporary storage. 3) The fly ash that has entered the secondary screening in the separation cylinder B can be driven by the starter motor D to rotate the spiral fan blades. The spiral fan blades will transfer the secondary screening fly ash from the separation cylinder B to the transfer frame and the interior of the primary ash silo in sequence.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The device innovatively introduces electric and magnetic field coupling technology. By setting an electromagnetic motor in the first separation chamber, the magnetic field strength can be set according to the needs. While the separation cylinder A rotates to classify particles, it accurately adsorbs magnetic particles in fly ash, achieving the dual effect of particle size classification and magnetic separation. Magnetic particles and coarse particles are isolated on the outside of the separation cylinder A, while non-magnetic fine particles enter the inside of the separation cylinder, effectively improving the purity of the classified product and meeting the application requirements of high-purity fly ash.

[0018] In the first separation chamber, motor A drives the separation cylinder A to rotate, generating airflow disturbance. Combined with the negative pressure of the cyclone separator, this accelerates the entry of fine particles into the separation cylinder, improving the efficiency of the first-stage classification. In the second separation chamber, motor B drives the lifting plate and separation cylinder B to move up and down through the U-shaped frame and transmission arm. At the same time, motor C drives the separation cylinder B to rotate. This dual turbulence ensures that the fly ash particles are fully dispersed, preventing particle agglomeration and significantly improving the efficiency of the second-stage classification.

[0019] The front end of the electromagnetic machine is equipped with a scraper that fits against the separation cylinder A. During the rotation of the separation cylinder A, the scraper can automatically scrape off the particles attached to its outer side to prevent the separation cylinder from clogging. At the same time, the scraper in the second separation chamber, driven by the cylinder, can clean the inner wall of the second separation chamber and related components, reduce particle adhesion, ensure long-term stable operation of the equipment, and reduce maintenance frequency.

[0020] The device achieves fine classification of fly ash through a three-stage grading structure. The first stage separates magnetic particles and coarse particles, which are collected in the third-stage ash silo 106. The second stage further subdivides the fine ash separated in the first stage, and particles that cannot enter the separation cylinder B are collected in the second-stage ash silo. The ultrafine ash in the separation cylinder B is transferred to the first-stage ash silo by a spiral fan blade. The multi-stage grading can produce fly ash products of different particle sizes according to actual needs, which are suitable for various application scenarios such as building materials, concrete, and roadbed materials, thereby improving the resource utilization value of fly ash. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0022] In the attached diagram: Figure 1 A schematic diagram of the left-hand structure of the high-efficiency fly ash classification device with electric and magnetic field coupling according to an embodiment of the present invention is shown. Figure 2 A side view of the high-efficiency fly ash classification device with electric and magnetic field coupling according to an embodiment of the present invention is shown. Figure 3 A schematic diagram of the left half-section structure of the high-efficiency fly ash classification device with electric and magnetic field coupling according to an embodiment of the present invention is shown. Figure 4 A half-section side view of the high-efficiency fly ash classification device with electric and magnetic field coupling according to an embodiment of the present invention is shown. Figure 5 An embodiment of the present invention is shown. Figure 3 A magnified view of the structure at point A in the middle; Figure 6 A side view of the assembly structure of some structural components of the auxiliary support and the lifting plate is shown according to an embodiment of the present invention. Figure 7 A schematic diagram of the overall half-section left view of the transfer frame according to an embodiment of the present invention is shown.

[0023] List of reference numerals 1. Main support; 101. First separation bin; 102. Feed pipe; 103. Motor A; 104. Separation cylinder A; 105. Cyclone separator; 106. Third-stage ash bin; 107. Screw conveyor; 108. Electromagnetic motor; 2. Auxiliary support; 201. Second separation bin; 202. Adjusting frame; 203. Motor B; 204. U-shaped frame; 205. Transmission arm; 206. Sliding component; 207. Second-stage ash bin; 3. Lifting plate; 301. Motor C; 302. Separation cylinder B; 303. Cylinder component; 304. Scraper frame; 4. Transfer frame; 401. Motor D; 402. Spiral fan blade; 403. First-stage ash bin. Detailed Implementation

[0024] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0025] Unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of this disclosure shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms such as those defined in a common dictionary shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as being interpreted in an idealized or highly formalized sense, unless expressly defined in the embodiments of this disclosure.

