CN214997765U - Mine ventilation device for coal mine production - Google Patents
Mine ventilation device for coal mine production Download PDFInfo
- Publication number
- CN214997765U CN214997765U CN202121100745.7U CN202121100745U CN214997765U CN 214997765 U CN214997765 U CN 214997765U CN 202121100745 U CN202121100745 U CN 202121100745U CN 214997765 U CN214997765 U CN 214997765U
- Authority
- CN
- China
- Prior art keywords
- filter screen
- ventilation pipe
- air
- box
- filter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000009423 ventilation Methods 0.000 title claims abstract description 58
- 239000003245 coal Substances 0.000 title claims abstract description 25
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 15
- 239000000428 dust Substances 0.000 claims abstract description 29
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 238000001816 cooling Methods 0.000 claims abstract description 21
- 238000002955 isolation Methods 0.000 claims abstract description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 14
- 238000004140 cleaning Methods 0.000 claims abstract description 13
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 6
- 238000001914 filtration Methods 0.000 claims abstract description 6
- 229920000742 Cotton Polymers 0.000 claims description 5
- 239000007921 spray Substances 0.000 abstract description 15
- 238000001035 drying Methods 0.000 abstract description 9
- 239000002245 particle Substances 0.000 abstract description 3
- 208000034699 Vitreous floaters Diseases 0.000 abstract 1
- 239000003570 air Substances 0.000 description 27
- 239000010410 layer Substances 0.000 description 4
- 241000282414 Homo sapiens Species 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 239000013618 particulate matter Substances 0.000 description 2
- 239000003208 petroleum Substances 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 206010066054 Dysmorphism Diseases 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- 241000220317 Rosa Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000002274 desiccant Substances 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002365 multiple layer Substances 0.000 description 1
- 238000011045 prefiltration Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Landscapes
- Filtering Of Dispersed Particles In Gases (AREA)
Abstract
The utility model discloses a mine ventilation device for coal mine production, the cleaning brush is arranged on the power output end of the right side of a double-shaft motor, one end of the left side of the ventilation pipe is communicated with a multifunctional box, the left side of an isolation component is provided with a drying filter box, the right side of the isolation component is provided with a cooling box, the utility model carries out multi-layer filtration on the sucked air through a first filter screen, a second filter screen and a third filter screen, can effectively filter particles and dust in the air, the filtered air enters the cooling box, a water pump converts the water flow at the bottom of the cooling box into a water curtain through a spray plate and a spray head to cool the air, the cooled air enters the multifunctional box, a driving motor drives the drying filter plate and an active filter plate to rotate, the drying filter plate filters the moisture of the air, the air is prevented from being excessively humid, and the active carbon filter plate adsorbs micro-floaters in the air, the air quality is improved.
Description
Technical Field
The utility model relates to a mine ventilation technical field specifically is a mine ventilation unit for coal mine production.
Background
Coal, called coal for short, is ancient plant remains, is buried under the stratum, and under the action of the pressure and temperature condition of air isolated by the crust, carbonized fossil minerals are produced, mainly mined by human beings and used as fuel, and the coal is used for modern industries, both heavy industry and light industry; the coal is called as the real grain of the industry, is one of the main energy sources used in the human world since the eighteenth century, and although the important position of the coal is gradually replaced by the petroleum at present, the coal inevitably goes to failure due to gradual depletion of petroleum resources in a long period of time in the future, the coal is greatly stored, and the rapid development of scientific technology is added, new technologies such as coal vaporization and the like are mature and widely applied, the coal is inevitably one of the energy sources which can not be replaced in human production and life, and a large amount of dust is accumulated in the mine to damage constructors in the process of coal mining, meanwhile, because the ventilation is poor, harmful gas cannot be discharged in time, and construction danger is easily caused, however, the ventilation device for coal mining used at the present stage cannot better filter air and can not cool discharged air, and a good working temperature environment is provided for staff.
Therefore, the mine ventilation device for coal mine production is provided.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a mine ventilation unit for coal mine production to solve the problem that proposes among the above-mentioned background art.
