Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/46—Details, e.g. noise reduction means
  • F23D14/62—Mixing devices; Mixing tubes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/02—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone
  • F23D14/04—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone induction type, e.g. Bunsen burner
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/46—Details, e.g. noise reduction means
  • F23D14/60—Devices for simultaneous control of gas and combustion air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
  • F23L3/00—Arrangements of valves or dampers before the fire
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N1/00—Regulating fuel supply
  • F23N1/02—Regulating fuel supply conjointly with air supply
  • F23N1/027—Regulating fuel supply conjointly with air supply using mechanical means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2203/00—Gaseous fuel burners
  • F23D2203/007—Mixing tubes, air supply regulation

Definitions

• the present invention relates to premix gas burners and to the mixing devices of said burners.
• the fuel used is generally natural gas, butane or propane. Said fuel is mixed with a oxidizing gas, generally air, and by means of a spark the flame is ignited.
• Premix gas burners are fed by a homogeneous mixture of a combustion gas and a combustible gas. This mixture is produced upstream of the means that generate the spark necessary to ignite the flame.
• This type of burner usually comprises a chamber or a mixing device where said oxidizing gas and said combustible gas are mixed before going to the exit point, that is to the point of ignition where the flame is produced.
• US20110139045A1 describes a premix gas burner comprising a mixing device.
• Said mixing device comprises a main body comprising an air intake duct (oxidizing gas) and an intake duct for a combustible gas.
• the main body comprises a main channel, arranged next to the combustion gas inlet duct, which in a strangulated area is divided into two channels.
• Each channel is connected to the gas inlet duct fuel through a fuel gas distribution channel, therefore, the fuel gas is sucked and mixed with the air passing through said strangled zone in both channels.
• One of the channels comprises an opening and closing element to regulate the flow of the mixture.
• the object of the invention is to provide a mixing device for a gas burner, as defined in the claims.
• the mixing device of the invention comprises a main body comprising a combustion gas inlet conduit, preferably air, and a combustible gas inlet conduit.
• the main body also comprises a main channel that is communicated with the combustion gas inlet duct so that a narrowing of the flow of the combustion gas occurs as it is forced to circulate through said main channel.
• the main channel is connected to the fuel gas inlet duct through a fuel gas distribution channel, the mixture of the fuel gas and the oxidizing gas in said main channel being propitiated.
• the main body also comprises an auxiliary channel communicated with the combustion gas inlet conduit, said auxiliary channel being arranged in the contour of the main channel, and an additional distribution channel communicated with the fuel gas inlet conduit, said channel being arranged of additional distribution close to the auxiliary channel.
• the mixing device also comprises a flexible membrane that is fixed to the main body and that in a rest position rests on the auxiliary channel and the additional distribution channel by sealing both channels.
• the membrane is configured to move by the action of the flow of the oxidizing gas that arrives through the combustion inlet duct when said flow exceeds a certain threshold, allowing the passage of combustion gas through the auxiliary channel and the passage of combustible gas to through the additional distribution channel.
• the mixing device of the invention it is possible to regulate the flow rate of the mixture of combustion gas and combustible gas of the gas burner of the invention to vary the power of the burner in a simple, reliable and economical way.
• the membrane thanks to the membrane the opening of the auxiliary channel, to allow the passage of the oxidizing gas, and of the additional distribution channel, to allow the passage of combustible gas, is gradual, which also allows a gradual variation of the pneumatic signal which controls the valve that manages the passage of fuel gas into the distribution channel and the additional fuel gas distribution channel.
• the regulation of the amount of combustible gas necessary to ensure a homogeneous mixture based on the input of the amount of oxidizing gas is carried out in an exact and precise manner, thereby achieving that the CO2 emission curve keep constant throughout the modulation range (regulation), avoiding the peaks that would be generated in case of a sharp opening of rigid opening and closing means.
• the mixing device by dispensing with dynamic mechanical elements, is more robust and reliable, since it does not need any maintenance.
• Figure 1 shows a perspective view of the mixing device according to an embodiment of the invention.
• Figure 2 shows a plan view of the mixing device of Figure 1.
• Figure 3 shows another perspective view of the mixing device of Figure 1 but with a sectioned portion.
• Figure 4 shows a sectional view of the mixing device of Figure 1.
• Figure 5 shows the membrane of the mixing device of Figure 1.
• Figure 6 shows a detail of the mixing device of Figure 1.
• Figure 7 shows a second embodiment of the membrane of the mixing device according to the invention.
• Figure 8A shows a third embodiment of the membrane of the mixing device according to the invention.
• Figure 8B shows the rear view of the membrane of Figure 8A.
