This specification relates generally to apparatuses, systems and methods for fuel combustion. This specification also relates generally to apparatuses, systems and methods for waste conversion, pollution control and gas refinement.
The following paragraphs are not an admission that anything discussed in them is prior art or part of the knowledge of persons skilled in the art.
U.S. Pat. No. 3,630,651 to Fay et al. discloses a dual vortex gaseous burner having a vortex tube, a separator tube, a pair of vortex chambers and an igniter. An oxidizer is injected tangentially through a jet in one of the vortex chambers forming a primary vortex between the separator tube and the vortex tube wall, while a fuel is injected tangentially through a jet in the other vortex chamber forming a secondary vortex between the igniter and the separator tube. An electric spark from the igniter produces ignition of the oxidizer and fuel at the boundary between the two vortices.
U.S. Pat. No. 5,055,030 to Schirmer discloses a method and apparatus for recovering hydrocarbons in which a first toroidal vortex of fuel and a combustion supporting gas is created with its center adjacent the axis of an elongated combustor; a second toroidal vortex of combustion supporting gas is generated between the first toroidal vortex; the fuel is burned in the presence of the combustion supporting gas to produce a fuel gas at the downstream end of the combustor; water is introduced into the flue gas adjacent the downstream end of the combustion to produce a mixture of flue gas and water; a major portion of the water is vaporized in a vaporizor to produce a mixture of flue gas and steam; and the mixture of flue gas and steam is injected into a hydrocarbon bearing formation.
The following introduction is intended to introduce the reader to this specification. One or more inventions may reside in a combination or sub-combination of the apparatus elements or method steps described below or in other parts of this document. The applicant(s) does not waive or disclaim rights to any invention or inventions disclosed in this specification merely by not describing such other invention or inventions in the claims.
In an aspect of this specification, a combustion method comprises: generating an axial vortex stream, and passing the axial vortex stream between a first end and a second end of a main chamber in a first linear direction; generating a peripheral vortex stream, and passing the peripheral vortex stream as a counterflow to the axial vortex stream in a direction generally opposing the first linear direction; and merging the peripheral vortex stream with the axial vortex stream to form a product stream, the product stream moving in the first linear direction to an outlet at the second end of the main chamber.
The axial vortex stream can include a first fuel and the peripheral vortex stream can include a first oxidant. The first fuel of the axial vortex stream and the first oxidant of the peripheral vortex stream can at least partially combust to form the product stream. The axial and peripheral vortex streams can be generated having the same rotational polarity. The peripheral vortex stream can be merged with the axial vortex stream proximate to the first end of the combustion chamber.
The peripheral vortex stream can be generated by tangentially introducing a first stream to the combustion chamber. The first stream can be introduced to form the peripheral vortex stream proximate to the second end of the combustion chamber. The first stream can include the oxidant. The first stream can include a second fuel. The first stream can include a first pre-chamber product stream from at least one first pre-chamber. The at least one first pre-chamber can include a source of a second fuel, a source of the oxidant, and an ignition source. The second fuel and the oxidant can have at least partially combusted in the at least one first pre-chamber to form the first pre-chamber product stream. The second fuel can have a higher heat of combustion than the first fuel.
The axial vortex stream can be formed upstream from an inlet at the first end of the main chamber, and the axial vortex stream can be passed through the inlet. The axial vortex stream can be generated by passing a second stream, and tangentially introducing a third stream to combine with the second stream. The second stream can include the first fuel and the third stream includes the oxidant. The third stream can include a second pre-chamber product stream from at least one second pre-chamber. The at least one second pre-chamber can include a source of a second fuel, a source of the oxidant, and an ignition source. The second fuel and the oxidant can have at least partially combusted in the at least one second pre-chamber to form the second pre-chamber product stream. The second fuel can have a higher heat of combustion than the first fuel.
The method can further comprise cooling the product stream to avoid recombination of molecules. A fourth gas stream can be introduced to the product stream downstream from the outlet to cool the product stream. The fourth gas stream can be tangentially introduced to the product stream.
Velocities of the axial and peripheral vortex streams can be controlled to provide substantially full combustion of the first fuel and the oxidant. Compositions of the axial and peripheral vortex streams can be controlled so as to provide a stoichiometric excess of oxidant relative to the first and second fuels. The method can further comprise monitoring combustion data representing at least one of temperature, fuel quantity, air quantity, and pressure, and using the data as feedback to control the axial and peripheral vortex streams. The data can be gathered using a microprocessor, and the microprocessor can calculate optimum control parameters using a mathematical combustion model.
In another aspect of this specification, an apparatus comprises a housing including interior sidewalls, the sidewalls defining a main chamber, the main chamber including an inlet, an outlet, and first and second ends, the inlet for passing an axial vortex stream to the first end, the axial vortex stream including a first fuel, the second end including an outlet for expelling a product stream, the main chamber including at least one first channel disposed between the first and second ends, the at least one first channel for introducing fluid into the main chamber to form a peripheral vortex stream including an oxidant as a counterflow to the axial vortex stream.
The interior walls of the main chamber can be generally cylindrical and converge in a flow direction of the axial vortex stream from the first end to the second end. The apparatus can further comprise a merging surface within the main chamber for merging the peripheral and axial vortex streams. The merging surface can be located along the sidewalls of the main chamber at the first end thereof. The merging surface can be frusto-toroidal in shape. The inlet can comprise a cylindrical sleeve extending into the main chamber, the sleeve for directing flow of the axial vortex stream into the main chamber. The sleeve can be frusto-conical in shape. The sleeve can include a plurality of apertures.
