[Urea Knowledge] Daily Question (50) 2010.02.08.

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Hide the answers; no scoring will be given in principle if they are not hidden. Specific hiding method: http://bbs.hcbbs.com/viewthread.php?tid=492556&highlight=%D2%FE%B2%D8 Variable-choice question: 1. The consequences of a full ammonium solution tank include ( ) A. Low pressure or high pressure, with liquid carried along in the gas phase during venting. B. It pollutes the environment and can cause ammonium carbonate solution to enter the hydrolysis system, leading to overpressure in that system. C. It pollutes the environment and can easily cause crystallization blockages in the vent lines. 2. The measures to reduce the urea hydrolysis rate during production are ( ). A. Reduce urine retention time. B. Lower the temperature. C. Increase pressure. 3. The possible causes of abnormal pressure difference ΔP between the medium-pressure decomposer and the liquid ammonia storage tank are ( ). A. Local blockage in the medium-pressure condenser. B. Blockage of the top pipe in the medium-pressure absorption tower. C. Blockage in the medium-pressure absorption tower. D. Ammonia condenser clogged. 4. An increase in the temperature at the bottom of the medium-pressure absorption tower will lead to ( ). A. The inlet pipeline is blocked. B. Vaporization of the high-pressure ammonium pump. 　　　　　　　 C. The ammonia booster pump is operating unstably. D. Rising CO2 content at the top. 5. The planned parking tower arrangement needs to be done ( ). A. Lower the liquid level in the medium-pressure ammonia tank and the ammonium carbonate solution tank. B. The liquid level in the steam condensate tank is kept at a high level. C. Increase the corrosion resistance of the synthesis tower. D. Confirm that the high-pressure discharge tower pipeline is unobstructed. The answers can be found here: 1. The consequences of a full ammonium solution tank include (AC). A. Low pressure or overpressure, with liquid being carried away in the gas phase. B. It pollutes the environment and can cause ammonium carbonate solution to enter the hydrolysis system, leading to overpressure in that system. C. It pollutes the environment and can easily cause crystallization blockages in the vent lines. 2. The measures to reduce the urea hydrolysis rate during production are (AB). A. Reduce urine retention time. B. Lower the temperature. C. Increase pressure. 3. The possible causes of abnormal pressure difference ΔP between the medium-pressure decomposer and the liquid ammonia storage tank are (ABCD). A. Local blockage in the medium-pressure condenser. B. Blockage of the top pipe in the medium-pressure absorption tower. C. Blockage in the medium-pressure absorption tower. D. Ammonia condenser clogged. 4. An increase in the bottom temperature of the medium-pressure absorption tower will lead to (ABCD). A. The inlet pipeline is blocked. B. Vaporization of the high-pressure ammonium pump. 　　　　　　　 C. The ammonia booster pump is operating unstably. D. Rising CO2 content at the top. 5. The planned parking tower arrangement should be (ABCD). A. Lower the liquid level in the medium-pressure ammonia tank and the ammonium carbonate solution tank. B. The liquid level in the steam condensate tank is kept at a high level. C. Increase the corrosion resistance of the synthesis tower. D. Confirm that the high-pressure discharge tower pipeline is unobstructed.