CA1164331A - Control apparatus for burners - Google Patents
Control apparatus for burnersInfo
- Publication number
- CA1164331A CA1164331A CA000373374A CA373374A CA1164331A CA 1164331 A CA1164331 A CA 1164331A CA 000373374 A CA000373374 A CA 000373374A CA 373374 A CA373374 A CA 373374A CA 1164331 A CA1164331 A CA 1164331A
- Authority
- CA
- Canada
- Prior art keywords
- pressure regulator
- air
- control
- gas
- control apparatus
- 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.)
- Expired
Links
Classifications
-
- 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
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2235/00—Valves, nozzles or pumps
- F23N2235/02—Air or combustion gas valves or dampers
- F23N2235/06—Air or combustion gas valves or dampers at the air intake
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2235/00—Valves, nozzles or pumps
- F23N2235/12—Fuel valves
- F23N2235/20—Membrane valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2237/00—Controlling
- F23N2237/16—Controlling secondary air
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Regulation And Control Of Combustion (AREA)
- Feeding And Controlling Fuel (AREA)
Abstract
Abstract of the Disclosure For simultaneously controlling the supply of gas and combustion air to a burner, a servo pressure regulator, controlled by a temperature sensor, is provided which on the one side controls the diaphragm actuator of the gas control valve and on the other side controls a control member in the combustion air supply.
Gas is fed to the burner via a first injector nozzle which simultaneously draws primary combustion air.
In order to heat the burner with the amount of secondary air necessary for achieving optimum combustion, a second injector nozzle is located opposite a secondary air inlet of the burner housing and is supplied with air under pressure from a controllable source of pressurized air in the form of a fan and an air control valve.
Gas is fed to the burner via a first injector nozzle which simultaneously draws primary combustion air.
In order to heat the burner with the amount of secondary air necessary for achieving optimum combustion, a second injector nozzle is located opposite a secondary air inlet of the burner housing and is supplied with air under pressure from a controllable source of pressurized air in the form of a fan and an air control valve.
Description
CONTROL APPARATUS FOR BURNERS
Back~round and Summar~ of the ~nvent on In a gas control apparatus earlier invented by Hendrikus Berkhof, the control pressure of a servo pressure regulator is used on one side for controlling the operator of an air flap. In this way, not only the amount of gas supplied to the burner but simultaneously also the amount of air is controlled in dependence on the demand of heat such that an almost complete combustion is achieved.
It is known that for optimum combustion of lm3 natural gas about lOm3 combustion a.ir are required.
For supplying gas and air to a water heater an injectcr nozzle is used connected to the gas supply pipe such that the gas stream simultaneously draws a corresponding air stream and supplies it to the burner. Even if the - gas supply is changed, the gas/air ratio remains almost constant at 1:6. Therewith, by this kind of primary air suction, only about 60% of the necessary combustion air are supplied to the burner. For this reason, an additional secondary air supply is required for the residual 4P% of combustion air. For this purpose, air suction holes are provided in the housing of the burner :25 with the size of these holes being chosen in accordance with the maximum flow of fuel gas. This, however, means that with reduced supply of gas an essential excess of air is present and the efficiency of the combustion decreases remarkably.
The invention is to achieve with economic means a simultaneous control of the gas supply and the supply of combustion air such that also when the demand of heat changes and therewith the fuel supply changes too, there 3 3 ~L
still will be supplied to the burner the optimum fuel/air ratio. On the other side, it is desired even at high flow of fuel to achieve this aim without expensive and space consuming air supply fans and air control flaps.
The invention makes it possible to supply to the burner permanent-ly the amount of gas and air suitable for optimum combustion by means of a common air control apparatus comprising a servo pressure regulator to which an additional air valve is connected. These control valves have to control relatively small flows of gas and air respectively while the primary air as well as the main portion of the secondary air is fed to the burner by means of the suction effect of the injector nozzles ~Venturi nozzles). A par-ticular advantage consists in the fact that wllen the burner is turned off there is almost no draft in the stack because the housing is closed. There-with the heat contained in the burner chamber does not escape through the stack. This together with the optimum combustion, leads to further saving of energy.
