Integrated equipment for multi-production of straw pyrolysis oil gas and biochar

Abstract

This invention relates to the field of pyrolysis oil and gas catalysis technology, and discloses an integrated equipment for the combined production of straw pyrolysis oil and gas and biochar, comprising a main body with a gas outlet pipe fixedly connected to the top of the main body. When gas pushes the movable plate to slide within the filling box, some of the gas is guided by the curvature of the inner wall of the curved surface in the middle of the movable plate, extending the residence time of the gas in the biochar particle layer. The returned gas then disturbs and continuously agitates the biochar particles, resulting in a more uniform arrangement of the biochar particles. This reduces the risk of uneven filling and the formation of loose channels within the filling box caused by gas agitation, ensuring sufficient contact between the gas and biochar particles as they pass through the flow layer, and improving the catalytic efficiency, surface area, and quality of the biochar particles for gas.

Description

Technical Field

[0001] This invention relates to the field of pyrolysis oil and gas catalysis technology, specifically to an integrated equipment for the combined production of straw pyrolysis oil and gas and biochar. Background Technology

[0002] The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar is an advanced biomass utilization system that integrates pyrolysis reaction, mobile catalysis, and multi-stage separation. It achieves efficient conversion of straw and co-production of multiple products by using the pyrolysis product biochar as a mobile catalyst.

[0003] In the catalytic process of straw pyrolysis oil and gas, the high-temperature pyrolysis gas generated after the straw is pyrolyzed in the pyrolysis furnace is generally introduced into the biochar packing layer through a pipe. This allows the biochar particles to come into contact with the flowing pyrolysis oil and gas, promoting the secondary cracking reaction of tar in the pyrolysis gas. Since the biochar particles in the biochar packing layer are in a moving state when the pyrolysis gas flows, when a large amount of pyrolysis gas passes through the biochar packing layer at a relatively fast speed, the biochar particles in the packing layer are prone to uneven distribution under the blowing of the pyrolysis gas. This can easily cause the biochar particles to form loose channels in the packing layer, resulting in most of the pyrolysis gas failing to come into sufficient contact with the biochar particles, affecting the catalytic efficiency of the pyrolysis oil and gas and the product quality. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated equipment for the combined production of straw pyrolysis oil and gas and biochar, so as to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] This invention relates to an integrated equipment for the combined production of straw pyrolysis oil and gas and biochar, comprising a main body, with an outlet pipe fixedly connected to the top of the main body, and further comprising:

[0007] The active mechanism, installed inside the main body, is used to ensure sufficient catalytic contact during gas catalysis.

[0008] The auxiliary mechanism is installed on the side wall of the active mechanism to ensure smooth gas flow.

[0009] Furthermore, the main body includes:

[0010] A connecting component is installed on the outer surface of the main body to facilitate the transport of gas and materials.

[0011] Furthermore, the actuating mechanism includes several return springs disposed inside the main body, and the actuating mechanism also includes:

[0012] The movable component is installed at the bottom of the return spring, which can reduce the uneven filling of biochar particles caused by excessive gas flow speed.

[0013] The rotating component is mounted at the bottom of the moving component.

[0014] Furthermore, the auxiliary mechanism includes several bending plates disposed at the bottom of the moving component, and the auxiliary mechanism also includes:

[0015] Deformation assembly, the deformation assembly is installed on the side wall of the bending plate;

[0016] A limiting component is installed at the bottom of the bending plate to ensure that the deformation component can bend under the impetus of the return airflow.

[0017] Furthermore, the connecting assembly includes an air inlet pipe fixedly connected to the bottom of the main body, two filling boxes are provided at the top of the air inlet pipe, a feed pipe is fixedly connected to the outer surface of the filling box, and the end of the feed pipe away from the filling box extends through to the outer wall of the main body;

[0018] The top of the filling box is conical, and the bottom of the filling box has several round holes.

