CN108104883B - Small-sized hydraulic security device - Google Patents
Small-sized hydraulic security device Download PDFInfo
- Publication number
- CN108104883B CN108104883B CN201711328766.2A CN201711328766A CN108104883B CN 108104883 B CN108104883 B CN 108104883B CN 201711328766 A CN201711328766 A CN 201711328766A CN 108104883 B CN108104883 B CN 108104883B
- Authority
- CN
- China
- Prior art keywords
- oil
- chamber
- accelerator
- valve
- power
- 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.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D17/00—Regulating or controlling by varying flow
- F01D17/10—Final actuators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D17/00—Regulating or controlling by varying flow
- F01D17/20—Devices dealing with sensing elements or final actuators or transmitting means between them, e.g. power-assisted
- F01D17/22—Devices dealing with sensing elements or final actuators or transmitting means between them, e.g. power-assisted the operation or power assistance being predominantly non-mechanical
- F01D17/26—Devices dealing with sensing elements or final actuators or transmitting means between them, e.g. power-assisted the operation or power assistance being predominantly non-mechanical fluid, e.g. hydraulic
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
- F01D21/02—Shutting-down responsive to overspeed
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Turbines (AREA)
Abstract
The invention relates to a small-sized hydraulic security device, which consists of an overspeed protection assembly, a low oil pressure protection assembly, a manual protection assembly and a remote control protection assembly, wherein a button in the manual protection assembly is connected with an oil switch of a throttle valve through a lever; a sleeve in the overspeed protection assembly is internally provided with a slide valve, a compression spring is connected below the slide valve, the upper part of the sleeve is provided with a valve disc through a spring, a bellows group is arranged above the valve disc, an oil pressure chamber G on the upper part of the sleeve is connected with an inner cavity of the bellows group and is connected with an outlet of a main oil pump, and an oil pressure chamber F is arranged in the middle of the sleeve; a piston in the low oil pressure protection assembly is connected with a return spring and a bushing, an oil chamber D at the lower part of the piston is communicated with a lubricating oil main pipe, and a power oil chamber E at the upper part of the piston is connected with an oil chamber J of a throttle by an oil chamber B and a C.
Description
Technical Field
The invention relates to a mechanical overspeed protector for a steam turbine, in particular to a hydraulic safety device.
Background
In order to ensure the safety of the operation of the steam turbine and to ensure that the steam turbine unit is prevented from being damaged or the accident is prevented from further expanding, a safety device is arranged. Conventionally, a mechanical overspeed protector mounted on a rotor is commonly used in a steam turbine, as shown in fig. 1 and 2. When the rotating speed of the steam turbine rises to 109% -112% of the rated rotating speed, the safety device acts immediately, the main throttle valve is closed, and the steam turbine unit enters a shutdown stage. The protector only has an overspeed protection function. However, the protector cannot realize the functions of low oil pressure protection, local manual protection and remote control protection of the turboset.
Disclosure of Invention
The invention provides a small-sized hydraulic security device, which carries out overspeed protection on a steam turbine set through an overspeed protection component according to the pressure of an outlet of a main oil pump with a shaft; according to the pressure of a main lubricating oil pipe of the steam turbine unit, low oil pressure protection is carried out on the steam turbine unit through a low oil pressure protection component; meanwhile, an oil circuit switch mechanical button is arranged, so that the function of on-site manual protection can be realized; in addition, the hydraulic protector is also provided with an electromagnet, so that the remote control protection function of the turboset can be realized.
In order to achieve the purpose, the technical scheme of the invention is as follows: a small-sized hydraulic security device comprises an overspeed protection assembly, a low oil pressure protection assembly, a manual protection assembly and a remote control protection assembly, wherein the manual protection assembly comprises a wrong accelerator, a button and a lever, the button is connected with an oil switch of the wrong accelerator through the lever, an oil cavity A at the lower part of the wrong accelerator is connected with an oil sliding channel, an oil discharge hole of the wrong accelerator is communicated with an oil return channel through an oil chamber H, and a power oil chamber I of the wrong accelerator is connected with a main accelerator; the accelerator is also provided with an oil chamber J connected with an oil pressure chamber F in the overspeed protection assembly, and an electromagnet of the remote control protection assembly is connected below the button; the overspeed protection assembly consists of a compression spring, a sleeve, a slide valve, a bellows group, a spring and a valve disc, wherein the slide valve is arranged in the sleeve, the compression spring is connected below the slide valve, the valve disc is arranged at the upper part of the sleeve through the spring, the bellows group is arranged above the valve disc, an oil pressure chamber G at the upper part of the sleeve is connected with the inner cavity of the bellows group and is connected with the outlet of a main oil pump, and an oil pressure chamber F is arranged at the middle part of the; the low oil pressure protection assembly is composed of a piston, a reset spring and a bushing, the reset spring is connected to the upper surface of the piston, the upper portion of the piston is provided with the bushing, an oil chamber D of the lower portion of the piston is communicated with a lubricating oil header pipe, the side surface of the upper portion of the piston is provided with a power oil chamber E, the side surface of the lower portion of the piston is provided with an oil chamber B and an oil chamber C, and the power oil chamber E is connected.
