Air assisted enclosed combustion device

Abstract

Air Assisted Enclosed Combustion Devices (AAECD) and methods are disclosed that provide maximum destruction efficiency of VOC's and methane greenhouse gases produced by oil production, site processing, storage, and transmission operations and produces no visible emission (smoke, soot, particulates) in the process. An exemplary AAECD may include a housing with an outer housing and a burner housing separated by an air gap. The AAECD is provided with a burner assembly, a blower assembly, and a suite of sensors in communication with an electronic control module having logic configured to receive input signals from the sensors, calculate an actual fuel-air ratio using the received input signals, compare the actual fuel-air ratio to a fuel-air ratio setpoint, and adjust a position of a throttle valve to control a rate and volume of air from a blower motor to the burner if the actual fuel-air ratio and the fuel-air ratio setpoint are different.

What is claimed is: 
     
         1 . An enclosed combustion device, comprising:
 a housing comprising an outer housing and a burner housing, the burner housing situated inside the outer housing and separated from the outer housing by an air gap;   a temperature sensor and an exhaust gas oxygen sensor mounted to the burner housing;   a burner assembly mounted inside the burner housing for burning a fuel, the burner assembly having at least one burner connected to an air manifold and a fuel manifold, the fuel manifold having a fuel supply pressure sensor and connectable to a source of the fuel;   a blower assembly connected to the air manifold, the blower assembly having a blower motor, an air plenum, and a throttle valve controller operably connected to a throttle valve situated inside the air plenum; and   an electronic control module having a processor and a non-transitory computer readable memory storing logic, the electronic control module in communication with the throttle valve controller, the temperature sensor, the exhaust gas oxygen sensor, and the fuel supply pressure sensor;   wherein the logic of the electronic control module is configured to receive input signals from the throttle valve controller, the temperature sensor, the exhaust gas oxygen sensor, and the fuel supply pressure sensor and cause the processor to calculate an actual fuel-air ratio using the received input signals, the logic further configured to cause the processor to compare the actual fuel-air ratio to a fuel-air ratio setpoint and cause the processor to send a signal to the throttle valve controller to cause the throttle valve controller to move the throttle valve to a desired position to control a rate and volume of air from the blower motor to the at least one burner if the actual fuel-air ratio and the fuel-air ratio setpoint are different.   
     
     
         2 . The enclosed combustion device of  claim 1 , wherein the electronic control module is configured to operate the enclosed combustion device in a closed-loop by calculating the actual fuel-air ratio and comparing the actual fuel-air ratio to a fuel-air ratio setpoint at predetermined intervals. 
     
     
         3 . The enclosed combustion device of  claim 2 , wherein the closed-loop is further defined as a first-closed loop that determines a position of the throttle valve at a first predetermined interval and a second closed-loop that determines the actual fuel-air ratio and compares the actual fuel-air ratio to the fuel-air ratio setpoint at a second predetermined interval that is longer than the first predetermined interval. 
     
     
         4 . The enclosed combustion device of  claim 1 , further comprising a catalyst positioned in an exhaust opening of the burner housing. 
     
     
         5 . The enclosed combustion device of  claim 1 , wherein the blower assembly further comprises an air filter positioned in the air plenum between the blower motor and the throttle valve. 
     
     
         6 . The enclosed combustion device of  claim 1 , further comprising a fuel shutoff valve and wherein the logic of the electronic control module is further configured to detect a combustion level that may cause visible emissions from the enclosed combustion device and, upon detecting a combustion level that may cause visible emissions, the logic causes the processor to send a signal to the fuel shutoff valve activating the fuel shutoff valve. 
     
     
         7 . The enclosed combustion device of  claim 6 , wherein the logic causes the electronic control module to send a message alerting an operator of the activation of the fuel shutoff valve. 
     
     
         8 . An enclosed combustion device, comprising:
 a housing comprising an outer housing and a burner housing, the burner housing situated inside the outer housing and separated from the outer housing by an air gap;   a temperature sensor and an exhaust gas oxygen sensor mounted to and extending inside the burner housing;   a burner assembly mounted inside the burner housing for burning a fuel, the burner assembly having a burner, a fuel-air mixing nozzle connectable to a source of the fuel, an air tube connecting the burner and the fuel-air mixing nozzle, a fuel supply pressure sensor, a variable speed blower motor, a variable frequency drive (VFD) connected to the variable speed blower motor, and an air intake plenum connecting the variable speed blower motor and the fuel-air mixing nozzle; and   an electronic control module having a processor and a non-transitory computer readable memory storing logic, the electronic control module in communication with the VFD, the temperature sensor, the exhaust gas oxygen sensor, and the fuel supply pressure sensor;   wherein the logic of the electronic control module is configured to receive input signals from the VFD, the temperature sensor, the exhaust gas oxygen sensor, and the fuel supply pressure sensor and cause the processor to calculate an actual fuel-air ratio using the received input signals, cause the processor to compare the actual fuel-air ratio to a fuel-air ratio setpoint, and cause the processor to send a signal to the VFD to cause the VFD to adjust a blower speed of the variable speed blower motor to control a rate and volume of air from the variable speed blower motor to the fuel-air mixing nozzle if the actual fuel-air ratio and the fuel-air ratio setpoint are different.   
     
     
         9 . The enclosed combustion device of  claim 8 , wherein the electronic control module is configured to operate the enclosed combustion device in a closed-loop by calculating the actual fuel-air ratio and comparing the actual fuel-air ratio to a fuel-air ratio setpoint at predetermined intervals. 
     