The apparatus can further comprise a first injection zone for producing a first stream, the first injection zone in fluid communication with the at least one first channel for providing the first stream to the main chamber, the first stream forming the peripheral vortex stream. The first injection zone can be generally annular in shape and extend radially around a circumference of the main chamber. The first injection zone can include a plurality of swirl vanes for directing rotational fluid flow. The first injection zone can include an oxidant source for injecting an oxidant to form at least a portion of the first stream. The oxidant source can be tangentially aligned within the first injection zone. The first injection zone can include a fuel source for injecting a second fuel to form at least a portion of the first stream. The fuel source can be tangentially aligned within the first injection zone. The first injection zone can include at least one pre-chamber, the at least one pre-chamber including a fuel source for supplying a second fuel, an oxidant source for supplying an oxidant, an igniter, and an outlet for exhausting a second pre-chamber product stream. The outlet of the at least one pre-chamber can be tangentially aligned within the first injection zone.
The apparatus can further comprise a primary chamber in fluid communication with the inlet of the main chamber. The primary chamber can include a primary inlet for receiving a second stream, and at least one second channel for supplying a third stream, the second and third streams mixing in the primary chamber to form the axial vortex stream. The primary inlet can be connected to a source of the first fuel, the first fuel forming at least a portion of the second stream. The apparatus can further comprise a second injection zone for producing the third stream, the second injection zone in communication with the at least one second channel for providing the third stream to the primary chamber. The second injection zone can be generally annular in shape and extend radially around a circumference of the primary chamber. The second injection zone can include a plurality of swirl vanes for directing rotational fluid flow. The second injection zone can include an oxidant source for injecting an oxidant to form at least a portion of the third stream. The oxidant source can be tangentially aligned within the second injection zone. The second injection zone can include at least one pre-chamber. The at least one pre-chamber can include a fuel source for supplying a second fuel, an oxidant source for supplying an oxidant, an igniter, and a pre-chamber outlet for exhausting a second pre-chamber product stream. The pre-chamber outlet of the at least one second pre-chamber can be tangentially aligned within the second injection zone.
The apparatus can further comprise an afterburner chamber in fluid communication with the outlet of the main chamber, the afterburner chamber for receiving the product stream and cooling the product stream. The afterburner chamber can include at least one third channel for introducing a fourth stream to the product stream, the fourth stream comprising a coolant fluid. The apparatus can further comprise a third injection zone for producing the fourth stream, the third injection zone in fluid communication with the at least one third channel for providing the fourth stream to the afterburner chamber. The third injection zone can be generally annular in shape and extend radially around a circumference of the afterburner chamber. The third injection zone can include a plurality of swirl vanes for directing rotational fluid flow.
In another aspect of this specification, a combustion system comprises: a source of a first fuel; a primary chamber connected to the source of the first fuel, the primary chamber receiving a second stream including the first fuel, the primary chamber adapted to tangentially introduce a third stream into the second stream to generate an axial vortex stream; and a main chamber connected to the primary chamber, the main chamber including an inlet for receiving the axial vortex stream from the primary chamber, the main chamber adapted to tangentially introduce a first stream to generate a peripheral vortex stream, the peripheral vortex stream moving as a counterflow to the axial vortex stream, the first stream including an oxidant, the first fuel in the axial vortex stream and the oxidant in the peripheral vortex stream at least partially combusting to form a product stream, the main chamber including an outlet for expelling the product stream.
In the main chamber, the first stream can be introduced adjacent to the outlet. At least a portion of the peripheral vortex stream can flow along a substantial length of the main chamber from the outlet to the inlet. The first stream can include the oxidant. The first stream can include a second fuel. The first stream can include a first pre-chamber product stream. The first pre-chamber product stream can include a second fuel, the second fuel at least partially combusted in the first pre-chamber product stream. The third stream can include the oxidant. The third stream can include a second fuel. The third stream can include a second pre-chamber product stream. The second pre-chamber product stream can include a second fuel, the second fuel at least partially combusted in the second pre-chamber product stream. The second fuel can have a higher heat of combustion than the first fuel.
The system can further comprise an afterburner chamber in fluid communication with the outlet of the main chamber, the afterburner chamber adapted to inject a fourth stream into the product stream, the fourth stream including a coolant fluid.
The system can further comprise a plurality of sensors for monitoring combustion data representing at least one of temperature, fuel quantity, air quantity, and pressure. The system can further comprise a microprocessor for collecting the data, the microprocessor adapted to use the data as feedback to control the axial and peripheral vortex streams. The microprocessor can be adapted to calculate optimum control parameters using a mathematical combustion model.
In another aspect of this specification, a method of gas refinement comprises: providing an axial stream, and passing the axial stream in a main chamber in a first linear direction from a first end towards a second end, the axial stream including at least one pollutant; generating a first peripheral vortex stream, the peripheral vortex stream including at least one reagent; and merging the first peripheral vortex stream with the axial stream to form a product stream, the at least one pollutant and the at least one reagent at least partially reacting in the product stream, the product stream moving in the first linear direction to an outlet at the second end of the main chamber.
The at least one pollutant can be selected from the group consisting of SO2, NOx and CO2. The at least one first reagent can be selected from the group consisting of NH3, CO(NH2)2, C, H2O and CaO. The at least one pollutant is selected from the group consisting of SO2 and NO2, and the at least one reagent is selected from the group consisting of NH3 and CO(NH2)2. The at least one pollutant comprises CO2, and the at least one reagent is selected from the group consisting of NH3, C, H2O and CaO. The peripheral vortex stream further comprises at least one second reagent selected from the group consisting of NaHCO3, CaCO3, CaO and Ca(OH)2.
The peripheral vortex stream can be passed as a counterflow to the axial vortex stream in a direction generally opposing the first linear direction. The peripheral vortex stream can be merged with the axial vortex stream proximate to the first end of the main chamber. The peripheral vortex stream can be generated by tangentially introducing a first stream to the combustion chamber, the first stream including the at least one first reagent. The first stream can be tangentially introduced proximate to a source of the at least one first reagent. The first stream can comprise an oxidant. The method can further comprise introducing a fuel to the first stream. The first peripheral vortex stream can be generated at least in part by tangentially introducing a first pre-chamber product stream from at least one first pre-chamber. The at least one first pre-chamber can include a source of a fuel, a source of the oxidant, and an ignition source, the fuel and the oxidant at least partially combusting in the at least one first pre-chamber to form the first pre-chamber product stream. The method can further comprise cooling the product stream to avoid recombination of molecules.