[0026] The terms "first," "second," and similar words used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a," "one," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. Likewise, the terms "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. In the following description, spatial and directional terms such as "upper," "lower," "front," "rear," "top," "bottom," "vertical," and "horizontal" may be used to describe embodiments of this disclosure; however, it should be understood that these terms are only for the convenience of describing the embodiments shown in the figures and do not require the actual device to be constructed or operated in a specific orientation. In the following description, the use of terms such as "connected," "joined," "fixed," and "attached" can refer to a direct connection between two elements or structures without other elements or structures, or to an indirect connection between two elements or structures via an intermediate element or structure, unless otherwise expressly stated herein.

[0027] Example: As attached Figure 1 To be continued Figure 7 As shown: This invention provides a high-efficiency fly ash classification device and method using electric and magnetic field coupling, comprising: a main support 1; a first separation chamber 101 fixedly installed above the main support 1; a feed pipe 102 provided at the front top of the first separation chamber 101; a motor A103 fixedly installed at the middle top of the first separation chamber 101; the shaft of the motor A103 fixedly connected to the middle top of a separation cylinder A104; the separation cylinder A104 located in the middle of the interior of the first separation chamber 101; a through slot opened at the middle bottom of the separation cylinder A104; and a cyclone separator 10 fixedly installed at the lower interior of the first separation chamber 101. 5. The top inlet of the cyclone separator 105 is located at the bottom slot of the separation cylinder A104. The bottom of the cyclone separator 105 is connected to the top rear of the screw conveyor 107. A three-stage discharge port is provided at the bottom rear of the first separation chamber 101. A three-stage ash silo 106 is fixedly installed at the rear of the main support 1. The top of the three-stage ash silo 106 is connected to the three-stage discharge port of the first separation chamber 101. An electromagnetic motor 108 is provided at the middle rear of the first separation chamber 101. A scraper is provided at the front end of the electromagnetic motor 108. The front scraper of the electromagnetic motor 108 is attached to the rear of the separation cylinder A104.

[0028] The main support 1 is fixedly connected to the rear end of the auxiliary support 2. The second separation chamber 201 is fixedly installed at the top of the auxiliary support 2. An adjusting frame 202 is fixedly installed at the upper middle position inside the second separation chamber 201. A motor B203 is fixedly installed at the front middle position of the adjusting frame 202. The rear end of the second separation chamber 201 is fixedly connected to the front end of the screw conveyor 107. A secondary ash silo 207 is connected to the lower position of the front end of the second separation chamber 201.

[0029] The rotating shaft of motor B203 is fixedly connected to the front end of U-shaped frame 204, U-shaped frame 204 is rotatably connected to the middle position inside the adjusting frame 202, and the middle protrusion of U-shaped frame 204 is rotatably connected to the top position of transmission arm 205.

[0030] The bottom position of the transmission arm 205 is rotatably connected to the top position of the sliding member 206. The sliding member 206 is slidably connected to the lower middle position inside the adjusting frame 202. The bottom middle position of the sliding member 206 is fixedly connected to the top middle position of the lifting plate 3.

[0031] The lifting plate 3 is slidably connected to the upper part of the second separation chamber 201. The bottom middle position of the lifting plate 3 is fixedly connected to the top position of the motor C301. The bottom rotating shaft of the motor C301 is fixedly connected to the top middle position of the separation cylinder B302. The separation cylinder B302 is located in the lower part of the second separation chamber 201, and a through groove is opened at the bottom middle position of the second separation chamber 201.

