CN209539407U - A kind of generator sealing oil cooler - Google Patents
A kind of generator sealing oil cooler Download PDFInfo
- Publication number
- CN209539407U CN209539407U CN201920163436.0U CN201920163436U CN209539407U CN 209539407 U CN209539407 U CN 209539407U CN 201920163436 U CN201920163436 U CN 201920163436U CN 209539407 U CN209539407 U CN 209539407U
- Authority
- CN
- China
- Prior art keywords
- shell
- water chamber
- oil cooler
- flange
- oil
- 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
Landscapes
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
The utility model discloses a kind of generators to seal oil cooler, belongs to oil cooler technical field.A kind of generator sealing oil cooler of the utility model includes shell, shell both ends pass through flanged joint respectively left water chamber and right water chamber, the top two sides in hull outside face are respectively arranged with sealing oil inlet and sealing oil export, the two sides that partition and left water chamber are equipped in the middle part of left water chamber are respectively arranged with cooling water inlet and cooling water outlet, and left water chamber and right water chamber are respectively arranged with blank flange far from one end of shell.The utility model aim is to overcome oil cooler not easy cleaning and the problem of oily side pollution easily occurs for while cleaning, and the oil cooler is easy to clean and judges the specific location of cooler copper tubes breakage, not only saves the repair time, but also can prevent from polluting oil cooler oil side.
Description
Technical field
The utility model relates to oil cooler technical fields, seal oil cooler more specifically to a kind of generator.
Background technique
Oil cooler is the matching used turbine oil cooling apparatus of steam turbine in electric system, and oil cooler is light pipe surface formula,
Using recirculated water as media implementation heat exchange, to guarantee that bearing inlets oil temperature reaches specified value, it is ensured that unit operates normally.
Oil cooler main component has upper lower water chamber, and shell piping and oil-filled pipeline are constituted, and inlet and outlet pipes are connected on shell, pass in and out oil pipe,
Drainpipe, oil exit pipe, exhaust pipe and temperature gauge stand.Cooling water flow path is generally double-flow, and oil cooler is generally vertical installation shape
Formula horizontal can also be installed.
In thermal power plant, since turbine speed is up to 3000r/min, so the cooling of its bearing shell is critically important,
Guarantee that turbine bearing pad is continuously safely operated at an established temperature, it is necessary to cool down to the oil of cooling bearing shell, conventional is cold
But mode is realized by column tube oil cooler, this kind of oil cooler be easy to happen in oily inleakage of cooling water in operation pollute it is cold
But the problem of water, cooling water by the consequence of oily pollution be it is extremely serious, cooling oil generally uses untreated river water straight
It connects in steel pipe, running temperature is often at 40 ° -50 °, therefore steel pipe internal-surface inevitably fouling, influences to conduct heat.Therefore
When needing artificial periodic cleaning, however cleaning oil cooler water side, it is necessary to it drains the oil to oily side, oily side contamination accident easily occurs,
And cleaning is inconvenient, therefore, how to improve oil cooler, makes its cleaning is more convenient to save trouble and do not allow the problem of easily causing oily side to pollute
Just become particularly important.
For the transformation of oil cooler structure, existing related art scheme is disclosed, such as number of patent application: 2014204398013,
The applying date on 08 06th, 2014, invention and created name are as follows: a kind of novel oil cooler, shell is interior equipped with cold water chamber and grease chamber, cold
The both ends of water chamber and grease chamber are respectively equipped with card, and cold water chamber is set to the top of grease chamber, and partition is equipped between cold water chamber and grease chamber,
Heat pipe passes through partition and is connected respectively with the card of cold water chamber and grease chamber, and in cold water chamber, heat pipe adds for the condensation segment setting of heat pipe
In grease chamber, the bringing-up section of heat pipe is equipped with several annular fins for hot arc setting, and heat pipe is close equipped with O-shaped graphite with partition junction
Seal, cold water chamber are equipped with inlet and outlet, and grease chamber is equipped with oil inlet and oil outlet, and oil outlet is equipped with temperature automatic alarm
It is respectively equipped with baffle plate between the heat pipe of device, cold water chamber and grease chamber, is equipped between the indoor baffle plate of oil and the outer wall of heat pipe
Filler material.Disadvantage is that: the cleaning of oil cooler is still inconvenient.
