阅读说明：本技术 一种高温熔渣余热回收用冷却熔渣破碎装置 (Cooling slag crushing device for recovering waste heat of high-temperature slag ) 是由 陆建宁 陆睿 郑璇 曹刚川 王圣冬 于 2021-08-03 设计创作，主要内容包括：本发明公开了一种高温熔渣余热回收用冷却熔渣破碎装置,包括破碎箱、柜体、底座和固定板,底座的顶部通过四根固定杆固定安装有固定板,固定板的安装破碎箱,破碎箱的底部贯穿固定板嵌入式安装有下料阀,破碎箱前端的固定板顶部安装有垫台,垫台的上端安装有两台电动机,电动机后端的破碎箱内部安装有辊轴,破碎箱的顶部安装有进料管,破碎箱后端的表面安装有检修门,且检修门后端的表面设置有标识。本发明通过设置有一系列的结构使本装置在使用的过程中能够有效地起到防止熔渣在破碎时出现堵塞的情况,可以在下料收集的过程中对所产生的灰尘进行回收以及便于使用人员对装置进行卸料等优点,优化使用过程。(The invention discloses a cooling slag crushing device for recovering waste heat of high-temperature slag, which comprises a crushing box, a cabinet body, a base and a fixing plate, wherein the top of the base is fixedly provided with the fixing plate through four fixing rods, the fixing plate is provided with the crushing box, the bottom of the crushing box penetrates through the fixing plate and is embedded with a blanking valve, the top of the fixing plate at the front end of the crushing box is provided with a cushion table, the upper end of the cushion table is provided with two motors, a roller shaft is arranged in the crushing box at the rear end of the motors, the top of the crushing box is provided with a feeding pipe, the surface at the rear end of the crushing box is provided with an access door, and the surface at the rear end of the access door is provided with a mark. The device has the advantages that the device can effectively prevent the slag from being blocked during crushing in the using process by arranging a series of structures, can recover the generated dust in the blanking and collecting process, is convenient for a user to unload the device, and the like, and optimizes the using process.)

1. The utility model provides a high temperature slag waste heat recovery is with cooling slag breaker, includes broken case (2), the cabinet body (5), base (6) and fixed plate (9), its characterized in that: the top of the base (6) is fixedly provided with a fixing plate (9) through four fixing rods (901), the fixing plate (9) is provided with a crushing box (2), the bottom of the crushing box (2) penetrates through the fixing plate (9) and is provided with a blanking valve (204) in an embedded mode, the top of the fixing plate (9) at the front end of the crushing box (2) is provided with a cushion table (804), the upper end of the cushion table (804) is provided with two motors (8), a roller shaft (803) is arranged in the crushing box (2) at the rear end of each motor (8), the top of the crushing box (2) is provided with a feeding pipe (201), the surface of the rear end of the crushing box (2) is provided with an access door (206), and the surface of the rear end of the access door (206) is provided with a mark (205);

the crushing box is characterized in that supporting frames (1) are installed at the tops of fixing plates (9) on two sides of the crushing box (2), a funnel (101) is installed between the supporting frames (1) at the upper end of the feeding pipe (201), a vibration motor (102) is fixedly installed on the surface of the funnel (101), a pressure detector (21) is installed in a base (6) between the fixing rods (901) in an embedded mode, a bearing plate (14) is installed at the top of the pressure detector (21), a protective guard (11) is installed on the periphery of the top of the bearing plate (14), hooks (13) are installed on two sides of the surface of the protective guard (11), a cross rod (12) is installed inside the hooks (13), a recovery box (10) is installed at the top of the bearing plate (14) between the protective guards (11), and a base plate (7) is installed at the front end of the bearing plate (14);

the cabinet is characterized in that a cabinet body (5) is installed at the top of a base (6) on one side of a fixing rod (901), an air guide pipe (15) is installed on the surface of the other side of the cabinet body (5), a cabinet door (501) is installed on the surface of the cabinet body (5) at the top of the cabinet body (5), a protective door (504) is installed on the surface of the cabinet body (5) at the top of the cabinet body (501), a control box (4) is installed on the surface of the protective door (504), two exhaust pipes (3) are installed at the top of the cabinet body (5), an inner box (20) is installed inside the cabinet body (5), a baffle (22) is installed at the upper end of the inner box (20), a fan (23) is installed inside the cabinet body (5) on the other side of the baffle (22), a filter (16) is installed on one side of the baffle (22), a primary filter layer (19) is arranged inside the filter (16), and a middle-level filter layer (18) is arranged at the upper end of the primary filter layer (19), the upper end of the middle filtering layer (18) is provided with a fine particle filtering layer (17).

