问题 问答题 简答题

试述立窑产量与风压、风量的关系?

答案

参考答案:

立窑中气体流动与燃料燃烧、传热及冷却直接有关,因此立窑通风的风压、风量对立窑的产量及动力消耗,煅烧操作等有大的影响。提高入窑气流速度,即表示窑内窑气流量的增加,使单位时间内燃烧更多的燃料,单位时间内发生的热量更多,为增产创造了有利条件。而窑内单位时间内发热量增加,则提高了燃烧速度,使窑内温度提高,窑内气体流速的增加使得温度提高,温度提高又使传热速度加快,反过来又促进燃烧速度的加快,故对提高窑产量是十分有利的,而且空气量的增加,又能使熟料冷却充分,提高熟料质量,增加熟料的余热利用,提高窑的热效率。

但如果空气量过大,在满足了窑内燃烧完全后还有剩余的,会造成由于废气量太多而带走更多的热量,结果会使窑的热效率热力强度降低,引起窑内燃烧温度降低,既降低了立窑的热效率,有直接影响熟料的质量而在窑内煅烧情况能适应的前提下,鼓风的气流速度越高,空气量越大,对煅烧越有利,能显著提高立窑的产量。

填空题

Part 4


Questions 26-45


·Read the following article and choose the best word for each space.
·For questions 26-45, mark one letter A, B, C or D on the Answer Sheet.

iPhone Left in Hot Car for Three Hours


The normally peaceful suburban town of Winnetka is still reeling following the news Monday (26) a local resident, whose name is being (27) by police pending a full investigation, left an iPhone unattended for more than three hours in a car (28) in the hot sun.
"Responding to calls from (29) . passersby, who observed the iPhone sitting in a vehicle in the parking (30) of the Westfield Shopping Center, police arrived on the (31) at approximately 4 p.m. and immediately intervened to save the device," said Winnetka police chief Douglas Blaine. "Security cameras have shown that the iPhone had been in the car— with the doors (32) and the windows rolled (33) —since 1 p.m. Due to the tragic and highly emotional (34) of this case, we cannot say any (35) at this time."
According to official police records, two officers forcibly (36) into the car at 4:07 p.m. and found the iPhone (37) face down on the dashboard. The iPhone at first showed no (38) of life, but after a tense few seconds, officers were able to wake it and get it to (39) to a series of simple touch commands. Police said that if the iPhone were left in the extreme (40) for any longer, it could have died.
The iPhone was rushed by ambulance to a nearby Apple facility for careful (41) .Miraculously, no damage to its memory, screen, or wireless capabilities was reported.
Upper-middle-class suburbanites from all over the North Shore area have reacted to the near-tragedy with an unprecedented outpouring of (42) . Hundreds of cards and letters have come streaming in, and local talk radio shows have been flooded (43) calls demanding that the iPhone’s (44) be prosecuted. Many have come forward offering to take the iPhone into their custody, and still (45) have donated free downloads, ringtones, and MP3s to the victimized object.

A.this

B.that

C.which

D.what

单项选择题