     
         10 . The enclosed combustion device of  claim 9 , wherein the closed-loop is further defined as a first-closed loop that determines the blower speed of the variable speed blower motor at a first predetermined interval and a second closed-loop that determines the actual fuel-air ratio and compares the actual fuel-air ratio to the fuel-air ratio setpoint at a second predetermined interval longer than the first predetermined interval. 
     
     
         11 . The enclosed combustion device of  claim 8 , further comprising a catalyst positioned in an exhaust opening of the burner housing. 
     
     
         12 . The enclosed combustion device of  claim 8 , further comprising a fuel shutoff valve installed in between the source of the fuel and the fuel-air mixing nozzle, and wherein the logic of the electronic control module is further configured to detect a combustion level that may cause emissions visible from outside the enclosed combustion device and, upon detecting a combustion level that may cause emissions visible from outside the enclosed combustion device, the logic causes the processor to send a signal to the fuel shutoff valve activating the fuel shutoff valve preventing fuel from reaching the fuel-air mixing nozzle. 
     
     
         13 . The enclosed combustion device of  claim 12 , wherein the logic causes the electronic control module to send a message alerting an operator of the activation of the fuel shutoff valve. 
     
     
         14 . The enclosed combustion device of  claim 8 , further comprising a flame detector, a coil, and an ignitor, wherein the logic of the electronic control device is further configured to receive a first signal from the flame detector indicating that a flame is no longer present in the burner and a second signal from the flame detector indicating that the flame is present in the burner, and in response to receiving the first signal the logic causes the electronic control device to perform at least one re-ignition cycle, the re-ignition cycle comprising:
 sending, by the processor of the electronic control device, a signal to the coil causing the coil to send an electrical current to the ignitor which causes the ignitor to spark; and   sending, by the flame detector, one of the first signal and the second signal to the electronic control device.   
     
     
         15 . The enclosed combustion device of  claim 14 , further comprising a fuel shutoff valve installed between the source of the fuel and the fuel-air mixing nozzle, and wherein the logic of the electronic control device is further configured to perform a predetermined number of re-ignition cycles and, if the second signal is received from the flame detector after a last one of the predetermined number of re-ignition cycles, the logic of the electronic control device causes the processor to send a signal to the fuel shutoff valve activating the fuel shutoff valve preventing fuel from reaching the fuel-air mixing nozzle. 
     
     
         16 . An enclosed combustion device, comprising:
 a housing comprising an outer housing and a burner housing, the burner housing situated inside the outer housing and separated from the outer housing by an air gap;   a temperature sensor mounted to and extending inside the burner housing;   a burner assembly mounted inside the burner housing for burning a fuel, the burner assembly having a burner mounted inside a burner chamber, an exhaust gas oxygen sensor mounted to and extending inside the burner chamber, a fuel supply line, a fuel supply pressure sensor installed in the fuel supply line, an air plenum, a fuel-air mixing nozzle, an air tube connecting the burner and the fuel-air mixing nozzle, a variable speed blower motor connected to the air plenum, a variable frequency drive (VFD) connected to the variable speed blower motor, and an ambient air intake concentrically surrounding and extending at least partially over the fuel-air mixing nozzle to draw ambient air around the fuel-air mixing nozzle and into the air tube; and   an electronic control module having a processor and a non-transitory computer readable memory storing logic, the electronic control module in communication with the VFD, the temperature sensor, the exhaust gas oxygen, and the fuel supply pressure sensor;   wherein the logic of the electronic control module is configured to receive input signals from the VFD, the temperature sensor, the exhaust gas oxygen sensor, and the fuel supply pressure sensor and cause the processor to calculate an actual fuel-air ratio using the received input signals, cause the processor to compare the actual fuel-air ratio to a fuel-air ratio setpoint, and cause the processor to send a signal to the VFD to cause the VFD to adjust a blower speed of the variable speed blower motor to control a rate and volume of air from the variable speed blower motor to the fuel-air mixing nozzle if the actual fuel-air ratio and the fuel-air ratio setpoint are different.   
     
     
         17 . The enclosed combustion device of  claim 16 , further comprising a pilot valve connected to the fuel supply line, wherein the pilot valve is positioned adjacent to the burner to ignite a fuel-air mixture in the burner. 
     
     
         18 . The enclosed combustion device of  claim 16 , wherein the burner assembly is a first burner assembly, the combustion device further comprising at least one second burner assembly and a first air plenum of the first burner assembly and a second air plenum of the second burner assembly are connected to an air manifold, the air manifold connected to the variable speed blower motor to distribute air from the variable speed blower motor to both the first burner assembly and the second burner assembly. 
     
     
         19 . The enclosed combustion device of  claim 16 , further comprising a flame detector, a coil, and an ignitor, wherein the logic of the electronic control device is further configured to receive a first signal from the flame detector indicating that a flame is no longer present in the burner and a second signal from the flame detector indicating that the flame is present in the burner, and in response to receiving the first signal the logic causes the electronic control device to perform at least one re-ignition cycle, the re-ignition cycle comprising:
 sending, by the processor of the electronic control device, a signal to the coil causing the coil to send an electrical current to the ignitor which causes the ignitor to spark; and   sending, by the flame detector, one of the first signal and the second signal to the electronic control device.   
     
     
         20 . The enclosed combustion device of  claim 19 , further comprising a fuel shutoff valve installed in the fuel supply line before the fuel-air mixing nozzle, and wherein the logic of the electronic control device is further configured to perform a predetermined number of re-ignition cycles if the second signal is received from the flame detector and, if the second signal is received from the flame detector after a last one of the predetermined number of re-ignition cycles, the logic of the electronic control device causes the processor to send a signal to the fuel shutoff valve activating the fuel shutoff valve preventing fuel from reaching the fuel-air mixing nozzle.