2. The cooling slag crushing device for recovering the waste heat of the high-temperature slag according to claim 1, characterized in that: connecting platform (302) is installed to blast pipe (3) outlying lower extreme, and installs four connecting bolt (301) between connecting platform (302) and the cabinet body (5).

3. The cooling slag crushing device for recovering the waste heat of the high-temperature slag according to claim 1, characterized in that: an observation window (502) is fixedly arranged on the surface of the cabinet door (501), and a handle (503) is arranged on the surface of the cabinet door (501) on the other side of the observation window (502).

4. The cooling slag crushing device for recovering the waste heat of the high-temperature slag according to claim 1, characterized in that: protective pipes (202) are arranged on the surfaces of the roller shaft (803) and the crushing box (2) on the periphery of the motor (8), and bolts (203) are arranged between the protective pipes (202) and the crushing box (2).

5. The cooling slag crushing device for recovering the waste heat of the high-temperature slag according to claim 1, characterized in that: the bottom of motor (8) is installed frame (802), and the block terminal is installed to the outside of motor (8), screw bolt (801) are installed to the inside of frame (802) and pad platform (804) screw thread.

6. The cooling slag crushing device for recovering the waste heat of the high-temperature slag according to claim 1, characterized in that: fixed platforms (903) are installed between the bottom of each fixed rod (901) and the base (6), and a fixed bolt (902) is installed between each fixed platform (903) and the base (6) in a threaded mode.

7. The cooling slag crushing device for recovering the waste heat of the high-temperature slag according to claim 1, characterized in that: a supporting table (103) is installed at the bottom of the supporting frame (1) on the two sides of the crushing box (2), and three groups of supporting bolts (104) are installed between the supporting table (103) and the fixing plate (9).

8. The cooling slag crushing device for recovering the waste heat of the high-temperature slag according to claim 1, characterized in that: two sets of wheels (1002) are installed to the bottom both sides of collection box (10), and the fixed surface of collection box (10) installs handle (1001).

Technical Field

The invention relates to the technical field of slag processing, in particular to a cooling slag crushing device for recovering waste heat of high-temperature slag.

Background

The slag is a vitreous nonmetal substance which is formed by coating iron ore on the surface of molten metal after smelting, the converter steelmaking process is carried out in a molten reaction medium, the slag is a product of a pyrogenic steelmaking process and mainly comprises oxides in metallurgical raw materials or melts formed by the oxides generated in the metallurgical process, the slag is mainly composed of oxides, such as CaO, FeO, MnO, MgO, Al2O3, SiO2, P2O5, Fe2O3 and the like, besides the oxides, the slag can also contain a small amount of other types of compounds or even metals, such as fluoride (CaF2), chloride (NaCl), sulfide (CaS, MnS), sulfate and the like, a large-volume slag object cannot be avoided in the slag granulation process, and the slag needs to be crushed when being used for facilitating the treatment of the slag by using personnel.

Through retrieval, publication number CN208661334U discloses a crushing and grading device for slag particles, a casing body is a shell of the crushing and grading device for slag particles, the casing body comprises an upper casing, the upper casing is fixedly arranged at the lower part of a fixed sieve, a lower casing is fixedly arranged at the lower part of the upper casing, and the upper casing and the lower casing are fixed through bolts; the fixed screen is fixedly arranged at the left side position of the upper part of the machine shell body; the driving shaft is fixedly arranged in the cavity on the left side of the machine shell body, the driven shaft is fixedly arranged at the position on the right side of the driving shaft, and the driving shaft and the driven shaft are arranged horizontally and meshed; the crushing cutter is respectively sleeved on the driving shaft and the driven shaft; two scrapers are fixedly arranged on the front side and the rear side of the crushing knife respectively; two cooling pipes are fixedly arranged.