When the button is moved upwards to the limit position to reset the oil switch of the accelerator in error, the oil switch in the accelerator in error is moved to the lower limit position, the oil switch is cut off to be communicated with the lubricating oil channel of the oil chamber A at the lower part of the accelerator in error, the oil discharge hole in the accelerator in error is communicated with the oil return channel through the oil chamber H, and the power oil from the power oil chamber I on the accelerator in error enters the main throttle; when the button is pressed down, the lever drives an oil switch in the accelerator to move upwards, a lower flange of the oil switch cuts off power oil supplied to a power oil chamber I of the main throttle, an upper flange enables the main throttle to be communicated with an oil chamber H, and the oil chamber H is communicated with return oil; meanwhile, the oil chamber A at the lower part of the accelerator is connected with an oil channel, so that oil enters the lower end face of an oil switch of the accelerator, the oil switch of the accelerator is kept at the upper position, the power oil supply to the main throttle is cut off, and the main throttle is closed.
When the electromagnet is powered in a remote control mode, the electromagnet is closed to drive the oil switch of the accelerator to act, the power oil supply to the main valve is cut off, and the main valve is closed.
When the turbine reaches the overspeed action value, the turbine shaft drives the oil pressure of the main oil pump outlet to raise the pressure in the oil pressure chamber G in the upper part of the sleeve and the pressure in the inner cavity of the connected bellows group to the upper limit value, the valve disc overcomes the force of the spring to move upwards, the power oil is opened to enter the inlet of the inner cavity of the sleeve, the differential area of the slide valve makes the slide valve move to the lower limit position rapidly under the action of the oil pressure, the upper edge of the middle flange of the slide valve is communicated with the oil pressure chamber G and the oil pressure chamber F, the power oil enters the oil pressure chamber F, the oil pressure chamber F is communicated with the oil chamber J of the accelerator by the cavity in the safety guard shell, the oil switch in the accelerator is moved to the upper limit position instantly, the power oil supply to the main valve is cut off.
When the pressure of the lubricating oil in the lubricating oil main pipe is reduced to an action value, the pressure in an oil chamber D at the lower part of the piston is reduced, and the piston is separated from the flange ground by the bushing under the action of the spring force and moves downwards; power oil from the power oil chamber E enters the oil chamber J of the wrong accelerator through the oil chambers B and C, so that an oil switch in the wrong accelerator is instantly moved to an upper limit position, the power oil supply to the main throttle is cut off, and the main throttle is closed.
The invention has the beneficial effects that:
the protector has small volume, compact structure and easy installation and disassembly, can realize the functions of overspeed protection, low oil pressure protection, on-site manual protection and remote control protection of the turboset, and can be expanded to large and medium-sized turbosets and other rotating mechanical units.
Drawings
FIG. 1 is a schematic view of a conventional mechanical overspeed safety device;
FIG. 2 is a cross-sectional view taken along A-A of FIG. 1;
fig. 3 is a sectional view of the structure of the small hydraulic security device of the present invention.
Detailed Description
The invention is further described with reference to the following figures and examples.
As shown in fig. 3, a small-sized hydraulic security device comprises an overspeed protection assembly, a low oil pressure protection assembly, a manual protection assembly and a remote control protection assembly, and comprises a throttle valve 1, a compression spring 2, a piston 3, a spring 4, a bushing 5, a sleeve 6, a slide valve 7, a bellows assembly 8, a spring 9, a valve disc 10, a button 11, a lever 12 and an electromagnet 13.
The manual protection assembly consists of a throttle valve 1, a button 11 and a lever 12, wherein the button 11 is connected with an oil switch of the throttle valve 1 through the lever 12, an oil chamber A at the lower part of the throttle valve 1 is connected with an oil lubricating channel, an oil discharging hole of the throttle valve 1 is communicated with an oil returning channel through an oil chamber H, and a power oil chamber I of the throttle valve 1 is connected with a main throttle valve; the accelerator pedal 1 is also provided with an oil chamber J connected with an oil pressure chamber F in the overspeed protection assembly, and the lower part of the button 11 is connected with an electromagnet 13 of the remote control protection assembly.
