DEGASSING METHOD, DEGASSING DEVICE AND USE OF SCREW ELEMENTS Russian patent published in 2018 - IPC B29C47/76 

FIELD: machine engineering.

SUBSTANCE: degassing device includes an extruder having a body and n drilled holes of the body B_n with the corresponding diameters D_n. Wherein n is an integer, preferably, an integer from 1 to 16. Preferably, the drilled holes in the body to intersect one another and be parallel in the case when n is greater than 1. One or more rotatable shafts W_n which in each case are concentrically arranged in one of the drilled holes of the body B_n, have the axis of rotation A_n and equipped with processing elements. The section profile of the shafts in the generatrix direction has m relative maximum R^m_{max n} of the radial extension value of the section profile to the axis A_n of shaft rotation W_n. Wherein M is an integer from 1 to 8. The maximum value R_{max n} for the radial extension of the section profile to the axis A_n of shaft rotation W_n. Wherein, for R_{max n} the relationship is the following: R_{max n} <=(D_n/2). A feeding zone, one or several degassing zones in each case including degassing opening suitable for withdrawal of volatile components of medium containing polymers from the extruder, an output zone. In terms of the processing elements, the extruder is equipped with screw elements SE with helix screw line movement t, which are designed so that at least two of the following three conditions are satisfied. 1) at the cross-section profile, for the radial extension of the profile curve, there is at least one relative maximum R^m_{max n}, for which it is true: 0.430 D_n ≤R^m_{max n}<0.485 D_n. 2) 1.60 D_n<t<3.00 D_n. 3) the cross-section profile of this particular screw element does not have active side surface on the front in the direction of rotation, in the region of the radial extension from 0.90 R_max to R_max of tangent angle b which is greater than 25°. The tangent angle b is defined as a smaller one among the two angles that are obtained by laying tangent to arbitrary point on profile section of the processing element, wherein the cross-section profile is not continuously differential and equal to 0° in an arbitrary point on the cross-section profile of the processing element, in which the cross-section profile is continuously differentiated.

EFFECT: increased degassing efficiency at low residual content of volatile components.

34 cl, 9 dwg, 3 tbl, 6 ex