The existing cooling slag crushing device for recovering the waste heat of the high-temperature slag has the following defects:

1. the existing cooling slag crushing device for recovering the waste heat of the high-temperature slag is simple in structure, the slag is easy to block in the slag crushing process, and the cooling slag crushing device is inconvenient for a user to clean, so that the working efficiency of the device in use is reduced;

2. the cooling slag crushing device for recovering the waste heat of the high-temperature slag is easy to generate a large amount of dust when the slag is crushed and then is recovered, the dust is discharged in the environment and easily affects the environment, and the dust easily enters the mouth and the nose of a user, so that the safety of the device is reduced;

3. in the blanking process, a user cannot weigh the load of the waste materials, and the situation of overweight and overweight easily occurs in use only by visual observation, so that the working difficulty of the user is increased, and the cooling slag crushing device for recovering the waste heat of the high-temperature slag is provided for solving the existing problems.

Disclosure of Invention

The invention aims to solve the defects in the prior art, such as: the existing cooling slag crushing device for recovering the waste heat of the high-temperature slag is easy to cause slag blockage in the slag crushing process, is inconvenient for cleaning by users, is easy to generate a large amount of dust when being recovered after the slag is crushed, and is easy to influence the environment when being discharged in the environment.

In order to achieve the purpose, the invention provides the following technical scheme: a cooling slag crushing device for recovering waste heat of high-temperature slag comprises a crushing box, a cabinet body, a base and a fixed plate, wherein the top of the base is fixedly provided with the fixed plate through four fixed rods;

the top of the fixed plates on two sides of the crushing box is provided with a support frame, a funnel is arranged between the support frames at the upper end of the feeding pipe, the surface of the funnel is fixedly provided with a vibration motor, a pressure detector is embedded in the base between the fixed rods, the top of the pressure detector is provided with a bearing plate, the periphery of the top of the bearing plate is provided with a guard rail, hooks are arranged on two sides of the surface of the guard rail, a cross rod is arranged in the hooks, the top of the bearing plate between the guard rails is provided with a recovery box, and the front end of the bearing plate is provided with a backing plate;

the cabinet body is installed at the base top of dead lever one side, the surface mounting of cabinet body opposite side has the bleed pipe, the surface rotation of the cabinet body installs the cabinet door, the cabinet body surface rotation at cabinet door top installs the guard gate, and the surface mounting of guard gate has the control box, two blast pipes are installed at the top of the cabinet body, the internally mounted of the cabinet body has the inner box, the baffle is installed to the inner box upper end, the cabinet body internally mounted of baffle opposite side has the fan, the filter is installed to one side of baffle, the inside of filter is provided with elementary filter layer, and the upper end of elementary filter layer is provided with the middle level filter layer, the upper end of middle level filter layer is provided with fine particle filter layer.

Preferably, the lower end of the periphery of the exhaust pipe is provided with a connecting table, and four connecting bolts are arranged between the connecting table and the cabinet body.

Preferably, the surface of the cabinet door is fixedly provided with an observation window, and the surface of the cabinet door at the other side of the observation window is provided with a handle.

Preferably, protective pipes are arranged on the surfaces of the roller shaft and the crushing box on the periphery of the motor, and bolts are arranged between the protective pipes and the crushing box.

Preferably, the bottom of motor is installed the frame, and the distribution box is installed to the outside of motor, threaded bolt is installed to the screw thread between the inside of frame and the pad platform.

Preferably, a fixing table is arranged between the bottom of each fixing rod and the base, and a fixing bolt is arranged between each fixing table and the base in a threaded manner.

Preferably, the bottom of the support frame of crushing case both sides is installed a supporting bench, and installs three group's brace bolts between supporting bench and the fixed plate.

