# US 5,800,792 A · Exhaust gas treatment unit and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,800,792 A - Document ID: US5800792A - Status: Granted - Kind: A - Application number: 08/646,329 - Filed: 1996-06-04 - Granted: 1998-09-01 - Earliest claimed: 1994-11-29 - Assignees: Teisan Kabushiki Kaisha - Inventors: Yoshihiro Ibaraki; Hidekazu Ina; Hideji Kawanaka - Web page: https://patentgrep.com/patent/US5800792A ## CPC - B01D 53/46: Removing components of defined structure - F23G 7/063: {electric heating} - F23J 15/025: {using filters} - F23J 15/06: of coolers - F23G 2207/101: for temperature - F23G 2207/30: Oxidant supply - F23G 2207/40: Supplementary heat supply - F23G 2208/10: Preventing or abating fire or explosion, e.g. by purging - F23G 2209/142: Halogen gases, e.g. silane - F23J 2219/60: Sorption with dry devices, e.g. beds - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - F23G: CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION - F23J: REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES (combustion apparatus for consuming smoke or fumes, e.g. exhaust gases, F23G7/06) ## Abstract The present invention relates to an exhaust gas treatment unit which possesses a stable treating capacity, with a reduced running cost. The exhaust gas treatment unit removes noxious gases such as monosilane contained in an exhaust gas by thermal decomposition. The exhaust gas treatment unit includes a heating drum (5) into which the exhaust gas and oxygen or air are introduced and a heating source (6) disposed on the outer periphery of the heating drum (5) so as to heat the inside of said heating drum (5). A temperature sensor (14) detects the temperature of the inside of said heating drum (5) in the vicinity of its outlet and a controller (16) controls the heating source (6) in accordance with a detected temperature value from the temperature sensor (14) so that the temperature of the inside of said heating drum (5) in the vicinity of the outlet is maintained within a predetermined temperature range. An air-cooled type cooling device (2) is connected to the outlet of the heating drum (5) to cool the exhaust gas. The running cost of the invention is lower than the running cost for other known devices in a large extent because metal oxide and chemical agents are not used in contrast to a chemical reaction type exhaust gas treatment unit. ## Claims ### Claim 1 An exhaust gas treatment unit for removing noxious gases contained in an exhaust gas by thermal decomposition comprising; a heating chamber into which exhaust gas and oxygen are introduced, the heating chamber having an outlet; a heating source disposed at an outer periphery of said heating chamber so as to heat an inside of said heating chamber; a temperature detector for detecting a temperature of the inside of said heating chamber in a vicinity of the outlet and outputting a detected temperature value; a valve for controlling the flow of oxygen into the heating chamber; a controller for controlling said heating source in accordance with the detected temperature value from said temperature detector so that the temperature of the inside of said heating chamber in the vicinity of the outlet is maintained within a predetermined temperature range, and for controlling the flow of oxygen into the heating chamber in accordance with the detected temperature value; and a cooling device connected to the outlet of said heating chamber. ### Claim 2 (depends on 1) An exhaust gas treatment unit according to claim 1, wherein the controller is set to control the heating source such that the temperature of the inside of said heating chamber in the vicinity of the outlet is maintained within the temperature range of from 350.degree.-500.degree. C. ### Claim 3 (depends on 1) An exhaust gas treatment unit according to claim 1, further comprising a filtering device for removing oxidation products from the exhaust gas exiting the cooling device. ### Claim 4 (depends on 1) An exhaust gas treatment unit according to claim 1, wherein the cooling device is an air-cooled cooling device. ### Claim 5 (depends on 4) An exhaust gas treatment unit according to claim 4, wherein the air-cooled cooling device includes a cooling pipe having fins on an exterior surface thereof and a fan for forcing air across the fins. ### Claim 6 (depends on 1) An exhaust gas treatment unit according to claim 1, further comprising means for removing oxidation products from an inside surface of the heating chamber. ### Claim 7 (depends on 6) An exhaust gas treatment unit according to claim 6, wherein the means for removing oxidation products includes a compressed gas source for introducing compressed gas into the heating chamber to remove oxidation products which have been deposited on the inside surface of the heating chamber. ### Claim 8 (depends on 1) An exhaust gas treatment unit according to claim 1, wherein the heating chamber is a substantially cylindrical heating drum. ### Claim 9 (depends on 8) An exhaust gas treatment unit according to claim 8, wherein the heating source is a cylindrical electric heater disposed around the outer periphery of the heating drum. ### Claim 10 (depends on 8) An exhaust gas treatment unit according to claim 8, wherein the substantially cylindrical heating drum has an axis which is positioned vertically. ### Claim 11 (depends on 1) An exhaust gas treatment unit according to claim 1, wherein the heating chamber and the cooling device are positioned within a ventilated casing to prevent exhaust gas from being released to the atmosphere. ### Claim 12 (depends on 1) The exhaust gas treatment unit of claim 1, wherein more than one temperature detector is used to detect the temperature of the inside of the heating chamber. ### Claim 13 (depends on 1) The exhaust gas treatment unit of claim 1, wherein the unit further comprises an inlet for the introduction of each the oxygen and exhaust gas, with the inlet being connected to a nozzle, through which the oxygen and exhaust gas are introduced into the heating chamber. ### Claim 14 A method of exhaust gas treatment for removing noxious gasses contained in an exhaust gas comprising: introducing an exhaust gas containing noxious gasses into a heating chamber; introducing oxygen into the heating chamber; heating the exhaust gas so as to thermally oxidatively decompose the noxious gasses; controlling the temperature of the heating chamber by controlling a heating source in accordance with a temperature value detected by a temperature sensor within the heating chamber; controlling the flow of oxygen into the heating chamber in accordance with a temperature value detected by a temperature sensor within the heating chamber; and cooling the exhaust gas exiting the heating chamber. ### Claim 15 (depends on 14) A method of exhaust gas treatment according to claim 14, further comprising a step of filtering the exhaust gas to remove oxidation products. ### Claim 16 (depends on 14) A method of exhaust gas treatment according to claim 14, wherein SiH.sub.4 is a noxious gas contained in the exhaust gas and the heating step causes the SiH.sub.4 in the exhaust gas to be oxidatively decomposed and converted to SiO.sub.2. ### Claim 17 (depends on 16) A method of exhaust gas treatment according to claim 16, further comprising a step of filtering the exhaust gas to remove the SiO.sub.2. ### Claim 18 (depends on 14) A method of exhaust gas treatment according to claim 14, wherein the temperature of the heating chamber is controlled to between 350.degree..about.500.degree. C. ### Claim 19 (depends on 14) A method of exhaust gas treatment according to claim 14, further comprising a step of removing oxidation products from an inside surface of the heating chamber by introducing pressurized gas to the heating chamber. ### Claim 20 (depends on 14) A method of exhaust gas treatment according to claim 14, wherein the step of cooling the exhaust gas includes cooling the exhaust gas in an air-cooled device. ### Claim 21 (depends on 14) The method of claim 14, wherein more than one temperature sensor is used within the heating chamber.