• Figure 9 shows a fourth embodiment of the membrane of the mixing device according to the invention.
• Figure 1 shows the mixing device 1 according to a preferred embodiment of the invention.
• the mixing device 1 comprises a main body 1a comprising an inlet duct 2 for a combustion gas, preferably air, and an inlet duct 3 for a combustible gas.
• the main body 1 a also comprises a main channel 4 which is communicated with the inlet duct 2 of the oxidizing gas so that a narrowing of the flow of the oxidizing gas occurs when being forced to circulate through said main channel 4.
• the main channel 4 it is communicated with the inlet conduit 3 of the fuel gas, as shown in figure 3, through a fuel gas distribution channel 3.1, the mixture of the fuel gas and the oxidizing gas in said main channel 4.
• Main channel 4 in the preferred embodiment of the invention is circular, as shown in the drawings, but other shapes are not ruled out.
• the main body 1a also comprises an auxiliary channel 5 communicated with the inlet duct 2 of the oxidizing gas, said auxiliary channel 5 being arranged in the contour of the main channel 4, and an additional distribution channel 3.2 communicated with the inlet conduit 3 of the fuel gas, said additional distribution channel 3.2 being arranged near the auxiliary channel 5.
• the mixing device 1 also comprises a flexible membrane 6, at least a portion of said membrane 6 being fixed to the main body 1a, which in a rest position it rests on the auxiliary channel 5 and the additional distribution channel 3.2 by blocking both channels 5 and 3.2.
• the membrane 6 is configured to move by the action of the flow of the oxidizing gas that arrives through the inlet duct 2 of the oxidizer when said flow exceeds a certain threshold value, allowing the passage of combustion gas through the auxiliary channel 5 and the passage of combustible gas through the additional distribution channel 3.2.
• the mixing device 1 of the invention it is possible to regulate the flow rate of the mixture of combustion gas and combustible gas in a simple, reliable and economical manner. Therefore, the regulation of the power of the burner of the invention is also carried out safely and reliably, being possible to achieve a regulation or modulation of power of at least 1 to 10. Also, thanks to the membrane 6 the opening of the Auxiliary channel 5, to allow the passage of the oxidizing gas, and of the additional distribution channel 3.2, to allow the passage of combustible gas, is gradual which also allows a gradual variation of the pneumatic signal commanded by a valve that manages the passage of the fuel gas to distribution channel 3.1 and additional distribution channel 3.2 for combustible gas.
• Said pneumatic signal is the pressure difference between the pressure of the flow of the combustion gas at the inlet of the inlet duct 2 and the flow of the combustion gas for example at the height where it meets the combustible gas in the main channel 4 and / or of the additional distribution channel 3.2.
• the strangled area of the mixing device 1 caused by the main channel 4 and by the additional distribution channel 3.2 decreases as the flow of oxidizing gas increases (as the passage section is increased total of the oxidizing gas), and combustible gas, and therefore also gradually increasing the power of the burner.
• the flexible membrane 6 of the invention which, as the person skilled in the art knows is a small thickness element, is effective even in the case of small variations in the flow of the oxidizing gas, thus allowing the pneumatic signal to be maintained sufficient to command said valve effectively and gradually.
• the regulation of the amount of combustible gas necessary to ensure a homogeneous mixture based on the input of the amount of oxidizing gas is carried out in an exact and precise manner, thereby achieving that the CO2 emission curve remain constant throughout the modulation range (regulation), avoiding the peaks that they would be generated in case of abrupt opening of rigid opening and closing means.
• the mixing device 1 a bypassing dynamic mechanical elements is more robust and reliable, since it does not need any maintenance. In addition, its manufacture and assembly are much easier due mainly to the absence of mechanical parts.
• the main body 1a according to the preferred embodiment of the invention comprises a main opening 10, preferably arranged centered with respect to the axial axis of the main body 1 a, and a main tube 9 disposed in said main opening 10.
• the main tube 9 comprises therein the main channel 4, as can be seen in the drawings (see, for example, figure 3 or 4), causing a throttling that favors the Venturi effect when the oxidizing gas from the inlet duct 2 is forced to pass through said main channel 4 of minor section.
• the main opening 10 comprises the auxiliary channel 5, as can be seen in the drawings (see, for example, figure 2 or 3), also providing a throttle that favors the Venturi effect when the oxidizing gas from the duct input 2 is forced to pass through said auxiliary channel 5 of smaller section if it is open, that is, if it is not obstructed by the membrane 6.
• the main body 1 a according to the preferred embodiment of the invention comprises a perimeter groove 11 arranged close to the main opening 10, as seen in Figures 3 and 4, the additional distribution channel 3.2 comprising said perimeter groove 1 1.