The overspeed protection assembly comprises a compression spring 2, a sleeve 6, a slide valve 7, a bellows group 8, a spring 9 and a valve disc 10, wherein the slide valve 7 is arranged in the sleeve 6, the compression spring 2 is connected below the slide valve 7, the valve disc 10 is arranged on the upper part of the sleeve 6 through the spring 9, the bellows group 8 is arranged on the valve disc 10, an oil pressure chamber G on the upper part of the sleeve 6 is connected with the inner cavity of the bellows group 8 and is connected with a main oil pump outlet, and an oil pressure chamber F is arranged in the middle of the sleeve 6.
The low oil pressure protection component consists of a piston 3, a return spring 4 and a bush 5, wherein the return spring 4 is connected to the upper surface of the piston 3, and the bush 5 is arranged at the upper part of the piston. The grease chamber D of 3 lower parts of piston communicates the lubricating oil main pipe, and 3 upper portion sides of piston are equipped with power grease chamber E, and the lower part side is equipped with grease chamber B, C, and power grease chamber E passes through grease chamber B, and C connects the grease chamber J of wrong gas 1.
The resetting of the oil switch is performed by moving the push button 11 of the oil switch upwards to the extreme position. At this time, the oil switch in the accelerator 1 moves to the lower limit position, the pressure in the oil chamber a at the lower part of the accelerator 1 disappears, the oil switch is cut off to be communicated with the lubricating oil channel of the oil chamber a at the lower part of the accelerator 1, and the oil discharge hole in the accelerator 1 is communicated with the oil return channel through the oil chamber H. Under the action of the spring, one end of the lever 12 is lifted, the oil switch at the other end is kept at the lower limit position, and the power oil from the power oil chamber I on the oil switch in the pilot throttle 1 is led into the main throttle.
When a button of an oil switch of the accelerator with mistake 1 is pressed, the lever 12 drives the oil switch in the accelerator with mistake 1 to move upwards, a lower flange of the oil switch cuts off power oil supplied to a power oil chamber I of a main valve, the main valve is communicated with the oil chamber H through an upper flange, and the oil chamber H is communicated with return oil. Meanwhile, in the shell of the safety device, lubricating oil from the oil chamber A and communicated with the power oil chamber I enters the lower end face of the oil switch, so that the oil switch in the accelerator 1 is kept at the upper position, the power oil supply to the main throttle valve is cut off, and the main throttle valve is closed.
When the electromagnet 13 is powered by a remote control mode, the electromagnet 13 is closed to drive the oil switch of the accelerator 1 to act, the power oil supply to the main valve is cut off, and the main valve is closed.
When the turbine reaches the overspeed value, the turbine shaft drives the oil pressure at the outlet of the main oil pump to raise the pressure in the oil pressure chamber G and the pressure in the inner cavity of the bellows group 8 connected to it to the upper limit value, the valve disc 10 moves upward against the force of the spring 9, and the inlet of the power oil into the inner cavity of the sleeve 6 is opened. Under the action of oil pressure, the differential area of the slide valve 7 causes the slide valve to move to the lower limit position rapidly, the compression spring 2 compresses the upper edge of the middle flange of the slide valve 7 to open a channel between an oil pressure chamber G and an oil pressure chamber F, power oil enters the oil pressure chamber F, the oil pressure chamber F is communicated with an oil chamber J of the pilot throttle 1 through a chamber in a safety guard shell, an oil switch in the pilot throttle 1 is moved to the upper limit position instantly, the power oil supply to a main throttle is cut off, and the main throttle is closed.
When the pressure of the lubricating oil in the lubricating oil main pipe decreases to an operating value, the pressure in the oil chamber D, i.e. the pressure in the lower part of the piston 3, drops and the piston moves away from the ground flange of the bush 5 and suddenly moves downward under the force of the spring 4. Power oil from the power oil chamber E enters the oil chamber J of the accelerator pedal 1 through the oil chambers B and C, so that an oil switch in the accelerator pedal 1 is instantly moved to an upper limit position, power oil supply to a main valve is cut off, and the main valve is closed.
