This type of extinguisher contains a charge of sodium bicarbonate powder. The container of this type...
extinguisher holds a steel capsule containing liquid carbon dioxide. On breaking the capsule, by depressing
the knob, the gas forces all the powder out of the discharge nozzle. The powder blankets the fire in a cloud
of dust, cutting off the supply of oxygen. If the fire is hot enough the sodium bicarbonate will decompose to
form sodium carbonate, carbon dioxide and water all of which will aid the smothering operation and give
some cooling effect. The extinguisher discharges in only 15 sec and it is thus important to aim the appliance
accurately. The operating pressure of this container is higher than that of the soda-acid type. It is
consequently hydraulically tested at a pressure of 35 bar.
参考解析:
1. What type of extinguisher does this paragraph talk about?
A. Dry power extinguisher
B. Carbon dioxide extinguisher
C. Foam extinguisher
D. Soda-acid extinguisher
2. Which of the following statements is not true?
A. Carbon dioxide in the capsule is used as an propellant.
B. When operating this extinguisher, we should break down the capsule.
C. The extinguisher should be turned upside down to depress the knob.
D. The blanketing agent is forced out.
3. According to this paragraph, the extinguishing principle of________ can be inferred.
A. covering the fire
B. cooling the temperature
C. smothering air
D. all of the above
4. This type of extinguisher can swiftly release the sodium bicarbonate powder in _______ seconds.
A. 15
B. 35
C. 20
D. 50