Broadly stated, according to the present invention there is pro-vided control apparatus for the supply of gas and combustion air to the burner of a water-, air-, or space-heater, including a servo pressure regulator and one diaphragm actuator each for a control valve in the gas supply line and for a control member in the air supply line with both dia-phragm actuators being controlled by the control pressure of the same servo pressure regulator, comprising the following features: a) the outlet of the gas control valve is connected to an injector nozzle located opposite the inlet of the burner with that injector nozzle simultaneously drawing primary air for the burner; b) the burner and a heat exchanging surface, heated by that burner~ are surrounded by a closed housing which has a secondary air inlet and a stack outlet; c) a second injector nozzle is located opposite the secondary air inlet and in operation draws secondary air into the housing with that injector nozzle being connected to a controllable source of air under pressure, the control input of which is connected to the servo pres-sure regulator.
The invention now will be described with reference to two embodi-ments as shown in the drawings.
Figures 1 and 2 together show an embodiment in which the servo pressure regulator is built upon a gas control apparatus and the additional secondary air valve is connec~ed to the servo pressure regulator by means of a conduit;
Figures 3 and 2 together show a second embodiment in which the servo pressure regulator is built together with the air valve and the gas control apparatus is connected to the pressure regulator by means of a pipe.
-2a-.':
3 3 t Description of Preferred Embodiment and O~eration Thereof ~ . .
The servo pressure regulator in both embodiments has the structure as known from German Patent 26 46 310 or corresponding U.S. Patent 4,182,488, issued January 8, 1980, for Pressure Regulator. However, other kinds of servo pressure regulators might be used as they for instance are described in German published patent applica-tion 29 03 203, or corresponding published British Patent application 8,002,446, filed January 24, 1980, Publication No. 204220A. In all cases, the output control pressure of the pressure regulator is controlled to a value which depends on the temperature measured by a temperature sensor. Normally, this temperature is the water tempera-ture either in the heat e~changer of the water heater or at its outlet.
In the first embodiment Figure 1 shows the gas valve together with the servo pressure regulator and the air control valve with associated fan while in Figure 2 a gas fired boiler is shown as load of the burner as it is for instance used for a central heating system.
The closure member 1 of the main gas valve is spring loaded in closing direction by means of a spring 2 and is lifted from its seat by a diaphragm actuator if the force on diaphragm 4 generated by the control pressure in chamber 3 exceeds the forces acting on the opposite side of the diaphragm and generated by the outlet pressure in outlet 5 supplemented by the force of spring 2.
Actuator chamber 3 receives its control pressure from the outlet chamber 9 of a servo pressure regulator 10 via a channel 6 and a switch-on solenoid valve 7, comprising a ~ . . .
~ 3~33~
closure member 8. The servo pressure regulator 10 is controlled by a tempera~ure sensor 11 as described in detail in German Patent 26 46 310.
With the outlet pressure at outlet 5 decreasing, the pressure in chamber 9 decreases and therewith the pressure in actuator chamber 3 increases.
Therefore~ the diaphragm 4 moves closure member 1 against the force of spring 2 in opening direction. Therewith the gas flow from inlet 12 to outlet 5 is increased. The flame safeguard apparatus shown in the left portion of the gas control apparatus and comprising a switch-on push-button 13, a power unit 14~ a safety valve 15 and a pilot valve 16 is10 generally known and is of no particular interest in connection with the present invention. The inlet pressure is fed to the pr0ssure regulator 10 via channel 17 and a ~hrottle 18 so that behind throttle 18 in space 19 the same control pressure is built up as in chamber 9. Chambers 9 and 19 communicate via switch-on valve 8 which in the shown position is open.
By means of a conduit 20, chamber 19 is connected to the actuator chamber 31 of a second servo pressure controlled air control valve 32.
Also in this case closure member 33 is by means of a rod 34 carried by diaphragm 35 and is biased in closing direction by means of a spring 36.
Inlet 37 of the air control valve is connected to a pressurized air gener-ator shown as a fan 38. The sensor 40 of a flow switch 41 is located in the outlet 39 of the air control valve. The normally open contact of the flow switch 31 is closed by the air stream and is located in the energizing circuit (not shown) of the switch-on solenoid valve 7.