Claims (5)
1. The utility model provides a small-size hydraulic pressure security device comprises overspeed protection subassembly, low oil pressure protection subassembly, manual protection subassembly and remote control protection subassembly, its characterized in that: the manual protection assembly consists of a throttle valve (1), a button (11) and a lever (12), wherein the button (11) is connected with an oil switch of the throttle valve (1) through the lever (12), an oil chamber A at the lower part of the throttle valve (1) is connected with a lubricating oil channel, an oil discharge hole of the throttle valve (1) is communicated with an oil return channel through an oil chamber H, and a power oil chamber I of the throttle valve (1) is connected with a main throttle valve; the accelerator (1) is also provided with an oil chamber J connected with an oil pressure chamber F in the overspeed protection assembly, and an electromagnet (13) of the remote control protection assembly is connected below the button (11); the overspeed protection assembly comprises a compression spring (2), a sleeve (6), a slide valve (7), a bellows group (8), a spring (9) and a valve disc (10), wherein the slide valve (7) is arranged in the sleeve (6), the compression spring (2) is connected below the slide valve (7), the valve disc (10) is arranged between the sleeve (6) and the spring (9), the bellows group (8) is arranged on the sleeve (6), an oil pressure chamber G at the upper part of the sleeve (6) is connected with the inner cavity of the bellows group (8) and is connected with the outlet of a main oil pump, and an oil pressure chamber F is arranged in the middle of the sleeve (6); the low oil pressure protection subassembly is by piston (3), reset spring (4), bush (5) are constituteed, piston (3) inside surface connection reset spring (4), upper portion is equipped with bush (5), the grease chamber D intercommunication lubricating oil house steward of the lower part of the adjacent part in piston (3) outside, piston (3) upper portion side is equipped with power grease chamber E, inside has grease chamber C, the lower part of the adjacent part in piston (3) outside is equipped with grease chamber B, when piston (3) move down, power grease chamber E passes through grease chamber B, the grease chamber J of wrong throttle (1) is connected to C.
2. The small hydraulic security device according to claim 1, wherein: when the button (11) is moved upwards to the limit position to reset the oil switch of the accelerator in error, the oil switch in the accelerator in error (1) is moved to the lower limit position, the oil switch is cut off to be communicated with the lubricating oil channel of the oil chamber A at the lower part of the accelerator in error (1), the oil discharge hole in the accelerator in error (1) is communicated with the oil return channel through the oil chamber H, and the power oil from the power oil chamber I on the accelerator in error (1) enters the main accelerator; when the button (11) is pressed, the lever (12) drives an oil switch in the accelerator (1) to move upwards, a lower flange of the oil switch cuts off power oil supplied to a power oil chamber I of the main throttle, the main throttle is communicated with the oil chamber H through an upper flange, and the oil chamber H is communicated with return oil; meanwhile, an oil chamber A at the lower part of the accelerator (1) is connected with a lubricating oil channel, so that lubricating oil enters the lower end face of an oil switch of the accelerator (1), the oil switch of the accelerator (1) is kept at the upper part, the power oil supply to a main valve is cut off, and the main valve is closed.
3. The small hydraulic security device according to claim 1, wherein: when the electromagnet (13) is powered by a remote control mode, the electromagnet (13) is attracted to drive the oil switch of the accelerator (1) to act, the power oil supply to the main valve is cut off, and the main valve is closed.
4. The small hydraulic security device according to claim 1, wherein: when the turbine reaches an overspeed action value, the pressure in an oil pressure chamber G at the upper part of a sleeve (6) and the pressure in an inner cavity of a bellows group (8) connected with the sleeve are increased to an upper limit value by the oil pressure of a main oil pump outlet driven by a turbine shaft, a valve disc (10) moves upwards against the force of a spring (9) to open an inlet of power oil entering the inner cavity of the sleeve (6), the differential area of a slide valve (7) enables the slide valve (7) to move to a lower limit position rapidly under the action of the oil pressure, the upper edge of a middle flange of the slide valve (7) is communicated with the oil pressure chamber G and an oil pressure chamber F, the power oil enters the oil pressure chamber F, the oil pressure chamber F is communicated with an oil chamber J of a wrong throttle (1) through a cavity in a protector shell, an oil switch in the wrong throttle (1) is moved to an upper limit position instantly, the power oil supply to the main steam valve is cut.