In order to achieve the above object, the utility model provides a following technical scheme: a mine ventilation device for coal mine production comprises a ventilation pipe, wherein an air suction opening is formed in the right side of the ventilation pipe, a double-shaft motor is arranged on the left side in the ventilation pipe and fixedly connected with the inner wall of the ventilation pipe through a fixed rod arranged at the top and the bottom of the double-shaft motor, a first filter screen, a second filter screen and a third filter screen are sequentially arranged on the right side of a first motor at equal intervals, a fan blade is arranged on a power output shaft on the left side of the first motor, a power output shaft on the right side of the double-shaft motor extends to the right side of the third filter screen, cleaning brushes are arranged on the right sides of the first filter screen, the second filter screen and the third filter screen, the cleaning brushes are all arranged on the power output end on the right side of the double-shaft motor, one end of the left side of the ventilation pipe is in through connection with a multifunctional box, an isolation assembly is arranged in the multifunctional box and comprises an isolation plate, a water absorption cotton plate is arranged at the top of the isolation plate, the isolation component is characterized in that a drying filter box is arranged on the left side of the isolation component, and a cooling box is arranged on the right side of the isolation component.
Preferably, the top in the cooling box is provided with a spray plate, the spray plate is provided with a plurality of groups of spray heads, the spray plate is connected with a water pump arranged at the bottom in the cooling box through a water pipe, and the right side of the bottom of the cooling box is provided with a water outlet.
Preferably, the top is provided with driving motor in the multi-functional case, driving motor power output shaft left side is provided with the active carbon filter, driving motor power output shaft right side is provided with dry filter.
Preferably, the suction opening is provided with a soil-proof net.
Preferably, the ventilation pipe openly sets up and is connected with the shutter through the hinge rotation, be provided with the upper fixed plate on the shutter, be provided with fixation nut on the upper fixed plate, be provided with the bottom plate on the ventilation pipe, just set up on the bottom plate with fixation nut assorted screw hole.
Preferably, the bottom of the ventilation pipe is provided with a dust collection box, the dust collection box is connected with a clamping groove formed in the bottom of the ventilation pipe in a sliding mode through sliding blocks arranged on the left side and the right side, and the bottom of the ventilation pipe is provided with a through hole matched with the dust collection box.
Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses a first filter screen, second filter screen and third filter screen carry out the multiple-layer filtering to the suction air, particulate matter and dust in can the effective filtration air, the air admission cooling case after filtering, the rivers of water pump with the cooling bottom of the case portion convert the water curtain into through shower plate and shower head and cool down to the air, the multi-functional case of entering after the cooling, driving motor drives dry filter and active filter rotatory, dry filter filters the moisture of air, prevent that the air is excessively moist, the active carbon filter adsorbs the small floater in the air, the utility model discloses simple structure can carry out effectual filtration and cooling to the air, improvement air quality and workman's operational environment.
Drawings
FIG. 1 is a diagram: the front sectional structure of the utility model is schematically shown;
FIG. 2 is a diagram of: the external structure of the ventilation pipe of the utility model is schematically shown;
FIG. 3 is a diagram of: the utility model discloses draught tube inner chamber structure sketch map.
In the figure: 1. a vent pipe; 2. a multifunctional box; 3. a cooling box; 31. a spray plate; 32. a shower head; 33. A water pump; 4. drying the filter box; 41. a drive motor; 42. an activated carbon filter plate; 43. drying the filter plate; 5. an air suction opening; 6. a double-shaft motor; 7. fixing the rod; 8. a first filter screen; 9. a second filter screen; 10. a third filter screen; 11. a cleaning brush; 12. an isolation component; 13. a separator plate; 14. a water absorbent cotton board; 15. a water outlet; 16. a dust collection box; 17. opening and closing the door; 18. an upper fixing plate; 19. fixing a nut; 20. a hinge; 21. soil-proof net 22, fan blade; 23. and a lower fixing plate.
