Analytical treatment of abnormal operation of turbine unit for air compressor design in petrochemical design He Weiji (Jinling Branch of China Petroleum & Chemical Corporation, Nanjing 210033, China) After careful inspection and analysis, improved the car The connection of the cylinder piston of the cylinder adjusts the meshing clearance of the gear of the disc drive, checks the direction of the motor of the disc drive, finally finds the root cause and takes correct measures to restore the normal operation of the disc brake.
The air compressor unit of the Coal Chemical Operation Department of Sinopec Jinling Branch is the key equipment of its air separation unit. Designed and manufactured by Man-Turbo, Germany, turbine model DK100/210R, rated speed 450r/min, rated power 43881kW, using RDV3 pneumatic electric disc brakes from German BHS company (see).
The working principle of the electric disk drive is: the crank motor (2) is started for about 1 second, the piston of the cylinder (8) starts to move, the swing arm (6) is pulled upward, and the inductance position sensor (7) is sequentially sensed. The three positions of â€œoffâ€, â€œtooth-toothâ€ and â€œengagementâ€ ensure that the motor (2) will run at full power after the crank pinion (4) is fully meshed with the large gear (5). Otherwise the cylinder piston will immediately push the swing arm (6) down to the locked position and repeat the above process until full engagement is achieved. Then installed in the turbine rotor car structure structure 1 - disk hand wheel; 2 - motor; 3 - housing; 4 - car pinion; 5 - large gear; 6 - swing arm; 7 - inductance position sensor; â€•Cylinder 1 Cranking Machine Working Abnormal Situation Introduction At the beginning of September 2010, the coal chemical operation department was shut down and overhauled as planned, and the air compressor unit turbine was used to carry out the speed control system transformation. In order to replace the electronic speed probe, it is necessary to disconnect the cylinder of the motor of the disk and then remove the cylinder and remove the whole of the disk. After the electronic speed probe is replaced and installed, the wiring of the disk, cylinder and motor is reset.
On the morning of September 23, the air separation unit was ready to drive, the air compressor unit started the vehicle according to the procedure, and the afternoon operator reflected the abnormality of the vehicle. After the investigation, it was found that the turbine rotor vibration value was abnormal at the moment of the gear size of the crankshaft (the initial value of the crank when the vehicle was parked was 50|xm, 110pm at this time), and it basically returned to normal after a few seconds. The stability value is 6~9pm, at this time it is 11~13(im), but the meshing gear pair is very loud, and the crankcase vibration feels strong, so the car is stopped immediately and checked.
2 Reason analysis The wheel size gear adopts an involute spur gear pair. According to the working principle, it is necessary to have two pairs of teeth participating in the meshing at the same time to ensure the continuous ratio transmission. Assuming that the meshing points of the working side tooth profiles of the two pairs of teeth are respectively K and F, then f and f must fall at the meshing line at the same time. On (see).
Major in mechanical engineering, bachelor's degree, current deputy chief of mechanical department, engineer, is now engaged in the management of mobile equipment. Tel: 025 Petrochemical Design > Standard Center Distance a = 0, 02 + / 2, the flank clearance of the gear pair will increase. When a' exceeds a certain value, it will start to appear when the ruler is disengaged. F has not been able to engage in the engagement. At this time, the gear cannot be continuously driven, and an impact phenomenon will occur. Long-term operation will damage the working tooth surface.
When the initial inspection of a'3 was carefully checked and it was found that the swing arm of the disc was in the locked position (ie, when the size of the wheel was completely disengaged), the inductive position sensor could not sense the "off" signal. Because the car is disassembled as a whole, the problem should not be caused by it. It is only possible that during the disassembly and assembly process of the cylinder, the oscillating arm does not return to the original installation position due to some negligence, and finally the flank clearance is excessive when the crank-size gear meshes.
The connection between the cylinder of the disc braker and the swing arm is as follows: the lower end of the cylinder piston rod is machined with an internally threaded hole, and is screwed to the upper end of the joint; a mounting groove and a pin hole are respectively formed on the lower end of the joint head and the swing arm for installation. Connect the plate and the connecting pin for transmission (see ).
It can be seen that there is a design defect in the threaded connection between the cylinder piston rod and the connector. First of all, there is no positioning measure, which means that the cylinder and the swing arm must be repeatedly adjusted after each disassembly and assembly of the cylinder. 1-position sensor; 2-cylinder; 3-connector; 4-piston rod; 5-connection Pin; 6-swing arm; 7-connector plate piston rod and connector relative position, and measure the meshing side clearance of the wheel size gear, and finally ensure that it meets the design standards; secondly there is no locking measures, then in the car process There is a possibility of relative rotation between the piston rod of the middle cylinder and the connecting head, which causes a change in the meshing flank clearance of the wheel-sized gear.
In response to the above problems, a careful discussion was made. It is considered that it is difficult to take very reasonable positioning measures at one time, but it can be easily and effectively locked by adding a lock nut (see). At the same time, the disc brake must be removed, the meshing side clearance of the disc size gear is measured and adjusted, and the gear size of the disc is checked.