Figure 2 shows as a load a heat exchanger 52 being surrounded by a closed housing 51. The heated water is supplied to one or several radia-tors via outlet 53. A main burner 54 heats the heat exchanger 52 where a pilot burner 55 is connected to the pilot outlet 25 of .. .
the gas control apparatus and a thermo~couple 56 moni-toring the pilot flame is connected to the power uni-t 14 oE ~he ignition safety apparatus. The combustion gases leave housing 31 via stack 57~ Located opposite inlet 5~ of main burner 54 is an injector nozzle 59 or Venturi nozzle through which gas flows into the main burner from out~et 5 of the gas control valve. Because of the suction effect of nozzle 59, the gas stream simul-taneously draws primary air which is fed to the main burner 54 as part of the combustion air. Further, housing 51 has an inlet 60 for secondary air and a second in~ector no~zle 51 is located opposite that inlet 60.
This second nozzle 61 is supplied with air under pressure from air control valve 32 and also draws additional combustion air due to its suction effect. This additional combustion air is supplied into the internal space of housing 51 where it is available for main burner 54 to achieve an almost complete combustion. At the other sides, housing 51 is closed.
The arrangement is chosen such that, with an increasing amount of gas at outlet 5 of the gas control apparatus, the amount of air under pressure supplied through air control valve 32 is increasing too and because of the ejector effect of the two nozzles 59 and 61, the main burner 54 is supplied with sufficient amount o primary and secondary air for obtaining a complete and optimum combustion of the gas volume as supplied. The amount of gas as fed by the gas control valve to nozzle 59 is controlled by means of the servo pressure regulator in in dependance on the temperature which is sensed by a temperature sensor 11. If without a demand for heat solenoid valve 7, ~ swltches to its opposi-te position, and therewith inhibits the connection between chambers 9 ~and 19, it turns out that the connection of air control ~valve 32 to chamber l9 is advantageous as by its separation J I ~.33 1 from chamber 9 when closing valve 8, the closing interval of the main val.ve is not delayed by the additional volume of actuator chamber 31. This ch.amber rather is separated from the volume of chamber 3 so that the pressure in this chamber can be quickl~ vented to the outlet side via channel ~, valve 8 and channel 26~ and the main gas valve 1 closes quic~ly. Since housing 51 with the exception of secondary air inlet 60 and stack 57 iS closed on all of its sides, there is almost no draw in the housing when the gas and secondary air supply are switched off.
Therefore, the heat contained in housing 51 does not escape through stack 57D Inlet opening 60 is essentially smaller than the secondary air slots of common boilers since the main portion of the secondary air is drawn by the suction effect of injector nozzle 51. If this injector effect is cut off, onl~ an insignificant amount of air flows through inlet 60.
~ n Figure 1, a modified embodiment is sho~n by dotted lilles. ~n this embodim~nt, the air control valve 0 32 is omi-tted and instead of this, a pneumatic-electrical c L ~ b~, c ;".~ ~ v i~
transducer ~ is connected to'control air conduit 20.
It is for instance supplied from the AC source and delivers at its output a direct current which in its amplitude is proportional to the pneumatic input signal.
This current is used as driving current for motor 43 of fan 38. In this way, with an increasing gas stream at ou-tlet 5 of the gas control valve, simultaneously the speed of the fan and therewith the amount o~ air supplied by fan 38 is increased which leads to a parallel gas and air volume control. The conversion of the pneumatic input signal of the transducer 32 into an electrical signal controlling the motor speed may be done in T~ell kno~n manner b~ means of phase shift control or pulse duration .~rcontrol .
.35 ~ further embodiment oE the invention provides -that the boiler 51 of Figure 2 is connected to the control ~ i64331 apparatus of Fi~ure 3~ ~n -this embodiment, the servo pressure regulator 10 does not act on the gas control apparatus 27 but on the air control valve 72. Therewi-th the amount of gas is tracking the amount of air supply.
For both embodiments according to Figures 1 and 3, it is valid that any leakage in conduit 20 results in closing the gas ~alve and the air valve so that -the apparatus is fail safeO The embodiment according to Figure 3 further has the advantage that the servo pressure regulator does not work with gas but with air and there:Eore, in case of a leakage, no gas can escape.
Therewith :;t is possible to produce the servo pressure regulator from less expensive material such as plastic.
