Heat exchanger for maintaining constant temperature in polymers has a heated internal torpedo with ends matched to those of the exchanger body ends forming a polymer flow channel

摘要

A tubular vessel with tapered ends has internal chambers(4) fed with heating fluid. An axial, central torpedo(7) forms an annular flow channel(6) for polymer with a wall(5) of the vessel. Both ends(7') of the torpedo are shaped to ease flow, the feed side being adapted to a diffusor shape in the vessel and the outlet side adapted to a funnel shape(9). Ribs(10) holding the torpedo inside the vessel eliminate flow dead spots. The hollow torpedo has supply and return connections for heating fluid. The opening angle of the diffusor and funnel shapes(8,9) is 20-65degrees, preferably 35-40degrees while the two ends(7') of the torpedo(7) have an opening angle 2-5degrees larger than that of the diffusor and funnel shapes. The height of the cylindrical polymer flow channel(6) is 20-70, preferably 40-60mm. Narrow flow guides positioned on at least part of the outer surface of the torpedo surface are inclined relative to the heat exchanger axis(A) and have decreasing spacing to the downstream side. Heating fluid enters the torpedo via a pipe(18) and flows through an annular return channel(14) surrounding the pipe before entering the return part(15) of the external heating chamber(16). The external heating chamber is fed principally from an inlet(17) at the same end as the polymer inlet. The funnel-shaped part of the vessel is a separate part which is connected to the main part by flanges.