5. The small hydraulic security device according to claim 1, wherein: when the pressure of the lubricating oil in the lubricating oil main pipe is reduced to an action value, the pressure in the oil chamber D is reduced, and the piston is separated from the bushing (5) under the action of the force of the spring (4) and moves downwards; power oil from a power oil chamber E enters an oil chamber J of the wrong accelerator (1) through oil chambers B and C, so that an oil switch in the wrong accelerator (1) is instantly moved to an upper limit position, power oil supply to a main throttle is cut off, and the main throttle is closed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711328766.2A CN108104883B (en) | 2017-12-13 | 2017-12-13 | Small-sized hydraulic security device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711328766.2A CN108104883B (en) | 2017-12-13 | 2017-12-13 | Small-sized hydraulic security device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108104883A CN108104883A (en) | 2018-06-01 |
| CN108104883B true CN108104883B (en) | 2020-05-05 |
Family
ID=62215795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711328766.2A Active CN108104883B (en) | 2017-12-13 | 2017-12-13 | Small-sized hydraulic security device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108104883B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109779702B (en) * | 2019-03-29 | 2024-01-26 | 中国船舶重工集团公司第七0四研究所 | Turbine bearing seat structure with highly integrated oil circuit |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3441040A (en) * | 1967-02-20 | 1969-04-29 | Gen Electric | Valve gear locking and emergency closing system |
| CN1749584A (en) * | 2005-09-20 | 2006-03-22 | 杭州和利时自动化有限公司 | Novel overspeed petective slide valve |
| CN101382158A (en) * | 2008-10-22 | 2009-03-11 | 北京瑞赛科技有限公司 | Hydraulic protector for electrohydraulic servo control system |
| US7874241B2 (en) * | 2005-04-19 | 2011-01-25 | Emerson Process Management Power & Water Solutions, Inc. | Electronically controllable and testable turbine trip system |
| CN103629194A (en) * | 2013-12-10 | 2014-03-12 | 沈阳东北电力调节技术有限公司 | Mechanical quick-operation type integrated electro-hydraulic actuator |
-
2017
- 2017-12-13 CN CN201711328766.2A patent/CN108104883B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3441040A (en) * | 1967-02-20 | 1969-04-29 | Gen Electric | Valve gear locking and emergency closing system |
| US7874241B2 (en) * | 2005-04-19 | 2011-01-25 | Emerson Process Management Power & Water Solutions, Inc. | Electronically controllable and testable turbine trip system |
| CN1749584A (en) * | 2005-09-20 | 2006-03-22 | 杭州和利时自动化有限公司 | Novel overspeed petective slide valve |
| CN101382158A (en) * | 2008-10-22 | 2009-03-11 | 北京瑞赛科技有限公司 | Hydraulic protector for electrohydraulic servo control system |
| CN103629194A (en) * | 2013-12-10 | 2014-03-12 | 沈阳东北电力调节技术有限公司 | Mechanical quick-operation type integrated electro-hydraulic actuator |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108104883A (en) | 2018-06-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9651048B2 (en) | Gas inlet valve for a compressor, compressor comprising a gas inlet valve of this type and method for operating a compressor comprising a gas inlet valve of this type | |
| CN108104883B (en) | Small-sized hydraulic security device | |
| CN101397994B (en) | Scroll compressor with high side to low side oil bleed valve | |
| CN103867441A (en) | Double-stage compressor | |
| SE538239C2 (en) | Actuator for axial displacement of an object | |
| CN201529631U (en) | Overflow valve used for high-pressure cleaning machine | |
| CN203756525U (en) | Double-stage compressor | |
| CN103883525A (en) | Double-stage compressor | |
| CN203756526U (en) | Double-stage compressor | |
| CN203463729U (en) | Valve for pneumatic pressure regulating, fast decompression and multi-torch operation | |
| CN100582538C (en) | Safe buffering two-way valve | |
| CN102352859B (en) | Multifunctional mini-resistance integrated protection device used for fan outlet side | |
| CN216429694U (en) | Steam turbine and generator set capable of being used for achieving one-key starting function | |
| CN110725959A (en) | Multifunctional butterfly valve for steam turbine | |
| CN110925170A (en) | Novel double-speed exhaust valve and intake valve with unloading function | |
| TWM568301U (en) | Gas-water separator structure of water pump | |
| CN102287164B (en) | Control valve for hydraulic well mouth safety valve control system | |
| US1475994A (en) | Means for priming pumps | |
| EP3649349B1 (en) | A minimum pressure valve and compressor comprising such a minimum pressure valve | |
| US1107533A (en) | Priming centrifugal pumps. | |
| CN212774436U (en) | Pneumatic magnetic circuit-breaking throttle device for security of steam turbine compressor unit | |
| CN212774435U (en) | Pneumatic circuit-breaking accelerator device for safety of steam turbine compressor unit | |
| US2234471A (en) | Valve mechanism for unloading compressors | |
| CN216429696U (en) | Emergency trip throttle and hanging brake hydraulic operating device of steam turbine | |
| CN202348738U (en) | Micro-resistance multifunction-integrated protection device for fan outlet side |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |