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
  • F23D14/02—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
  • F23D14/045—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 with a plurality of burner bars assembled together, e.g. in a grid-like arrangement
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
  • F23D2900/00017—Assembled burner modules
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
  • F23D2900/14—Special features of gas burners
  • F23D2900/14641—Special features of gas burners with gas distribution manifolds or bars provided with a plurality of nozzles

Definitions

• the present invention relates to an innovative power adjustment system for atmospheric gas burners with multiple injectors for cooking tops, in particular household cooking tops.
• atmospheric burner it is meant a burner where the air-gas mixture is obtained by the effect of the gas supply pressure using the principle of the tube ejector of Venturi and without the aid of fans.
• the ejectors are extremely simple, economical and reliable devices and it is for this reason that they are used for the air-fuel gas mixing in the burners of cooking tops. Substantially all of the household gas cooking tops currently on the market use atmospheric burners.
• the pressure energy of a motor fluid available at a nozzle located at the inlet of a Venturi tube is transformed into kinetic energy; the high-velocity jet coming out from the nozzle induces and drags an induced fluid flow at a lower pressure; both flows are conveyed within the Venturi groove where they mix and recover part of the pressure; then the mixing continues in a diverging section (which is the Venturi diffuser) where additional kinetic energy is recovered in static pressure.
• a diverging section which is the Venturi diffuser
• fuel gas and combustion air are substantially completely mixed.
• This configuration includes a Venturi with a completely linear development arranged horizontally and parallel to the cooking top (conversely, in the STD burners the STD diffuser is instead radial).
• the linear diffuser leads to a further mixing chamber that occupies the internal volume of the burner wherein the mixing of primary air and fuel gas continues and completes
• Figure 2c shows a comparison between the two types in section.
• the adjustment of the thermal power of the STD or LIN burner is generally carried out by means of a manual rotary valve for adjusting the flow of fuel gas (hereafter simply "adjusting valve") located upstream of the Venturi ejector; by continuously reducing the supply pressure to the ejector a continuous adjustment of said thermal power between a minimum and 100% of the nominal power is obtained.
• adjusting valve for adjusting the flow of fuel gas
• thermocouple flame sensor
• the linear movement safety valves carry special sealing members (gaskets), the adjusting valves ("taps") are plug valves the sealing whereof is guaranteed by the presence of lubricating grease in the gap between the rotating trim and the seat, these members being generally made by chip removal from brass or aluminium blanks; unsuitable for serving as a safety device.
• burners equipped with more than one ejector also called “special burners” or “poly-injectors”
• flame zone for example multiple concentric crowns of flames.
• Each crown of flames of the special burner normally requires a dedicated gas supply line that develops from the corresponding special valve to the injector and, at least in some cases, of a corresponding igniter (and relative flame sensor) with clear drawbacks in terms of structural complexity and overall dimensions. Even the adjustment of the thermal power of those special burners appears complex and delicate.
• an STD multi-burner comprising two concentric crowns of flames (one internal centripetal and one external centrifugal), each separately fed by its own Venturi ejector and adjusted by a single special adjusting valve operable by the user through a control knob; turning the control knob starting from the OFF position the innermost crown is enabled and the thermal power thereof is continuously adjusted from its maximum (i.e., the crown ignites at full power) to its minimum, when a small unstable angular sector is reached, followed by the enabling of the outer crown and the concomitant switching off of the first.
• the modulation curve resulting from such typical management of a special burner is by portions continuous and strongly non-linear, as clearly visible in figure 3a, where the abscissa shows the angle of rotation of the special valve control, while the ordinate indicates the corresponding thermal power of the burner; there should be noted the three operating zones of the special burner.
• This modulability of the power may be overabundant compared to the practical needs, being it sufficient, as also in the electric cookers, a discrete adjustment with a sufficient number of "steps" (see Fig. 3b), while its implementation may result, especially for users with little experience, non-intuitive and not always easy and immediate to understand.
• the main object of the present invention is to provide a "special" atmospheric burner suitable for use for cooking tops, household in particular, which eliminates at least partly the drawbacks listed above.
• the main object of the present invention is to provide a sequential adjustment system of the thermal power of a "special" household burner with multiple injectors adapted to increase safety against the inadvertent access of fuel gas to the burner.
• a further object of the present invention is to provide a simplification and a reduction of the overall dimensions of the supply and control line of the burners of a cooking top, preferably "special burners”.
• a further object of the present invention is to achieve the previous objects through innovative pneumatic or electronic or electromechanical controls.
• a further object of the present invention is to control and manage the ignition of the plurality of flame zones of the special burner by means of a single igniter and flame sensor.
• FIG. 1 schematically shows a conventional layout of a cooking top and a safety valve according to the prior art.
• FIG. 2a shows, in a graphical legend, arrows symbolizing air-gas mixtures of different titre and inflow rate that are used by way of example, without any intent to provide quantitative data, in other figures;
• Figs 2b and 2c schematically show, respectively, a typical Venturi ejector according to the prior art for an atmospheric burner and a comparison between a burner with horizontal Venturi configuration and a burner with vertical Venturi configuration;
• Figs. 3a and 3b show, respectively, the modulation curves of the thermal power of a conventional burner and of a "special burner" according to the invention
• FIG. 4a, 4b, 4c, 4d, 4e, 4f and 4g schematically show a "special burner" and the relevant feeding and control system according to different variants of the invention
• Fig. 5 shows the ignition and modulation diagram of the thermal power of the "special burner" of Fig. 4a;
• FIG. 6 shows an ignition and modulation diagram of the thermal power of the "special burner" of Fig. 4c;
• Fig. 7 shows the ignition and modulation diagram of the thermal power of the "special burner" of Fig. 4d;
• FIG. 8 shows, in multiple cutaway views, a component of the control line of the "special burner" of the invention
• Fig. 9 shows, in a cutaway view and according to a possible variant, a power and modulation button of the thermal power of the "special burner" of the invention
• FIG. 10 shows a cooking top implementing multiple "special burners" according to a first variant of the invention
• FIG. 1 1 shows a cooking top implementing multiple "special burners" according to a second variant of the invention
• Fig. 12 shows a cooking top implementing multiple "special burners" according to a further variant of the invention
• FIG. 13 shows a cooking top implementing multiple "special burners" according to a further variant of the invention
• Fig. 14 shows a cooking top implementing multiple "special burners" according to a last variation of the invention.
• any possible spatial reference in this report such as the terms vertical/horizontal or lower/upper refers to the position in which the elements are located in the annexed figures while spatial terms such as previous/subsequent, upstream/downstream should be understood with reference to the direction of circulation of the flows of airforms.
• arrows are drawn, each of which symbolizes a flow of mixture of a different speed and titre. These arrows are used in many of the subsequent figures to exemplify without any intent to provide quantitative indications, the substantial state of the air, gas and mixture thereof at various points upstream, downstream and inside the illustrated burners.
• the cup 14 which defines therein the air-fuel gas mixing chamber, a plurality "n" of contiguous flame generation zones FLn each served by its own “Venturi” ejector EJ.n adapted to the above mixing and at the inlet whereof corresponding injectors INJ.n for the supply of fuel gas are positioned.
• Each "Venturi” ejector EJ.n comprises, as is known (see, for example, Fig. 2b), a first converging section 10 (or simply the “convergent") wherein the pressure energy of the fuel gas available at injector INJ.n is transformed into kinetic energy and wherein a combustion air flow is carried over by said high speed fuel gas jet; a groove 1 1 where the fuel gas and the combustion air are mixed recovering part of the pressure energy; a final diverging section 12 (also called Venturi "diffuser 12") along which said mixing continues and where additional kinetic energy is recovered in static pressure.
• the flame zones FL adjuents FL ! , FL 2 , FL 3 , FL 4 may consist, without distinction, in a plurality of concentric crowns of flames or have other shapes as long as contiguous, each one to all the subsequent (e.g., without any limiting intent, four concentric crowns or contiguous "groups of slots" FL ! , FL 2 , FL 3 , FL 4 ).
• At at least one flame zone FLn hereinafter referred to as main FL] , a known ignition device IGN (also called “igniter IGN”) is provided, for example of the piezoelectric type.
• Said contiguous flame zones FLn are adjacent to one another such that none (except, as will be seen, the main one FL may be fed and activated by its own dedicated ejector EJ.n without there being at least one adjacent flame zone FLn already ignited.
• flame detector FD flame detector
• thermal power of such a special burner 1 (also called “poly-injector burner 1 ”) is exclusively a function of the number of flame zones FLrada simultaneously active.
• the burner 1 operates at the minimum power P m j n when only the main flame zone FLi is activated while it reaches its maximum power P max when all its flame zones FLrada are simultaneously enabled.
• Reference numeral 2 denotes a push-button panel, comprising at least one button 20. n for the activation of said special burner 1 and for its modulation in power.
• said push-button panel 2 may be of the electromechanical or electronic or pneumatic type and is connected to the injectors INJ.n of the special burner 1 by means of at least one control line 3, 3.n.
• a single control line 3 adapted to serve all the injectors INJ.n of the burner 1 (see. Figs. 4c, 4d. 4e, 4f) or. alternatively, as many dedicated control lines 3, 3.1 ... 3.n as said injectors INJ.n (i.e. one for each injector INJ.n) as shown in Fig. 4a or 4b may be provided.
• Said at least one control line 3.n may be connected directly to the at least one button 20.
• said push-button panel 2 or, according to some variants (of the electric type), to an electrical control circuit CMD capable of receiving specific control signals from the same push-button panel 2 (said circuit CMD, as shall be seen, being capable of receiving signals also from the flame detector FD and sending second signals to the igniter IGN and to a valve of the burner 1 , which shall be referred to as "safety SV").
• control system of the burner 1.
• control system 2 shall be referred to shortly with the description of some preferred and functional embodiments thereof.
• said push-button panel 2 is shown in the annexed figures of the type comprising at least one mechanical button, nothing prevents it from providing, without any exhaustive intent, rotary or linear potentiometers or any other type of control known to manufacturers and designers of cooking tops.
• a single gas supply line 4 (also referred to as "adduction line 4") serves the entire plurality of injectors INJ.n of the special burner 1. arranged in series to each other.
• Said supply line 4 is shut-off by a known and conventional safety valve SV against gas leaks found in case of accidental and sudden switching off of the flame or malfunctioning of the burner 1.
• said safety valve SV is placed upstream of the plurality of injectors INJ.n of the special burner 1.
• said safety valve SV e.g., an electro-actuator
• said safety valve SV is piloted by the push-button panel 2 of the burner 1 to switch from a "normally closed” to an "open” configuration, suitable for the passage of fuel gas, and that is maintained as such as long as the above flame detector FD senses at least one active flame zone FLRAN.
• the absence of such signal will determine, on the contrary, the closing of said safety valve SV and the subsequent shut-off of the supply line 4, thus interrupting the supply of fuel gas to the special burner 1.
• Appropriate and known wirings 50, 51 connect respectively the safety valve SV and the flame detector FD to the push-button panel 2 while a cable 52 controls the ignition of the igniter IGN.
• each injector ENJ.n of the burner 1 is equipped with a special shutter device 6 (see in particular Fig. 8). "normally closed”, but capable of allowing or preventing, on command, the exit of the gases towards the corresponding ejector EJ.n for the activation of the relative flame zone FLn but at the same time ensuring its passage towards the next injector INJ.n (with respect to the travelling direction of the gas along the only one supply line 4).
• Said shutters 6 are interlocked to the flame detector FD.
• shutter device 6 and injector INJ.n are represented as strongly integrated to each other to form a single valve body, nothing prevents that they can also be logically and physically separate elements.
• each injector INJ.n besides feeding the corresponding ejector EJ.n, thus acts also as a gas shut-off valve ensuring a further safety against gas leaks towards the external household environment with the burner 1 switched off or in the event of accidental switching off of the flame.
• the linear shutters in the closed position ensure an intrinsically better sealing of the corresponding conventional adjusting taps.
• Known electromechanical or pneumatic actuators 7 guide the switching of the shutter device 6 from its natural closed to open configuration of the injector INJ.n and vice versa.
• suitable electric actuators 7 may be of the type (only schematically shown in the annexed figures) comprising a coil substantially wound around the shutter device 6 and capable of converting the electric signal generated and transmitted to it by the push-button panel 2 through the aforesaid at least one control line 3 (in this case, therefore, of electrical type) into an electromagnetic field, causing a linear movement thereof.
• the special burner 1 of the invention implements, moreover, a double security level (or system) against gas leaks in case of incomplete ignition thereof or accidental switching off of the flame ensured, on the one hand, by the safety valve SV located along said fuel gas supply line 4 upstream of the same said plurality of injectors INJ.n and, on the other hand, by each of the same injectors INJ.n that by means of their respective shutter devices 6 act, as seen, as shut-off valves, said safety valve SV and shutter devices 6 being capable of closing instantaneously (or remaining closed) in the absence of a flame signal detected by at least one flame detector FD of the special burner 1.
• the "normally closed" safety valve SV of the fuel gas supply line 4 is forcibly opened, the shutter device 6 of the first injector INJ. l is retracted, thereby opening the access of the gas to the corresponding ejector EJ. l , and the igniter IGN for the ignition of the flame in the main flame zone FLi is activated.
• the flame detector FD creates an electric voltage (which is a function, as known, of the local temperature reached therein) that keeps both the safety valve SV and the injector INJ.l in open position.
• the main flame zone FLi therefore remains ignited and the special burner 1 , as anticipated, is at its minimum thermal power.
• the adjustment of the level of thermal power of the special burner 1 of the invention goes through the successive and incremental enabling of the other ejectors EJ.n through the opening of the shutter devices 6 of the corresponding injectors INJ.n and in such a way that each pair of consecutively fed flame zones FLn are adjacent to each other (see the "steps" modulation curve of Fig. 3b).
• said modulation of the thermal power of the special burner 1 is subject to the contiguity of its flame zones FLn, meaning that a flame zone FL n cannot be fed and activated by its own dedicated ejector EJ.n without there being at least one adjacent flame zone already ignited; e.g., the flame zone FL 2 may be enabled, only after the activation of the contiguous main flame zone FLi and so on for the subsequent flame zones FL 3 , FL 4 of the special burner 1.
• each pair of flame zones FLn, including the main one, which are fed in sequence are adjacent to each other.
• Fig. 4a shows in more detail a first version of the control system of the special burner 1.
• Said control system provides a common electromechanical push-button panel 2 comprising a number of buttons 20.n, 20.1....20.4 equal to that of the activatable flame zones FLn where said number of zones is less or equal to the number of injectors INJ.n of the special burner 1.
• each button 20.n is connected by means of one own control line 3, 3.1....3.4 to the corresponding injector INJ.n or to as many groups of injectors INJ.n; as many control lines 3.n are therefore provided as the flame zones, each of which is equipped with at least one injector INJ.n of the special burner 1 to be managed.
• Each button 20. n of the push-button panel 2 is therefore capable of enabling the corresponding flame zone FLn according to the sequence previously described in general terms, by simply using known switching means for electrical signals. At least one of said buttons 20. n of the push-button panel 2, is connected, besides to the corresponding injector INJ.n (or, as it shall be understood, to the corresponding group of injectors INJ.n"), as anticipated, also to the igniter IGN and flame detector FD of the special burner 1 and to the safety valve SV of the fuel gas supply line 4.