• the perimeter groove 11 surrounds the auxiliary channel 5, said perimeter groove 11 and said auxiliary channel 5 being separated by a separation wall 8, the main opening 10 being contained within the interior of said separation wall 8.
• the perimeter groove 11, the main opening 10 and the main tube 9 are coaxial.
• the main body 1 a comprises at least one support arm 12.1 that joins the main tube 9 with the contour of the main opening 10, the fuel gas distribution channel 3.1 reaching the main channel 4 of the main tube 9 through one of said support arms 12.1, as shown in figures 3 and 4.
• the distribution channel 3.1 is a linear channel of preferably circular section that communicates with the main channel 4 approximately halfway up of said main channel 4.
• the main body 1 a comprises a second support arm 12.1 aligned with the first support arm 12.1, the main tube 9 being arranged between both support arms 12.1.
• the membrane 6 according to the preferred embodiment of the invention comprises a central opening 6.4 to allow the passage of the main tube 9, as shown in Figure 1, the membrane 6 being fixed to said main tube 9 in the preferred embodiment of the invention, as will be detailed later.
• the membrane 6 comprises two wings 6.3, one on each side of the support arms 12.1, said wings 6.3 being supported on said support arms 12.1 so that each wing 6.3 can move, pivoting with respect to the zones fixed to the main body 1a, pushed by the flow of the oxidizer when said flow exceeds a certain threshold value, opening the passage of the auxiliary channel 5 and the additional distribution channel 3.2.
• the membrane 6 returns to the rest position, the wings 6.3 again blocking the auxiliary channel 5 and the additional distribution channel 3.2.
• the wings 6.3 can also be fixed to the support arms 12.1.
• the flow of the oxidizer is regulated by means of ventilation of the gas burner.
• the default gas burner is regulated to work at low power, that is, so that the membrane 6 is in the rest position, feeding the burner head only with the combustion gas / fuel mixture from the main channel 4.
• the wings 6.3 will be raised by opening the auxiliary channel 5 and the additional distribution channel 3.2, thus increasing the flow of the oxidizing gas / fuel mixture.
• the wings 6.3 will open more or less depending on the flow of the oxidizer, that is, depending on the power of the ventilation means.
• the opening of the wings 6.3 of the membrane 6 is gradual, it is also possible to gradually regulate the valve that manages the passage of the combustible gas, as already explained above. Therefore, the regulation of the amount of combustible gas necessary to ensure a homogeneous mixture based on the input of the amount of oxidizing gas is carried out in an exact and precise manner, whereby the emission curve of C0 is achieved 2 remain constant throughout the modulation range (regulation), avoiding the peaks that would be generated in case of abrupt opening of rigid opening and closing means.
• the combustion gas and the combustible gas pass to an outlet duct 13 comprised in the main body 1 a and then disposed of the main channel 4, the auxiliary channel 5 and the additional distribution channel 3.2.
• Said outlet duct 13 is connected to a distributor, not shown in the drawings, which helps distribute and direct said mixture to the burner head so that the corresponding flame is produced in the presence of a spark.
• the membrane 6, also comprises a support face 6.1, arranged on the back of the membrane 6, which comprises a flat surface that in the rest position rests on the auxiliary channel 5 and the additional distribution 3.2 plugging both channels 5 and 3.2, and an outer face 6.2, disposed on the obverse of the membrane 6, comprising at least one reinforcing rib 7 protruding from said outer face 6.2, as shown for example in Figure 1
• the support face 6.1 of the membrane 6 in the rest position rests on the outer surface of the support arms 12.1, the outer surface of the separation wall 8, and a third support surface 12.3 extending radially from the additional distribution channel 3.2, preferably being the membrane 6 fixed to the main body 1 around the main tube 9 and the support arms 12.1.
• the outer surfaces of the support arms 12.1 and the separation wall 8 and said third support surface 12.3 are at the same level.
• the support face 6.1 of the membrane 6 can comprise a perimeter lip, preferably arranged next to the flat face to favor the sealing of the auxiliary channel 5 and the additional distribution channel 3.2.
• Said perimeter lip may be supported, for example, on the third bearing surface 12.3 when the membrane 6 is in the rest position.
• the membrane 6 according to the preferred embodiment of the invention comprises a plurality of radial reinforcement ribs 7, as can be seen in Figure 1.
• the membrane 6 can also comprise at least one diametral reinforcement rib 7 ', which may be said reinforcement rib 7 'divided into several portions.
• the reinforcing ribs 7 and 7 prevent the wings 6.3 from oscillating, that is to say that they have a reciprocating movement, when said wings 6.3 are moved away from the resting position pushed by the flow of the oxidizing gas.