[0019] Furthermore, several return springs are arranged in groups of four inside the filling box, and the tops of the four return springs are fixedly connected to the top inner wall of the filling box.

[0020] The moving component includes a movable plate fixedly connected to the bottom of four return springs, and the side wall of the movable plate has several round holes.

[0021] The bottom of the movable plate is rotatably connected to three connecting rods. The end of the connecting rod away from the movable plate is rotatably connected to a tripod. The middle part of the movable plate is semi-circular, and the side wall of this semi-circular structure does not have round holes, so as to block the flowing gas and slide under the push of the gas.

[0022] Furthermore, the rotating assembly includes two rotating plates slidably connected to the outer surface of the tripod, and a central shaft is rotatably connected between the two rotating plates;

[0023] The central shaft is rotatably connected inside the filling box.

[0024] Furthermore, several bent plates are fixedly connected to the inner wall of the filling box;

[0025] The deformation assembly includes corrugated sheets fixedly connected to the top of several bent plates.

[0026] Furthermore, a sliding ring is fixedly connected to the side of the corrugated sheet away from the bending plate;

[0027] Several connecting springs are fixedly connected to the bottom of the sliding ring. The end of the connecting spring away from the sliding ring is fixedly connected to the top of the bending plate. The corrugated sheet can be a thin metal corrugated sheet, which can withstand a certain temperature and also has elastic deformation capability.

[0028] Furthermore, the limiting component includes a retaining ring disposed at the bottom of several bent plates, and several retaining rods are fixedly connected to the outer surface of the retaining rings, and the several retaining rods are fixedly connected to the inner wall of the filling box.

[0029] The present invention has the following beneficial effects:

[0030] 1. In this invention, when the gas pushes the movable plate to slide within the filling box, some of the gas will be deflected by the curvature of the inner wall of the curved surface in the middle of the movable plate, prolonging the residence time of the gas in the biochar particle layer. At this time, the deflected gas will disturb the biochar particles and continuously turn them over, so that the biochar particles are continuously and evenly arranged. This reduces the situation where the biochar particles form loose channels in the filling box due to uneven filling caused by the gas blowing. It ensures sufficient contact between the gas and the biochar particles when passing through the biochar particle flow layer, improving the catalytic efficiency, area, and quality of the biochar particles for the gas.

[0031] 2. In this invention, when the gas flows back and passes through the corrugated sheet surface attached to the side wall of the bending plate, the backflowing gas and the normally flowing upward gas in the filling box can cause the bending plate to drive the corrugated sheet to oscillate back and forth. When multiple bending plates oscillate, the reverse flow velocity of the airflow can be broken, thereby reducing the collision between the backflowing gas and the normally flowing gas, which would affect the efficiency of the upward flow of the gas and the gas obstruction. This can further improve the catalytic efficiency of biochar for pyrolysis oil and gas.

[0032] 3. This invention, by guiding the rising airflow from the edge of the filling box to the center of the filling box, can reduce the excessive cross-impact of the rising gas and the returning gas on the biochar particles. This can prevent the biochar particles from being excessively worn and broken under the impact of the returning cross-flow and being carried out of the filling box. At the same time, it can further improve the catalytic intensity of the biochar particle layer on the gas and the integrity of the particle layer, thereby enhancing the catalytic efficiency for pyrolysis oil and gas.

[0033] 4. In this invention, when the connecting rod is swaying, it can drive the two rotating plates after the movement to swing back and forth around the central axis through the tripod. Through the swinging of the rotating plates after multiple movements and the guidance of the rising gas by the side walls of the rotating plates, the uniformity of the initial distribution of the rising gas can be significantly increased, which can further enhance the uniformity of the gas-biochar particle contact distribution. This is conducive to the smooth movement of biochar particles on a wider gas velocity interface, further reducing the uneven distribution of biochar particles while further enhancing the sufficiency and stability of the contact between biochar particles and gas.