Preferably, two groups of wheels are installed on two sides of the bottom of the recycling box, and a handle is fixedly installed on the surface of the recycling box.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, the vibrating motor is fixedly arranged on the surface of the funnel, so that molten slag to be crushed is guided into the funnel when the device is used, the capacity of the device can be enlarged by using the funnel, the funnel can be driven to vibrate after the vibrating motor is electrified, the situation that the molten slag is blocked before entering the feeding pipe can be avoided, the position of the funnel on the top of the fixed plate can be limited by using the support frame when the device is used, and the molten slag in the crushing box can be cleaned by opening the access door, so that the practicability of the device is improved.

2. According to the invention, the dust generated in the discharging process of the discharging valve is introduced into the cabinet body by the fan through the air-entraining pipe, the dust in the gas is treated by the filter after introduction, the large, medium and small floaters in the gas are respectively filtered by the primary filter layer, the medium filter layer and the fine particle filter layer, the filtered gas is discharged from the exhaust pipe, and the filtered impurities are stored by the inner box, so that the waste residues are more conveniently treated by a user.

3. According to the invention, the pressure detector is embedded in the base between the fixed rods, the pressure detector is used for detecting the weight of the top of the bearing plate when the recovery box is used, and the detected data is displayed by the control box, so that a user can judge the weight of slag discharged by the discharge valve more conveniently, the condition that the recovery box is under low load and overloaded is avoided, the position of the recovery box on the top of the bearing plate is limited by the guard rail and the cross rod, and the condition that the recovery box sideslips due to uneven ground is avoided.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a rear view of the present invention;

FIG. 3 is a partial structural view of the fixing plate and the base of the present invention;

FIG. 4 is a front view of the present invention;

FIG. 5 is a side view of the present invention;

FIG. 6 is a schematic view of a partial structure of the cabinet and the recycling bin of the present invention;

fig. 7 is a partial structural schematic view of the crushing box of the present invention.

In the figure: 1. a support frame; 101. a funnel; 102. a vibration motor; 103. a support table; 104. a support pin; 2. a crushing box; 201. a feed pipe; 202. a protective tube; 203. a bolt; 204. a discharge valve; 205. identifying; 206. an access door; 3. an exhaust pipe; 301. a connecting bolt; 302. a connecting table; 4. a control box; 5. a cabinet body; 501. a cabinet door; 502. an observation window; 503. a handle; 504. a protective door; 6. a base; 7. a base plate; 8. an electric motor; 801. a threaded bolt; 802. a frame; 803. a roll shaft; 804. a cushion table; 9. a fixing plate; 901. fixing the rod; 902. a fixing bolt; 903. a fixed table; 10. a recycling bin; 1001. a handle; 1002. a wheel; 11. protecting the fence; 12. a cross bar; 13. hooking; 14. a bearing plate; 15. a bleed pipe; 16. a filter; 17. a fine particle filtration layer; 18. a middle-stage filter layer; 19. a primary filtration layer; 20. an inner box; 21. a pressure detector; 22. a baffle plate; 23. a fan.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1-7, an embodiment of the present invention is shown: a cooling slag crushing device for recovering waste heat of high-temperature slag comprises a crushing box 2, a cabinet body 5, a base 6 and a fixing plate 9, wherein the top of the base 6 is fixedly provided with the fixing plate 9 through four fixing rods 901, the fixing plate 9 is supported by the fixing rods 901 when in use, the crushing box 2 is installed and fixed by the fixing plate 9 after being supported, the crushing box 2 is installed on the fixing plate 9, the bottom of the crushing box 2 is provided with a blanking valve 204 in an embedded mode through the fixing plate 9, the top of the fixing plate 9 at the front end of the crushing box 2 is provided with a cushion table 804, the upper end of the cushion table 804 is provided with two motors 8, a roller shaft 803 is installed inside the crushing box 2 at the rear end of each motor 8, the top of the crushing box 2 is provided with a feeding pipe 201, the slag which needs to be crushed enters the inside the crushing box 2 through the feeding pipe 201 when in use, the two motors 8 are electrified to respectively drive the roller shaft 803 to rotate forwards and reversely inside the crushing box 2, therefore, the slag entering the crushing box 2 is crushed, the slag is convenient to recycle by a user, the processed slag is discharged through the discharging valve 204, the access door 206 is installed on the surface of the rear end of the crushing box 2, the mark 205 is arranged on the surface of the rear end of the access door 206, when the slag is blocked in the crushing box 2, the motor 8 is stopped, the slag in the crushing box 2 can be cleaned by opening the access door 206, the practicability of the device is improved, the device can be introduced in a text mode when the device is used by using the mark 205, and the user can use the device more conveniently;

