【Test Your Knowledge】Basic Chemical Engineering Knowledge (23)
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1. When shutting down a centrifugal compressor, it is necessary to __________________ the valve at the same time; first stop the main unit and wait until it has come to a complete stop before ___________________. 2. The maximum operating temperature for stainless steel valves in production is __________. 3. During the gas absorption process, an excessively high operating gas velocity can lead to a large amount of _________, and may even result in __________, thereby preventing the absorption process from proceeding. 4. There are three feed inlets in a certain distillation tower; when the feed temperature decreases, the load on the __________ section increases, so it is necessary to switch to feeding through the ______________ inlet. 5. The hydrocarbons in the feedstock oil for cracking are classified by structure into _______, _______, _______, and _______. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is ________. A. It is related to the level of the liquid in the container, but not to the pressure in the container or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the pressure in the container. C. It is related to both the pressure in the container and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the water flows in a laminar flow state, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, what is its critical flow velocity? A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. Which of the following materials is suitable as an insulating material? ________ A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with the relative volatility values α as given; among them, the one that is easiest to separate is ________. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is ________ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than Answer key: 1. Shut off the intake and exhaust, as well as the fuel pump and cooling water. 2. 600℃ 3. Foaming entrainment, liquid flooding 4. Distillation upward Previous question 5. Alkanes, alkenes, cycloalkanes, aromatics 6. D ； 7.B ； 8.C ； 9.A ； 10.C ； Did you get it right? This post was last edited by zhangyong6404 on 2009-4-6 16:24.]
2. The maximum operating temperature for stainless steel valves in production is _200 degrees Celsius_. 3. During the gas absorption process, an excessively high operating gas velocity can lead to excessive __bubbling___, and may even cause __fluidization___, thereby preventing absorption from taking place. 4. In a certain distillation column, there are three feed inlets. When the feed temperature decreases, the load on the ___recovery section___ increases; therefore, it is necessary to switch to using the feed inlet located ___higher up__. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is __D___. A. It is related to the level of the liquid in the container, but not to the pressure in the container or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the pressure in the container. C. It is related to both the pressure in the container and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the flow is laminar, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is __B, C__. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. The substance suitable as an insulating material is ___C__. A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with relative volatility values α as given; the one that is easiest to separate is __D___. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is ___C___ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than Not quite sure
2. The maximum operating temperature for stainless steel valves in production is _200 degrees Celsius_. 3. During the gas absorption process, an excessively high operating gas velocity can lead to excessive __bubbling___, and may even cause __fluidization___, thereby preventing absorption from taking place. 4. In a certain distillation column, there are three feed inlets. When the feed temperature decreases, the load on the ___recovery section___ increases; therefore, it is necessary to switch to using the feed inlet located ___higher up__. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is __D___. A. It is related to the level of the liquid in the container, but not to the pressure in the container or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the pressure in the container. C. It is related to both the pressure in the container and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the flow is laminar, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is __B, C__. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. The substance suitable as an insulating material is ___C__. A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with relative volatility values α as given; the one that is easiest to separate is __D___. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is ___C___ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than
1. When shutting down a centrifugal compressor, it is necessary to simultaneously ____close the outlet____________ valve; first stop the main engine and wait until it has come to a complete stop, before then ______closing the inlet valve_____________. 2. The maximum operating temperature for stainless steel valves in production is ___450℃______. 3. During the gas absorption process, if the operating gas velocity is too high, it will cause a large amount of _____ solution to be carried out of ___, and may even lead to _______ liquid flooding___, thereby preventing absorption from taking place. 4. In a certain distillation column, there are three feed inlets. When the feed temperature decreases, the load on the ______recovery section____ increases; therefore, it is necessary to switch to the feed inlet located _____higher up__. 5. The hydrocarbons in the feedstock oil for cracking are classified by structure into _____aromatic hydrocarbons__, ___saturated hydrocarbons__, _____unsaturated hydrocarbons__, and __polymers__. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is _____D___. A. It is related to the level of the liquid in the container, but not to the pressure in the container or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the pressure in the container. C. It is related to both the pressure in the container and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the water flows in a laminar flow pattern, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is ____D___. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. Which of the following materials is suitable as an insulating material? ___A_____ A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with the relative volatility values α as given; the one that is easiest to separate is ____A____. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is _____B___ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than Last edited by dyzdyz12345 on 2009-4-5 23:07]
1. Intake and exhaust； Stop the oil pump and cooling water. 2. 200℃ 3. The liquid is carried away ； Foaming 4, Stripping section ； 5. Alkanes ； olefins ； naphthenes ； Aromatic hydrocarbons: 6, D, 7, B, 8; C or D is acceptable, with C being better. 9, D; 10, C. Last edited by lxl328 on 2009-4-5 23:25.]
