Skill test questions for the oxygen production workshop

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Skill Test Questions for Oxygen Production Workshop (I) I. Fill in the blanks (20 points) 1. The model of the centrifugal compressor used in the workshop’s air separation unit is _, with a rated exhaust volume of m3/h. 2. When the pressure in the main air compressor oil supply pipe is ≤, the auxiliary oil pump starts automatically; it stops automatically when the lubricating oil pressure drops to /. 3. The air compressor anti-surge device causes the V1015 pneumatic control valve to open slightly when the resistance in the piping system increases and the exhaust pressure rises above a certain level, allowing air to be released in order to maintain stable pressure. When the outlet pressure continues to increase and reaches another specified level, the V1015 valve triggers an alarm interlock, which causes it to open further. If the outlet pressure keeps rising still, the safety valve will activate. 4. During operation of the air compressor bearings, it is considered normal for the bearing temperature to be higher than the oil supply temperature. 5. Since combustion or explosion can occur easily when oxygen comes into contact with oil, the cylinders of oxygen compressors are equipped with lubrication. 6. The function of the packing in the oxygen compressor stuffing box is . 7. The function of the oil scraper in the oxygen compressor is . 8. The working parts of a piston compressor are _, _, _, _; the moving parts are _, _, _. II. True or False Questions (20 points)
1. When it is not convenient to use nitrogen or oil-free dry air, an oxygen compressor can be tested at low pressure first. ( )
2. In the event of a fire in an oxygen compressor, it is necessary to shut down the machine immediately, cut off the gas supply, and trigger an alarm signal. ( )
3. A filter made of copper wire or stainless steel should be installed at the inlet of the oxygen compressor. ( )
4. The cooler of an air compressor not only serves to cool the air but also helps to remove water from it. ( )
5. Before starting the compressor, it is necessary to check the safety devices, instruments, and gauges, as well as confirm the status of the valves. ( )
6. Isothermal compression refers to a compression process in which the temperature remains constant. ( )
7. In a centrifugal compressor, the higher the gas flow velocity at the outlet of the working wheel, the greater the expansion effect provided by the diffuser. ( )
8. A centrifugal compressor increases the speed of the gas due to the rotation of the high-speed impeller, and then raises its pressure through the expansion process. ( )
9. All types of compressors can operate in reverse. ( )
10. An increase in the suction resistance at the first stage of an air compressor will not affect its normal operation. ( )

III. Multiple Choice Questions (20 points)
1. What is the function of the oil cooler in an air compressor? ( )
A. To lower the oil temperature
B. To raise the oil temperature
C. To increase the viscosity of the oil
D. To filter the oil
2. What type of oil pump is used in air compressors? And what type is used in oxygen and nitrogen compressors? ( )
A. Screw pump
B. Gear pump
C. Centrifugal pump
D. Pipeline pump
3. What are the signs of surge in an air compressor? ( )
A. The outlet pressure increases, the flow rate decreases to a certain level, and the unit becomes unstable.
B. There are significant fluctuations in the flow rate over a short period.
C. Severe vibration occurs.
D. Abnormal noises are heard.
4. What can cause wear of the bearings in an air compressor? ( )
A. Poor quality oil
B. Fluctuations in the power supply
C. Excessively high oil temperature
D. Operating the compressor in reverse
5. What factors can affect the exhaust volume of an air compressor? ( )
A. Insufficient voltage or lower power supply frequency
B. High intake resistance
C. High intake temperature
D. Poor cooling performance of the intercooler

IV. Short Answer Questions (40 points)
1. What effects do excessively high and low oil temperatures have on the operation of an air compressor? 2. What causes abnormal noises in the oxygen compressor cylinder? How to handle it? 3. What conditions must be met when starting the air compressor so that the DCS system indicates that it is permissible to start? 4. What causes the low oil pressure in the gear oil pump of a piston compressor? How to handle it