# US 2017/0254533 A1 · Thin premixed atmospheric domestic burner

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- Number: US 2017/0254533 A1
- Document ID: US20170254533A1
- Status: Published application
- Kind: A1
- Application number: 15/506,532
- Filed: 2015-08-21
- Published: 2017-09-07
- Earliest claimed: 2014-08-29
- Assignees: Tre P Engineering S.R.L.
- Applicants: Tre P Engineering S.R.L.
- Inventors: Rosalino Usci; Michele Marcantoni
- Web page: https://patentgrep.com/patent/US20170254533A1

## CPC

- F23D 14/06: with radial outlets at the burner head
- F23D 2900/14063: for cooking ranges having one flame ring fed by multiple venturis
- F23D: BURNERS

## Abstract

The object of the present invention is an atmospheric gas burner (300) for cooking tops (400), in particular household cooking tops (400), where the air-gas mixture is obtained by the effect of the gas supply pressure using the principle of the tube ejector (10; 310) of Venturi that has a sufficient quantity Z≧1 of ejectors (310) to supply, globally, the maximum power (Wb) provided for the same burner (300). Each of said ejectors (310) develops on a horizontal plane, has the axis of its diffuser (315) which in the first stretch (322) is substantially rectilinear and tangential to a circle with centre on the central axis (324) of said burner (300) while in the second stretch (323) gradually bends substantially as a spiral towards the same central axis (324), leads, downstream of said diffuser (315), to a converging channel (327) which gradually bends vertically upwards and which, in turn, leads to one or more diffusion chambers (328) to which one or more flame spreading caps (318) act as a cover.

## Claims

### Claim 1

An atmospheric gas burner for cooking tops where the air-gas mixture is obtained by the effect of the gas supply pressure using the principle of the tube ejector of Venturi, comprising a quantity Z≧1 of ejectors able to supply, globally, the maximum power (Wb) provided for the same burner wherein each of said ejectors is configured to develop on a horizontal plane,
wherein each of the ejectors has the axis of its diffuser which in a first stretch is substantially rectilinear and tangential to a circle with centre on the central axis of said burner while in a second stretch gradually bends substantially, still on said horizontal plane, as a spiral towards the same central axis,
wherein each of the ejectors leads, downstream of said diffuser, to a converging channel which gradually bends vertically upwards and which, in turn, leads to one or more diffusion chambers to which one or more flame spreading caps act as cover.

### Claim 2

The atmospheric burner according to claim, 1, wherein when said ejectors are in a quantity Z≧2 they engage, according to said substantially tangential direction, on the outer circumferential wall in a plurality of sectors thereby forming at least for a first portion thereof, the second stretch of said diffusers, circularly distributed below said one or more flame spreading caps each of said sectors receiving one of more of said ejectors.

### Claim 3 (depends on 2)

The atmospheric burner according to claim 2, wherein said flame spreading cap is common to two or more of said Z ejectors provided.

### Claim 4 (depends on 1)

The atmospheric burner according to claim 1, characterised in that the power (Wej) of each of said Z ejectors is comprised between 40 and 1200 Watts according to the type of fuel.

### Claim 5 (depends on 1)

The atmospheric burner according to claim 1, characterised in that each of said Z ejectors has a size comprising:
a diameter (d) of the nozzle of said ejectors comprised between 0.08 and 0.85 mm;
1/750<R<1/500, where R is the ratio between the sections of Venturi groove and the nozzle of said ejectors;
1<L00/D<1.5, where L00 is the distance of said nozzle from the inlet of said groove and D is the diameter of said groove;
2<(L20/D)<4,where L20 is the length of said groove;
2° <B2<4°; where B2 is the maximum opening semiangle of each of said diffusers;
6<(L30/D)<12; where L30 is the length of said diffuser;
converging section of said ejectors of elliptical profile and jointed at the inlet of said groove; and
a Venturi axis of said ejectors substantially rectilinear in the first stretch after the groove.

### Claim 6 (depends on 1)

The atmospheric burner according to claim 1, wherein a narrow section zone is provided within or at the end or downstream of said second stretch of said diffusers, whereat whereas the section narrowing is sufficient to take the pressure of the mixture below the atmospheric pressure, and complementary air can reach the said mixture.

### Claim 7 (depends on 1)

The atmospheric burner according to claim 1, wherein the geometry thereof is such as to allow the mixture that reaches said flame spreading cap to have titre≧stoichiometric ratio STC.

### Claim 8 (depends on 2)

The atmospheric burner according to claim 2, wherein two sectors are joined in a single conveying chamber which develops about said central axis and is of suitable shape to cause a horizontal vortex of the mixture introduced and where said plurality of ejectors comes out with an preferably axial-symmetrical arrangement.

### Claim 9 (depends on 8)

The atmospheric burner according claim 8, wherein the quantity Z of said ejectors is an even number and at least the pairs of said ejectors which are axially symmetrical are sized for the same maximum power (Wej).

### Claim 10 (depends on 8)

The atmospheric burner according to claim 8, wherein the flows of said mixture singularly induced by each of said ejectors flow into said single flame spreading cap due to the fact that the upper and lower walls, of said conveying chamber, while they get closer to the central axis, approach to each other forming an annular converging channel deviate vertically upwards transforming said annular channel from centripetal to axial said annular channel leads to a diffusion chamber of larger diameter than the annular channel and of suitable shape to allow an expansion and the formation of a toroidal vortex of the said mixture and delimited on top by said flame spreading cap.

