摘要:
In a method for improving heat transfer in a heat exchanger, in which a heating medium passes through heat exchange elements 1,8 which transfer their heat to a liquid with which they are in contact and which is located in the jacket region 3 of the heat exchanger, the liquid between the heat exchange elements in the jacket region 3 is heated locally to such a high temperature by means of additional heating elements 2,9 that nucleate boiling occurs in the liquid on the surface of these additional heating elements 2,9 and the resulting vapour bubbles ascend between the normal heating exchange elements 1,8 in the jacket region 3. For this purpose an evaporative condenser containing vertically superimposed heat exchange elements 1,8 extending in a horizontal direction and a shell enclosing the jacket region 3 of the heat exchange elements 1,8 is provided, in which additional heating elements 2,9 connected to a heating medium circuit which is separate from the heat exchange elements 1,8 are arranged beneath the heat exchange elements 1,8, preferably in the bottom third of the vertical arrangement.
摘要:
In the thermal separation of solutions and suspensions into a free-flowing solid and into a largely solid-free distillate, the useful product can be almost completely recovered in a pure state, and the amount of waste product can thus be reduced, by carrying out the concentrating in a first heatable flow pipe (6) up to an upper limit which is given by a creeping coverage of the inside wall with solid and/or by a total blockage of the flow cross-section and then continuing the concentrating in a second flow pipe (9) which is made as a rotary pipe or as a paddle shaft apparatus and whose inside wall (12) is scraped continuously, and separating the vapors and solids from one another at the end of this flow pipe (9).
摘要:
Viscous copper-containing catalyst waste is split up into solid particles and gaseous dichlorobutene along a steadily curved flow path, the liquid film flowing along an inner tube wall being driven along by the gas flowing at a higher rate in the core.
摘要:
This invention relates to a process for the production of polycarbonate agglomerate of high bulk density from polycarbonate solutions, in which the organic solvent is stripped from a solution of polycarbonate by means of steam, and which is characterised in that the resulting suspension of polycarbonate particles, condensed water and water- and solvent vapor is fed in a tube or tubular heat exchanger to a separator which is partially filled with water and which is under elevated pressure. The polycarbonate agglomerates are discharged, together with part of the water, via a pressure lock at the bottom of the separator.
摘要:
Benzoyl chloride is prepared by a process in which the high-boiling residue obtained in the catalytic oxidation of toluene with oxygen or oxygen-containing gases in the liquid phase is largely freed of heavy metal salts which are present, and is then chlorinated at elevated temperatures, optionally under the action of light, and the benzoyl chloride is then separated off.
摘要:
A process of evaporating a viscous polymer solution is described. The process includes: (a) providing a viscous polymer solution including at least 30 wt. % of solvents and monomers; (b) introducing the viscous polymer solution into a heated helix (5), the heated helix having a vapor exit velocity of 200 to 300 m/s, (a film flow including a two-phase mixture of polymer melt, and solvent vapors and monomer vapors being formed within the helix); (c) forwarding the film flow from helix (5) into a heated vapor separator (6); (d) expanding the two-phase mixture of polymer melt, and solvent vapors and monomer vapors of the film flow within vapor separator (6) at an absolute pressure of 10 mbar to 800 mbar, (a bottom product including a concentrated melt of the polymer is formed within the vapor separator); and (e) withdrawing the bottom product from vapor separator (6). Each of the helix (5) and vapor separator (6) have a separate heating device, and each of heating device independently provides a temperature that is above the softening point of the polymer.
摘要:
In concentrating solutions containing 1 to 10% by weight of salts and resins, the yield and economics and trouble-free running can be improved by using a flow tube which has a steady curvature at least in the last third and is sized in its diameter in such a way that the mean flow velocity at the tube outlet is at least 50 m/second, and at least 90% by weight of the vaporizable components are evaporated off at driving temperature gradients of 20.degree. to 200.degree. C. between the heating medium and the solution.
摘要:
This invention relates to a process for carrying out reactions which primarily occur during the transport of compounds in the liquid phase or at the liquid-gas interface. Starting components are reacted with one another and/or with gases of the inner space in a multi-phase flow tube having a liquid ring flow which may contain dissolved and/or dispersed constituents. Any necessary heat exchange takes place between the liquid and the wall of the tube or the gases.
摘要:
This invention relates to a process for producing a homopolymer or co-polymer of an aromatic vinyl monomer by anionically polymerizing a monomer mixture in the absence of oxygen in a tubular coil evaporator.
摘要:
The present invention provides a process for the isolation of partially crystalline polycarbonate powder or oligocarbonate powder from solutions thereof, in which process the organic solvent of a polycarbonate solution is vaporized in a heat exchanger, optionally with incorporation of steam, or in a holding tube with incorporation of steam and the pasty mixture of concentrated solution, solvent vapor and optionally water is separated in a separator. In this process, the solvent vapor is condensed in a heat exchanger downstream from the separator. The solvent is vaporized in the heat exchanger by indirect input of heat through the heat exchanger walls and vaporization may be promoted by preheating the polycarbonate or oligocarbonate solution in an upstream heat exchanger or by introducing steam or both.