the top of the fixing plate 9 at both sides of the crushing box 2 is provided with the supporting frames 1, the funnel 101 is arranged between the supporting frames 1 at the upper end of the feeding pipe 201, the surface of the funnel 101 is fixedly provided with the vibrating motor 102, the slag to be crushed is guided into the funnel 101 when in use, the capacity of the device can be enlarged by using the funnel 101, the funnel 101 can be driven to vibrate after the vibrating motor 102 is electrified, thereby the situation that the slag is blocked before entering the feeding pipe 201 can be avoided, the position of the funnel 101 at the top of the fixing plate 9 can be limited by using the supporting frames 1 when in use, the pressure detector 21 is embedded in the base 6 between the fixing rods 901, the top of the pressure detector 21 is provided with the bearing plate 14, the pressure detector 21 is used for detecting the weight at the top of the bearing plate 14 when in use, and the detected data is displayed by using the control box 4, therefore, a user can judge the weight of slag discharged by the blanking valve 204 more conveniently, the situations of low load and overload of the recovery box 10 are avoided, the periphery of the top of the bearing plate 14 is provided with the protective guard 11, the two sides of the surface of the protective guard 11 are provided with the hooks 13, the cross rods 12 are arranged in the hooks 13, the top of the bearing plate 14 between the protective guard 11 is provided with the recovery box 10, the front end of the bearing plate 14 is provided with the backing plate 7, the slag discharged from the blanking valve 204 can be stored by using the recovery box 10 when in use, the positions of the recovery box 10 on the top of the bearing plate 14 are limited by using the protective guard 11 and the cross rods 12 in the storage process, the situation that the recovery box 10 sideslips due to uneven ground is avoided, the cross rods 12 are drawn out from the hooks 13 after the recovery box 10 is loaded, and the recovery box 10 can slide out from the inside of the bearing plate 14 after being drawn out, the backing plate 7 can be used for facilitating a user to slide the recycling box 10 out of the top of the bearing plate 14, so that the practicability of the device is improved;

the top of a base 6 at one side of a fixed rod 901 is provided with a cabinet body 5, the surface of the cabinet body 5 is rotatably provided with a cabinet door 501, the surface of the cabinet body 5 at the top of the cabinet door 501 is rotatably provided with a protective door 504, when in use, the cabinet door 501 and the protective door 504 can be used for a user to conveniently detect and maintain a structure arranged inside the cabinet body 5, the practicability of the device is improved, the surface at the other side of the cabinet body 5 is provided with an air-entraining pipe 15, the top of the cabinet body 5 is provided with two exhaust pipes 3, the cabinet body 5 is internally provided with an inner box 20, the upper end of the inner box 20 is provided with a baffle 22, the cabinet body 5 at the other side of the baffle 22 is internally provided with a fan 23, one side of the baffle 22 is provided with a filter 16, the inside of the filter 16 is provided with a primary filter layer 19, the upper end of the primary filter layer 19 is provided with a middle filter layer 18, and the upper end of the middle filter layer 18 is provided with a fine particle filter layer 17, when the device is used, after the fan 23 is powered on, dust generated in the discharging process of the blanking valve 204 is guided into the cabinet body 5 through the air guide pipe 15, the dust in the gas is treated through the filter 16 after the dust is guided into the cabinet body, large, medium and small floaters in the gas are respectively filtered through the primary filter layer 19, the medium filter layer 18 and the fine particle filter layer 17, the filtered gas is discharged from the exhaust pipe 3, the filtered impurities are stored through the inner box 20, therefore, the device is more convenient for a user to treat waste residues, the practicability of the device is improved, the control box 4 is installed on the surface of the protective door 504, the control box 4 is electrically connected with the vibrating motor 102, the motor 8, the blanking valve 204 and the fan 23 through leads, and the user can control the operation of the device through the control box 4 after the connection, and therefore the practicability of the device is improved.

