公开(公告)号：EP0062466A1

公开(公告)日：1982-10-13

申请号：EP82301618.3

申请日：1982-03-26

申请人： English Electric Valve Company Limited

发明人： Edgington, Bruce Robert ,  Jones, Eric

IPC分类号： G01N27/16

CPC分类号： G01N27/16

摘要： Combustible-gas detectors (of the kind in which a heatable wire filament constituting the detector element exhibits a change in resistance occasioned by the change in its temperature which occurs due to the oxidation of a combustible gas passing over it) usually embed the wire filament in a pellet of ceramic material coated with, or including therewithin, an oxidation catalyst. Unfortunately non-volatile residues - such as lead or silicone vapours - can poison the catalyst and/or obstruct the normal flow of gas to the element's surface, so reducing the sensitivity of the device.
The present invention allows the construction of a detector pellet having greater resistance to catalyst poisoning, especially by silicones, achieving this by building the pellet as a multilayered structure rather like an onion. The invention provides a combustible-gas detector element comprising a heatable wire filament (10; preferably a helical platinum wire) embedded in a pellet formed overall of an oxidation catalyst (preferably palladium) and a porous non-catalytic inert carrier therefor (preferably 75wt% alumina, 25wt% zeolite), wherein the pellet has a laminated, onion-like structure, and consists of a multiplicity (preferably 6 to 20) of concentric layers in which layers of carrier (11,13,15,17; preferably in pairs) alternate with layers of catalyst (12,14,16).

摘要翻译： 可燃气体检测器（其中构成检测器元件的可加热丝灯丝由于通过其的可燃气体的氧化而发生的温度变化而引起的电阻变化）通常将线丝嵌入 涂覆有氧化催化剂或包含氧化催化剂的陶瓷材料颗粒。 不幸的是，非挥发性残留物（例如铅或有机硅蒸汽）可能会使催化剂中毒和/或阻碍气体正常流向元件表面，从而降低了设备的灵敏度。 本发明允许构建具有更大的耐催化剂中毒性，特别是硅氧烷的检测器颗粒，通过将沉淀物构建为多层结构而不是洋葱来实现。 本发明提供一种可燃气体检测器元件，其包括嵌入由氧化催化剂（优选钯）形成的颗粒和其多孔非催化惰性载体（优选75重量％）的可加热丝细丝（10;优选螺旋铂丝） 氧化铝，25重量％沸石），其中颗粒具有层叠的洋葱状结构，并且由多个（优选6至20个）同心层组成，其中载体层（11,13,15,17;优选成对地） ）与催化剂层（12,14,16）交替。