EP3943815A1 - Liquid-fuel multistage burner - Google Patents

Liquid-fuel multistage burner Download PDF

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Publication number
EP3943815A1
EP3943815A1 EP21187540.6A EP21187540A EP3943815A1 EP 3943815 A1 EP3943815 A1 EP 3943815A1 EP 21187540 A EP21187540 A EP 21187540A EP 3943815 A1 EP3943815 A1 EP 3943815A1
Authority
EP
European Patent Office
Prior art keywords
liquid
fuel
pumping device
feeding
atomizing nozzle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP21187540.6A
Other languages
German (de)
French (fr)
Inventor
Michele Bedoni
Flavio Comencini
Simone MARCHIORI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Riello SpA
Original Assignee
Riello SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Riello SpA filed Critical Riello SpA
Publication of EP3943815A1 publication Critical patent/EP3943815A1/en
Pending legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D11/00—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
    • F23D11/24—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space by pressurisation of the fuel before a nozzle through which it is sprayed by a substantial pressure reduction into a space
    • F23D11/26—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space by pressurisation of the fuel before a nozzle through which it is sprayed by a substantial pressure reduction into a space with provision for varying the rate at which the fuel is sprayed
    • F23D11/28—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space by pressurisation of the fuel before a nozzle through which it is sprayed by a substantial pressure reduction into a space with provision for varying the rate at which the fuel is sprayed with flow-back of fuel at the burner, e.g. using by-pass
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D11/00—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
    • F23D11/24—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space by pressurisation of the fuel before a nozzle through which it is sprayed by a substantial pressure reduction into a space
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
    • F23K5/00—Feeding or distributing other fuel to combustion apparatus
    • F23K5/02—Liquid fuel
    • F23K5/14—Details thereof
    • F23K5/142—Fuel pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
    • F23K5/00—Feeding or distributing other fuel to combustion apparatus
    • F23K5/02—Liquid fuel
    • F23K5/14—Details thereof
    • F23K5/142—Fuel pumps
    • F23K5/145—Fuel pumps combined with fans
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
    • F23K5/00—Feeding or distributing other fuel to combustion apparatus
    • F23K5/02—Liquid fuel
    • F23K5/14—Details thereof
    • F23K5/147—Valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
    • F23K2300/00—Pretreatment and supply of liquid fuel
    • F23K2300/20—Supply line arrangements
    • F23K2300/201—Pumps

Definitions

  • the invention relates to a liquid-fuel multistage burner.
  • the invention relates to a liquid-fuel multistage burner of the type comprising a combustion head; a hydraulic circuit to feed liquid fuel to the combustion head; and a first pneumatic circuit to feed oxidizing air to the combustion head.
  • the hydraulic circuit comprises an atomizing nozzle projecting into the combustion head; a pumping device to feed liquid fuel from a containing tank to the atomizing nozzle; and an electrically operated flow rate adjuster, which is mounted between the pumping device and the atomizing nozzle so as to selectively control the liquid fuel flow rate fed to the atomizing nozzle and, hence, the heat power of the burner.
  • the burner further comprises a second pneumatic circuit to feed a flow of air under pressure, which is suited to atomize the liquid fuel, to the atomizing nozzle.
  • the first pneumatic circuit generally comprises a motor-driven impeller connected to the combustion head and the second pneumatic circuit comprises a compressor connected to the atomizing nozzle.
  • the object of the invention is to provide a liquid-fuel multistage burner, which does not suffer from the drawbacks described above and can be manufactured in a simple and economic fashion.
  • number 1 indicates, as a whole, a liquid-fuel multistage burner.
  • the burner 1 comprises a combustion head 2; a hydraulic circuit 3 to feed liquid fuel to the head 2; and a pneumatic circuit 4 to feed oxidizing air to the head 2.
  • the hydraulic circuit 3 comprises an atomizing nozzle 5, which is mounted inside the head 2, and a first pumping device 6, specifically a gear pump, to feed liquid fuel from a containing tank (which is not shown) to the nozzle 5.
  • the device 6 is connected to an output shaft 7 of an operating motor 8, specifically a brushless electric motor, whose operation is selectively controlled by an electronic control unit 9 of the burner 1.
  • the hydraulic circuit 3 further comprises two feeding branches 10, 11, which are arranged in parallel to one another between the device 6 and the nozzle 5 and are connected to one another downstream of the device 6 and upstream of the nozzle 5.
  • the branch 10 is provided with a check valve 12, which is mounted along the branch 10 and comprises a valve body 13, a ball shutter 14 and a spring 15, which is interposed between the valve body 13 and the shutter 14 so as to move the shutter 14 to - and normally hold it in - a closing position to close the valve 12.
  • a check valve 12 which is mounted along the branch 10 and comprises a valve body 13, a ball shutter 14 and a spring 15, which is interposed between the valve body 13 and the shutter 14 so as to move the shutter 14 to - and normally hold it in - a closing position to close the valve 12.
  • the branch 11 is provided with a second pumping device 16, which is mounted along the branch 11, is connected to the unit 9 and comprises a pump body 17 and an electrically operated piston 18, which is engaged in the pump body 17 in a sliding manner.
  • the pneumatic circuit 4 comprises an impeller 19, which is coupled to the shaft 7 of the motor 8 in angularly fixed manner and is pneumatically connected to the head 2.
  • the operation of the motor 8 is controlled by the unit 9 so as to allow the pumping device 6 to feed, along the branch 10, liquid fuel at a feeding pressure that is such as to:
  • the branches 10, 11 are connected to one another upstream of the nozzle 5, the liquid fuel fed by the pumping device 16 to the nozzle 5 and, hence, to the valve 12 cooperates with the spring 15 in order to move the shutter 14 to its closing position.
  • the liquid fuel fed to the nozzle 5 has a feeding pressure which is substantially the same as the delivery pressure of the pumping device 16 and greater than the delivery pressure of the pumping device 6 and is such as to ensure:
  • the burner 1 leads to some advantages that are mainly due to the fact that:
  • the two branches 10, 11 are arranged in parallel between the pumping device 6 and the nozzle 5, are not connected to one another upstream of the nozzle 5 and are provided with respective electrically operated pumping devices, which are configured to feed liquid fuel to the nozzle 5 with different feeding pressures.