[0032] Among them, a cylinder component 303 is fixedly installed at the bottom rear position of the lifting plate 3, and the cylinder component 303 is located directly behind the motor C301.

[0033] The rear telescopic rod of the cylinder component 303 is fixedly connected to the upper front position of the scraper 304. The scraper 304 is located directly behind the second separation chamber 201. When the cylinder component 303 is in the retracted state, the front end of the scraper 304 is in contact with the rear position of the second separation chamber 201.

[0034] The second separation chamber 201 is fixedly installed at the bottom of the transfer frame 4. The upper middle part of the transfer frame 4 is inserted into the through groove at the bottom of the second separation chamber 201. The bottom of the transfer frame 4 is fixedly installed with a motor D401.

[0035] Among them, the upper part of the rotating shaft of motor D401 is fixedly connected to the bottom part of the spiral fan blade 402. The spiral fan blade 402 is located in the middle of the groove inside the second separation chamber 201. The bottom front part of the transfer frame 4 is provided with a primary ash hopper 403.

[0036] When using: First, fly ash is introduced into the first separation chamber 101 through the feed pipe 102. Next, the motor A103 is started to drive the separation cylinder A104 to rotate, causing airflow disturbance in the fly ash inside the first separation chamber 101. At the same time, the cyclone separator 105 is activated to generate negative pressure, allowing smaller particles to enter the separation cylinder A104 for separation. Meanwhile, the magnetic field strength of the electromagnetic motor 108 is set to ensure effective adsorption of magnetic particles without affecting the normal separation of non-magnetic particles, isolating magnetic particles and larger fly ash particles to the outside of the separation cylinder A104. The magnetic particles and larger fly ash particles are then collected and stored in the third-stage ash silo 106. During the rotation of the separation cylinder A104, the scraper of the electromagnetic motor 108 can scrape and clean the outer circumference of the separation cylinder A104 to prevent blockage.

[0037] After primary screening in separator A104, the fly ash from primary screening is transferred to the interior of the second separation chamber 201 via screw conveyor 107. Next, motor B203 is started, driving U-shaped frame 204 to rotate within adjusting frame 202. U-shaped frame 204, via transmission arm 205, drives sliding member 206 to slide up and down within adjusting frame 202, thereby moving lifting plate 3 and separator B302 up and down. Lifting plate 3 and separator B302 turbulentize the fly ash inside the second separation chamber 201, allowing it to enter the interior of separator B302 for secondary screening. Simultaneously, motor C301 is started, rotating separator B302 and creating negative pressure inside, accelerating the grading efficiency of the secondary screening process. Fly ash that cannot enter the separation cylinder B302 from the second separation bin 201 is subsequently transferred to the secondary ash bin 207 for temporary storage. The fly ash that enters the separation cylinder B302 for secondary screening can be driven by the start motor D401 to rotate the spiral fan blade 402. The spiral fan blade 402 will transfer the secondary screened fly ash from the separation cylinder B302 to the transfer frame 4 and the primary ash silo 403 in sequence.

[0038] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. The scope of protection of this disclosure shall be determined by the scope of the claims.

