电站锅炉制粉系统是如何分类的？
参考答案：
制粉系统从系统风压方面可分为正压式和负压式；从工作流程方面又可分为直吹式和中间储仓式两类。所谓直吹式制粉系统，就是原煤经过磨煤机磨成煤粉后直接吹入炉膛进行燃烧；而中间储仓式制粉系统是将制备出的煤粉先储存在煤粉仓中，然后根据锅炉负荷需要，再从煤粉仓取出经给粉机送入炉膛燃烧。直吹式制粉系统制备出的煤粉一般是被具有一定风压的一次风吹至炉膛的，系统处于正压状态，所以直吹式制粉系统一般属于正压式制粉系统；而在中间储仓式制粉系统中制备出的煤粉一般是由排粉风机抽出的，系统处于负压状态，所以中间储仓式制粉系统一般属于负压式制粉系统。
摘录信息（共5小题；每小题2分，满分10分） 阅读下面短文，根据所读内容在文后第53至第57小题的空格里填上适当的单词或短语，并将答案转写到答题卡上。 注意：每空不超过3个单词。 Some beach creatures are wonderful -- like dolphins, but others are dangerous. Here are some examples of harmful beach creatures. Puffer Fish Puffer Fish, found in all Japanese seas, have very interesting features. They are very easy to catch but must not be eaten because their flesh and organs contain a poison. Anyone who does eat the flesh can become sick very quickly. They may even stop breathing. The Blue Bottle The Blue Bottle is found in most Caribbean waters. Blue Bottles float lightly on the surface of the water but their tentacles (触须) can be as long as 10 metres. Blue Bottles are much less dangerous than some other jellyfish but they can give a swimmer a bad sting (刺) if the swimmer accidentally touches them. Stingrays There are many different kinds of stingrays in Mauritius waters. They usually swim and feed on the bottom of the sea. Accidents can happen if people stand on them or try to pick them up. Stingrays have a sting on their tail. These stings have poison on them. If someone is stung the wound can easily become infected. Title : 53
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