The same :is true in both embodiments for the air control valve~ A further advantage of the embodiment according to Figure 3 consists in that one can omit the flow switch 40, 41~ III this embodiment, the ~as valve 27 can only open if :Ean 38 operates and therewith an air stream is ~resent~
With respect to the embodiment of Fi~ure 1 it should be noted that, when a demand for heat is no longer present, the gas valve closes immediately while the air control valve 32 first moves into its completely open position and therewith the burner chamber is purged for a 25; while~ Not before the fan ~ terminates operation, the `-~ air supply is switched off. For switchin~ oEf fan 38, a contact is used which closes when solenoid valve 7, 8 is switched off, this contact separates the fan motor from the mains supply. S1D~ 6 ~
An adjustable throttle 73~provided between the air control valve 32 or 72 respectively and the other injector nozzle 61 makes it possible to adjust a desired gas/air ra-tio and therewith a sufficient air surplus for ob~aining vfull combustion. Because of the use of the two injector ~3~5 inozzles 59 and 61; :the s~urce 3~ of pressuxized air has to ~ ~16~331 supply only a relatively small amount of air. Without the in~ector nozzles, about lOm of air had to be supplied by fan 38 Eor burning lm3 natural gas with 20% excess of air. By using the injector nozzles, however, the fan 38 itself only has to supply 0.5m3. A further advantage is that not only changes of the supply pressure in the gas supply are removed, but this also applies to the supply of combustion air.
Back~round and Summar~ of the ~nvent on In a gas control apparatus earlier invented by Hendrikus Berkhof, the control pressure of a servo pressure regulator is used on one side for controlling the operator of an air flap. In this way, not only the amount of gas supplied to the burner but simultaneously also the amount of air is controlled in dependence on the demand of heat such that an almost complete combustion is achieved.
It is known that for optimum combustion of lm3 natural gas about lOm3 combustion a.ir are required.
For supplying gas and air to a water heater an injectcr nozzle is used connected to the gas supply pipe such that the gas stream simultaneously draws a corresponding air stream and supplies it to the burner. Even if the - gas supply is changed, the gas/air ratio remains almost constant at 1:6. Therewith, by this kind of primary air suction, only about 60% of the necessary combustion air are supplied to the burner. For this reason, an additional secondary air supply is required for the residual 4P% of combustion air. For this purpose, air suction holes are provided in the housing of the burner :25 with the size of these holes being chosen in accordance with the maximum flow of fuel gas. This, however, means that with reduced supply of gas an essential excess of air is present and the efficiency of the combustion decreases remarkably.
The invention is to achieve with economic means a simultaneous control of the gas supply and the supply of combustion air such that also when the demand of heat changes and therewith the fuel supply changes too, there 3 3 ~L
still will be supplied to the burner the optimum fuel/air ratio. On the other side, it is desired even at high flow of fuel to achieve this aim without expensive and space consuming air supply fans and air control flaps.
The invention makes it possible to supply to the burner permanent-ly the amount of gas and air suitable for optimum combustion by means of a common air control apparatus comprising a servo pressure regulator to which an additional air valve is connected. These control valves have to control relatively small flows of gas and air respectively while the primary air as well as the main portion of the secondary air is fed to the burner by means of the suction effect of the injector nozzles ~Venturi nozzles). A par-ticular advantage consists in the fact that wllen the burner is turned off there is almost no draft in the stack because the housing is closed. There-with the heat contained in the burner chamber does not escape through the stack. This together with the optimum combustion, leads to further saving of energy.
Broadly stated, according to the present invention there is pro-vided control apparatus for the supply of gas and combustion air to the burner of a water-, air-, or space-heater, including a servo pressure regulator and one diaphragm actuator each for a control valve in the gas supply line and for a control member in the air supply line with both dia-phragm actuators being controlled by the control pressure of the same servo pressure regulator, comprising the following features: a) the outlet of the gas control valve is connected to an injector nozzle located opposite the inlet of the burner with that injector nozzle simultaneously drawing primary air for the burner; b) the burner and a heat exchanging surface, heated by that burner~ are surrounded by a closed housing which has a secondary air inlet and a stack outlet; c) a second injector nozzle is located opposite the secondary air inlet and in operation draws secondary air into the housing with that injector nozzle being connected to a controllable source of air under pressure, the control input of which is connected to the servo pres-sure regulator.
The invention now will be described with reference to two embodi-ments as shown in the drawings.
