主权项 |
1. An apparatus comprising:
a housing having a central axis, a first end and a second end, wherein the housing defines an inlet opening, and wherein the inlet opening opens into the first end of the housing proximate a first end wall; an outlet tube defining an outlet opening that extends from inside the housing and through the first end wall; and a projection attached to a second end wall of the housing and extending into the housing, wherein the outlet tube and projection are aligned with and centered relative to the central axis, and wherein the inlet opening has a diameter “d” and the end of the projection is spaced from the outlet tube between 1 d and 2 d. |