• n is that 20.1 adapted to enable the main flame zone FLi of the burner 1 , where said zone FLi is that expected to ignite first.
• a push thereof will command, therefore, the opening of said safety valve SV and the at least one main injector INJ. l and the simultaneous activation of the igniter IGN capable of "igniting" (through the known spark produced thereby) the air- fuel mixture intended to said main flame zone FL ⁇
• the switching off of the second flame zone FL of the special burner 1 will be achievable by pressing the button 20.4 dedicated to the enabling of the fourth and last flame zone FL 4 (see position of the representation of a user "hand” at point (iv) of Fig. 5).
• each injector 12.n is controlled by a special and dedicated control line 3; 3.1....3.4....3.n.
• control lines 3.n are connected directly to an electrical control circuit CMD capable of:
• the push-button panel 2 may comprise a pair of buttons 20. n represented symbolically in Fig. 4b by a first key (+) 20.1 and by a second key (-) 20.2 connected to said electrical control circuit CMD; with a first pressing of the key (+) 20.1 there will be, therefore, the activation of the main flame zone FLi while each subsequent pressing will result in the enabling of those contiguous until the desired thermal power for the special burner 1 is reached.
• electrical control circuit CMD to recognize if the pressing exerted on said button (+) 20.1 corresponds to that for the first ignition of the special burner 1 or to that for increasing the power thereof depending on whether the flame signal from the flame detector FD is received or not.
• the electrical control circuit CMD will manage the sequential switching off of the flame zones FLrada already activated until the minimum thermal power of the burner 1 or its final switching off is reached.
• the actuators 7 that move the shutter devices 6 of each injector INJ.n are all connected in series to each other by a single control line 3. in this example of the pneumatic type (exactly as the injectors INJ.n with their own dedicated gas supply line 4).
• said push-button panel 2 may comprise at least one button 20.1 , called “ignition”, adapted to activate the igniter IGN and to allow the switching of the safety valve SV from its "normally closed” to "open” position (activating, as a consequence, the main flame zone FLO and at least one button 20.2, called “selection”, which behaves, as anticipated, as a “compression” volumetric pump adapted to discretely increase the pressure of the control line 3 at each repeated pushing thereof so as to sequentially activate, in the manners that shall be described, the contiguous flame zones FLn of the special burner 1.
• ignition adapted to activate the igniter IGN and to allow the switching of the safety valve SV from its "normally closed” to "open” position (activating, as a consequence, the main flame zone FLO and at least one button 20.2, called “selection”, which behaves, as anticipated, as a “compression” volumetric pump adapted to discretely increase the pressure of the control line 3 at each repeated pushing thereof so as to sequentially activate
• a further safety discharge device consists of a "normally open” discharge solenoid valve DV in communication with the external household environment pilotable by the ignition button 20.1 and kept in a closed position by the flame detector FD.
• said discharge solenoid valve DV In the absence of flame in the main flame zone FLi or in case of accidental switching off thereof, said discharge solenoid valve DV returns to its normally open position discharging the compressed air and causing the closing of all the shutter devices 6 of the injectors INJ.n that the control line 3 serves; this ensures, as a consequence, an additional level of security for the special burner 1.
• a nozzle 80 and a gas compartment 81 connected to the fuel gas supply line 4 while of said shutter device 6 there are shown a pneumatic chamber 60 in fluid communication with the above pneumatic control line 3 and the shutter "pin" 61 capable of being moved from a "normally closed” to an "open” position (and vice versa) of the nozzle 80 by means, e.g., of the above pneumatic actuator 7.
• Said actuator 7 may comprise a pneumatic piston 70 and a mechanically adjustable stationary spring 71 with settable preload to keep its piston in a "normally closed” position, e.g., by means of a threaded ring nut 72 or a screw.
• said piston 70 may alternatively consist in a known bistable piston.