Abstract

A liquid-fuel multistage burner has a combustion head (2) provided with an atomizing nozzle (5), a pneumatic circuit (4) to feed oxidizing air to the combustion head (2), a pumping device (6) to feed liquid fuel from a containing tank to the atomizing nozzle (5), and two feeding branches (10, 11), which are arranged in parallel to one another between the pumping device (6) and the atomizing nozzle (5) so as to feed liquid fuel to the atomizing nozzle (5) with respective feeding pressures, which are different from one another.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • This patent application claims priority from Italian patent application no. 102020000017968 filed on 24/07/2020 .
    • TECHNICAL FIELD
  • The invention relates to a liquid-fuel multistage burner.
    • BACKGROUND ART
  • In particular, the invention relates to a liquid-fuel multistage burner of the type comprising a combustion head; a hydraulic circuit to feed liquid fuel to the combustion head; and a first pneumatic circuit to feed oxidizing air to the combustion head.
  • The hydraulic circuit comprises an atomizing nozzle projecting into the combustion head; a pumping device to feed liquid fuel from a containing tank to the atomizing nozzle; and an electrically operated flow rate adjuster, which is mounted between the pumping device and the atomizing nozzle so as to selectively control the liquid fuel flow rate fed to the atomizing nozzle and, hence, the heat power of the burner.
  • The burner further comprises a second pneumatic circuit to feed a flow of air under pressure, which is suited to atomize the liquid fuel, to the atomizing nozzle.
  • The first pneumatic circuit generally comprises a motor-driven impeller connected to the combustion head and the second pneumatic circuit comprises a compressor connected to the atomizing nozzle.
  • Known liquid-fuel multistage burners of the type described above are affected by some drawbacks, which are mainly due to the fact that the electrically operated flow rate adjuster always has to be supplied with power for any heat power of the burner, in order to ensure the supply of liquid fuel to the atomizing nozzle.
  • Furthermore, the presence of the two pneumatic circuits and, hence, of the impeller, of the compressor and of the relative operating motors makes known liquid-fuel multistage burners of the type described above relatively complex and expensive.
    • DISCLOSURE OF INVENTION
  • The object of the invention is to provide a liquid-fuel multistage burner, which does not suffer from the drawbacks described above and can be manufactured in a simple and economic fashion.
  • According to the invention, there is provided a liquid-fuel multistage burner as claimed in the appended claims.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • The invention will now be described with reference to the accompanying figure, which schematically shows a nonlimiting embodiment thereof.
    • BEST MODE FOR CARRYING OUT THE INVENTION
  • With reference to the accompanying figure, number 1 indicates, as a whole, a liquid-fuel multistage burner.
  • The burner 1 comprises a combustion head 2; a hydraulic circuit 3 to feed liquid fuel to the head 2; and a pneumatic circuit 4 to feed oxidizing air to the head 2.
  • The hydraulic circuit 3 comprises an atomizing nozzle 5, which is mounted inside the head 2, and a first pumping device 6, specifically a gear pump, to feed liquid fuel from a containing tank (which is not shown) to the nozzle 5.
  • The device 6 is connected to an output shaft 7 of an operating motor 8, specifically a brushless electric motor, whose operation is selectively controlled by an electronic control unit 9 of the burner 1.
  • The hydraulic circuit 3 further comprises two feeding branches 10, 11, which are arranged in parallel to one another between the device 6 and the nozzle 5 and are connected to one another downstream of the device 6 and upstream of the nozzle 5.