Claims

1. A high-efficiency fly ash classification device with electric and magnetic field coupling, characterized in that, include: Main support (1); A first separation chamber (101) is fixedly installed at the upper position of the main support (1), and a feed pipe (102) is provided at the front of the top of the first separation chamber (101). A motor A (103) is fixedly installed at the middle of the top of the first separation chamber (101). The rotating shaft of the motor A (103) is fixedly connected to the middle of the top of the separation cylinder A (104). The separation cylinder A (104) is located in the middle of the interior of the first separation chamber (101). A through groove is opened at the middle of the bottom of the separation cylinder A (104). A cyclone separator (105) is fixedly installed at the lower position inside the first separation chamber (101). The top of the cyclone separator (105) The inlet is located at the bottom slot of the separator A (104). The bottom of the cyclone separator (105) is connected to the top rear of the screw conveyor (107). A three-stage discharge port is provided at the bottom rear of the first separation chamber (101). A three-stage ash silo (106) is fixedly installed at the rear of the main support (1). The top of the three-stage ash silo (106) is connected to the three-stage discharge port of the first separation chamber (101). An electromagnetic motor (108) is provided at the middle rear of the first separation chamber (101). A scraper is provided at the front end of the electromagnetic motor (108). The scraper at the front end of the electromagnetic motor (108) is attached to the rear of the separator A (104). The front end of the main support (1) is fixedly connected to the rear end of the auxiliary support (2). The top of the auxiliary support (2) is fixedly installed with a second separation chamber (201). An adjustment frame (202) is fixedly installed in the middle of the upper part of the second separation chamber (201). A motor B (203) is fixedly installed in the middle of the front end of the adjustment frame (202). The rear end of the second separation chamber (201) is fixedly connected to the front end of the screw conveyor (107). A secondary ash silo (207) is connected to the lower part of the front end of the second separation chamber (201). The rotating shaft of the motor B (203) is fixedly connected to the front end of the U-shaped frame (204), the U-shaped frame (204) is rotatably connected to the middle position inside the adjusting frame (202), and the middle protrusion of the U-shaped frame (204) is rotatably connected to the top position of the transmission arm (205). The bottom position of the transmission arm (205) is rotatably connected to the top position of the sliding member (206), the sliding member (206) is slidably connected to the lower middle position inside the adjusting frame (202), and the bottom middle position of the sliding member (206) is fixedly connected to the top middle position of the lifting plate (3). The lifting plate (3) is slidably connected to the upper part of the second separation chamber (201). The bottom middle position of the lifting plate (3) is fixedly connected to the top position of the motor C (301). The bottom shaft of the motor C (301) is fixedly connected to the top middle position of the separation cylinder B (302). The separation cylinder B (302) is located in the lower part of the second separation chamber (201), and a through groove is opened at the bottom middle position of the second separation chamber (201). Motor B (203) drives the lifting plate (3) and the separation cylinder B (302) to move up and down through the U-shaped frame (204) and the transmission arm (205). At the same time, motor C (301) drives the separation cylinder B (302) to rotate. The double turbulence ensures that the fly ash particles are fully dispersed. A transfer frame (4) is fixedly installed at the bottom of the second separation chamber (201). The upper middle part of the transfer frame (4) is inserted into the through groove at the bottom of the second separation chamber (201). A motor D (401) is fixedly installed at the bottom of the transfer frame (4). The upper part of the rotating shaft of the motor D (401) is fixedly connected to the bottom part of the spiral fan blade (402). The spiral fan blade (402) is located in the middle of the groove inside the second separation chamber (201). The bottom front part of the transfer frame (4) is provided with a primary ash silo (403). The fly ash that enters the separation cylinder B (302) for secondary screening can be driven by starting the motor D (401) to rotate the spiral fan blade (402). The spiral fan blade (402) will transfer the secondary screened fly ash from the separation cylinder B (302) to the interior of the transfer frame (4) and the primary ash silo (403) in sequence.

2. The high-efficiency fly ash classification device with electric and magnetic field coupling as described in claim 1, characterized in that: A cylinder component (303) is fixedly installed at the bottom rear position of the lifting plate (3), and the cylinder component (303) is located directly behind the motor C (301).

3. The high-efficiency fly ash classification device with electric and magnetic field coupling as described in claim 2, characterized in that: The rear telescopic rod of the cylinder component (303) is fixedly connected to the front upper position of the scraper (304). The scraper (304) is located directly behind the second separation chamber (201). When the cylinder component (303) is in the retracted state, the front end of the scraper (304) is attached to the rear position of the second separation chamber (201).

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