In yet another aspect of this specification, an apparatus for gas refinement comprises: a housing including interior sidewalls, the sidewalls defining a main chamber, the main chamber including first and second ends and an inlet for introducing an axial stream that passes in a first linear direction from the first end to the second end of the main chamber, the axial stream including at least one pollutant, the second end including an outlet for expelling a product stream; at least one first channel disposed between the first and second ends of the main chamber; and a first injection zone for producing a first stream, the first injection zone including a source of at least one first reagent, the first injection zone in fluid communication with the at least one first channel for providing the first stream to the main chamber to form a peripheral vortex stream, the at least one pollutant in the axial stream and the at least one reagent in the peripheral vortex stream at least partially reacting in the product stream.
The at least one pollutant can be selected from the group consisting of SO2 and NO2, and the at least one reagent can be selected from the group consisting of NH3 and CO(NH2)2. The at least one pollutant can be CO2, and the at least one reagent can be selected from the group consisting of NH3, C, H2O and CaO.
The first injection zone can be generally annular in shape and extend radially around a circumference of the main chamber. The third injection zone can include a plurality of swirl vanes for directing rotational fluid flow. The first injection zone can include an oxidant source for injecting an oxidant to form at least a portion of the first stream. The oxidant source can be tangentially aligned within the first injection zone. The oxidant source can be proximate to the source of the at least one first reagent. The first injection zone can include a fuel source for injecting a fuel to form at least a portion of the first stream. The first injection zone can include at least one pre-chamber. The at least one pre-chamber can include a fuel source for supplying a second fuel, an oxidant source for supplying an oxidant, an igniter, and an outlet for exhausting a second pre-chamber product stream.
The apparatus can further comprise an afterburner chamber in fluid communication with the outlet of the main chamber, the afterburner chamber for receiving the product stream and cooling the product stream.
The skilled person in the art will understand that the drawings, described below, are for illustration purposes only. The drawings are not intended to limit the scope of the applicant's teachings in any way.
Various apparatuses or methods will be described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover apparatuses or methods that are not described below. The claimed inventions are not limited to apparatuses or methods having all of the features of any one apparatus or method described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or method described below is not an embodiment of any claimed invention. The applicant(s), inventor(s) and/or owner(s) reserve all rights in any invention disclosed in an apparatus or method described below that is not claimed in this document and do not abandon, disclaim or dedicate to the public any such invention by its disclosure in this document.
Applicant's teachings relate to the use of at least one combustion chamber in which an axial vortex stream is passed in a first linear direction, and a peripheral vortex stream is passed as a counterflow to the axial vortex stream in a direction generally opposing the first linear direction. The peripheral and axial vortex streams are merged to form a product stream, the product stream moving in the first linear direction to an outlet of the chamber.
Applicant's teachings can be directed to a variety of application areas, including but not limited to: thermochemical processing and utilization of solid domestic, industrial, medical and biological waste; production of artificial fuels (for example, methanol dimethyl-ether, biodiesel, benzene); reducing the presence of airborne pollutants and/or greenhouse gases from emission sources, e.g., industrial plants, coal-fired electricity generating stations, incinerators, cars, trucks, ships, etc.; burning of gaseous waste with low thermal coefficients with stable composition and non-stationary parameters; burning of liquid waste with high and low thermal coefficients; combustion of liquid and gaseous fuel mixes (including waste); acceleration of different thermochemical reactions; utilization in diesel generators and boilers; heat generations, for example, combustion systems of airplanes and ships; etc.
Applicant's teachings can be implemented as a retrofit to existing industrial apparatuses to reduce the presence of airborne pollutants and/or greenhouse gases from existing emission sources, and can be scalable depending on energy and waste conversion demands of a particular application. The combustion process can be computer-controlled, whereby feedback data can be monitored and adjustments can be made to operating parameters.
The apparatus 100 can be used for the combustion and decomposition of gaseous fuels or waste having relatively low heats of combustion, unstable parameters and non-standard characteristics (e.g., pressure and temperature characteristics). For example, the apparatus 100 can be implemented for: thermochemical processing and utilization of solid domestic and industrial residue; processing of medical and biological residue; or production of artificial fuels (for example but not limited to methanol, dimethyl-ether, bio-diesel, benzene). In a specific example, the apparatus 100 can be used to combust pyrolysis gas resulting from the burning of solid waste in the thermochemical reactor, the pyrolysis gas having a relatively low heat of combustion (e.g., 4-12 MJ/kg) and unstable components due to different burning products and non-stationary parameters of the gaseous quantity.
The primary combustion chamber 102 includes a fuel source 112 for delivering a stream to the primary combustion chamber 102 comprising a first fuel. The primary combustion chamber 102 can include an air or oxidant source 114. The main combustion chamber 104 can include a fuel source 116 and an air or oxidant source 118. The second pre-chamber 108 can include an air or oxidant source 120 and fuel source 122, and the first pre-chamber 110 can include an air or oxidant source 124 and a fuel source 126.
Formation and burning of a fuel-air mix can take place in the primary and main combustion chambers 102, 104. The multiple-stage combustion can take place in sequence, providing an increase in fuel burning completeness. Use of the pre-chambers 108, 110 to the primary and main combustion chambers 102, 104 can stabilize the combustion process and reduce or eliminate flame interruption during non-steady fuel supply from the fuel source 112 to the primary combustion chamber 102, which can increase reliability and stability of the combustion process.
Referring to
In some examples, the main chamber 104 includes an inlet 132, an outlet 134, and first and second ends 136, 138. The inlet 132 can be proximate to the first end 136 and receives an axial vortex stream 140. The outlet 134 can be proximate to the second end 138 and receives a product stream 142, and passes the product stream to the afterburner chamber 106. The main chamber 104 can include at least one first channel 144 disposed between the first and second ends 136, 138, the at least one channel 144 for introducing fluid into the main chamber 104 to form a peripheral vortex stream 146 as a counterflow to the axial vortex stream 140. The peripheral and axial vortex streams 146, 140 have the same rotational polarity.
In some examples, and with reference to
The first injection zone 148 can include an oxidant source 118 for injecting an oxidant to form at least a portion of the first stream 150. The oxidant source 118 can be tangentially aligned within the first injection zone 148 for directing rotational fluid flow. The oxidant source 118 can be for example but not limited to, an air ejector.
The first injection zone 148 can also include one or more fuel sources 116A, 1168 for injecting a second fuel to form at least a portion of the first stream 150. The second fuel can be richer than the first fuel, i.e. the second fuel can have a higher heat of combustion than the first fuel. In some examples, the fuel sources 116A, 116B can direct a liquid fuel into the first injection zone 148, the liquid fuel having a relatively high heat of combustion. The fuel sources 116A, 116B can be tangentially aligned within the first injection zone 148 for directing rotational fluid flow. Fuel sources 116A, 116B need not be identical.
The first injection zone 148 can also include one or more first pre-chambers 110A, 110B. Each of the one or more first pre-chambers 110A, 110B can include respective air or oxidant sources 124A, 124B for supplying an oxidant, fuel sources 126A, 126B for supplying a second fuel, ignition sources or igniters 154A, 154B, and outlets 156A, 156B for exhausting a first pre-chamber product stream into the first injection zone 148. The first pre-chamber outlets 156A, 156B can also be tangentially aligned within the first injection zone 148 for directing rotational fluid flow. The first pre-chambers 110A, 1106 and associated components need not be identical.
A maximum burning temperature of the product stream 142 in the main chamber 104 can be reached due to the injection of second fuel entering the main chamber 104 by way of the fuel source 116 and pre-chambers 110 (via the peripheral vortex stream 146). The extra supply of fuel to the main chamber 104 can provide for the near stoichiometric condition to provide complete combustion of first fuel from the fuel source 112 having relatively low heat of combustion.
Referring to
With reference to
In some examples, and with reference to
The second injection zone 172 can include an oxidant source 114 for injecting an oxidant to form at least a portion of the third stream 170. The oxidant source 114 can be tangentially aligned within the second injection zone 172 for directing rotational fluid flow.
The second injection zone 172 can also include one or more second pre-chambers 108A, 108B. Each of the one or more second pre-chambers 108A, 108B can include respective fuel sources 122A, 122B for supplying a second fuel, oxidant sources 120A, 120B for supplying an oxidant, ignition sources or igniters 154A, 154B, and second pre-chamber outlets 174A, 174B for exhausting a second pre-chamber product stream into the second injection zone 172. The second pre-chamber outlets 174A, 174B can be tangentially aligned within the second injection zone 172 for directing rotational fluid flow. The second pre-chambers 108A, 108B and associated components need not be identical.
The use of one or more pre-chambers 108A, 108B can provide an increase in fluid velocity in the second injection zone 172 which can lead to an increase in radial and axial static pressure gradients within the primary combustion chamber 102. An increase in static pressure gradients can serve to draw in first fuel from the fuel source 112, and lead to a temperature increase within the primary chamber 102, which can stabilize the burning process of the incoming first fuel if the first fuel is unstable with non-stationary parameters.
The exit of the product stream 142 from the main chamber 104 and the entrance of the first fluid stream 150 (which forms the peripheral vortex stream 146) can be provided at roughly the same cross-sectional position within the main chamber 104 in a direction orthogonal to the longitudinal axis of the main chamber 104. Consequently, the peripheral vortex stream 146 serves to cover substantially the entire length of the main chamber 104 and thus shield the interior sidewalls 130 from the axial vortex and product streams 140, 142, which can be of relatively high temperature. The sidewalls 130, therefore, can be fabricated to tolerate lower temperatures. In other words, although temperatures along the center axis of the main chamber 104 can reach relatively high values, the temperature at the sidewalls 130 can remain substantially cooler during steady state combustion as a result of the peripheral vortex stream 146. In some examples, the temperature in the axial vortex stream 140 could reach more than 2,000 degrees Celsius, whereas the temperature at the internal walls of the main combustion chamber heat pipe does not exceed 400 to 500 degrees Celsius, resulting in improved reliability and longer lifespan of the main chamber 104.
With continued reference to
In the afterburner chamber 106, the product stream can be cooled to prevent or reduce recombination of molecules. In particular, the afterburner chamber 106 can provide for finalizing of the fuel burning and accordingly decreasing of emissions by mixing, dilution and cooling of the burned products. Also, the use of the kinetic energy of the product stream 142 from the main chamber 104 can require less reliance on external air or oxidant sources. The afterburner chamber 106 can expel the cooled product stream 142 through the afterburner outlet 180.
With reference to cross-section a-a in
where: P* is the complete pressure of the gas stream, [Pa]; P is the statistical pressure of the gas stream, [Pa];
is the dynamic pressure of the gas stream or speed pressure, [Pa], [kg/m3·m2/s2]; ρ is the density of the gas, [kg/m3]; w=√{square root over (wz2+wφ2)} is the total stream speed, [m/s]; wz is the axial component of the speed; and wφ is the tangential component of the speed.
Alternatively, it is possible to use the following equation to model the pressure:
where: k is the adiabat constant of the gas
where Cp is the isobar thermal capacity of the gas [kJ/kg·K] and Cv is the isochronous thermal capacity of the gas, [KJ/kg·K]); M is the Mach's number in the stream; w is the total stream speed; a is the acoustic speed of the stream; R is the constant of the supplied gas (depends on the gas components); and T is the gas temperature.
During the movement of the second stream 166 along a-a to b-b, a temperature drop can be possible. Pressure change between a-a to b-b without a pressurized supply from fuel source 112 can be provided by the incoming pressure of the third stream 170 from the first injection zone 148.
In the cross-section b-b, relatively high centrifugal forces can be acting in accordance with the following equation:
where: m is the mass of the gas [kg]; Wφ is the tangential component of the speed in this cross-section [m/s]; and z is the radius where the gas element is located [m].
A high gradient of static pressure can be formed by the centrifugal forces in cross-section b-b. Therefore, the static pressure of the fluid decreases along the radius of the cross-section, and it reaches minimal value on the center axis (see
Between b-b and c-c in the primary chamber 102, the fuel air mixture is formed, comprising first fuel from source 112, oxidant from source 114, pre-chamber product stream from pre-chamber 108, and a portion of the peripheral vortex stream 146 that passes through the apertures 162 to combine with the axial vortex stream 140.
The burning process of the fuels between b-b and c-c can cause the temperature to increase rapidly (see
At cross-section d-d, the first stream 150 enters the first channel 144 and forms the peripheral vortex flow 146 with axial component speed wz. The distribution of tangential and axial components of the speed in the cross-section d-d is shown in
Between c-c and d-d, the peripheral vortex stream 146 is losing its tangential speed adjacent to the product stream 142. In addition, along with a reduction of the axial speed of the peripheral flow, mass transfer from the peripheral vortex stream 146 to the product stream 140 (moving in generally opposite linear direction) intensifies due to the formation of anisotropic turbulence between the streams.
The temperature changes of the gas in axial (I) and peripheral (II) streams are shown in
The apparatus 200 can be used for the combustion and decomposition of gaseous fuels or waste having relatively low heats of combustion, stable parameters and non-standard pressure and temperature characteristics. In a particular example, the apparatus 200 could be used for heat production systems (e.g., coal-fired electricity plants) using after-burning of gaseous substances for production of specific substances and their regeneration. In some examples, the apparatus 200 can be utilized for burning pyrolysis gas produced during the processing of industrial waste, e.g., polishing discs, wood waste, etc. The pyrolysis gas obtained in these processes can have relatively low heats of combustion, unstable composition, significant amount of hydrocarbons, and non-stationary consumption parameters. In examples involving combustion of pyrolysis gas from a thermal-chemical reactor, negative pressure of the second stream 266 from the fuel source 212 can be desirable to prevent or reduce leakage of pyrolysis gas to the atmosphere. In such examples, an ejector can be placed at the inlet to the primary chamber 202 to pressurize the second stream 266, e.g., −5 to 0 mm of water column.
Stable composition of the gaseous fuels permits the use of the main chamber 204 without a pre-chamber. Similar to the apparatus 100, stabilization of the burning process can take place due to the use of at least one pre-chamber 208 connected to the second injection zone 272 of the primary chamber 202.
In contrast with the apparatus 100, thermal stress within the first injection zone 248 and on the sidewalls 230 of the main chamber 204 can be reduced due to the absence of burning products streaming into and out of the first injection zone 248. Furthermore, the system of air and fuel supply to the first injection zone 248 of the main chamber 202 can be simplified.
The apparatus 300 can be used for the combustion and decomposition of gaseous fuels or waste having relatively low thermal capacity, stable parameters, stable pressure and temperature characteristics, but with pressurized supply of the fuel to the primary chamber 302. In some examples, the apparatus 300 can be used for thermo-chemical waste processing installations where pressure below atmosphere is not required. In other examples, the apparatus 300 can be used for afterburning of burned products of harmful emissions (e.g., car emissions).
The flow formation within the primary chamber 302 is due to the use of the oxidant source 314 introduced tangentially within the second injection zone 372. In some examples, the oxidant source 314 can include an air ejector, with the air from the ejector mixing with the first fuel to form the axial vortex stream 140. Similar to the apparatus 100, stabilization of the burning process can take place due to the use of at least one pre-chamber 310 connected to the first injection zone 348 of the main chamber 304.
In contrast with the apparatus 100, thermal stress within the second injection zone 372 and within the primary chamber 302 can be reduced due to the absence of a burning products streaming into and out of the second injection zone 372. Furthermore, the radial gradient of static pressure at the entrance of the primary chamber 302 can be reduced. Moreover, construction of the primary chamber 302 can be simplified due to the absence of a pre-chamber.
The apparatus 400 can be used for the combustion and decomposition of liquid fuels having both low and high heats of combustion. In particular, the apparatus 400 can be used to achieve simultaneous burning of liquid waste with high and low heats of combustion, e.g., simultaneous burning of sewage and oil refinery waste (benzene, acetone, etc). The apparatus 400 can also be used in industrial construction devices with sewage and liquids having high heats of combustion, such as paint industry with sewage and different chemicals, alcohol production industry with sewage and alcohol waste, liquids used to wash heating tanks, etc.
For the burning of liquid fuels with low and high heats of combustion simultaneously, the fuel with higher heat of combustion can be provided using one or more fuel sources 416, connected to the first injection zone 448. The fuel with lower heat of combustion can be provided through the fuel source 422 of the one or more pre-chambers 408 connected to the second injection zone 472. Alternatively, the fuel with higher heat of combustion can be provided through the fuel source 422 of the one or more pre-chambers 408 connected to the second injection zone 472. Oxidant or air from the oxidant source 418 and fuel from the fuel source 416 can mix in the first injection zone 448 and enhance the quality of burning downstream in the main chamber 404. Similar to the apparatuses 100 and 200, stabilization of the burning process can take place due to the use of at least one pre-chamber 408 connected to the second injection zone 472 of the primary chamber 402.
In contrast with the apparatus 100, thermal stress within the first injection zone 448 and on the sidewalls 430 of the main chamber 404 can be reduced due to the absence of a burning products from a pre-chamber, and thermal stress within the second injection zone 472 and within the primary chamber 402 can be reduced due to the fact that the burning process there takes place with reduced oxidant or air. The construction of the primary and main chambers 402, 404 is also simplified due to the absence of a pre-chambers and oxidant sources, respectively.