Figures 1 and 2 together show an embodiment in which the servo pressure regulator is built upon a gas control apparatus and the additional secondary air valve is connec~ed to the servo pressure regulator by means of a conduit;
Figures 3 and 2 together show a second embodiment in which the servo pressure regulator is built together with the air valve and the gas control apparatus is connected to the pressure regulator by means of a pipe.
-2a-.':
3 3 t Description of Preferred Embodiment and O~eration Thereof ~ . .
The servo pressure regulator in both embodiments has the structure as known from German Patent 26 46 310 or corresponding U.S. Patent 4,182,488, issued January 8, 1980, for Pressure Regulator. However, other kinds of servo pressure regulators might be used as they for instance are described in German published patent applica-tion 29 03 203, or corresponding published British Patent application 8,002,446, filed January 24, 1980, Publication No. 204220A. In all cases, the output control pressure of the pressure regulator is controlled to a value which depends on the temperature measured by a temperature sensor. Normally, this temperature is the water tempera-ture either in the heat e~changer of the water heater or at its outlet.
In the first embodiment Figure 1 shows the gas valve together with the servo pressure regulator and the air control valve with associated fan while in Figure 2 a gas fired boiler is shown as load of the burner as it is for instance used for a central heating system.
The closure member 1 of the main gas valve is spring loaded in closing direction by means of a spring 2 and is lifted from its seat by a diaphragm actuator if the force on diaphragm 4 generated by the control pressure in chamber 3 exceeds the forces acting on the opposite side of the diaphragm and generated by the outlet pressure in outlet 5 supplemented by the force of spring 2.
Actuator chamber 3 receives its control pressure from the outlet chamber 9 of a servo pressure regulator 10 via a channel 6 and a switch-on solenoid valve 7, comprising a ~ . . .
~ 3~33~
closure member 8. The servo pressure regulator 10 is controlled by a tempera~ure sensor 11 as described in detail in German Patent 26 46 310.
With the outlet pressure at outlet 5 decreasing, the pressure in chamber 9 decreases and therewith the pressure in actuator chamber 3 increases.
Therefore~ the diaphragm 4 moves closure member 1 against the force of spring 2 in opening direction. Therewith the gas flow from inlet 12 to outlet 5 is increased. The flame safeguard apparatus shown in the left portion of the gas control apparatus and comprising a switch-on push-button 13, a power unit 14~ a safety valve 15 and a pilot valve 16 is10 generally known and is of no particular interest in connection with the present invention. The inlet pressure is fed to the pr0ssure regulator 10 via channel 17 and a ~hrottle 18 so that behind throttle 18 in space 19 the same control pressure is built up as in chamber 9. Chambers 9 and 19 communicate via switch-on valve 8 which in the shown position is open.
By means of a conduit 20, chamber 19 is connected to the actuator chamber 31 of a second servo pressure controlled air control valve 32.
Also in this case closure member 33 is by means of a rod 34 carried by diaphragm 35 and is biased in closing direction by means of a spring 36.
Inlet 37 of the air control valve is connected to a pressurized air gener-ator shown as a fan 38. The sensor 40 of a flow switch 41 is located in the outlet 39 of the air control valve. The normally open contact of the flow switch 31 is closed by the air stream and is located in the energizing circuit (not shown) of the switch-on solenoid valve 7.
Figure 2 shows as a load a heat exchanger 52 being surrounded by a closed housing 51. The heated water is supplied to one or several radia-tors via outlet 53. A main burner 54 heats the heat exchanger 52 where a pilot burner 55 is connected to the pilot outlet 25 of .. .
the gas control apparatus and a thermo~couple 56 moni-toring the pilot flame is connected to the power uni-t 14 oE ~he ignition safety apparatus. The combustion gases leave housing 31 via stack 57~ Located opposite inlet 5~ of main burner 54 is an injector nozzle 59 or Venturi nozzle through which gas flows into the main burner from out~et 5 of the gas control valve. Because of the suction effect of nozzle 59, the gas stream simul-taneously draws primary air which is fed to the main burner 54 as part of the combustion air. Further, housing 51 has an inlet 60 for secondary air and a second in~ector no~zle 51 is located opposite that inlet 60.
This second nozzle 61 is supplied with air under pressure from air control valve 32 and also draws additional combustion air due to its suction effect. This additional combustion air is supplied into the internal space of housing 51 where it is available for main burner 54 to achieve an almost complete combustion. At the other sides, housing 51 is closed.
