# US 4,396,369 A · Furnace air volume control apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,396,369 A - Document ID: US4396369A - Status: Granted - Kind: A - Application number: 06/217,225 - Filed: 1980-12-17 - Granted: 1983-08-02 - Earliest claimed: 1979-12-17 - Assignees: SERVO-Instrument - Inventors: Gustav Kaessmann - Web page: https://patentgrep.com/patent/US4396369A ## CPC - F23N 5/006: {the detector being sensitive to oxygen} - F23N 1/042: {using electronic means} - F23N 5/003: {using detectors sensitive to combustion gas properties (F23N5/02, F23N5/18 - F23N5/26 take precedence)} - F23N 5/082: {using electronic means} - F23N 2223/04: Memory - F23N 2223/08: Microprocessor; Microcomputer - F23N 2225/02: filling height in burners - F23N 2227/04: Prepurge - F23N 2233/06: at the air intake - F23N 2233/08: with variable speed - F23N 2235/04: in stacks - F23N 2235/06: at the air intake - F23N 2235/10: power assisted, e.g. using electric motors - F23N: REGULATING OR CONTROLLING COMBUSTION (control devices specially adapted for combustion apparatus in which combustion takes place in a fluidised bed of fuel or other particles F23C10/28; condition responsive controls for regulating combustion in domestic stoves with open fires for solid fuel F24B1/187) ## Abstract A furnace air volume control apparatus for controlling the volume of furnace air to achieve efficient burning is disclosed. The apparatus includes regulating valves positioned within supply air inlets and exhaust gas outlets of the furnace. A measured data receiver positioned on the exhaust gas side transmits a measuring signal to a control unit connected to the regulating valves. The control unit includes a storage unit for storing valve positions assigned to respective burner loads. By monitoring various exhaust gas parameters with the measured data receiver and control unit valve position, adjustment in response to changes in the burner load is possible by comparing a previously stored valve position recalled from the storage unit with a characteristic curve. The valve adjusting value stored in the storage unit is essentially congruent with the change in burner load. After exhaust gas stabilization has occurred in response to different burner loads precise correction of the valve position value occurs. ## Claims ### Claim 1 A furnace air volume control apparatus for controlling furnace air volume of furnace (1) with at least one regulator valve (7, 22) for changing the volume of furnace air with a measured-data receiver (25) positioned on an exhaust gas side and transmitting a measuring signal to a control unit (9), said control unit regulating the position of said regulator valves for the purpose of changing furnace air volume, the improvement comprising storage unit means connected to the control unit (9) for storing the position of said valves (7, 22) for controlling furnace air volume. ### Claim 2 (depends on 1) A furnace air volume control apparatus according to claim 1, wherein said storage unit is capable of storing the new adjusted value of said valve positions (7, 22) for controlling the furnace air volume in a given situation of external control of the burning corresponding to the desired oxygen value in the case of a given burner load. ### Claim 3 (depends on 1, 2) A control apparatus according to claim 1 or 2, wherein said storage unit is capable of remembering whether the position assigned to the respective burner load was entered based upon a larger or smaller burner load. ### Claim 4 (depends on 1) A control apparatus according to claim 1, wherein said measured value receiver (25) is capable of measuring flue gas density and soot density in oil burning furnaces, CO-value for gas burning furnaces, and further includes a sensor (19) for the optical detection of the flame temperature spectrum. ### Claim 5 (depends on 1) A control apparatus according to claim 1, wherein said regulator valves (7, 22) controlling furnace air volume are positioned on the supply air side and exhaust gas side and adjusted in relation to each other, said valves capable of being affected simultaneously by said control unit (9). ### Claim 6 (depends on 5) A control apparatus according to claim 5, further comprising a value-receiver positioned on the exhaust gas side of the furnace for measuring oxygen values and pressure. ### Claim 7 (depends on 1) A control apparatus according to claim 1, further comprising means for fully opening the regulator valves (7, 22) during burner switch off and malfunction or before start up of the flame. ### Claim 8 (depends on 1) A control apparatus according to claim 1, further including means for fully opening said regulator valves (7, 22), said means energizing said valves when the permissible oxygen band width per burner load or other threshold values and in the case of the response of other monitoring functions is exceeded, said means energizing said valves to fully open position, and a time switch device for monitoring the fully open valve position, wherein said time switch device is operative to transmit a signal causing a disturbance report and switch off the burner when an indicated time interval is exceeded. ### Claim 9 (depends on 1) A control apparatus according to claim 1, further comprising an adjusting device for the adjustment of the permissible oxygen band width corresponding to the course of a desired curve of the oxygen value as a function of the burner load. ### Claim 10 (depends on 1) A control apparatus according to claim 1, further comprising potentiometers connected to said regulator valves, wherein said potentiometers correspond to the respective adjusting value and the responder values of the potentiometers are compared by addressing limit switches and are monitored by them.