The apparatus 500 can be used for the combustion and decomposition of gaseous fuels or waste having relatively low heats of combustion, unstable parameters and non-standard characteristics simultaneously with gaseous wastes that result from the burning of liquid waste having high heats of combustion. In some examples, the apparatus 500 can be used for after-burning of gaseous emissions containing unburned hydrocarbons for the purpose of controlling emissions.
The at least one pre-chamber 510 can be operated such that the air or oxidant source 524 provides an excess of air for the burning of second fuel from the fuel source 526, and subsequently the fuel from fuel source 516. Fuels injected via sources 526 or 516 can be the same or different. Similar to the apparatuses 100 and 300, stabilization of the burning process can take place due to the use of at least one pre-chamber 510 connected to the first injection zone 548 of the main chamber 504.
In contrast with the apparatus 100, the construction of the main chamber 504 can be simplified as a result of the absence of a direct oxidant source and necessary connections. Furthermore, velocity of the peripheral vortex stream 546 in the main chamber 504 can be increased, and accordingly the level of radial and axial gradients of static pressure can be increased, leading to an increase in turbulence and intensification of combustion.
The apparatus 600 can be used for the combustion of gaseous waste with low heats of combustion, with unstable compositions, and non-stationary parameters, jointly with gaseous waste that results from the burning of liquid waste. Additional fuel (i.e. the second fuel) is provided through the first injection zone 648 to increase the temperature in the main chamber 604 to a maximum, thus enabling decomposition and burning of hydrocarbons, resulting in relatively low emissions in the product stream 642.
In contrast with apparatus 100, the quality of the mix in the primary chamber 602 can be increased due to the increase of the temperature and air consumption which enters with the burning product stream from the at least one pre-chamber 608. Consumption of the fuel from the pre-chamber 608 of the primary chamber 602 can be increased. Accordingly, radial and axial gradients of static pressure can be increased at the inlet 664 of the primary chamber 602, which can lead to improvement of the injection properties of the second injection zone 672 and pressure decrease of gaseous and liquid fuel mix entering the primary chamber 602. Absence of an oxidant source in the second injection zone 672 simplifies construction of the primary chamber 602.
The apparatus 700 can be used for the combustion of gaseous fuel with low heats of combustion, non-stable composition and non-stationary parameters, jointly with gaseous waste resulting from the burning of liquid waste with low heats of combustion. The apparatus 700 is similar to the apparatus 600, with the difference that the burning process in the main chamber 704 can be more intense than that of the main chamber 604. The apparatus 700 can be useful for mobile systems.
All oxidant or air for the working process in the primary and main chambers 702, 704 enters from their respective pre-chambers 708, 710. The maximum temperature in the burning zone of the main chamber 704 can be achieved due to the burning of fuel having a relatively high heat of combustion, which enters the main chamber 704 via source 716. Absence of an oxidant source in the first or second injection zones 748, 772 simplifies construction of the primary and main chambers 702, 704.
The apparatus 800 can be used for the combustion and decomposition of liquid fuels having a low and high thermal capacity, with stable parameters. The first liquid fuel is provided to the main chamber 804 via fuel source 816. In some examples, the first fuel can be a water emulsion fuel. A second fuel, which can be gaseous fuel having a higher heat of combustion than the first fuel, can be provided to the main chamber via fuel source 826. Oxidant or air is provided to the main chamber via oxidant sources 818, 824. Stabilization of the combustion can be realized by the at least one pre-chamber 810, that serves to ignite a fuel-air mixture.
The apparatus 900 can be used for the combustion and decomposition of liquid and gas fuels having high heat of combustion with stationary characteristics and stable parameters. The apparatus 900 is similar to apparatus 800, except that the liquid or gaseous fuels burned have relatively high heats of combustion. The apparatus 900 can be utilized for combusting gas, liquid fuel, or a combination of two or three phase fuels.
In apparatus 900, the at least one pre-chamber 910 works as an igniter. The formation of the air-fuel mix begins in the first injection zone 948 and forms the peripheral vortex stream 946, which in turn forms the axial vortex stream 940.
The apparatus 1000 can be used for the combustion and decomposition of liquid fuels, gaseous fuels, solid fuels, dust-like fuels, and two and three phase fuels. The apparatus 1000 can be particularly useful for systems where multi-phase fuels are used, e.g., burning of solid or dust-like fuels such as wood dust, coal dust, sometimes mixed with liquid fuels (liquid hydrocarbons) or gaseous fuels (natural gas, black oil, bio-gas, synthetic gas), etc.
With reference to
The inventors have developed a mathematical model to establish and control system parameters to optimize combustion performance. Control of primary parameters using a computer or microprocessor means can provide for system performance optimization. Optimization can serve to reduce the energy supply to the system, improve emission reduction and increase burning efficacy of a broad range of fuels. The mathematical model can permit the ability to perform analytical modeling of the combustion chamber system for different configurations and applications to obtain the values of combustion parameters and configurations.
In accordance with the mathematical model, the following parametric equation consists of the product of several dimensionless complex parameters:
A
ij
×F
ij
×B
ij
×C
ij
×G
ji=1 (Eq. 4)
Aij, Fij Bij, Cij, and Gji are the integral parameters which define the working characteristics and geometric sizes of components of a given combustion system, where: Aij is a thermal parameter and depends on the air excess coefficient during fuel combustion, temperatures of the fuel combustion, air and fuel temperature at the entrance to the primary and main chambers and pre-chambers, and type of first and second fuels and their chemical composition; Fij is a geometry parameter and depends on the geometry of each component of the apparatus; Bij is a first hydrodynamic parameter and depends on the relative speed of incoming and outgoing reactants and product in each component of the apparatus; Cij is a second hydrodynamic parameter and depends on the static pressure of reactants products in each of the components of the apparatus; and Gij is an emission parameter and depends on air consumption in the main and primary combustion chambers. The indices i and j correspond with the entrance and exit, respectively, to each chamber of the apparatus.