• Sealing members 62 keep the pneumatic chamber 60 and gas compartment 81 strictly separate.
• the pneumatic chamber 60,- adjacent to the gas compartment-Si- of the injector INJ.n, is in overpressure relative to the outside environment so as to avoid the emission of fuel gas to the outside (e.g., in the cooking top) in case of damage/or wear of the sealing members 62.
• each subsequent pressing of the selection button 20.2 will correspond to a discrete increase in the pressure in the control line 3 up to the minimum level necessary for the opening of the first closed shutter in the sequence of the shutter devices 6 of each injector INJ.n - with the special burner 1 ignited by pressing the selection button 20.2 all the way down (which, as seen, works as a volumetric pump) it is possible to obtain a decrease in pressure to the various shutter devices 6 of the injectors INJ.n that one by one sequentially close until the minimum pressure of the pneumatic control line is reached (equal, actually, to that of gas supply). With the special burner 1 switched off, therefore, the pressure gradient between pneumatic chamber 60 and gas compartment 81 is zeroed and with it the risk of gas leak to the external household environment.
• the shutter devices 6 of the plurality of injectors INJ.n are located, as seen, in the "normally closed” position thereby preventing the inflow of fuel gas towards the respective injectors INJ.n; said ignition and power modulation system of a special burner 1 is therefore intrinsically safe.
• FIG. 6 An ignition (or switching off) and adjustment diagram of the thermal power of a special burner 1 according to such variant is shown in Fig. 6 and provides by way of a non-limiting example the following steps: once the special burner 1 is activated to its minimum thermal power (that is, the only main zone FLi is enabled; see (i) and (ii) in Fig. 6). a further succession of presses of the latter will correspond to the ignition of the immediately contiguous flame zone FL 2 (see (iii) in Fig.
• the pneumatic control system for the ignition of the special burner 1 of the invention may be, alternatively, also of the "vacuum type"; Fig. 9 therefore shows the relative button 20. n.
• the at least one button 20.n of the push-button panel 2 is a tubular body comprising an outer liner 21 fixed to a support (e.g., to the aesthetic face of a cooking top P) in turn comprising a connecting channel 22 to the pneumatic control line 3 and a relative non-return valve VNR1.
• a movable key 23 is capable of shifting vertically, when pressed, within said fixed liner 21 so as to open, for the reasons which will be clarified shortly, said "normally closed” valve VNR1.
• an inner pre-compressed spring 28 is capable of returning said valve VNR1 to the "normally closed” position.
• the at least one button 20. n for the "compression" pneumatic system previously described and shown in Fig. 8 may be constructively identical to this "vacuum” one except for the inversion of the direction of operation of the two valves VNR1 and VNR2.
• FIG. 4f A particular application of said vacuum pneumatic control is shown in Fig. 4f according to which the activation of the special burner 1 is managed by a single button 20.n capable of acting on a microswitch MT of an electromechanical control group SWT, suitably connected and/or wired to the igniter IGN, to the discharge DV and safety SV valve capable of intercepting the fuel gas supply line 4.
• said electromechanical group SWT starts from the special burner 1 in OFF configuration, with a first partial push on button 20. n, exerted for a predetermined period of time (preferably in the order of some seconds), said electromechanical group SWT provides, by means of specific signals along suitable dedicated connecting wirings, for closing the discharge valve DV, simultaneously opening the safety valve SV and enabling the igniter IGN for the ignition of the main flame zone FLi.
• the above flame detector FD shall keep the discharge valve DV in "closed” configuration and the safety one SV in "open” position; otherwise the safety valve SV is immediately closed interrupting, as seen, the gas flow to the burner 1 , while the discharge valve DV is opened to restore the pressure along the pneumatic control line 3 of the injectors INJ.n, avoiding gas leaks.
• control line of the injectors INJ.n of the special burner 1 of the invention may also be obtained by providing electrically and/or electronically managed shutter devices 6.
