问题 问答题 简答题

用蒸汽往复泵给锅炉上水应怎样操作,有哪些注意事项?

答案

参考答案:

(1)先开启通到锅炉给水管上的阀门,再开启通到水源(水箱或水池)进水管上的阀门。

(2)开启汽缸低部的泄水旋塞,排放积水。开启水缸上部的空气旋塞,排放空气。

(3)保持汽缸废气管畅通,如管上装有阀门应予开启,以备排放废气。

(4)滑动环不得处于正中间位置,否则难以启动水泵。上水时,稍开蒸汽阀门,使蒸汽缓慢进入配汽箱,到从汽缸泄水旋塞中冒出干蒸汽。暖管结束后,先关闭放水旋塞,再逐渐开大蒸汽阀门使水泵运转,当水缸空气旋塞中流不出带气泡的水流时,即可关闭空气旋塞,使水泵向锅炉进水。

(5)锅炉进水完毕,先缓慢关闭蒸汽阀门,再关闭进水管和给水管上的阀门。

单项选择题

When I was young, my parents ran a snack bar in our small town.

One evening in early April, my mother told me to fill in at the snack bar (1) a worker who had the flu. I told her I would mess it up, (2) I had never worked at the bar before. I (3) that instead of making money, I would end up owing it.

"You can do it, " said my mother, " (4) , you won’t get much business until lunch. "

"But I’ll never remember the orders, and I’m no good (5) money. Please, Mom, don’t (6) me. "

"Then I’ll help you", she said.

I shrugged my shoulders. I thought my mother’s (7) was a bad one, but I (8) .

When I got to the bar the next day, I found my mother was (9) . Because the weather that day was rainy and cold, people wanted hot snacks and drinks. (10) , I was really slow at taking the orders and making change. The line of people grew, and everybody seemed (11) , I was so nervous that my hands shook, and I (12) a cup into pieces. What a mess! Then my mother came to (13) me, and she also showed me how to make (14) If someone gave me $ 5 for something that cost $ 3.25, I handed over (15) quarters and a dollar and said, "75 cents makes four dollars, plus one dollar makes five. " Things went more (16) after that.

By the end of the day, I could remember orders, (17) the bill, and make change quickly with a smile. I was even a little (18) when the sun came out and dried up business. My mother said she was proud of me, and when she (19) that I work at the snack bar again next year, I did not even shrug. I was too busy (20) the restaurant I would open one day.

4()。

A. Therefore

B. However

C. Besides

D. Yet

多项选择题