The information disclosed in the background technology section is intended only to increase the understanding to general background of the invention, without answering
When being considered as recognizing or imply that the information constitutes the prior art already known to those of ordinary skill in the art in any form.
Utility model content
1. utility model technical problems to be solved
A kind of generator sealing oil cooler of the utility model has aimed to overcome that oil cooler not easy cleaning and cleaning
When the problem of oily side pollution easily occurs, provide a kind of generator sealing oil cooler, the oil cooler is easy to clean and judges cold
But the specific location of device copper pipe breakage not only saves the repair time, but also can prevent from polluting oil cooler oil side.
2. technical solution
In order to achieve the above objectives, technical solution provided by the utility model are as follows:
A kind of generator of the utility model seals oil cooler, including shell, shell both ends pass through flanged joint respectively
There are left water chamber and right water chamber, the top two sides in hull outside face are respectively arranged with sealing oil inlet and sealing oil export, left water chamber
Middle part is equipped with partition and the two sides of left water chamber are respectively arranged with cooling water inlet and cooling water outlet, and left water chamber and right water chamber are separate
One end of shell is respectively arranged with blank flange.
Further improved as the utility model, the both ends of shell pass through shell flange and panel flange respectively with
Left water chamber is connected with right water chamber, and shell flange is the flange around the setting of shell end outer wall, and panel flange is to be separately positioned on
The whole face plate flange of left water chamber and right water chamber end, and the through-hole passed through for heat exchanger tube is offered on panel flange.
It further improves as the utility model, is provided with not on the lateral surface of left water chamber, right water chamber and shell
Less than one exhaust outlet.
It is further improved as the utility model, cooling water inlet, cooling water outlet, sealing oil inlet and Seal Oil
Exit is provided with thermometer.
It is further improved as the utility model, enclosure interior is provided with heat exchanger tube, length of the heat exchanger tube along shell
Side upwardly extends, and the two sides of heat exchanger tube are each passed through the through-hole on the panel flange of shell two sides.
It is further improved as the utility model, is provided with sealing ring between shell flange and panel flange.
It is further improved as the utility model, is provided with sewage draining exit on the lateral surface of shell.
It is further improved as the utility model, cooling water inlet top is provided with diversion pipe.
It is further improved as the utility model, the cross section of heat exchanger tube is ellipse.
3. beneficial effect
Using technical solution provided by the utility model, compared with prior art, have the following beneficial effects:
(1) a kind of generator of the utility model seals oil cooler, left water chamber and right water chamber one end far from shell point
It is not provided with blank flange, blank flange is used cooperatively with water chamber flange, for sealing the outside of left water chamber and right water chamber,
In, water chamber flange is the wall surface flange being sheathed on the outer wall of left water chamber and right water chamber, and bolt passes through blank flange and water chamber method
Blank flange is fastened on the outside of left water chamber and right water chamber by the bolt hole on orchid, and left water chamber and right water chamber is made to form a closing
Space structure need to only remove water side both ends when oil cooler needs to clean oil cooler water side during usual maintenance and maintenance
Blank flange, can exchange heat pipe inner wall carry out periodic cleaning, it is not necessary to again in oil cooler housing hollow Seal Oil carry out
It drains the oil processing, not only saves the repair time, but also can prevent from directly removing oil cooler oil side contamination accident caused by panel flange
Generation;When sealing oil system is in operating status, open oil cooler water side exhaust outlet can determine whether when discovery has oil spill to go out
Disrepair phenomenon occurs for oil cooler heat exchanger tube, need to only remove oil cooler water side both ends blank flange at this time, opens oil cooler Seal Oil
The valve of import and Seal Oil exit, if breakage has occurred in that root heat exchanger tube that discovery has Seal Oil to overflow, available copper is stifled
Head carries out quick blocking, until all heat exchanger tubes are overflowed without Seal Oil, then examines qualification.