• the actuators 7 of each shutter 6 are preferably:
• actuators of the electric type comprising, as said, excitation coils of relative electromagnets, electrically connected in parallel to each other, and dimensioned to accept a predetermined range of voltage values
• An electrical control circuit CMD connected to the push-button panel 2, transforms each pressing on button 20.1 and/or 20.2 into a voltage signal that increases or decreases discretely, obtaining a modulation of the thermal power of the special burner 1 (see steps (i), (ii), (iii), (iv) of Fig. 7), similarly to what achievable with the pneumatic system described above.
• the simultaneous pressure of the two buttons 20.1 , 20.2 with the burner 1 switched off determines, instead, the ignition (more precisely, the activation of the main flame zone FL l5 as shown in (i) of Fig. 7).
• each injector INJ.n may be obtained by providing different alternative solutions.
• each stationary spring will exceed the electromagnetic force of the respective electroactuator 7 thereby closing the shutter device 6 whereon they rest.
• electroactuators 7 and stationary springs all identical to each other.
• the sequential opening or closing (more generally the '"tripping") of the shutter is obtained by simply adjusting the preloads of their stationary springs on different values.
• electroactuators 7 such as, for example, linear stepping motors or the like; in this case, the control line 3 would become an actual data BUS, where the master is the push-button panel 2 and the relative electrical control circuit CMD (which becomes an actual electronic card having calculation capabilities) and the slaves are the actuators 7 of the shutters 6 of the injectors INJ.n that would thereby be networked together.
• Fig. 4g finally shows a last variant of the control and adjustment system of a special burner 1.
• Said variant provides an electrical control circuit CMD of the special burner 1 connected, on one side, to a push-button panel 2 comprising a single button 20 therefore capable of functioning both as a power and selection button and on the other side to the single electrical control line 3 of the injectors INJ.n.
• a short pressing of said button 20 shall correspond to a power reduction (or switching off of the burner 1 if it is the only main flame zone FLi to be active), while a long press corresponds to an increase in said power. It shall be the electrical control circuit CMD to recognize if a long press on the button corresponds or not to the first ignition (that of the main flame zone FLi) according to the reception or not of the flame signal sent by the flame detector FD, to which it is connected.
• the electrical control circuit CMD opens the safety valve SV feeding the burner 1 with fuel gas, enables the igniter IGN, to which it is connected, and sends the signal for opening the injector INJ. l installed upstream of the main flame zone FLi through said electrical control line 3.
• Fig. 10 shows a cooking top P comprising four special burners 1 of the type just described, each in its turn comprising four injectors INJ.n feeding, as seen, an equal number of flame zones FLn.
• the cooking top illustrated has three security levels; a first security level (called “base level”) is ensured by a known general safety solenoid valve SSV ("normally closed") capable of cutting off the general line L for the supply of fuel gas (represented in Fig. 10 by the thick grey line and from which, downstream of the same valve SSV, a plurality of gas supply lines 4 is branched, one for each single burner 1 , represented in the figure in "dotted line”) when no special burner 1 is ignited.
• base level a known general safety solenoid valve SSV
• SSV normally closed
• a second security level is represented by the safety valves SV (as seen, "normally closed” as well ) supplied with each burner 1 and adapted to interrupt the fuel supply line of the single burner 1 (dotted line of Fig. 10) in the absence of the confirmation signal from its flame detector FD; a third security level guaranteed by the shutters 6 of each injector L J.n connected in series through a single control line 3 (see dashed-dotted line of Fig. 10), the electrical control circuit CMD that transmits a closing signal when the flame detector FD detects the accidental switching off of the flame or when the burner 1 is switched off.
• This redundancy may advantageously be used to make simplified versions of the cooking top P always comprising at least two security levels. Even in the absence of the general safety valve SSV, in fact, the security against fuel gas leaks in the absence of flame would be guaranteed by at least the safety valve SV of each special burner 1 and by each shutter of the plurality of injectors INJ.n that feed it.