  • The branch 10 is provided with a check valve 12, which is mounted along the branch 10 and comprises a valve body 13, a ball shutter 14 and a spring 15, which is interposed between the valve body 13 and the shutter 14 so as to move the shutter 14 to - and normally hold it in - a closing position to close the valve 12.
  • The branch 11 is provided with a second pumping device 16, which is mounted along the branch 11, is connected to the unit 9 and comprises a pump body 17 and an electrically operated piston 18, which is engaged in the pump body 17 in a sliding manner.
  • The pneumatic circuit 4 comprises an impeller 19, which is coupled to the shaft 7 of the motor 8 in angularly fixed manner and is pneumatically connected to the head 2.
  • According to a first operating mode corresponding to a first heat power of the burner 1:
    • the pumping device 16 is not activated so as to prevent liquid fuel from flowing along the branch 11; and
    • the motor 8 is activated by the unit 9 with a first rotation speed so as to allow the pumping device 6 and the impeller 19 to supply the nozzle 5 and the combustion head 2, respectively, with a liquid fuel flow rate and with an oxidizing air flow rate, respectively, which are such as to ensure a correct combustion of the liquid fuel as well as the delivery of the first heat power of the burner 1.
  • With regard to what discussed above, it should be pointed out that the operation of the motor 8 is controlled by the unit 9 so as to allow the pumping device 6 to feed, along the branch 10, liquid fuel at a feeding pressure that is such as to:
    • exert upon the shutter 14 a thrust that, in any case, is greater than the thrust exerted upon the shutter 14 by the spring 15, thus moving the shutter 14 to an opening position to open the valve 12; and
    • ensure the atomization of the liquid fuel flowing out of the nozzle 5.
  • In a second operating mode corresponding to a second heat power of the burner 1, which is greater than the first heat power:
    • the motor 8 is activated by the unit 9 with a second rotation speed, which is higher than the first rotation speed, so as to allow the pumping device 6 and the impeller 19 to supply the nozzle 5 and the combustion head 2, respectively, with a liquid fuel flow rate and with an oxidizing air flow rate, respectively, which are such as to ensure a correct combustion of the liquid fuel as well as the delivery of the second heat power of the burner 1; and
    • the pumping device 16 is activated by the unit 9 so as to supply the nozzle 5 with liquid fuel at a feeding pressure which is greater than the feeding pressure of the pumping device 6.
  • Since the branches 10, 11 are connected to one another upstream of the nozzle 5, the liquid fuel fed by the pumping device 16 to the nozzle 5 and, hence, to the valve 12 cooperates with the spring 15 in order to move the shutter 14 to its closing position.
  • As a consequence, the liquid fuel fed to the nozzle 5 has a feeding pressure which is substantially the same as the delivery pressure of the pumping device 16 and greater than the delivery pressure of the pumping device 6 and is such as to ensure:
    • the correct atomization of the liquid fuel flowing out of the nozzle 5; and
    • the correct delivery of the second heat power.
  • The burner 1 leads to some advantages that are mainly due to the fact that:
    • the pumping device 16 is supplied with power only when the second heat power of the burner 1 is requested; and
    • the connection of the branches 10, 11 upstream of the nozzle 5 allows the check valve 12 to be used, namely a relatively simple and economic mechanical valve, which is configured to close due to the thrust of the liquid fuel fed by the pumping device 16.
  • According to a variant which is not shown herein, the two branches 10, 11 are arranged in parallel between the pumping device 6 and the nozzle 5, are not connected to one another upstream of the nozzle 5 and are provided with respective electrically operated pumping devices, which are configured to feed liquid fuel to the nozzle 5 with different feeding pressures.

