问题 单项选择题

大型原油罐绝热层施工中,依托焊接在罐壁上的保温支架,将绝热材料制品绑紧、定位的施工方法是()。

A.拼砌法

B.充填法

C.捆扎法

D.粘贴法

答案

参考答案:C

解析:

(一)捆扎法施工

捆扎法是把绝热材料制品敷于设备及管道表面,再用捆扎材料将其扎紧、定位的方法。适用于软质毡、板、管壳,硬质、半硬质板等各类绝热材料制品。配套的捆扎材料有镀锌铁丝、包装钢带、粘胶带等,此方法最适合于管道和中、小型圆筒设备的绝热。用于大型简体设备及管道时,需依托固定件或支承件来捆扎、定位。应注意捆扎间距要符合规范的要求,每块绝热制品上的捆扎件,不得少于两道且不得采用螺旋式缠绕捆扎。双层或多层的绝热层绝热制品,应逐层捆扎,并应对各层表面进行找平和严缝处理。

(二)粘贴法施工

粘贴法是用各类胶粘剂将绝热材料制品直接粘贴在设备及管道表面的施工方法。适用于各种轻质绝热材料制品,如泡沫塑料类,泡沫玻璃,半硬质或软质毡、板等。当选用粘贴法进行绝热层施工时需要注意胶粘剂的性能影响,即胶粘剂的使用温度必须符合被绝热的介质温度,对所用绝热材料和被绝热的材料表面没有腐蚀,而且又有相当强的粘结性。

(三)浇注法施工

浇注法是将配制好的液态原料或湿料倒入设备及管道外壁设置的模具内,使其发泡定型或养护成型的一种绝热施工方法。液态原料目前多采用聚氨酯溶剂,湿料是轻质粒料与胶结料和水的拌合物。该法较适合异形管件的绝热以及室外地面或地下管道绝热。

浇注法绝热层施工中的注意事项:

1.每次配料必须在规定时间内用完。

2.大面积浇注时,应设对称多浇口.分段分片进行。并以倒料均匀、封口迅速等操作来控制浇注质量。

3.浇注时应一次浇注成型,当间断浇注时.施工缝宜留在伸缩缝的位置上。

4.试块的制作,应在浇注绝热层时,同时进行。

(四)喷涂法施工

1.喷涂法是利用机械和气流技术将料液或粒料输送、混合,至特制喷枪口送出,使其附着在绝热面成型的一种施工方法。该法与浇注法同属现场配料、现场成型的施工方法。

2.室外进行喷涂时,风力大于三级、酷暑、雾天及雨天,均不宜施工。

(五)充填法施工

1.充填法是用粒状或棉絮状绝热材料填充到设备及管道壁外的空腔内的施工方法。该法在缺少绝热制品的条件下采用,此外也适用于对异形管件做成外套的内部填充。

2.充填法绝热层施工的注意事项是:充填填料时,应边加料,边压实,并应施压均匀,致使密度一致;各种充填结构的填料层,严禁架桥现象产生;对有振动部位的绝热层,不得采用充填法施工。

(六)拼砌法施工

1.拼砌法是用块状绝热制品紧靠设备及管道外壁砌筑的施工方法,分为干砌和湿砌。

2.干砌是将绝热块沿钢结构与构件排列,缝隙可用散棉填实。

湿砌则将绝热块涂抹胶泥,并整齐砌筑,拼缝与缺损处可用胶泥填料,还可辅以用铁丝网捆扎,加强其整体强度。拼砌法常用于保温,特别是高温炉墙的保温层砌筑。

多项选择题
填空题

Today, we’ll talk about what other effects watching TV might produce on children. Children should be (1) a lot of television, many experts and parents agree, but there is at least one circumstance when it might be beneficial: (2) . A recent study conducted by Italian researchers found that children (3) immediately preceding and during blood tests experienced less pain than children whose mothers (4) during the procedure, or children whose mothers were present but (5) .
The research, led by Carlo Brown, MD, at the University of Siena, is published in the Archives of Disease in Childhood. (6) the study. None received any type of anesthesia; the children and their mothers (7) . Both the group whose mothers attempted to distract them from the blood tests and those whose mothers simply observed reported (8) than the group who watched cartoons. For that group, the levels of pain were less and the children were better able to (9) .
One of the possible explanations is that children might have (10) during the procedures, exacerbating their perception of pain. "The higher pain level reported by children during (11) shows the difficulty mothers have in interacting positively (12) in their children’s life," the authors write.
However, they stressed that (13) still provided benefits, noting that the children would (14) during the procedures. "Indeed, children state that having their parent present (15) when in pain," say the authors.
Another possibility offered for consideration is the notion that the (16) might release pain-quelling endorphins. Endorphins, (17) produced by the pituitary gland, resemble opiates in their ability to produce analgesia and a sense of well-being. In other words, they might (18) .
In any case, the study results suggest that health workers should (19) to watch television during painful procedures (20) .