• the wings 6.3 are symmetrical, in this way the forces necessary to move said wings 6.3 from the resting position are balanced, whereby the wings 6.3 will move simultaneously.
• FIG. 7 A second embodiment of the membrane 6 is shown in Fig. 7.
• This membrane 6 also comprises two wings 6.3 and all the features described above, but unlike the membrane 6 of the first embodiment, said wings 6.3 are contained in a flange 6.5 perimeter, said flange 6.5 supported and additionally fixed on the third support surface 12.3 of the main body 1 a. This configuration allows a greater fixation of the membrane 6 to the main body 1 a.
• the membrane 6 is cup-shaped, as shown in Figures 8A and 8B.
• the outer circumferential wall 6.6 of said bowl and / or the upper flange 6.7 is fixed to the main body 1 a, preferably to the inner wall of the outlet duct 13.
• the membrane 6 of this embodiment preferably comprises four wings 6.3 arranged in the base of the bowl that opens and closes from the main tube 9, depending on the flow of oxidizing gas that arrives through the inlet duct 2, as already explained above.
• the partition of these four wings 6.3 forms a cross, said cross being preferably arranged so that it does not coincide with the support arms 12.1 of the main body 1a, that is to say so that neither side of the cross coincides or is aligned with the support arms 12.1.
• the bowl-shaped membrane 6 may comprise a diametral reinforcing rib 7 'arranged near the main tube 9, that is to say near the edge of the central opening 6.4 of the membrane 6 itself, which is divided into several portions, preferably a for each wing 6.3, as shown in Figure 9, which shows a fourth embodiment of the membrane 6.
• this membrane 6 can also comprise more diametric and / or radial reinforcement ribs 7 ’.
• the wings 6.3 are also symmetrical so that the forces necessary to move said wings 6.3 away from the resting position are also balanced so that they move simultaneously.
• the membrane 6 (according to any of the described embodiments) is fixed to the main body 1a by overmolding, thus obtaining a compact and robust mixing device 1 with a simple and economical design.
• the junction zones between the membrane 6 and the main body 1 a correspond to the fixing zones described for each embodiment.
• the membrane 6 of the invention can also be fixed to the main body 1a, in the fixing areas described for each embodiment, by ultrasound, by welding or by the application of an adhesive.
• part of the main body 1a could be deformed to trap at least a portion of the membrane 6, once the membrane 6 has been arranged in the final position, trapping at least a portion of the membrane 6.
• the main tube of the main body 1a is deformed by trapping the edge of the central opening 6.4 of the membrane 6.
• the main tube 9, comprises a flat face 15 arranged at least on one side cooperating with a corresponding flat face of the membrane 6 arranged in the central opening 6.4, as shown in the figure 7, to ensure the correct placement of the membrane 6 of the invention on the main body 1 a of the mixing device 1.
• the main tube 9 can comprise two flat faces 15 arranged on two opposite sides, each cooperating with a corresponding flat face 15 ’of the membrane 6, arranged facing each other in the central opening 6.4, to facilitate its assembly.
• the membrane 6 of the invention is made of silicone, EPDM or NBR (nitrile butadiene) and the main body 1a of the mixing device 1 is made of rigid plastic, preferably polyamide, or metal.
• the C02 emission curve of the gas burner is kept constant throughout the entire modulation range, that is to say of regulation, avoiding the peaks that would be generated in case of an abrupt opening and closing of the channel auxiliary 5 and additional distribution channel 3.2.
• rigid opening and closing means were used instead of the flexible membrane 6, as in the case of US20110139045A1, said opening, and also the closing, would be immediate, whereby in a relatively short time the variation of the gas fuel and combustion gas before the opening of the additional distribution channel 3.2 and the auxiliary channel 5, and just after the opening would be elevated giving rise to said unwanted peaks.
• the main body 1a of the mixing device 1 comprises fixing means, preferably a plurality of holes 14 arranged diametrically as can be seen, for example, in Figure 1, to allow the mixing device 1 to be attached to the gas burner.
• the combustion gas used in the burner and the mixing device 1 of the invention is air and the combustion gas can be natural gas, butane or propane.
• the invention also relates to a gas burner comprising the mixing device of the invention.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Feeding And Controlling Fuel (AREA)

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Citations (9)

• 2018
  • 2018-01-09 EP EP18382003.4A patent/EP3508788B1/de active Active
  • 2018-12-28 WO PCT/ES2018/070838 patent/WO2019138146A1/es active Application Filing
  • 2018-12-28 CN CN201890001457.6U patent/CN212930063U/zh active Active
  • 2018-12-28 KR KR2020207000040U patent/KR200497783Y1/ko active IP Right Grant

Patent Citations (9)

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