Further, the connection platform 302 is installed to the peripheral lower extreme of blast pipe 3, and installs four connecting bolt 301 between connection platform 302 and the cabinet body 5, utilizes the connection platform 302 can enlarge the area of contact between blast pipe 3 bottom and the cabinet body 5 when using to utilize connecting bolt 301 will connect the platform 302 and be connected and dismantle between blast pipe 3 and the cabinet body 5, thereby improve the practicality of device.

Further, the fixed surface of cabinet door 501 installs observation window 502, and the cabinet door 501 surface mounting of observation window 502 opposite side has handle 503, utilizes observation window 502 can more make things convenient for the user of service to observe the inside of the cabinet body 5 when using, utilizes handle 503 can more make things convenient for the user of service to carry out rotation regulation use to cabinet door 501 when using.

Further, protective pipe 202 is installed on the surface of the roller shaft 803 and the crushing box 2 on the periphery of the motor 8, and a bolt 203 is installed between the protective pipe 202 and the crushing box 2, the protective pipe 202 can be installed and disassembled by the bolt 203, and the protective pipe 202 protects the motor 8 after installation, so that the protection effect is improved.

Further, a rack 802 is installed at the bottom of the motor 8, a distribution box is installed on the outer side of the motor 8, a threaded bolt 801 is installed between the inside of the rack 802 and the pad 804 through threads, and the rack 802 and the threaded bolt 801 can be used for improving the overall stability of the motor 8 in use.

Further, a fixing table 903 is installed between the bottom of each fixing rod 901 and the base 6, a fixing bolt 902 is installed between each fixing table 903 and the base 6 through threads, the area of contact between the fixing rod 901 and the base 6 can be enlarged by using the fixing table 903 when the fixing rod 901 is used, and the fixing rod 901 can be installed and detached by using the fixing bolt 902.

Further, a supporting table 103 is installed at the bottom of the supporting frame 1 on two sides of the crushing box 2, three groups of supporting bolts 104 are installed between the supporting table 103 and the fixing plate 9, the supporting table 103 and the supporting bolts 104 can be used for installing and disassembling the supporting frame 1, and the practicability of the device is improved.

Further, two sets of wheels 1002 are installed to the bottom both sides of collection box 10, and the fixed surface of collection box 10 installs handle 1001, utilizes wheel 1002 and handle 1001 can more make things convenient for the user to remove collection box 10 when using, improves the flexibility of device.

The working principle is as follows: guiding slag to be crushed into the hopper 101, utilizing the hopper 101 to expand the capacity of the device, utilizing the vibration motor 102 to drive the hopper 101 to vibrate after being electrified, entering the crushing box 2 through the feeding pipe 201, utilizing the two motors 8 to respectively drive the roller shaft 803 to rotate forward and backward in the crushing box 2 after being electrified, thereby realizing crushing processing of the slag entering the crushing box 2, discharging the processed slag through the discharging valve 204, utilizing the recycling box 10 to store the slag discharged from the discharging valve 204, utilizing the guard rail 11 and the cross bar 12 to limit the position of the recycling box 10 on the top of the bearing plate 14 in the storing process, utilizing the pressure detector 21 to detect the weight on the top of the bearing plate 14, utilizing the control box 4 to display the detected data, utilizing the air-guiding pipe 15 to guide the dust generated in the discharging process of the discharging valve 204 into the cabinet body 5 after the fan 23 is electrified, after introduction, dust in the gas is treated by the filter 16, large, medium and small floaters in the gas are filtered by the primary filter layer 19, the intermediate filter layer 18 and the fine particle filter layer 17, respectively, and the filtered gas is discharged from the exhaust pipe 3, and the filtered impurities are stored in the inner box 20.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.