[0034] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0037] Figure 2 This is a schematic diagram of the overall partial cross-sectional structure of the present invention;

[0038] Figure 3 This is a partial cross-sectional schematic diagram of the active mechanism of the present invention;

[0039] Figure 4 This is a partial cross-sectional schematic diagram of the filling box of the present invention;

[0040] Figure 5 This is a bottom view of the moving component structure of the present invention;

[0041] Figure 6 This is a partial cross-sectional schematic diagram of the rotating component of the present invention;

[0042] Figure 7 This is a partial cross-sectional schematic diagram of the limiting component of the present invention;

[0043] Figure 8 This is a schematic cross-sectional view of the rear half of the moving mechanism of the present invention.

[0044] The attached diagram lists the components represented by each number as follows:

[0045] In the diagram: 1. Main body; 101. Air outlet pipe; 11. Connecting assembly; 111. Air inlet pipe; 112. Filling box; 113. Feed pipe; 2. Movable mechanism; 201. Return spring; 21. Moving assembly; 211. Movable plate; 212. Connecting rod; 213. Tripod; 22. Rotating assembly; 221. Central shaft; 222. Rotating plate; 3. Auxiliary mechanism; 301. Bending plate; 31. Deformation assembly; 311. Corrugated sheet; 312. Sliding ring; 313. Connecting spring; 32. Limiting assembly; 321. Fixing ring; 322. Fixing rod. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0047] Please see Figure 1 - Figure 8 As shown, this invention is an integrated equipment for the combined production of straw pyrolysis oil and gas and biochar, including a main body 1, with an outlet pipe 101 fixedly connected to the top of the main body 1, and further including:

[0048] The active mechanism 2 is installed inside the main body 1 to ensure sufficient catalytic contact during gas catalysis.

[0049] Auxiliary mechanism 3 is installed on the side wall of the active mechanism 2. The operation of auxiliary mechanism 3 ensures smooth gas flow.

[0050] Entity 1 includes:

[0051] Connection component 11 is installed on the outer surface of the main body 1 to realize the conveying of gas and materials.

[0052] The movable mechanism 2 includes several return springs 201 disposed inside the main body 1. The movable mechanism 2 also includes:

[0053] The movable component 21 is installed at the bottom of the return spring 201, which can reduce the uneven filling of biochar particles caused by excessive gas flow speed.

[0054] Rotating component 22 is mounted on the bottom of moving component 21.

[0055] The auxiliary mechanism 3 includes several bending plates 301 disposed at the bottom of the moving component 21, and the auxiliary mechanism 3 also includes:

[0056] Deformation component 31 is installed on the side wall of bending plate 301;

[0057] A limiting component 32 is installed at the bottom of the bending plate 301 to ensure that the deformation component 31 can bend under the push of the return airflow.

[0058] The connecting assembly 11 includes an air inlet pipe 111 fixedly connected to the bottom of the main body 1. Two filling boxes 112 are provided on the top of the air inlet pipe 111. A feed pipe 113 is fixedly connected to the outer surface of the filling box 112. The end of the feed pipe 113 away from the filling box 112 extends through to the outer wall of the main body 1.

[0059] The top of the filling box 112 is conical, and the bottom of the filling box 112 has several round holes. First, the air inlet pipe 111 is connected to the exhaust pipe of the external pyrolysis furnace through the pump body, and the air outlet pipe 101 is connected to the external condensation equipment. Then, the staff opens the two feed pipes 113 and puts the biochar particles into the interior of the filling box 112.

[0060] Several return springs 201 are arranged in groups of four inside the filling box 112, and the tops of the four return springs 201 are fixedly connected to the top inner wall of the filling box 112.

[0061] The movable component 21 includes a movable plate 211 fixedly connected to the bottom of four return springs 201, and the side wall of the movable plate 211 is provided with several round holes.