(2) a kind of generator of the utility model seals oil cooler, on the lateral surface of left water chamber, right water chamber and shell
It is provided with a no less than exhaust outlet, by vent, can effectively reduce shell, left water chamber and the indoor temperature of right water,
Further increase heat transfer efficiency.
(3) a kind of generator of the utility model seals oil cooler, is additionally provided with sewage draining exit on the lateral surface of shell, leads to
Can periodically the inner cavity of shell be cleaned by crossing sewage draining exit, to extend the service life of shell.
(4) the utility model a kind of generator seal oil cooler, cooling water inlet, cooling water outlet, Seal Oil into
Mouth and Seal Oil exit are provided with thermometer, convenient for controlling the disengaging temperature of cooling water and Seal Oil, help to realize certainly
Dynamicization control.
(5) a kind of generator of the utility model seals oil cooler, and cooling water inlet top is provided with diversion pipe, can be with
Uniform fluid flow is set laterally to wash away heat exchanger tube.
(6) a kind of generator of the utility model seals oil cooler, and the both ends of shell are respectively on the outer wall around setting
There is shell flange, be provided with panel flange on the left water chamber end face opposite with shell, on the right water chamber end face opposite with shell
It is provided with panel flange, panel flange is the whole face plate flange arrangement for closing left water chamber and right water chamber internal cavity, and panel flange
Flange panel on offer the through-hole crossed for heat exchange tube, the bolt hole that bolt passes through on shell flange and panel flange will be left
Water chamber and right water chamber are fastened on the both ends of shell respectively, and flange arrangement is simple, easy for assemble or unload.
Detailed description of the invention
It, below will be to use required in embodiment in order to illustrate more clearly of the technical solution of the utility model embodiment
Attached drawing be briefly described, it should be understood that the following drawings illustrates only some embodiments of the utility model, therefore should not be by
Regard the restriction to range as, for those of ordinary skill in the art, without creative efforts, may be used also
To obtain other relevant attached drawings according to these attached drawings.
Fig. 1 is the structural schematic diagram that generator seals oil cooler in the prior art;
Fig. 2 is that a kind of generator of the utility model seals the structural schematic diagram of oil cooler.
Label declaration in schematic diagram:
110, shell;111, oil inlet is sealed;112, oil export is sealed;120, left water chamber;121, cooling water inlet;122,
Cooling water outlet;123, partition;130, right water chamber;140, shell flange;150, panel flange;160, water chamber flange;170, blind
Plate flange.
Specific embodiment
It is practical new below in conjunction with this to keep the objectives, technical solutions, and advantages of the embodiments of the present invention clearer
Attached drawing in type embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that is retouched
The embodiment stated is the utility model a part of the embodiment, instead of all the embodiments.Therefore, below to providing in the accompanying drawings
The detailed description of the embodiments of the present invention be not intended to limit the range of claimed invention, but only
Indicate the selected embodiment of the utility model.Based on the embodiments of the present invention, those of ordinary skill in the art are not having
Every other embodiment obtained under the premise of creative work is made, is fallen within the protection scope of the utility model.
For the content for further appreciating that the utility model, the utility model is described in detail in conjunction with the accompanying drawings and embodiments.
Embodiment 1
As shown in Figure 1, conventional generator sealing oil cooler is mainly by left water chamber 120, shell 110, heat exchanger tube and the right side
The composition such as water chamber 130, wherein left water chamber 120 and right water chamber 130 are one side closed hemispherical dome structure, outside 110 both ends of shell
It is provided with shell flange 140 on wall, left water chamber 120 and right water chamber 130 are provided with panel flange close to the side of 110 end of shell
150, bolt passes through the bolt hole on shell flange 140 and panel flange 150, and left water chamber 120 and right water chamber 130 are fastened on shell
The both ends of body 110.Panel flange 150 is the whole face plate flange arrangement for closing left water chamber 120 and 130 inner cavity cavity of right water chamber, and
The through-hole crossed for heat exchange tube is offered on 150 flange panel.Sealing oil inlet 111 and Seal Oil are provided on shell 110
Outlet 112 is provided with cooling water inlet 121 and cooling water outlet 122 on left water chamber 120, be additionally provided in the middle part of left water chamber 120 every
Plate 123, for separating oil cooler cooling water intake chamber and water-supplying chamber.When carrying out oil cooler cleaning, need to remove panel flange
150, but due to oil cooler cooling water side and Seal Oil side isolation be by locking panel flange 150 realize, once remove face
Plate flange 150, the Seal Oil that will result directly in oil cooler cavity are largely revealed.Therefore generator sealing oil system is in operation
Inconvenience cleaning oil cooler, easily causes copper pipe in oil cooler to block, to influence heat transfer effect, and is difficult to judge copper pipe in oil cooler
Damaged specific location.