The parameter Aij determines the working regime, based on the following correlations: coefficients of air excess; fuel composition; temperature of the reactants and products, which are supplied into the primary and main combustion chamber and pre-chambers. The air excess coefficient should be α0=αp=0 for the air, which is supplied through the injection zones of the primary and main combustion chambers. Thus:
A
ij
=A
ij(αi,αj,Loi,Loj,Hui,Huj,TiB,TjB,TiT,TiT), (Eq. 5)
where: αi, αj are coefficients of the air excess; Loi, Loj (kg air/kg fuel) are coefficients which take into consideration the quantity of the air required for the burning of 1 kg of the fuel; Hui, Huj (kJ/kg) are combustion heat coefficients of 1 kg of the fuel; TiB, TjB (K) are air temperatures at the entrance; and TiT, TjT(K) are fuel temperatures at the entrance.
The geometric parameter Fij determines the influence of the geometric sizes of the main components of the primary and main combustion chambers on the flow path of a given combustion system. Therefore, the main elements of the flow path include size and shape of the injection zones of the primary and main chambers, pre-chamber outlets to the injection zones and location of the pre-chambers, inlets and outlets of the primary and main chambers, etc.
The parameter Bij determines the influence of the non-dimensional speed of streams within the chambers, where:
B
ij
=B
ij(Mi,Mj), (Eq. 6)
where Mi and Mj are the Mach's numbers of the corresponding flow cross-section.
The parameter Cij determines the influence of static pressures in the peripheral vortex formation, where:
C
ij
=C
ij(Pi,Pi and other), (Eq. 7)
where Pi, Pj are static pressures in the corresponding cross-section of the flow.
The parameter Gji determines the correlation of the consumption in the related cross-section of the flow, where:
G
ji
=G
ji(Gj,Gi), (Eq. 8)
where Gj and Gi reflect air consumption.
Referring to
The microprocessor control unit 3016 can be a small computer on a single integrated circuit consisting of a relatively simple CPU combined with support functions such as a crystal oscillator, timers, watchdog, serial and analog connections, etc. Program memory in the form of flash or OTPROM can also be included, typically along with limited read/write memory. In some examples, the microprocessor control unit 3016 can include a PIC16, PIC18 or dsPIC30 device. A computer 3022 can be connected to the microprocessor control unit 3016, for example, via RS-232 through a DB9 serial connector. An interface 3024 to the microprocessor control unit 3016 can include a keypad and a display.
Using feedback means, the temperature in the combustion zone of the main chamber 104 can be measured and supported at its maximum value, to provide decomposition and burning of all organic fuel components by controlling the coefficient of the air excess and fuel consumption via the main combustion fuel source. For this purpose, in some examples, to support the maximum temperature the coefficient of the air excess can be selected between 1.01 and 1.05. At the outlet 134 of the chamber 104, a gas analyzer can provide measurement of residual contaminant in the product stream and this information can be fed back to a microprocessor control unit 3016. The microprocessor control unit 3016 can provide initial settings of one or more primary parameters. With the feedback from the gas analyzer, general optimization of primary parameters can be achieved.
Referring back to
Using a prototype model of the apparatus 100, the inventors ran a verification test to confirm the results of the mathematical model described above. The test results are provided below in Table 1. The relative low error values indicate reasonable validation of the model.
Applicant's teachings also relate to the use of reagents to refine gaseous streams containing pollutants. Refinement of flue gases can be carried out using a multistage vortex counterflow combustion apparatus, which can be similar to the apparatuses 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000. Thermochemical processes in the chamber(s) are taking place in vortex flows of the mixture of flue gases, water, burning products and/or chemical reagents. Vortex flows can have unique characteristics, can intensify thermochemical processes, and can increase refinement efficiency. Pollutants targeted during the refinement can include sulfur dioxide SO2, nitrogen oxides NOx and/or carbon dioxide CO2. During refinement, solid and gaseous components can be produced. Solid components can be non-toxic and can be recycled. Gaseous components, for example, N2, O2 and water steam, can be emitted into the atmosphere without the need for further processing.
Combustion apparatuses taught herein are appropriate for implementation as a thermochemical reactor for at least the following reasons. High temperatures promote relatively high chemical reaction speeds, since an increase in temperature generally leads to an increase in the kinetic energy and number of collisions of chemical particles. Furthermore, the presence of anisotropic turbulence in a reaction environment can promote more complete mixing of the reagents, which can also lead to an increase in reaction speed. The presence of intense acoustic oscillations can yet also lead to the increase of the chemical reaction speed, because it can produce a mechanical effect on the reagent particles. The reagent particles are stirred intensively and collide with each other, which can lead to the formation of free radicals on the outer surface of the particles.
Various chemical reagents can be used, depending on the composition of the gaseous stream to be refined and which pollutants are desired to be removed by the refinement processes. The following examples are intended to be illustrative but non-limiting.
In a first example, an ammoniac method can be implemented to provide for the simultaneous refinement of flue gases from SO2 and NO2 in the combustion apparatus. This method is relatively simple and can produce finished products that may be recycled. For the reaction, ammonia NH3 or carbamide CO(NH2)2 can be used as chemical reagents. Solid products can include ammonium sulfate (NH4)2.SO4, which is a mineral fertilizer. Gaseous products can include nitrogen N2 and water steam H2O. The following chemical reactions can take place:
4NH3+3NO2=3.5N2+6H2O−1627.07 kJ/mole (Eq. 9)
CO(NH2)2+H2O═CO2+2NH3+136.08 kJ/mole (Eq. 10)
It is noted that flue gases can contain nitrogen oxides NO and NO2, but NO typically immediately oxidizes to NO2, and therefore only NO2 is considered. Besides the chemical reactions involving the interaction of NH3 with NO2, reactions with sulfur dioxide SO2 may also be taking place in accordance with the following:
2SO2+O2=2SO3−185.9 kJ/mole (Eq. 11)
SO3+H2O═H2SO4−125.2 kJ/mole (Eq. 12)
2NH3+H2SO4═(NH4)2SO4−275.9 kJ/mole (Eq. 13)
In a second example, simultaneous use of two chemical reagents can be implemented for the refining of flue gases from SO2 and NO2 in the combustion apparatus. A first one of the reagents can be NH3 or CO(NH2)2. A second one of the reagents can be powdery sodium bicarbonate, calcium carbonate, calcium oxide or calcium hydroxide, which can be supplied in atomized form into the combustion apparatus.