[0062] Three connecting rods 212 are rotatably connected to the bottom of the movable plate 211. A tripod 213 is rotatably connected to the end of the connecting rod 212 away from the movable plate 211. The middle part of the movable plate 211 is semi-circular, and the side wall of this semi-circular structure does not have a circular hole, so as to block the flowing gas and slide under the push of the gas. When the gas flows upward through the filling box 112, the gas will pass through the biochar particles inside the filling box 112 and come into contact with the area of ​​the semi-circular structure in the middle of the movable plate 211. Then, as the subsequent gas continues to flow upward, the movable plate 211 will slide upward under the continuous flow and push of the gas.

[0063] The rotating assembly 22 includes two rotating plates 222 that are slidably connected to the outer surface of the tripod 213, and a central shaft 221 is rotatably connected between the two rotating plates 222;

[0064] The central shaft 221 is rotatably connected inside the filling box 112. When the connecting rod 212 shakes, it can drive the two rotating plates 222 to swing back and forth around the central shaft 221 through the tripod 213. After multiple movements, the swing of the rotating plates 222 and the guidance of the rising gas by the side wall of the rotating plates 222 are achieved.

[0065] Several bent plates 301 are fixedly connected to the inner wall of the filling box 112;

[0066] The deformation assembly 31 includes a corrugated sheet 311 fixedly connected to the top of a plurality of bent plates 301.

[0067] A sliding ring 312 is fixedly connected to the side of the corrugated sheet 311 away from the bending plate 301;

[0068] Several connecting springs 313 are fixedly connected to the bottom of the sliding ring 312. The end of the connecting spring 313 away from the sliding ring 312 is fixedly connected to the top of the bending plate 301. The corrugated sheet 311 can be a thin metal corrugated sheet, which can withstand a certain temperature and has elastic deformation capability. When the corrugated sheet 311 is attached to the side wall of multiple bending plates 301, the movement of the corrugated sheet 311 will drive the sliding ring 312 to slide downward. At this time, the sliding ring 312 and the outer surface of the movable plate 211 will present a stepped misalignment distribution.

[0069] The limiting component 32 includes a fixing ring 321 disposed at the bottom of several bending plates 301. Several fixing rods 322 are fixedly connected to the outer surface of the fixing ring 321. The several fixing rods 322 are fixedly connected to the inner wall of the filling box 112. Since the bottom of the bending plate 301 is in contact with the surface of the fixing ring 321, when the bending plate 301 is pushed by the reverse airflow, the bending plate 301 will bend downward on the surface of the fixing ring 321. When the bending plate 301 bends downward, the bottom of the bending plate 301 will form a curved arc.

[0070] In use, the inlet pipe 111 is first connected to the exhaust pipe of the external pyrolysis furnace through the pump body, and the outlet pipe 101 is connected to the external condensation equipment. Then, the operator opens the two feed pipes 113 and puts the biochar particles into the filling box 112. When the straw inside the pyrolysis furnace is pyrolyzed, the pyrolysis oil and gas produced by the straw pyrolysis will enter the interior of the main body 1 through the inlet pipe 111 and flow upward. When the pyrolysis oil and gas flow upward, it will enter the filling box 112 through the round hole at the bottom of the filling box 112 and flow upward. When the gas flows through the filling box 112, the gas will come into contact with the biochar particles inside the filling box 112, and the biochar particles will be in motion with the airflow to promote the secondary cracking reaction of tar in the gas, thereby improving the quality of bio-oil and fuel gas. Then, the catalyzed gas will enter the subsequent condensation equipment through the outlet pipe 101, thereby achieving the catalytic treatment of pyrolysis oil and gas.