As shown in Fig. 2, a kind of generator sealing oil cooler of the present embodiment can effectively solve problem above, specifically
Ground, the oil cooler of the present embodiment include shell 110, and 110 both ends of shell pass through flanged joint respectively left water chamber 120 and You Shui
Room 130, left water chamber 120 and 130 both ends of right water chamber are dismountable flange arrangement, wherein the both ends of shell 110 pass through shell
Body flange 140 and panel flange 150 are connected with left water chamber 120 and right water chamber 130 respectively, and shell flange 140 is around shell 110
The flange of end outer wall setting, panel flange 150 is the whole face plate method for being separately positioned on 130 end of left water chamber 120 and right water chamber
Orchid, and the through-hole passed through for heat exchanger tube is offered on panel flange 150.Specifically, ring on the outer wall is distinguished at the both ends of shell 110
It is provided around shell flange 140, panel flange 150, right water chamber 130 are provided on left water chamber 120 end face opposite with shell 110
Panel flange 150 is also equipped on the end face opposite with shell 110, panel flange 150 is to close left water chamber 120 and right water chamber
The whole face plate flange arrangement of 130 internal cavities, and the through-hole crossed for heat exchange tube is offered on the flange panel of panel flange 150,
Left water chamber 120 and right water chamber 130 are fastened on shell by the bolt hole that bolt passes through on shell flange 140 and panel flange 150 respectively
The both ends of body 110, flange arrangement is simple, easy for assemble or unload.
In the present embodiment, the top two sides of 110 lateral surface of shell are respectively arranged with sealing oil inlet 111 and sealing oil export
112, Seal Oil enters in 110 cavity of shell from sealing oil inlet 111 carries out cooling processing;In the middle part of left water chamber 120 be equipped with every
Plate 123, and the two sides of left water chamber 120 are respectively arranged with cooling water inlet 121 and cooling water outlet 122, partition 123 is by left water chamber
About 120 two parts are divided into cooling water intake chamber and cooling water water-supplying chamber, divide outside cooling water intake chamber and cooling water water-supplying chamber
It is not provided with cooling water inlet 121 and cooling water outlet 122.Left water chamber 120 and right water chamber 130 one end far from shell 110 point
It is not provided with blank flange 170, blank flange 170 is used cooperatively with water chamber flange 160, for sealing left water chamber 120 and You Shui
The outside of room 130, wherein water chamber flange 160 is the wall surface flange being sheathed on the outer wall of left water chamber 120 and right water chamber 130, spiral shell
Blank flange 170 is fastened on left water chamber 120 and right water chamber by the bolt hole that bolt passes through on blank flange 170 and water chamber flange 160
130 outside makes left water chamber 120 and right water chamber 130 form an enclosure space structure.The oil cooler of the present embodiment is being tieed up usually
When needing to clean oil cooler water side during shield and maintenance, the blank flange 170 at water side both ends need to be only removed, it can heat exchanging
Inside pipe wall carries out periodic cleaning, it is not necessary to carry out processing of draining the oil to the Seal Oil in 110 cavity of oil cooler shell again, both save inspection
It repairs the time, and can prevent from directly removing the generation of oil cooler oil side contamination accident caused by panel flange 150.When Seal Oil system
System opens oil cooler water side exhaust outlet in operating status, when discovery has oil spill to go out, that is, it is broken to can determine whether that oil cooler heat exchanger tube occurs
Damage phenomenon.Oil cooler water side both ends blank flange 170 need to be only removed at this time, open oil cooler sealing oil inlet 111 and Seal Oil
The valve at 112 is exported, if breakage has occurred in that root heat exchanger tube that discovery has Seal Oil to overflow, available copper plug carries out quick
It blocks, until all heat exchanger tubes are overflowed without Seal Oil, then examines qualification.