The arrangement is chosen such that, with an increasing amount of gas at outlet 5 of the gas control apparatus, the amount of air under pressure supplied through air control valve 32 is increasing too and because of the ejector effect of the two nozzles 59 and 61, the main burner 54 is supplied with sufficient amount o primary and secondary air for obtaining a complete and optimum combustion of the gas volume as supplied. The amount of gas as fed by the gas control valve to nozzle 59 is controlled by means of the servo pressure regulator in in dependance on the temperature which is sensed by a temperature sensor 11. If without a demand for heat solenoid valve 7, ~ swltches to its opposi-te position, and therewith inhibits the connection between chambers 9 ~and 19, it turns out that the connection of air control ~valve 32 to chamber l9 is advantageous as by its separation J I ~.33 1 from chamber 9 when closing valve 8, the closing interval of the main val.ve is not delayed by the additional volume of actuator chamber 31. This ch.amber rather is separated from the volume of chamber 3 so that the pressure in this chamber can be quickl~ vented to the outlet side via channel ~, valve 8 and channel 26~ and the main gas valve 1 closes quic~ly. Since housing 51 with the exception of secondary air inlet 60 and stack 57 iS closed on all of its sides, there is almost no draw in the housing when the gas and secondary air supply are switched off.
Therefore, the heat contained in housing 51 does not escape through stack 57D Inlet opening 60 is essentially smaller than the secondary air slots of common boilers since the main portion of the secondary air is drawn by the suction effect of injector nozzle 51. If this injector effect is cut off, onl~ an insignificant amount of air flows through inlet 60.
~ n Figure 1, a modified embodiment is sho~n by dotted lilles. ~n this embodim~nt, the air control valve 0 32 is omi-tted and instead of this, a pneumatic-electrical c L ~ b~, c ;".~ ~ v i~
transducer ~ is connected to'control air conduit 20.
It is for instance supplied from the AC source and delivers at its output a direct current which in its amplitude is proportional to the pneumatic input signal.
This current is used as driving current for motor 43 of fan 38. In this way, with an increasing gas stream at ou-tlet 5 of the gas control valve, simultaneously the speed of the fan and therewith the amount o~ air supplied by fan 38 is increased which leads to a parallel gas and air volume control. The conversion of the pneumatic input signal of the transducer 32 into an electrical signal controlling the motor speed may be done in T~ell kno~n manner b~ means of phase shift control or pulse duration .~rcontrol .
.35 ~ further embodiment oE the invention provides -that the boiler 51 of Figure 2 is connected to the control ~ i64331 apparatus of Fi~ure 3~ ~n -this embodiment, the servo pressure regulator 10 does not act on the gas control apparatus 27 but on the air control valve 72. Therewi-th the amount of gas is tracking the amount of air supply.
For both embodiments according to Figures 1 and 3, it is valid that any leakage in conduit 20 results in closing the gas ~alve and the air valve so that -the apparatus is fail safeO The embodiment according to Figure 3 further has the advantage that the servo pressure regulator does not work with gas but with air and there:Eore, in case of a leakage, no gas can escape.
Therewith :;t is possible to produce the servo pressure regulator from less expensive material such as plastic.
The same :is true in both embodiments for the air control valve~ A further advantage of the embodiment according to Figure 3 consists in that one can omit the flow switch 40, 41~ III this embodiment, the ~as valve 27 can only open if :Ean 38 operates and therewith an air stream is ~resent~
With respect to the embodiment of Fi~ure 1 it should be noted that, when a demand for heat is no longer present, the gas valve closes immediately while the air control valve 32 first moves into its completely open position and therewith the burner chamber is purged for a 25; while~ Not before the fan ~ terminates operation, the `-~ air supply is switched off. For switchin~ oEf fan 38, a contact is used which closes when solenoid valve 7, 8 is switched off, this contact separates the fan motor from the mains supply. S1D~ 6 ~
An adjustable throttle 73~provided between the air control valve 32 or 72 respectively and the other injector nozzle 61 makes it possible to adjust a desired gas/air ra-tio and therewith a sufficient air surplus for ob~aining vfull combustion. Because of the use of the two injector ~3~5 inozzles 59 and 61; :the s~urce 3~ of pressuxized air has to ~ ~16~331 supply only a relatively small amount of air. Without the in~ector nozzles, about lOm of air had to be supplied by fan 38 Eor burning lm3 natural gas with 20% excess of air. By using the injector nozzles, however, the fan 38 itself only has to supply 0.5m3. A further advantage is that not only changes of the supply pressure in the gas supply are removed, but this also applies to the supply of combustion air.