The drawings are for illustrative purposes only and are not to be construed as limiting the patent; for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
Example 1
Referring to fig. 1-3, the present invention provides a technical solution: a mine ventilation device for coal mine production comprises a ventilation pipe 1, an air suction opening 5 is arranged on the right side of the ventilation pipe 1, a double-shaft motor 6 is arranged on the left side in the ventilation pipe 1, the double-shaft motor 6 is fixedly connected with the inner wall of the ventilation pipe 1 through a fixed rod 7 arranged at the top and the bottom, a first filter screen 8, a second filter screen 9 and a third filter screen 10 are sequentially arranged on the right side of the double-shaft motor 6 at equal intervals, the diameter of a through hole on the surface of the first filter screen 8 is larger than that of the second filter screen 9, the diameter of a through hole on the surface of the second filter screen 9 is larger than that of the third filter screen 10, dust pumped into air can be filtered layer by layer through the first filter screen 8, the second filter screen 9 and the third filter screen 10, fan blades 22 are arranged on a power output shaft on the left side of the double-shaft motor 6, a power output shaft on the right side of the double-shaft motor 6 extends to the right side of the third filter screen 10, cleaning brushes 11 are arranged on the right sides of the first filter screen 8, the second filter screen 9 and the third filter screen 10, cleaning brush 11 all sets up on 6 right side power take off ends of biax motor, it can be to first filter screen 8 to drive cleaning brush 11 rotation through biax motor 6, the dust of second filter screen 9 and third filter screen 10 surface accumulation carries out cleaning treatment, prevent to block up, 1 left side one end through connection multifunctional box 2 of ventilation pipe, be provided with isolation component 12 in the multifunctional box 2, isolation component 12 includes division board 13, division board 13 top is provided with the cotton board 14 that absorbs water, division board 13 can be kept apart by the rivers in cooling box 3, the cotton board 14 that absorbs water carries out prefilter to the moisture in the air, isolation component 12 left side is provided with dry rose box 4, division component 12 right side is provided with cooling box 3.
Referring to fig. 1, a spray plate 31 is arranged at the top inside the cooling box 3, a plurality of groups of spray headers 32 are arranged on the spray plate 31, the spray plate 31 is connected with a water pump 33 arranged at the bottom inside the cooling box 3 through a water pipe, a water outlet 15 is arranged at the right side of the bottom of the cooling box 3, a water discharge valve is arranged on the water outlet 15, water flow is output into the spray plate 31 through the water pump 33, and then the water curtain is converted into a water curtain through the spray headers 32 to cool high-temperature air.
Referring to fig. 1, a driving motor 41 is arranged at the top inside the multifunctional box 2, an activated carbon filter plate 42 is arranged on the left side of a power output shaft of the driving motor 41, a drying filter plate 43 is arranged on the right side of the power output shaft of the driving motor 41, the driving motor 41 drives the activated carbon filter plate 42 and the drying filter plate 43 to rotate, the activated carbon filter plate 42 can adsorb floating particles in the air, and a drying agent filled inside the drying filter plate 43 can filter moisture in the air.
Referring to fig. 2, the suction opening 5 is provided with an earth-proof net 21, and the earth-proof net 21 is made of iron to prevent large particles from entering the ventilation pipe 1.
Example 2
Referring to fig. 2, the front surface of the ventilation pipe 1 is rotatably connected with an opening and closing door 17 through a hinge 20, an upper fixing plate 18 is arranged on the opening and closing door 17, a fixing nut is arranged on the upper fixing plate 18, a lower fixing plate 23 is arranged on the ventilation pipe 1, a threaded hole matched with the fixing nut 19 is formed in the lower fixing plate 23, the fixing nut 19 is detached, the opening and closing door 17 can be opened to clean and maintain the inside of the ventilation pipe 1, and a sealing rubber strip is arranged at the closing position of the opening and closing door 17 and the ventilation pipe 1, so that the sealing performance can be enhanced.
Referring to fig. 2, a dust collection box 16 is arranged at the bottom of the ventilation pipe 1, the dust collection box 16 is connected with a clamping groove arranged at the bottom of the ventilation pipe 1 in a sliding manner through sliding blocks arranged on the left side and the right side, a through hole matched with the dust collection box 16 is formed in the bottom of the ventilation pipe 1, dust accumulated on the surfaces of the first filter screen 8, the second filter screen 9 and the third filter screen 10 can fall into the dust collection box 16 through the through hole in the bottom of the ventilation pipe 1 after being cleaned by the cleaning brush 11, and the dust collection box 16 is connected with the ventilation pipe 1 in a sliding manner, so that the dust in the dust collection box 16 can be cleaned conveniently in a later period.
The working principle is as follows: when the dust collection box is used, the double-shaft motor 6 is started to drive the fan blades 22 to rotate so as to suck external air into the dust collection box through the air suction opening 5, the first filter screen 8, the second filter screen 9 and the third filter screen 10 can filter dust entering air in the ventilation pipe 1 layer by layer, the cleaning brush 11 is driven to rotate through the double-shaft motor 6 so as to clean the dust accumulated on the surfaces of the first filter screen 8, the second filter screen 9 and the third filter screen 10 and prevent blockage, the dust accumulated on the surfaces of the first filter screen 8, the second filter screen 9 and the third filter screen 10 can fall into the dust collection box 16 through the through hole at the bottom of the ventilation pipe 1 after being cleaned by the cleaning brush 11, the dust collection box 16 is connected with the ventilation pipe 1 in a sliding manner, the dust in the dust collection box 16 can be cleaned conveniently in the later period, water flow is output into the spray plate 31 through the water pump 33, and then is converted into a water curtain through the spray head 32 so as to cool high-temperature air, driving motor 41 drives the rotation of active carbon filter 42 and dry filter 43, and the floating particulate matter in the active carbon filter 42 can the air adsorbs, and the inside drier of filling of dry filter 43 can filter the moisture in the air, and the air of handling is discharged through leading to the left exhaust pipe of many multi-functional case 2, dismantles fixation nut 19, can open door 17 that opens and shuts and advance clean the maintenance to ventilation pipe 1 inside.
The utility model discloses the standard part that uses all can purchase from the market, and dysmorphism piece all can be customized according to the description with the record of drawing of description, and the concrete connection mode of each part all adopts conventional means such as ripe bolt, rivet, welding among the prior art, and machinery, part and equipment all adopt prior art, and conventional model, including circuit connection adopts conventional connection mode among the prior art, does not detailed here again.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (6)
1. A mine ventilation device for coal mine production, includes ventilation pipe (1), its characterized in that: an air suction opening (5) is formed in the right side of the ventilation pipe (1), a double-shaft motor (6) is arranged on the left side in the ventilation pipe (1), the double-shaft motor (6) is fixedly connected with the inner wall of the ventilation pipe (1) through a fixed rod (7) arranged at the top and the bottom, a first filter screen (8), a second filter screen (9) and a third filter screen (10) are sequentially arranged on the right side of the double-shaft motor (6) at equal intervals, fan blades (22) are arranged on a power output shaft on the left side of the double-shaft motor (6), a power output shaft on the right side of the double-shaft motor (6) extends to the right side of the third filter screen (10), cleaning brushes (11) are arranged on the right sides of the first filter screen (8), the second filter screen (9) and the third filter screen (10), the cleaning brushes (11) are all arranged on the power output end on the right side of the double-shaft motor (6), one end on the left side of the ventilation pipe (1) is communicated with the multifunctional box (2), be provided with isolation component (12) in multi-functional case (2), isolation component (12) are provided with cooling box (3) including division board (13), and division board (13) top is provided with cotton board (14) that absorbs water, and isolation component (12) left side is provided with dry filtration case (4), and isolation component (12) right side is provided with.
2. The mine ventilation device for coal mine production of claim 1, wherein: the top in cooling box (3) is provided with shower plate (31), is provided with multiunit shower head (32) on shower plate (31), and shower plate (31) are connected with water pump (33) of setting in cooling box (3) bottom through the water pipe, and cooling box (3) bottom right side is provided with outlet (15).
3. The mine ventilation device for coal mine production of claim 1, wherein: the top is provided with driving motor (41) in multi-functional case (2), and driving motor (41) power output shaft left side is provided with active carbon filter (42), and driving motor (41) power output shaft right side is provided with dry filter (43).
4. The mine ventilation device for coal mine production of claim 1, wherein: the suction opening (5) is provided with a soil-proof net (21).
5. The mine ventilation device for coal mine production of claim 1, wherein: the front surface of the ventilation pipe (1) is rotatably connected with an opening and closing door (17) through a hinge (20), an upper fixing plate (18) is arranged on the opening and closing door (17), a fixing nut is arranged on the upper fixing plate (18), a lower fixing plate (23) is arranged on the ventilation pipe (1), and a threaded hole matched with the fixing nut (19) is formed in the lower fixing plate (23).