When the present embodiment is specifically used, cooling water enters cooling water intake chamber from cooling water inlet 121, and flows into heat exchange
In pipe, cooling water is successively returned to the lower part cooling water of left water chamber 120 after heat exchanger tube and right water chamber 130 in shell 110
It in water-supplying chamber, loops back and forth like this, the cooling after Seal Oil enters 110 cavity of shell from sealing oil inlet 111, in heat exchanger tube
Water carries out cooling heat exchange processing to the Seal Oil in 110 cavity of shell, and the Seal Oil after cooling treatment goes out from Seal Oil again
Mouth 112 is discharged, and supply generator uses.
Embodiment 2
A kind of generator of the present embodiment seals oil cooler, and structure is substantially the same manner as Example 1, further, this
Shell 110 is internally provided with heat exchanger tube in embodiment, and heat exchanger tube extends along the length direction of shell 110, and the two of heat exchanger tube
Side is each passed through the through-hole on 110 two sides panel flange 150 of shell, and the quantity of heat exchanger tube is more.Heat exchanger tube in the present embodiment
Cross section be ellipse, since elliptical tube has the characteristics that flow resistance is small, in order to reduce the flowing of sealing oil system
Resistance reduces operating cost, selects elliptical heat exchange tube.
No less than one exhaust is provided in the present embodiment on the lateral surface of left water chamber 120, right water chamber 130 and shell 110
Mouthful, by vent, it can effectively reduce the temperature in shell 110, left water chamber 120 and right water chamber 130, further increase biography
The thermal efficiency.In addition, it is additionally provided with sewage draining exit on the lateral surface of shell 110, it can be periodically to the inner cavity of shell 110 by sewage draining exit
It is cleaned, to extend the service life of shell 110.
In the present embodiment at cooling water inlet 121, cooling water outlet 122, sealing oil inlet 111 and sealing oil export 112
It is provided with thermometer, convenient for controlling the disengaging temperature of cooling water and Seal Oil, helps to realize automation control.Cooling water into
121 tops of mouth are provided with diversion pipe (in figure and being not drawn into), uniform fluid flow can be made laterally to wash away heat exchanger tube.
Sealing ring is provided between shell flange 140 and panel flange 150 in the present embodiment.Specifically adopted in the present embodiment
With O-shaped carbon seal ring, have many advantages, such as that thermal stability is high, corrosion-resistant and be not easy not aging and embrittlement, it can be in harsh operating condition
Under the conditions of use steady in a long-term, reduce maintenance cost.
Schematically the utility model and embodiments thereof are described above, description is not limiting, attached drawing
Shown in be also one of the embodiments of the present invention, actual structure is not limited to this.So if this field
Those of ordinary skill enlightened by it, without deviating from the purpose of the present invention, not inventively design
Frame mode similar with the technical solution and embodiment, all should belong to the protection range of the utility model.
Claims (9)
1. a kind of generator seals oil cooler, it is characterised in that: including shell (110), shell (110) both ends pass through method respectively
Orchid is connected with left water chamber (120) and right water chamber (130), the top two sides of shell (110) lateral surface be respectively arranged with Seal Oil into
Mouth (111) and sealing oil export (112), left water chamber (120) middle part are equipped with the two sides difference of partition (123) and left water chamber (120)
It is provided with cooling water inlet (121) and cooling water outlet (122), left water chamber (120) and right water chamber (130) are far from shell (110)
One end be respectively arranged with blank flange (170).
2. a kind of generator according to claim 1 seals oil cooler, it is characterised in that: the both ends of shell (110) are equal
It is connected respectively with left water chamber (120) and right water chamber (130) by shell flange (140) and panel flange (150), shell flange
(140) for around shell (110) end outer wall setting flange, panel flange (150) be separately positioned on left water chamber (120) and
The whole face plate flange of right water chamber (130) end, and the through-hole passed through for heat exchanger tube is offered on panel flange (150).
