问题 问答题 简答题

真空泵为什么需要配备真空罐和水封罐?

答案

参考答案:

真空泵在卸油系统中可以用来引油和清舱,但其工作原理决定了输送介质不能进入泵腔,因而真空泵必须配备容量足够大的真空罐或缓冲罐,以便接纳清舱的油品,并保证油品不会进入泵腔。另一方面,真空泵运转时,部分用作水环的水会随氧化从出口排出,为了分离和回收自来水,并及时向真空泵壳内补充水,使泵壳内的水量满足规定值的要求,泵的排出端必须置气水分离器(水罐),并与泵人供水口形成回路,依靠气水分离器中水的静压力向泵供水。

单项选择题

(C)


Is there anything more important than health I don’t think so. "Health is the greatest wealth," wise people say. You can’t be good at your studies or work well when you are ill.
If you have a headache, toothache, backache, earache or bad pain in the stomach, if you complain of a bad cough, if you run a high temperature and have a bad cold, or if you suffer from high or low blood pressure, I think you should go to the doctor.
The doctor will examine your throat, feel your pulse, test your blood pressure, take your temperature, sound your heart and lungs, test your eyes, check your teeth or have your chest Xrayed. After that, he will advise some treatment, or some medicine. The only thing you have to do is to follow his advice.
Speaking about doctor’s advice, I can’t help telling you a funny story.
An old gentleman came to see the doctor. The man was very ill. He told the doctor about his weakness, memory loss and serious problems with his heart and lungs. The doctor examined him and said there was no medicine for his disease.
He told his patient to go to a quiet place for a month and have a good rest. He also advised him to eat a lot of meat, drink two glasses of red wine every day and take long walks. In other words, the doctor advised him to follow the rule: "Eat at pleasure, drink with measure and enjoy life as it is." The doctor also said that if the man wanted to be well again, he shouldn’t smoke more than one cigarette a day.
A month later the gentleman came into the doctor’s office. He looked much more cheerful and much happier. He thanked the doctor and said that he had never felt a healthier man.
"But you know, doctor," the man went on saying, "it’s not easy to begin smoking at my age.\

The writer thinks that ______.

A. health is more important than wealth
B. work is as important as studies
C. medicine is more important than pleasure
D. nothing is more important than money

选择题