6. The mine ventilation device for coal mine production of claim 1, wherein: the bottom of the ventilation pipe (1) is provided with a dust collection box (16), the dust collection box (16) is connected with a clamping groove arranged at the bottom of the ventilation pipe (1) in a sliding mode through sliding blocks arranged on the left side and the right side, and the bottom of the ventilation pipe (1) is provided with a through hole matched with the dust collection box (16).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202121100745.7U CN214997765U (en) | 2021-05-21 | 2021-05-21 | Mine ventilation device for coal mine production |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202121100745.7U CN214997765U (en) | 2021-05-21 | 2021-05-21 | Mine ventilation device for coal mine production |
Publications (1)
Publication Number | Publication Date |
---|---|
CN214997765U true CN214997765U (en) | 2021-12-03 |
Family
ID=79132268
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202121100745.7U Expired - Fee Related CN214997765U (en) | 2021-05-21 | 2021-05-21 | Mine ventilation device for coal mine production |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN214997765U (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114534395A (en) * | 2022-02-16 | 2022-05-27 | 福建省中菲薄膜科技有限公司 | Purification mechanism and purification method for film production |
CN114777250A (en) * | 2022-04-15 | 2022-07-22 | 邓良玉 | Building site heating installation ventilation unit |
CN115596721A (en) * | 2022-11-18 | 2023-01-13 | 意朗智能科技(南通)有限公司(Cn) | Air inlet filtering device for air compressor |
-
2021
- 2021-05-21 CN CN202121100745.7U patent/CN214997765U/en not_active Expired - Fee Related
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114534395A (en) * | 2022-02-16 | 2022-05-27 | 福建省中菲薄膜科技有限公司 | Purification mechanism and purification method for film production |
CN114534395B (en) * | 2022-02-16 | 2023-06-09 | 福建省中菲薄膜科技有限公司 | Purification mechanism and purification method for film production |
CN114777250A (en) * | 2022-04-15 | 2022-07-22 | 邓良玉 | Building site heating installation ventilation unit |
CN114777250B (en) * | 2022-04-15 | 2023-12-22 | 中建三局集团(江苏)有限公司 | Building site heating installation ventilation unit |
CN115596721A (en) * | 2022-11-18 | 2023-01-13 | 意朗智能科技(南通)有限公司(Cn) | Air inlet filtering device for air compressor |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN214997765U (en) | Mine ventilation device for coal mine production | |
CN211358185U (en) | Self-cleaning formula environmental protection dust collecting equipment | |
CN206549321U (en) | A kind of efficient cyclone dust arrester | |
CN211659493U (en) | Low-pressure pulse cloth bag dust removal equipment capable of reducing flue gas humidity | |
CN211486929U (en) | Roots blower filter equipment | |
CN211274095U (en) | Building site uses high-efficient dust device | |
CN213101331U (en) | Electric automation equipment dust collector | |
CN213912933U (en) | Flue gas purification device based on industrial energy conservation and emission reduction analysis and optimization system | |
CN116059749A (en) | Treatment device for carbon anode roasting flue gas | |
CN211462594U (en) | Dust treatment device for hydraulic blasting | |
CN211987745U (en) | Workshop air dust remover | |
CN208340374U (en) | A kind of wet scrubber | |
CN207936336U (en) | Air cleaning unit in a kind of architectural environment | |
CN221896641U (en) | Dust collector for coal mine safety production tunnel | |
CN207561862U (en) | A kind of shutter cleaning device | |
CN218480689U (en) | Operating room purifies degree of depth dehumidifier | |
CN205287981U (en) | Clean environmental protection equipment of high -efficient air dust | |
CN219502360U (en) | Dust collecting equipment is used in aerated concrete block production | |
CN221618882U (en) | Carbon dioxide capturing device in flue gas of coal-fired power plant | |
CN214035745U (en) | Coal mine ventilation dust-proof device | |
CN208389691U (en) | A kind of air-flow pulverizing mill dust-extraction unit | |
CN216149264U (en) | Carbon emission is with exhaust emission carbon collection device | |
CN214108125U (en) | Dust removal ash removal device for environmental engineering | |
CN221182201U (en) | High-efficient dust collecting equipment | |
CN218890329U (en) | Integrated efficient wet dust collector for mine |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
GR01 | Patent grant | ||
GR01 | Patent grant | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20211203 |
|
CF01 | Termination of patent right due to non-payment of annual fee |