| 摘要 |
<p>It comprises several passages of a generally spiralled shape in which the direction is inverted at midway and is comprised of at least two prismatic or cylindrical elements (15, 17, 17a) forming at least one spiral, imbricated into each other with their spirals oriented in opposite directions, in such a manner as to define a front wall (15) having at least one inlet opening (E) and a rear wall having at least one outlet openings (S). These openings (E, S) are connected by a part having an approximately constant cross section comprised of a decreasing spiral followed by an increasing spiral.</p> |