2~7 part name is the same; 8-lock mother when the car is removed (the cylinder is installed on the car, it has not been removed), it is found that the pinion gear is intact, and the tooth surface of the gear tooth is universal. Slight peeling, but does not affect the continued use. So we carefully trimmed the large gears and glued all the metal impurities with the dough.
Then, the lead wire is placed on the tooth surface of the large gear, and the disk is reset. Forcibly start the cylinder piston so that it is in the completely "engaged" position, and then carry out the appropriate manual turning by the turning handwheel of the disc motor, then remove the disc, measure the thickness of the lead wire, and calculate the meshing teeth of the disc size gear. Side clearance (that is, the same tooth He Weiji. The abnormality of the working condition of the turbine unit of the air compressor unit is the sum of the thicknesses of the lead wires on both sides).
If the meshing tooth gap is out of tolerance, the lock nut can be loosened, the piston rod can be twisted, and the relative position of the piston rod and the connecting head can be adjusted appropriately to adjust the meshing side clearance. Finally, it is necessary to remember to lock the lock nut. (When the meshing tooth side clearance of the wheel size gear is too large, the piston rod needs to be moved downward; when the meshing tooth side clearance of the wheel size gear is too small, the piston rod needs to be moved upward.) Then repeat the above measurement and adjustment process. Make sure that the meshing flank clearance of the wheel size gears meets the design criteria (30~0.35mm).
4 Check again and deal with the air compressor unit cranking procedure in the early morning of September 24, 2010, but found that the turbine rotor vibration value is still abnormal at the moment of the gear size meshing, and the cranking device has strong vibration and meshing noise. Huge, so immediately notify the operator to stop the car.
We re-analyzed the previous repair plan and repair process to confirm that there should be no problem, so we decided to remove from the simplest place: first check if the cranking motor is rotating correctly.
When the disc is in the "off" state, the motor of the disc motor is forced to run. It has been observed that the actual direction of rotation of the motor is opposite to that of the direction of rotation. Contact the electrical service personnel immediately to adjust the wiring and run again to confirm that the motor rotation of the disc drive is correct.
After everything was ready, we started the air compressor unit cranking procedure again and found that the car drive operation has returned to normal: the gear size of the gear is meshed instantaneously, and the turbine rotor vibration value is 50 pm when the car is parked. Turbine rotor vibration value is 7~9pm (69jjun when parking); the vibration of the on-site disc housing is combined with the gear of the turning gear, and the noise is not abnormal.
S Cause Analysis When the disc drive is working normally, the disc pinion (4) will withstand the reaction force F given by the large gear (5), which will always press the pinion pinion in the engaged position.
(h) When the motor rotates in the reverse direction, the "3, 4, 5" device name in the pinion diagram of the pinion is the same as "" when it is rotated in the normal direction with the motor.
When the disc motor rotates in the reverse direction, the crank pinion (4) will bear the reaction force F' given by the large gear (5), which will push the pinion pinion away from the meshing position, so in actual operation, The pinion gear of the car is constantly slipping and jumping. Because the pinion of the crankshaft has a higher hardness than the tooth surface of the large gear, the tooth surface of the gear tooth has a slight peeling phenomenon, and it is inevitable that the gear pair meshing noise will be very large when the car is cranked.
In summary, the fundamental reason for the abnormal operation of the car is that the motor of the car is incorrectly wired and reversely rotated.
He is in the stomach-chuanwei factory 3,000 tons / year bio-based ethylene project test device in the Sinopec Group Company in the National Development and Reform Commission project, the Sichuan Wei plant responsible for the design and construction of the 3,000 tons / year bio-based ethylene project, successfully completed in recent days The exchange has laid a solid foundation for the next step of the project.
The bio-based ethylene industrialization by using renewable resources to produce ethanol and dehydrating ethanol to ethylene is a sustainable development path and one of the development directions for replacing petroleum resources in the future. To implement the national high-tech industrialization of bio-based materials. Strategic deployment, Chuanwei plant actively explores and develops new technologies in the field of green low-carbon environmental protection and sustainable development. On April 18, 2011, the construction of a 3,000-ton/year bio-based ethylene project test facility was started. The project utilizes the multi-stage adiabatic fixed-bed technology independently developed by the Shanghai Petrochemical Research Institute. After the test device is successfully driven, it will be developed on this basis. The annual output of 10,000 tons of bio-based ethylene technology package will eventually form China's bio-based ethylene industrialization technology with independent intellectual property rights and advanced technical and economic indicators.
Powder Transmission Spiral Conveyor, Screw Conveyor
Spiral conveyor Application:
Spiral conveyor is widely used in various industries, such as building materials, chemical industry, electric power, metallurgy, mine, coal, grain etc.It applies to all kinds pf powder ,and small block grannlar materials , such as pulverized coal , gravel , sand and lump coal , cement , grains , etc ., does not apply to transfer easily degenerate , viscous large and easy to agglomeration of materials , Screw Conveyor working environment temperature should be -20---+50Â°C range , the transportation of materials temperature below 200Â°C, the largest dip 20Â°.
Material Transmission Spiral Conveyor,Powder Transmission Spiral Conveyor,Horizontal Screw Conveyor Tlss ,Spiral Screw Conveyor
Dingzhou Yongsheng Grain & Oil Machinery Co.,Ltd. , https://www.oilpresschina.com