# US 2013/0153177 A1 · Method for heating up or keeping warm the flow paths of a process plant > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153177 A1 - Document ID: US20130153177A1 - Status: Published application - Kind: A1 - Application number: 13/635,441 - Filed: 2011-04-12 - Published: 2013-06-20 - Earliest claimed: 2010-04-14 - Inventors: Eberhard Kuske; Johannes Menzel - Web page: https://patentgrep.com/patent/US20130153177A1 ## CPC - F28D 15/00: Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls {; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies (F28D17/00, F28D19/00, F28D20/00 take precedence)} - B01J 8/0285: {Heating or cooling the reactor (for tubular reactors in furnaces B01J8/062)} - B01J 19/0013: {Controlling the temperature of the process} - F24H 1/10: Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium - B01J 2208/00053: of the heat exchange medium - B01J 2219/0006: of the heat exchange medium - B01J 2219/00204: of the heat exchange system - B01J 2219/00238: of the heat exchange system - F28D 21/00: Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00 - F28F 2250/08: Fluid driving means, e.g. pumps, fans - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22) - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) ## Abstract The invention relates to a method for heating up or keeping warm the flow paths of a process plant, wherein a stream of fluid provided for heating up or keeping warm the flow paths is guided in a circuit which comprises a heating device (8) for warming up the stream of fluid. According to the invention, to equalize the pressure loss occurring in the circuit, the stream of fluid is supplied as a suction medium to a jet pump (5) arranged in the circuit and is exposed there to a pumping medium supplied at a higher pressure. ## Claims ### Claim 1 A method of heating or keeping warm the flow passages of a process plant for the catalytic conversion of constituents of a process fluid outside the process operation during which the process fluid flows into the plant and there is subjected to a chemical or physical treatment or conversion, a fluid flow provided instead of the process fluid outside the process operation for heating or keeping warm the flow passages being guided in a closed loop containing a heater for warming up the fluid flow, wherein to compensate for the pressure loss occurring in the closed loop the fluid flow is fed as an inlet fluid to a jet pump in the closed loop and there is acted on with a motive fluid fed at a higher pressure. ### Claim 2 (canceled) ### Claim 3 (depends on 1) The method according to claim 1, wherein flow passages of the process plant contain at least one apparatus holding bulk solids. ### Claim 4 (depends on 1) The method according to claim 1, wherein a pressure within the entire closed loop is greater than 5 bar. ### Claim 5 (depends on 1) The method according to claim 1, wherein the volumetric flow of the fluid flow provided for heating or keeping warm the flow is less than 15% of a nominal volumetric flow for which the process plant is designed with full work load in normal operation. ### Claim 6 (depends on 1) The method according to claim 1, wherein an inert gas, preferably nitrogen or carbon dioxide, is fed to the jet pump as a motive fluid. ### Claim 7 (depends on 1) The method according to claim 1, wherein a fluid containing gaseous constituents and water vapor is fed as motive fluid to the jet pump. ### Claim 8 (depends on 1) The method according claim 1, wherein water vapor is fed as motive fluid to the jet pump. ### Claim 9 (depends on 8) The method according to claim 8, wherein before return of the fluid flow to the jet pump, water is condensed out and removed from the fluid flow, the quantity of water condensed out of the fluid flow corresponding to the quantity of water fed to the jet pump as water vapor as motive fluid. ### Claim 10 (depends on 1) The method according to claim 1, wherein part of the fluid guided in the closed loop is extracted. ### Claim 11 (depends on 10) The method according to claim 10, wherein a volumetric flow of the extracted part corresponds to the volumetric flow of the fed-in motive fluid. ### Claim 12 (depends on 10) The method according to claim 10, wherein the extracted part of the fluid is guided for heat recovery via a heat exchanger, the motive fluid being preheated with the recovered heat. ### Claim 13 (depends on 1) The method according to claim 1, wherein a heat exchanger that is acted on with a heating medium is used as a heater for heating the fluid flow. ### Claim 14 (depends on 1) The method according to claim 1, wherein an electrically operated heating element is used as a heater for heating the fluid flow. ### Claim 15 (depends on 1) The method according to claim 1, wherein the motive fluid is held in a pressure tank. ### Claim 16 (depends on 1) The method according to claim 1, wherein the process plant has at least two stages and that a flow splitter containing a flow controller is provided seen in the flow direction behind the jet pump, flow splitter renders possible a variable division of the fluid flow between the first stage and the second stage. ### Claim 17 A method of operating a process plant for the catalytic conversion of constituents of a process fluid where during normal operation of the plant the process fluid is fed into the plant, then passed through flow passages and flowed in a treatment stage over a bulk catalyst, and thereafter fed out of the plant, the method comprising, for heating or keeping warm the flow passages outside of normal operation, the steps of: providing a recovery line forming with the flow passages a closed loop passing through the treatment stage, through a heater, and from an inlet to an outlet of a jet pump having a motive-fluid nozzle; and supplying a motive fluid under higher pressure than the process fluid in the closed loop to the nozzle so as to circulate the process fluid through the closed loop such that heat picked up from the heater is transferred to the flow passages and bulk material in the treatment stage.