| 摘要 |
<p><PICT:0394406/III/1> In a process for the catalytic combustion of ammonia, the gas mixture is passed through the catalyst with a linear flow velocity which exceeds the linear velocity of combustion under the conditions existing in the catalyst. The velocity of the mixture may be higher on entering the free gas space before the catalyst than it is through the catalyst proper. A suitable catalyst consists of galloon or twilled galloon fabric of platinum-rhodium alloy, and cooling, e.g. by a liquid layer of water or nitric acid, may be applied if necessary. In the arrangement shown, the gas mixture passes through a ring of circular holes 4 in the gas distributing disc 3 and radially along the space 8 between the disc 3 and a parallel disc 5 with very high velocity. After changing direction it then passes with lower velocity through the catalyst consisting of platinum fabric 6 stretched across the passage 13. In a modification the gas mixture passes radially through a number of parallel passages between several annular discs and then through the catalyst fabric as before. Specification 236,145, [Class 1 (i), Chemical processes &c.], is referred to.</p> |
