| 摘要 |
<p>The vapor generator is formed with a flue of rectangular cross section and a funnel of four trapezoidal walls which define a rectangular opening. The tubes of the funnel and flue extend helically and connect each to the other. The funnel tubes in the larger trapezoidal walls have transition portions which are disposed at greater angles to form a smooth transition into the funnel tubes of the smaller trapezoidal walls.</p> |