It’s so hard; I don’t seem to know the answers to many of them
1. When shutting down a centrifugal compressor, it is necessary to __close the inlet and exhaust______ valves at the same time; first stop the main engine and wait until it has come to a complete stop, and then ______shut down the oil pump and cooling water system________. 2. The maximum operating temperature for stainless steel valves in production is __450℃___. 3. During the gas absorption process, if the operating gas velocity is too high, a large amount of ___liquid will be carried out of ___, and this can even lead to ___liquid flooding____, preventing absorption from taking place. 4. In a certain distillation column, there are three feed inlets. When the feed temperature decreases, the load on the ______ stripping section ______ section increases; therefore, it is necessary to switch to the feed inlet located _____ above_____. 5. The hydrocarbons in the feedstock oil for cracking are classified by structure into ___alkanes____, ___olefins____, __cycloalkanes___, and __aromatic hydrocarbons_____/. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is ___D______. A. It is related to the level of the liquid in the container, but not to the pressure in the container or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the pressure in the container. C. It is related to both the pressure in the container and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the flow is laminar, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is ___C____. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. The substance suitable as an insulating material is ___C______. A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with relative volatility values α as given; the one that is easiest to separate is ____D____. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is ___C_____ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than
1 Shut off the intake and exhaust gases, as well as the oil pump and cooling water. 2 450°C 3 The liquid is carried out; flooding occurs. 4 Distillation section, upper part. 5 Alkanes, olefins, naphthenes, and aromatics. 6 d 7 b 8 c 9 d 10 c
1. When shutting down a centrifugal compressor, it is necessary to _close both the inlet and outlet____ valves at the same time; first stop the main engine and wait until it has come to a complete stop, before _______shutting down the oil pump and the cooling water system______________. 2. The maximum operating temperature for stainless steel valves in production is ____450 degrees_____ . 3. During the gas absorption process, if the operating gas velocity is too high, it will cause a large amount of ___liquid to be carried out of ______, and may even lead to _____liquid flooding_____, thereby preventing absorption from taking place. 4. In a certain distillation column, there are three feed inlets. When the feed temperature decreases, the load on the _____recovery section_____ increases; therefore, it is necessary to switch to the feed inlet located at __________. 5. The hydrocarbons in the feedstock oil for cracking are classified by structure into ___alkanes____, ____naphthenes___, ___olefins____, and ___aromatic hydrocarbons____. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is ____d____. A. It is related to the level of the liquid in the container, but not to the container pressure or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the container pressure. C. It is related to both the container pressure and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the water flows in a laminar flow state, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is ____b___. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. The substance suitable as an insulating material is _____c___. A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with the relative volatility values α as given; among them, the one that is easiest to separate is ______ d __. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is _____c___ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than
1. When our L-type centrifugal compressor (oil-free pump, manual oiling) is shut down, open the bypass valve (i.e., the valve that connects the inlet and outlet), while closing the inlet and outlet valves (surge occurs severely during this time). After the motor has been stopped for a while, turn off the cooling water (in cases of long shutdown periods). I’m not arguing with LZ. There are just too many types of compressors, and the shutdown procedures vary as well :)
1 Shut off the intake and exhaust gases, as well as the oil pump and cooling water. 2 450°C 3 The liquid is carried out; flooding occurs. 4 Distillation section, upper part. 5 Alkanes, olefins, naphthenes, and aromatics. 6 d 7 b 8 c 9 d 10 c
1. Close the outlet valve and the inlet valve. 2. 450°C. 3. Solution is carried out; flooding occurs. 4. Retention section, upper part. 5. Aromatic hydrocarbons, saturated hydrocarbons, unsaturated hydrocarbons, polymers. 6. D. 7. D. 8. A. 9. A. 10. B
1. When shutting down a centrifugal compressor, it is necessary to simultaneously ____close the inlet and exhaust ____valves; first stop the main engine and wait until it has come to a complete stop, before then ____shutting down the oil pump and cooling water system__. 2. The maximum operating temperature for stainless steel valves in production is ___450 degrees______. 3. During the gas absorption process, if the operating gas velocity is too high, a large amount of ___liquid will be carried out of ___, and this can even lead to __liquid flooding__, preventing absorption from taking place. 4. In a certain distillation column, there are three feed inlets. When the feed temperature decreases, the load on the __rectifying section__ increases; therefore, it is necessary to switch to using the feed inlet located in the _____upper part_____ of the column. 5. The hydrocarbons in the feedstock oil for cracking are classified by structure into __alkanes_____、_naphthenes______、___olefins____ and ___aromatic hydrocarbons____. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is __D______. A. It is related to the level of the liquid in the container, but not to the container pressure or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the container pressure. C. It is related to both the container pressure and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the water flows in a laminar flow state, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is __B_____. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. The substance suitable as an insulating material is __C______. A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with the relative volatility values α as given; the one that is easiest to separate is ___D_____. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is __C______ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than
1. Shut in, exhaust； Oil pump shutdown and cooling water; 2,600°C; 3, foam entrainment ； Foaming 4, Stripping section ； Previous: 5, Alkanes ； olefins ； naphthenes ； Aromatic hydrocarbons 6, D 7, B 8, C 9, A 10, C
1. When shutting down a centrifugal compressor, it is necessary to close the inlet and exhaust valves at the same time; first stop the main engine and wait until it has come to a complete stop before shutting down the oil pump and the cooling water system. 2. The maximum operating temperature for stainless steel valves in production is (450 degrees). 3. During the gas absorption process, an excessively high operating gas velocity can lead to a large amount of liquid being carried away, and may even cause flooding, thereby preventing absorption from taking place. 4. There are three feed inlets in a certain distillation column; when the feed temperature decreases, the load on the stripping section increases, so it is necessary to switch to the upper feed inlet. 5. The hydrocarbons in the feedstock oil for cracking are classified by structure into (alkanes), (naphthenes), (olefins), and (aromatics). 6. Use a pressure transmitter to measure the liquid level in the container; the measurement result is (D). A. It is related to the level of the liquid in the container, but not to the container pressure or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the container pressure. C. It is related to both the container pressure and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the flow is laminar, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is (B). A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. Which of the following substances is suitable as an insulating material? (C) A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with the relative volatility values α as given; among them, the one that is easiest to separate is (D). A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is (C) the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than
1 Shut off the intake and exhaust gases, as well as the oil pump and cooling water. 2 200°C 3 The liquid is carried out; flooding occurs. 4 5 Alkanes, olefins, cycloalkanes, and aromatics. 6 D 7 B 8 C 9 D 10 C
1. When shutting down a centrifugal compressor, it is necessary to close both the inlet and outlet valves at the same time. First, stop the main engine and wait until it has come to a complete stop, after which ______ shut down the oil pump and the cooling water system________. 2. The maximum operating temperature for stainless steel valves in production is ___600℃______. 3. During the gas absorption process, an excessively high operating gas velocity can lead to the entrainment of a large amount of _____foam____, and may even cause _______liquid flooding___, thereby preventing absorption from taking place. 4. In a certain distillation column, there are three feed inlets. If the feed temperature decreases, the load on the ______distillation______ section increases; therefore, it is necessary to switch to an additional feed inlet located _____above_____ that section. 5. The hydrocarbons in the feedstock oil for cracking are classified by structure into _____aromatic hydrocarbons__, ___alkanes____, _____naphthenes__ and __olefins____. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is _____D___. A. It is related to the level of the liquid in the container, but not to the pressure in the container or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the pressure in the container. C. It is related to both the pressure in the container and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the flow is laminar, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is ____B____. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. The substance suitable as an insulating material is ___C______. (Metals have the highest thermal conductivity.) A. λ=204 W/m·K. B. λ=46.5 W/m·K. C. λ=0.15 W/m·K. D. λ=0.21 W/m·K. 9. There are four ideal solutions composed of two components, with relative volatility values α as given; the one that is easiest to separate is ____D____. (The volatility of Solution D is 10 times that of the other solution.) A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is _____C___ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than