Claims (10)

  1. A liquid-fuel multistage burner comprising a combustion head (2); a hydraulic circuit (3) to feed liquid fuel to the combustion head (2); and a pneumatic circuit (4) to feed oxidizing air to the combustion head (2); the hydraulic circuit (3) comprising an atomizing nozzle (5) projecting into the combustion head (2) and a first pumping device (6) to feed liquid fuel from a containing tank to the atomizing nozzle (5); and characterized in that the hydraulic circuit (3) further comprises two feeding branches (10, 11), which are arranged in parallel to one another between the first pumping device (6) and the atomizing nozzle (5) and are configured to feed liquid fuel to the atomizing nozzle (5) with respective feeding pressures, which are different from one another.
  2. A liquid-fuel multistage burner according to claim 1, wherein the hydraulic circuit (3) comprises, for each feeding branch (10, 11), a respective control device to selectively control the feeding of liquid fuel along the feeding branch (10, 11).
  3. A liquid-fuel multistage burner according to claim 1 or 2, wherein the hydraulic circuit (3) further comprises a valve device (12), which is mounted along a first feeding branch (10), and a pressure adjusting device (16), which is mounted along a second feeding branch (11).
  4. A liquid-fuel multistage burner according to claim 3, wherein the two feeding branches (10, 11) are connected to one another downstream of the valve device (12) and of the pressure adjusting device (16) and upstream of the atomizing nozzle (5).
  5. A liquid-fuel multistage burner according to claim 3 and 4, wherein the pressure adjusting device (16) comprises a second pumping device (16), which is mounted along the second feeding branch (11) so as to feed liquid fuel to the atomizing nozzle (5) with a feeding pressure which is greater than a feeding pressure of the first pumping device (6).
  6. A liquid-fuel multistage burner according to any one of the claims from 3 to 5, wherein the valve device (12) comprises a check valve, which is mounted so as to open due to the thrust of the liquid fuel fed along the first feeding branch (10) by the first pumping device (6).
  7. A liquid-fuel multistage burner according to claim 6, when it depends on claim 5, wherein the two feeding branches (10, 11) are connected to one another downstream of the check valve and of the second pumping device (16) and upstream of the atomizing nozzle (5) so as to allow the liquid fuel fed by the second pumping device (16) to close the check valve.
  8. A liquid-fuel multistage burner according to any one of the preceding claims, wherein the pneumatic circuit (4) comprises an impeller (19) to generate an oxidizing air flow.
  9. A liquid-fuel multistage burner according to claim 8 and further comprising one single operating motor (8) to control the operation of the impeller (19) and of the first pumping device (6).
  10. A liquid-fuel multistage burner according to claim 8 or 9, when they depend on claim 5, and further comprising an electronic control unit (9) to selectively control the operation of the impeller (19), of the first pumping device (6) and of the second pumping device (16).
EP21187540.6A 2020-07-24 2021-07-23 Liquid-fuel multistage burner Pending EP3943815A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT102020000017968A IT202000017968A1 (en) 2020-07-24 2020-07-24 MULTISTAGE LIQUID FUEL BURNER

Publications (1)

Publication Number Publication Date
EP3943815A1 true EP3943815A1 (en) 2022-01-26

Family

ID=72709742

Family Applications (1)

Application Number Title Priority Date Filing Date
EP21187540.6A Pending EP3943815A1 (en) 2020-07-24 2021-07-23 Liquid-fuel multistage burner

Country Status (2)

Country Link
EP (1) EP3943815A1 (en)
IT (1) IT202000017968A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1096237A (en) * 1953-11-04 1955-06-16 Improvements to mechanical spray burners used for heating industrial fireplaces with high calorific inertia
DE2418886A1 (en) * 1974-04-19 1975-10-30 Allweiler Ag Burner operating pump unit - with reserve pump and emergency pressure maintaining device
JP2003065532A (en) * 2001-08-27 2003-03-05 Noritz Corp Fuel spraying combustion apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1096237A (en) * 1953-11-04 1955-06-16 Improvements to mechanical spray burners used for heating industrial fireplaces with high calorific inertia
DE2418886A1 (en) * 1974-04-19 1975-10-30 Allweiler Ag Burner operating pump unit - with reserve pump and emergency pressure maintaining device
JP2003065532A (en) * 2001-08-27 2003-03-05 Noritz Corp Fuel spraying combustion apparatus

Also Published As

Publication number Publication date
IT202000017968A1 (en) 2022-01-24

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