| 摘要 |
1279121 Press drying E I DU PONT DE NEMOURS & CO 5 Sept 1969 [13 Sept 1968] 44158/69 Heading F4G In an open-barrel press dryer part of which comprises a water-vaporizing section, comprising a screw 50 positioned coaxially within an open barrel 60, the free volume between the screw and barrel in this section being from 8 to 18% of the total available barrel volume. The barrel has water outlets in the form of longitudinal slots, and the diameter of the screw at the discharge end is larger than at the input end. The water vaporizing section is immediately preceded by a dewatering section having a greater proportion of free volume to total available volume than said water-vaporizing section. This equipment is particularly suitable for drying EPDM-type elastomers and improved drying of natural rubber and styrene-butadiene polymers can be obtained by its use. |