Claims (20)
PROPERTY OR RIGHT IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Control apparatus for the supply of gas and combustion air to the burner of a water-, air-, or space-heater, including a servo pressure regulator and one diaphragm actuator each for a control valve in the gas supply line and for a control member in the air supply line with both diaphragm actuators being controlled by the control pressure of the same servo pressure regulator, comprising the following features:
a) the outlet of the gas control valve is connected to an injector nozzle located opposite the inlet of the burner with that injector nozzle simultaneously drawing primary air for the burner;
b) the burner and a heat exchanging surface, heated by that burner, are surrounded by a closed housing which has a secondary air inlet and a stack outlet;
c) a second injector nozzle is located opposite the secondary air inlet and in operation draws secondary air into the housing with that injector nozzle being connected to a controllable source of air under pressure J the control input of which is connected to the servo pressure regulator.
a) the outlet of the gas control valve is connected to an injector nozzle located opposite the inlet of the burner with that injector nozzle simultaneously drawing primary air for the burner;
b) the burner and a heat exchanging surface, heated by that burner, are surrounded by a closed housing which has a secondary air inlet and a stack outlet;
c) a second injector nozzle is located opposite the secondary air inlet and in operation draws secondary air into the housing with that injector nozzle being connected to a controllable source of air under pressure J the control input of which is connected to the servo pressure regulator.
2. Control apparatus according to claim servo1, wherein a pneumatic/electrical transducer is provided between the servo pressure regulator and the supply circuit for the fan motor.
3. Control apparatus according to claim 1, wherein the controllable source of air under pressure consists of a fan and an air control valve, connected in series with the fan.
4. Control apparatus according to claim 1, wherein the servo pressure regulator is controlled by a temperature sensor, measuring the water temperature in the water heater.
5. Control apparatus according to claim 2, wherein the servo pressure regulator is controlled by a temperature sensor, measuring the water temperature in the water heater.
6. Control apparatus according to claim 3, wherein the servo pressure regulator is controlled by a temperature sensor, measuring the water temperature in the water heater.
7. Control apparatus according to claim 3, wherein the servo pressure regulator is mounted on the housing of the gas control valve and the diaphragm chamber of the air control valve is connected to the servo pressure regulator by means of a control pressure conduit.
8. Control apparatus according to claim 4, wherein the servo pressure regulator is mounted on the housing of the gas control valve and the diaphragm chamber of the air control valve is connected to the servo pressure regulator by means of a control pressure conduit.
9. Control apparatus according to claim 1, wherein the servo pressure regulator is mounted on the housing of the air control valve and the diaphragm chamber of the gas control valve is connected to the servo pressure regulator via a control pressure conduit.
10. Control apparatus according to claim 3, wherein the servo pressure regulator is mounted on the housing of the air control valve and the diaphragm chamber of the gas control valve is connected to the servo pressure regulator via a control pressure conduit.
11. Control apparatus according to claim 4, wherein the servo pressure regulator is mounted on the housing of the air control valve and the diaphragm chamber of the gas control valve is connected to the servo pressure regulator via a control pressure conduit.
12. Control apparatus according to claim 7, wherein the servo pressure regulator is mounted on the housing of the air control valve and the diaphragm chamber of the gas control valve is connected to the servo pressure regulator via a control pressure conduit.
13. Control apparatus according to claim 1, wherein the gas control valve and the air control valve are located in a common housing.
14. Control apparatus according to claim ~, wherein the gas control valve and the air control valve are located in a common housing.
15. Control apparatus according to claim 3, comprising a solenoid valve, switching the gas supply from inlet via a throttle to the pressure regulator on or off and being located between the throttle and the pressure regulator, wherein the second diaphragm actuator is connected to the control pressure conduit between the throttle and the solenoid valve.