In a third example, ammonia NH3 can be used as the chemical reagent. The following reaction can take place in the combustion apparatus:
CO2+2NH3═CO(NH2)ONH4−2,552.73 kJ/kg CO2 (Eq. 14)
where CO(NH2)ONH4 is carbamic acidic ammonium, which can become carbamide, is accordance with the following reaction:
CO(NH2)ONH4═CO(NH4)2+H2O+483.3 kJ/kg CO(NH2)2 (Eq. 15)
A refined product stream from the combustion apparatus can then undergo separation procedure to separate solid materials from the gaseous stream.
In a fourth example, carbon, water and calcium oxide CaO can be used as chemical reagents. Chemical reactions in the combustion apparatus can produce calcium carbonate CaCO3, which can be used as a fertilizer. Calcium carbonate CaCO3 can also be used for the refinement of flue gases from sulfur dioxide SO2. The following chemical reactions can take place in the combustion apparatus:
CO2+C=2CO+174.18 kJ/mole or 3,958.64 kJ/kg CO2 (Eq. 16)
CO+H2O+CaO═CaCO3+H2−199.3 kJ/mole or −1.993 kJ/kg CaCO3 (Eq. 17)
In a fifth example, CO2 can be reduced or substantially eliminated from an incoming gaseous stream utilizing the combustion apparatuses as described herein, with which the following sequence of reactions can be performed:
CO2+3H2(Copper and Aluminum Catalyst)→CH3OH+H2O (Eq. 18)
2CH3OH→C2H6O+H2O (Eq. 19)
C4H8O2+CH3OH(H2SO4 as a catalyst)→C3H6O2+C2H5OH (Eq. 20)
Equations 18 and 19 can take place in the main chamber, whereas Equation 20 can take place in an additional reaction chamber. One or more separators and/or chemical storage mechanisms can also be installed downstream from the additional reaction chamber.
Combustion apparatuses can be tailored for the refinement of various pollutants from gaseous streams and for the introduction of various reagents, and are based on vortex counterflow combustion apparatuses, which can complete thermochemical processes required for the refinement of gaseous streams with generally high quality, high speed and high efficiency.
Referring particularly to
Referring particularly to
Referring particularly to
The thermochemical parameters of temperature, static pressure, ingredients, and the flow structure (temperature fields, pressures and speeds) can influence the speed of chemical reactions in the apparatus 1100, and the refinement of the input stream 1112. Furthermore, concentrations of the chemical reagents and their distribution among the chambers 1102, 1104, 1106 can influence the speed of chemical reactions in the apparatus 1100. Supply or introduction of the one or more reagents to the chambers 1102, 1104, 1106 can be selectively controlled by the sources 1184, 1186, 1190, respectively. Concentrations of chemical reagents and their distribution among the chambers 1102, 1104, 1106 can be controlled to enable complete or near complete reactions.
Different chemical reagents can be supplied into the apparatus 1100, depending on the components to be refined. Furthermore, the reagent supplied to source 1184 need not be the same chemical compound as that supplied at source 1186, and nor does the reagent supplied to source 1186 need not be the same chemical compound supplied at source 1190. In some examples, it may be desirable to introduce reagents at sources 1184, 1186, but not at source 1190. Various configurations are possible and within the scope of the applicant's teachings herein.
The apparatus 1200 includes an injection nozzle 1296 for supplying or introducing a gaseous stream to be refined into the main chamber 1204. In some examples, the gaseous stream can be formed upstream of the injection nozzle 1296 by the mixture of flue gases along with fuel and/or oxidant. The injection nozzle 1296 is positioned at the first end 1236 generally at a central apex point of the spherical end surface 1282. The apparatus 1200 does not include a primary chamber.
Referring particularly to
The apparatus 1200 can be implemented in situations where the flow rate of gaseous stream to be refined is relatively high, and also either the temperature of the gaseous stream to be refined is high enough for the desired reactions or the reactions can occur at relatively low temperature, so heating is not required and thus no primary chamber is necessary. One limitation to the design of the apparatus 1200 is that relatively high stress can be put on the injection nozzle 1296 to provide the required pressure of gaseous stream being introduced to the main chamber 1204. Another limitation to the design of the apparatus 1200 is that there is no second injection zone and thus there is one less source for supplying reagents.
A gaseous stream to be refined is introduced to the first injection zone 1348 via inlet or source 1312. An ignition source or igniter 1354 is provided within the inlet 1312 to ignite the incoming stream as it is being tangentially supplied to the first injection zone 1348. Like apparatus 1200, apparatus 1300 does not include a primary chamber.
Referring particularly to
The apparatus 1300 can also be implemented in situations where the flow rate of gaseous stream to be refined is relatively high, and also either the temperature of the gaseous stream to be refined is high enough for the desired reactions or the reactions can occur at relatively low temperature, so heating is not required and thus no primary chamber is necessary.
While the applicant's teachings are described in conjunction with various embodiments, it is not intended that the applicant's teachings be limited to such embodiments. The applicant's teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art.
This application claims the benefit of U.S. Provisional Application No. 61/118,300 filed Nov. 26, 2008, which is hereby incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA09/01717 | 11/26/2009 | WO | 00 | 5/26/2011 |
Number | Date | Country | |
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61118300 | Nov 2008 | US |