### Claim 11 (depends on 10)

The atmospheric burner according to claim 10, wherein said diffusion chamber is put into communication with the outside environment by means of an axial channel, internal to said annular converging channel, along which the external air may be drawn due to the depression procured at the centre of the horizontal vortex said annular converging channel forming said narrow section zone.

### Claim 12 (depends on 11)

The atmospheric burner according to claim 11, wherein a globe valve is provided in said axial channel, suitable for modulating the quantity of said air that can be drawn through the same axial channel.

### Claim 13 (depends on 11)

The atmospheric burner according to claim 11, wherein said globe valve is one-way and with adjustable preload.

### Claim 14 (depends on 8)

atmospheric burner according to claim 8, wherein deflectors are provided inside said conveying chamber, consisting of an accelerating blade array where each pair of adjacent blades describes a converging conduit having said pair of blades as vertical walls and the said upper and lower walls of the same conveying chamber as lower and upper walls, said blade array being arranged along the zone where the flows of two consecutive of said ejectors come in to contact.

### Claim 15 (depends on 8)

The atmospheric burner according to claim 8, said ejectors are provided with a low load loss non-return valve adapted to avoid backflows of said mixture towards the inner compartment of said cooking top.

### Claim 16 (depends on 15)

The atmospheric burner according to claim 15, said non-return valves are one-way valves located at the inlet or at an intermediate point of the Venturi of said ejectors.

### Claim 17 (depends on 15)

The atmospheric burner according to claim 15, wherein said non-return-valves are electro-mechanically actuated shut-off valves which close at the command of the gas valve whenever it shuts off the correspondent ejector and are located at the inlet or at an intermediate point of the Venturi of said ejectors.

### Claim 18 (depends on 17)

The atmospheric burner according to claim 17, wherein said shut off valves are located at the inlet of said Venturi and have a shutter comprising a sliding collar on the nozzle of said ejectors.

### Claim 19 (depends on 1)

The atmospheric burner according to claim 1, wherein it provides a number Z of said sectors separate from each other and in each of which one and only one of said ejectors engages, said sectors leading to its own consecutive conduit also completely separate from the other conduits up to correspondent Z sectors of the said diffusion chamber.

### Claim 20 (depends on 19)

The atmospheric burner according to claim 19, wherein said Z sectors and consecutive conduits are obtained by providing that the already said conveying chamber, annular channel, diffusion chamber and any axial channel rooms from which complementary air can be drawn are divided into said Z conduits from said Z vertical partitions.

### Claim 21 (depends on 21)

The atmospheric burner according to claim 21, wherein the plan pattern of said partitions is spiral-wise according to the lines that the flows of said mixture would take if said partitions were absent.

### Claim 22 (depends on 19)

The atmospheric burner according to claim 19, wherein said flame spreading cap is composed of one or more elements separate from each other and each intended to cover only one or more of said Z sectors wherein said diffusion chamber is divided into.

### Claim 23 (depends on 6)

The atmospheric burner according to claim 6, wherein said narrow section zone is a narrow section zone located substantially at the end or within the said second stretch of said diffusers, caused by a distributing body which obstructs part of the channel for the flow of the mixture, the section narrowing being such as to take the pressure of the mixture below the atmospheric pressure, said distributing body being provided with openings adapted to provide complementary air AIR13c to the mixture.

### Claim 24 (depends on 1)

The atmospheric burner according to claim 1, wherein its component elements comprise a single modular element, unchanging as the said power (Wb) of the same burner changes, comprising said ejector and, what of dimensionally unchanging is associated to the same ejector, a series of interlayer elements alternative to one another, specific for quantity and shape for each number Z of ejectors provided and/or each of said required powers (Wb) of the burner, substantially with a plan shape of slices of various angular width and by interlayer to the two or more of said unchanging modular elements provided.

### Claim 25 (depends on 1)

The atmospheric burner according to claim 1, wherein said one or more flame spreading caps have slots of increasing section from the inside towards the outside of the same caps from a minimum section to a maximum section thereof wherein the said minimum section ensures an outflow rate Vmax≧Vf for the maximum flame speed Vf and the minimum flow rate of said mixture, expectable; its maximum section ensures an outflow rate Vmin≦Vf for the minimum of said flame speed Vf and the maximum flow rate of said mixture, expectable.

### Claim 26 (depends on 1)

The atmospheric burner according to claim 1, wherein it provides said slots and said flame spreading caps specific for various gas families.

### Claim 27 (depends on 1)

The atmospheric burner according to claim 1, wherein said one or more flame spreading caps are of a material resistant to combustion temperatures.

### Claim 28 (depends on 1)

A method for adjusting the power of an atmospheric burner according to claim 1, wherein all said ejectors are modulated simultaneously in parallel.

### Claim 29 (depends on 28)

The method for adjusting the power of an atmospheric burner according to claim 28, wherein the power of a first group of said ejectors is modulated from the minimum to the maximum before proceeding to modulate a second one and so on.

### Claim 30 (depends on 28)

The method for adjusting the power of an atmospheric burner according to claim 28, characterised in that two or more of said ejectors are activated in progression, each of which is either disabled or operational at its maximum power.