APPARATUS FOR APPLYING FOAMED POLYMERIC INSULATION ONTO TUBE Russian patent published in 2001 - IPC

FIELD: applying protective coatings onto outer surface of tubes, preferably foamed insulation material onto surface of single tubes according to technique "pipe-in-pipe". SUBSTANCE: apparatus includes frame, front and rear supporting walls with axial opening, delivery union and shaping unit. In order to reduce material consumption and to enhance insulation quality, apparatus is made rotatable. Supporting walls are arranged one opposite to another at ends of apparatus according to mirror fashion and they include stationary washer 5. Holder 4 includes in zone of engaging with washer two radially arranged scrapers 9 in the form of two mutually spaced trihedral prisms. Holder and washer have mutually matched pouring openings. At operation linearly movable wall is moved backwards in order to provide possibility for placing in washers rigid outer tubular envelope 11 whose position is fixed. Then tube 13 is passed through openings "a" and "b" in such a way that its end portions are exposed. Liquid foaming composition is introduced through union and opening "b" into cavity "a" and then washer rotation drive is energized for intensively agitating foaming liquid composition with uniform distribution of air bubbles. Leakage of foaming composition through opening "a" and union is prevented due to minimum gap of rubbing pair holder-washer. Composition passed outwards at matching openings of union and washer is scraped out by means of scrapers 9. When composition is solidified rear wall is moved to the right777; tube is rolled out along rollers in position suitable for removing it and transporting to stacking station. EFFECT: lowered material consumption, stable quality of tube insulation coating. 2 cl, 5 dwg