[0071] As the gas flows upward through the filling box 112, it passes through the biochar particles inside the filling box 112 and comes into contact with the semi-circular structure in the middle of the movable plate 211. As the gas continues to flow upward, the movable plate 211 slides upward under the continuous flow and pushing of the gas. As the movable plate 211 slides upward, the semi-circular structure in the middle of the movable plate 211 reduces its distance from the conical outlet at the top of the filling box 112 and reduces the flow area of ​​the gas through the outlet of the filling box 112, thus exhibiting... Figure 8 As shown in state G, by reducing the flow area of ​​the gas through the outlet of the filling box 112, the upward flow velocity of the gas in the filling box 112 can be reduced. Simultaneously, when the movable plate 211 slides upward, the sliding of the movable plate 211 will drive the tripod 213 to slide upward via the connecting rod 212. When the tripod 213 slides upward, it will drive the two rotating plates 222 to rotate relative to each other. At this time, the two rotating plates 222 can form a V-shape at the bottom of the movable plate 211, presenting a shape as shown in state G. Figure 8 As shown in state H, when the gas pushes the movable plate 211 to slide within the filling box 112, some of the gas will be deflected by the bending of the inner wall of the arc surface in the middle of the movable plate 211, prolonging the residence time of the gas in the biochar particle layer. At this time, the deflected gas will disturb the biochar particles and continuously turn them over, so that the biochar particles are continuously and evenly arranged. This can reduce the situation where the biochar particles are unevenly filled in the filling box 112 due to the gas blowing, causing the biochar particles to form loose channels in the filling box 112. This ensures sufficient contact between the gas and the biochar particles when passing through the biochar particle flow layer, improving the catalytic efficiency, area and quality of the biochar particles for the gas.

[0072] When the gas pushes the movable plate 211 upward and a return flow occurs guided by the curved surface in the middle of the movable plate 211, the returning gas will exert a pushing force on the corrugated sheet 311. When the sidewall of the corrugated sheet 311 is pushed by the return airflow, it will stick to the sidewall of the multiple bent plates 301. At the same time, when the corrugated sheet 311 is sticking to the sidewall of the multiple bent plates 301, the movement of the corrugated sheet 311 will drive the sliding ring 312 to slide downward. At this time, the sliding ring 312 and the outer surface of the movable plate 211 will have a stepped misalignment. At this time, the movable plate 211 and the filling box 112 A flow channel can be opened between the inner walls. At the same time, when the gas flows back and passes through the corrugated sheet 311 attached to the side wall of the bending plate 301, the backflowing gas and the gas flowing upward normally through the filling box 112 can cause the bending plate 301 to drive the corrugated sheet 311 to oscillate back and forth. When multiple bending plates 301 oscillate, the reverse flow velocity of the airflow can be broken, thereby reducing the collision between the gas and the normally flowing gas during the backflow, which would affect the efficiency of the gas flow upward and the gas obstruction. This can further improve the catalytic efficiency of biochar for pyrolysis oil and gas.

[0073] When the returning gas pushes the corrugated sheet 311 to adhere to the surface of the bending plate 301, the bottom of the bending plate 301 contacts the surface of the fixing ring 321. When the bending plate 301 is pushed by the returning airflow, it bends downward on the surface of the fixing ring 321. When the bending plate 301 bends downward, the bottom of the bending plate 301 forms a curved arc. At this time, the curved arc at the bottom of the bending plate 301 can guide the rising gas towards the center of the filling box 112. By guiding the rising airflow at the edge of the filling box 112 towards the center of the filling box 112, the excessive cross-impact of the rising gas and the returning gas on the biochar particles can be reduced. This can prevent the biochar particles from being excessively worn and broken under the impact of the returning cross-airflow and being carried out of the filling box 112. At the same time, it can further improve the catalytic intensity of the biochar particle layer on the gas and the integrity of the particle layer, and enhance the catalytic efficiency for pyrolysis oil and gas.

[0074] When the movable plate 211 is pushed by the gas to make the two rotating plates 222 form a V-shaped structure, the side wall of the rotating plate 222 can guide the rising airflow at an angle. At the same time, when the returning airflow blows and disturbs and turns the biochar particles, the turning of the biochar particles and the return of the gas can drive the connecting rod 212 to shake. When the connecting rod 212 shakes, it can drive the two rotating plates 222 to swing back and forth around the central axis 221 through the tripod 213. After multiple movements, the swing of the rotating plate 222 and the guidance of the rising gas by the side wall of the rotating plate 222 can significantly increase the uniformity of the initial distribution of the rising gas, and further enhance the uniformity of the gas-biochar particle contact distribution. This is conducive to the smooth movement of biochar particles on a wider gas velocity interface, further reducing the uneven distribution of biochar particles while further enhancing the sufficiency and stability of the contact between biochar particles and gas.