• a further simplified variant, illustrated in Fig. 1 1 provides the absence of the safety valve SV of the single special burner 1. Even in this case a basic level of security is still guaranteed through the general safety valve SSV and a second security level guaranteed by the shutters 6 of the injectors INJ.n of each special burner 1.
• all flame detectors FD of the plurality of special burners 1 of the cooking top P are directly connected, through cables 55, to the general safety valve SSV thus capable to return to the "normally closed" position already in the event of accidental switching off of the flame of one of said burners 1 of the cooking top P.
• Fig. 12 shows a further variant according to which the safety function consisting in the closing of the injectors INJ.n in the event of accidental switching off of the flame, rather than being assigned to the electrical control circuit CMD, is attributed to special safety relays K (for example, dual input of which one timed), normally open, one for each special burner 1.
• special safety relays K for example, dual input of which one timed
• the safety function of disabling the injectors INJ.n in the event of accidental switching off of the flame has been attributed to normally open special safety relays K(i) (for example of the solid state type).
• Each relay is connected in series to its injectors INJ.n control line 3 so as to cut it off in case of absence of flame; while the flame signal from said detector FD is able to keep them in the closed position.
• the CMD group will provide a first signal (e.g. a voltage) to the control line 3 of the injectors of the burner of level L K closely below the minimum level of activation of the injector INJ. l (that shall be called Li).
• the signal level L must be able to close K(i) but not sufficient to open the first injector of the series.
• the device K(i) can be equipped with such a timing that, after a few seconds from the first reception of the signal L .
• K(i) it can be kept closed only by the signal of the flame detector FD and, in the absence of this, returns to the open position forcing the user to repeat the procedure of first ignition. In this way overlaps between the control signal of the power level of the burner (Li ⁇ L 2 ⁇ L 3 ⁇ L 4 ) and the ignition signal L (where L ⁇ LI) are avoided.
• a safety functional group SFT which is assigned the task of constantly receiving the flame signals from the flame detectors FD of each special burner 1 of the cooking top P and to compare them with the information of the ignition state of said burners 1 coming from the electronic control board CMD.
• the safety functional group SFT will command the closure of the general safety valve SSV.
• the safety functional group SFT is also able to force said general safety valve SSV in "open" configuration in case of first ignition of the burner 1 (that is, as repeatedly said, of his main flame zone FLj).
• Said data line 56 finally allows the electrical control circuit CMD to receive the information on flame presence and to close, through the relative control lines 3 of the shutters, all the injectors INJ.n in case of accidental switching off or failed ignition of the burner 1.
• Fig. 14 finally shows one last construction variant for a cooking top P which comprises:
• a single control line 3 continues that, from the electronic control circuit CMD, joins in a sequence all the special burners 1 of the same cooking top P (rather than having as many dedicated control lines as the burners 1 of the cooking top P, as in the constructive examples of Figs. 10-13), said single control line 3 serving, as seen, all the injectors INJ.n of each burner.
• Said control line 3 is a BUS that connects all the electric actuators 7 that are of the bistable type (or the like) that become interlocked and addressed by the CMD device.
• injector INJ.n it may be also meant a group of injectors INJ.n, all serving the same flame zone FLn, with the understanding that said group of injectors INJ.n is piloted like a single injector E J.n.

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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)
• Regulation And Control Of Combustion (AREA)
• Gas Burners (AREA)

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• 2015
  • 2015-11-18 DE DE212015000268.3U patent/DE212015000268U1/de active Active
  • 2015-11-18 ES ES201790005U patent/ES1214916Y/es active Active
  • 2015-11-18 PL PL126383U patent/PL70720Y1/pl unknown
  • 2015-11-18 RO ROU201700021U patent/RO201700021U1/ro unknown
  • 2015-11-18 WO PCT/IB2015/002168 patent/WO2016079584A2/en active Application Filing
  • 2015-11-18 CN CN201590001136.2U patent/CN210267210U/zh active Active

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