3. a kind of generator according to claim 1 seals oil cooler, it is characterised in that: left water chamber (120), right water chamber
(130) and on the lateral surface of shell (110) it is provided with a no less than exhaust outlet.
4. a kind of generator according to claim 1 seals oil cooler, it is characterised in that: cooling water inlet (121), cold
But thermometer is provided at water out (122), sealing oil inlet (111) and sealing oil export (112).
5. a kind of generator according to claim 2 seals oil cooler, it is characterised in that: setting inside shell (110)
There is heat exchanger tube, heat exchanger tube extends along the length direction of shell (110), and the two sides of heat exchanger tube are each passed through shell (110) two
Through-hole on side panel flange (150).
6. a kind of generator according to claim 2 seals oil cooler, it is characterised in that: shell flange (140) and face
Plate flange is provided with sealing ring between (150).
7. a kind of generator according to claim 1 seals oil cooler, it is characterised in that: the lateral surface of shell (110)
On be provided with sewage draining exit.
8. a kind of generator according to claim 1-7 seals oil cooler, it is characterised in that: cooling water inlet
(121) top is provided with diversion pipe.
9. a kind of generator according to claim 5 seals oil cooler, it is characterised in that: the cross section of heat exchanger tube is ellipse
It is round.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201920163436.0U CN209539407U (en) | 2019-01-30 | 2019-01-30 | A kind of generator sealing oil cooler |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201920163436.0U CN209539407U (en) | 2019-01-30 | 2019-01-30 | A kind of generator sealing oil cooler |
Publications (1)
Publication Number | Publication Date |
---|---|
CN209539407U true CN209539407U (en) | 2019-10-25 |
Family
ID=68272400
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201920163436.0U Expired - Fee Related CN209539407U (en) | 2019-01-30 | 2019-01-30 | A kind of generator sealing oil cooler |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN209539407U (en) |
-
2019
- 2019-01-30 CN CN201920163436.0U patent/CN209539407U/en not_active Expired - Fee Related
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN207439189U (en) | A kind of exhaust steam afterheat recycling device for aerated brick field | |
CN207848993U (en) | A kind of high steam pipeline leakage protection from hazards device | |
CN209539407U (en) | A kind of generator sealing oil cooler | |
CN109183139B (en) | Main furnace chamber structure applied to single crystal furnace | |
CN219102964U (en) | Novel spiral membrane type deaerator for horizontal tower | |
CN110108138A (en) | A kind of heat exchanger apparatus | |
CN209326396U (en) | A kind of condenser of the heating power with stainless steel cooling pipe | |
CN210321318U (en) | Tubular heat exchanger suitable for closed circulation technology water supply system of hydropower station | |
CN206190336U (en) | Turbo generator hydrogen cooler | |
CN112179178B (en) | Energy-saving heat exchange equipment | |
CN204987945U (en) | High -efficiency heat exchanger | |
CN207922904U (en) | A kind of cooling circulating water unit | |
CN207936775U (en) | A kind of water cooling petticoat pipe | |
CN209244615U (en) | A kind of turbine low pressure cylinder cooling device | |
CN111551051A (en) | Semicircular fin heat exchange tube type flue gas cooling and heat exchange waste heat utilization system | |
CN210948812U (en) | Steam turbine bearing heat sink | |
CN206477972U (en) | Air compressor machine thermal energy recovering hot-water machine | |
CN206160772U (en) | Heat exchanger | |
CN217442056U (en) | Automatic flushing device for cooler | |
CN218511510U (en) | Smoke cooler of smelting furnace | |
CN221881425U (en) | Waste heat steam boiler for recycling high-temperature flue gas | |
CN208295507U (en) | Using the boat remodeling gas turbine powered generator lubricating oil system of panel cooler | |
CN219283976U (en) | Indirect heat exchange energy utilization system of blast furnace slag flushing water | |
CN218674347U (en) | Steam-water sampling centralized cooling device for closed boiler | |
CN215725405U (en) | Pipe box of non-screwed plug type air cooler and non-screwed plug type air cooler |
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: 20191025 Termination date: 20210130 |
|
CF01 | Termination of patent right due to non-payment of annual fee |