1. When shutting down a centrifugal compressor, it is necessary to __close the outlet____________ valve at the same time; stop the main engine first and wait until it has come to a complete stop before __closing the inlet valve__. 2. The maximum operating temperature for stainless steel valves in production is ___450℃______. 3. During the gas absorption process, if the operating gas velocity is too high, it will cause a large amount of _____ solution to be carried out of ___, and may even lead to _______ liquid flooding___, thereby preventing absorption from taking place. 4. There are three feed inlets in a certain distillation tower; when the feed temperature decreases, the load on the ---------- section increases, so it is necessary to switch to the ------------- feed inlet. 5. The hydrocarbons in the cracking feed oil are classified by structure into?????. 6. The liquid level in a container is measured using a pressure transmitter, and the measurement result is _____a___. A. It is related to the level of the liquid in the container, but not to the container pressure or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the container pressure. C. It is related to both the container pressure and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure that the water flows in a laminar flow regime, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is ____a___. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. Which of the following substances is suitable as an insulating material? ___d_____ A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with the relative volatility values α as given; among them, the one that is easiest to separate is ____d____. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is _____a___ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than
1. When shutting down a centrifugal compressor, it is necessary to __stop the motor and close the outlet__ valve at the same time; first stop the main unit and wait until it has come to a complete stop, before __shutting down the auxiliary oil system____. 2. The maximum operating temperature for stainless steel valves in production is ___450℃______. 3. During the gas absorption process, an excessively high operating gas velocity can lead to a large amount of ___liquid droplets being entrained___, and may even result in ___liquid flooding_______, thereby preventing absorption from taking place. 4. In a certain distillation column, there are three feed inlets. When the feed temperature decreases, the load on the ___distillation__ section increases; therefore, it is necessary to switch to using the feed inlet located ___higher up__. 5. The hydrocarbons in the feedstock oil for cracking are classified by structure into ___linear alkanes____, ___naphthenes____, ___aromatics____, and ___isoparaffins____. 6. The liquid level in the container is measured using a pressure transmitter, and the measurement result is ____B____. A. It is related to the level of the liquid in the container, but not to the container pressure or the density of the medium. B. It is related to both the level of the liquid in the container and the density of the medium, but not to the container pressure. C. It is related to both the container pressure and the density of the medium, but not to the level of the liquid in the container. D. It is related to all three factors. 7. Water flows through a pipe with a diameter of 20 mm; to ensure laminar flow, given that the density of water is 103 Kg/m3 and its viscosity is 1.0 mPa·s, the critical flow velocity is ___D____. A. 0.01 m/s B. 0.1 m/s C. 0.2 m/s D. 0.02 m/s 8. The substance suitable as an insulating material is ____C____. A. λ=204 w/m·K. B. λ=46.5 w/m·K. C. λ=0.15 w/m·K. D. λ=0.21 w/m·K. 9. There are four ideal solutions composed of two components, with the relative volatility values α as given; the one that is easiest to separate is ____A____. A. α=2.0 B. α=0.2 C. α=1.0 D. α=0.1 10. Compared to the heat load, the heat transfer rate is ___D_____ the heat load. A. Equal to B. Less than C. Greater than or equal to D. Greater than
1. Intake and exhaust； Stop the oil pump and cooling water. 2. 200℃ 3. The liquid is carried away ； Foaming 4, 5, alkanes ； olefins ； naphthenes ； Aromatic hydrocarbons: 6, D, 7, B, 8; C or D is acceptable, with C being better. 9, D; 10, C
1. Shut in, exhaust； Oil pump shutdown and cooling water; 2,600°C; 3, foam entrainment ； Foaming 4, Stripping section ； Previous: 5, Alkanes ； olefins ； naphthenes ； Aromatic hydrocarbons 6, D 7, B 8, C 9, D 10, C