| 摘要 |
<p>1,111,722. Mixing fluent streams, coating apparatus. M. F. SMITH. 28 Oct., 1964, No. 44004/64. Headings B1C and B2L. [Also in Division D1] Apparatus for mixing a powder and a gas comprises a tube 70 having a plurality of flow-straightening means such as screens 72 to produce a laminar flow, and powder and compressed air inlets 48, 58 mutually arranged at an acute angle. A constriction 60 in the air inlet produces in the chamber 56 abrupt reduction in the velocity of the gas and improved mixing. The screens have apertures in registration and about ten times the particle average diameter. The tube outlet end may be unobstructed or have a shaped orifice (see Fig. 2, not shown) or a concentric conical body which produces a divergent flow (see Figs. 3, 8, 10, 11, 12 and 13, not shown). The invention may be embodied as a coating apparatus e.g. to produce a coating 78 of a thermoplastic material on a body 72 which may be rotated or given helical motion and internally heated, Fig. 7. A vacuum hood 82 is positioned to collect and recycle undeposited material and an intermittent air blast 77 may divert the stream so that the body 72 can be exchanged without extending the coated area. Other embodiments are a self propelled device incorporating an air compressor and infra-red heating lamps for coating the interior of a pipe (see Figs. 8-11, not shown); a telescoping reciprocating device with a telescopic vacuum hood for coating the internal walls and bottom of a container, see Figs. 12 and 13, not shown) and a device for coating wire (see Fig. 14, not shown and Division D1-2) in which the heat may be provided by a laser beam or the residual heat of extrusion. The thermoplastic material may be PVC or polyethylene of submicron size up to about 250 microns.</p> |