16. Control apparatus according to claim 4, comprising a solenoid valve, switching the gas supply from inlet via a throttle to the pressure regulator on or off and being located between the throttle and the pressure regulator, wherein the second diaphragm actuator is connected to the control pressure conduit between the throttle and the solenoid valve.
17. Control apparatus according to claim 7, comprising a solenoid valve, switching the gas supply from inlet via a throttle to the pressure regulator on or off and being located between the throttle and the pressure regulator, wherein the second diaphragm actuator is connected to the control pressure conduit between the throttle and the solenoid valve.
18. Control apparatus according to claim 9, comprising a solenoid valve, switching the gas supply from inlet via a throttle to the pressure regulator on or off and being located between the throttle and the pressure regulator wherein the second diaphragm actuator is connected to the control pressure conduit between the throttle and the solenoid valve.
19. Control apparatus according to claim 13, comprising a solenoid valve, switching the gas supply from inlet via a throttle to the pressure regulator on or off and being located between the throttle and the pressure regulator, wherein the second diaphragm actuator is connected to the control pressure conduit between the throttle and the solenoid valve.
20. Control apparatus according to claim 1, wherein an adjustable throttle is provided between the source of pressurized air and the second injector nozzle.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3044678.7 | 1980-11-27 | ||
| DE19803044678 DE3044678A1 (en) | 1980-11-27 | 1980-11-27 | Control for gas-fired water or air heater - controls supply of both fuel gas and combustion air without delay using temp. sensor, valve and setting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1164331A true CA1164331A (en) | 1984-03-27 |
Family
ID=6117713
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000373374A Expired CA1164331A (en) | 1980-11-27 | 1981-03-19 | Control apparatus for burners |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS5792618A (en) |
| CA (1) | CA1164331A (en) |
| DE (1) | DE3044678A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3339518C2 (en) * | 1982-10-30 | 1995-11-16 | Vaillant Joh Gmbh & Co | Gas heated heat source |
-
1980
- 1980-11-27 DE DE19803044678 patent/DE3044678A1/en not_active Withdrawn
-
1981
- 1981-03-19 CA CA000373374A patent/CA1164331A/en not_active Expired
- 1981-03-20 JP JP56041619A patent/JPS5792618A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5792618A (en) | 1982-06-09 |
| DE3044678A1 (en) | 1982-06-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4688547A (en) | Method for providing variable output gas-fired furnace with a constant temperature rise and efficiency | |
| US4340355A (en) | Furnace control using induced draft blower, exhaust gas flow rate sensing and density compensation | |
| US7523762B2 (en) | Modulating gas valves and systems | |
| US5520533A (en) | Apparatus for modulating the flow of air and fuel to a gas burner | |
| US6971871B2 (en) | Variable low intensity infrared heater | |
| US5735503A (en) | Servo pressure regulator for a gas valve | |
| CA1209898A (en) | Control system for a gas heated water or air heater | |
| US4334855A (en) | Furnace control using induced draft blower and exhaust gas differential pressure sensing | |
| EP0062854A1 (en) | Gas-fired water or air heater | |
| CA1228795A (en) | Fuel gas control | |
| JPH0355424A (en) | Gas burner controller | |
| GB2075718A (en) | Method and apparatus for combustion control | |
| CA1164331A (en) | Control apparatus for burners | |
| KR100193320B1 (en) | Supply and purge valves of steam and fuel oil with cooling steam | |
| JPH05256422A (en) | Gas combustion device | |
| WO1988009463A1 (en) | Gas-air ratio control valve for gas burners | |
| CA2229129C (en) | A differential pressure modulated gas valve for single stage combustion control | |
| RU2324113C1 (en) | Double-stage air compound gas burner | |
| US5190452A (en) | Heat exchanger control system, control valve device therefor and methods of making the same | |
| US4695052A (en) | Hot water heating system using a heat consumption meter | |
| EP0481040A1 (en) | A method of regulating a gas-fired heat-generating appliance, and the relative appliance | |
| DK148726B (en) | TEMPERATURE SENSOR CONTROLLED CONTROLLER FOR A GAS COVERED WATER OR AIR HEATER | |
| CA1294344C (en) | Gas-fired furnace control apparatus and method for maintaining an optimum fuel air ratio | |
| EP0131235A1 (en) | Heating System | |
| US4272957A (en) | Fuel control system for a ram jet engine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |