Screw pumps synthesis

Example 6.2 The Synthesis of the Inverse Single Screw Pump There is, however, another, more elegant way to relax the channel-length constraint, as shown in Fig. E6.2. After one circumference, a flow channel formed by the moving and stationary planes of a given width can be twisted helically by an amount equal to the width of the channel to create a much longer helical channel on the same roll or shaft. The channel itself can be simply machined onto the inner surface of the stationary cylinder or barrel. 

Figure 4.30 Scheme for polyether polyol fabrication by anionic polymerisation of alkylene oxides, initiated by glycerol or diols (variant). 1 - Reactor for potassium glycerolate synthesis 2 - Reactor for prepolyether synthesis 3 - Reactor for polyether synthesis 4 - Reactor for purification 5 - Filter press 6 - Storage tank for final purified poly ether 7 - Heat exchangers for removal of the reaction heat 8 - Condensers 9 - Vacuum pumps 10 - Vessels for distilled water 11 - Recirculation pumps 12 - Gear pump or screw (or double screw) pump... 

The synthesis equipment consists of a stainless steel cylinder with an inside diameter of 100 mm and a height of 265 mm and is shown schematically in Fig. 1. The wall of the cylinder is 3 mm and the top plate 10 mm in thickness. The cylinder is mounted with 12 MX10 stainless steel screws on a base plate made of stainless steel. The base plate is furnished with a rabbet which contains the O-ring Teflon seal between the cylinder flange and base. In addition, three 6-mm o.d. stainless steel lines are welded to the base. One line leads to a vacuum pump, another line to the gas bottle, and the third to a mechanical safety valve which opens for pressure higher than 75 atm. The inlet line has connections to a... 

The reaction between aminopropyl-terminated fluids and diisocyanates (Eq. 3), on the other hand, proceeds smoothly either in solution or in the bulk within a few minutes. We were able to obtain molecular weights up to 150 000 Da. For economic reasons we favor the synthesis of the block copolymers in the melt. By using a twin-screw extrader we are able to produce the material simply by feeding the starting materials with separate pumps into the fu t zone of the extruder [3]. 

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