[0075] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An integrated equipment for the combined production of straw pyrolysis oil and gas and biochar, comprising a main body (1), wherein a gas outlet pipe (101) is fixedly connected to the top of the main body (1), characterized in that, Also includes: The active mechanism (2) is installed inside the main body (1) to ensure sufficient catalytic contact during gas catalysis; The auxiliary mechanism (3) is installed on the side wall of the active mechanism (2) to ensure smooth gas flow through its operation.

2. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 1, characterized in that: The main body (1) includes: A connecting component (11) is installed on the outer surface of the main body (1) to facilitate the transport of gas and materials.

3. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 2, characterized in that: The movable mechanism (2) includes several return springs (201) disposed inside the main body (1), and the movable mechanism (2) further includes: The moving component (21) is installed at the bottom of the return spring (201) to reduce the uneven filling of biochar particles caused by excessive gas flow speed. Rotating component (22) is mounted on the bottom of moving component (21).

4. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 3, characterized in that: The auxiliary mechanism (3) includes a plurality of bent plates (301) disposed at the bottom of the moving component (21), and the auxiliary mechanism (3) further includes: Deformation component (31), said deformation component (31) is installed on the side wall of the bending plate (301); A limiting component (32) is installed at the bottom of the bending plate (301) to ensure that the deformation component (31) can bend under the push of the reversing airflow.

5. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 4, characterized in that: The connecting assembly (11) includes an air inlet pipe (111) fixedly connected to the bottom of the main body (1). Two filling boxes (112) are provided on the top of the air inlet pipe (111). A feed pipe (113) is fixedly connected to the outer surface of the filling box (112). The end of the feed pipe (113) away from the filling box (112) extends through to the outer wall of the main body (1). The top of the filling box (112) is conical, and the bottom of the filling box (112) has several round holes.

6. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 5, characterized in that: Several of the aforementioned return springs (201) are arranged in groups of four inside the filling box (112), and the tops of the four return springs (201) are fixedly connected to the top inner wall of the filling box (112). The moving component (21) includes a movable plate (211) fixedly connected to the bottom of the four return springs (201), and the side wall of the movable plate (211) is provided with a plurality of circular holes. The bottom of the movable plate (211) is rotatably connected to three connecting rods (212), and the end of the connecting rod (212) away from the movable plate (211) is rotatably connected to a tripod (213).

7. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 6, characterized in that: The rotating assembly (22) includes two rotating plates (222) slidably connected to the outer surface of the tripod (213), and a central shaft (221) is rotatably connected between the two rotating plates (222). The central shaft (221) is rotatably connected inside the filling box (112).

8. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 5, characterized in that: Several of the aforementioned bent plates (301) are fixedly connected to the inner wall of the filling box (112); The deformation component (31) includes a corrugated sheet (311) fixedly connected to the top of a plurality of bent plates (301).

9. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 8, characterized in that: A sliding ring (312) is fixedly connected to the side of the corrugated sheet (311) away from the bending plate (301). The bottom of the sliding ring (312) is fixedly connected to a plurality of connecting springs (313), and the end of the connecting spring (313) away from the sliding ring (312) is fixedly connected to the top of the bending plate (301).

10. The integrated equipment for the combined production of straw pyrolysis oil and gas and biochar according to claim 4, characterized in that: The limiting component (32) includes a fixing ring (321) disposed at the bottom of a plurality of bending plates (301), and a plurality of fixing rods (322) are fixedly connected to the outer surface of the fixing ring (321), and the plurality of fixing rods (322) are fixedly connected to the inner wall of the filling box (112).

Images