RU2455564C1 - Gas burner for ovens - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: gas burner (1) for ovens or roasters includes Venturi tube (2) for mixing of fuel gas and primary air, the main distributing chamber (3) continued in longitudinal direction of movement of mixed flow and located downstream of Venturi tube (2), as well as at least one supply chamber (22a, 22b) located outside the main chamber (3) and equipped with outlet holes (4; 4a, 4b, 4c, 4d) of gas mixed with primary air; at that, the main chamber (3) and at least one external chamber (22a, 22b) are hydraulically interconnected at least throughout longitudinal length of the main chamber (3) by means at least of one through hole (16a, 16b, 17a, 17b); at least one through hole (16a, 16b, 17a, 17b) has larger cross section in the upstream section relative to longitudinal direction of the mixed flow direction and smaller cross section in the downstream section at least of one longitudinal length of the main chamber (3).

EFFECT: invention allows obtaining uniform flame throughout the longitudinal size of the burner.

11 cl, 6 dwg

Description

FIELD OF THE INVENTION

The invention relates to a gas burner for stoves or grills, containing a venturi for mixing fuel gas and primary air, a main chamber, continuing in the longitudinal direction of the mixture flow and located behind the venturi, as well as at least one chamber outside the main chamber, hydraulically interconnected with the latter and provided with openings for discharging a mixture of gas and primary air.

State of the art

Known gas burners for domestic stoves or grills, containing a first elongated chamber for distributing the fuel mixture of gas and primary air, located directly behind the mixing tube having a Venturi effect, and a second supply chamber, which is in fluid communication with the first chamber and provided externally with outlets for release of the fuel mixture. The shape and dimensions of the channels for the movement of the fuel mixture from the distribution chamber to the feed chamber, as well as the shape of the feed chamber and the corresponding outlet openings, determine the local thermodynamic characteristics of the mixture inside the burner, in particular the successive pressure and concentration, and thereby determine the shape, profile and distribution flame outside the outlets of the second chamber.

For example, US Pat. No. 3,156,292 describes a similar gas burner for furnaces in which a tubular distribution chamber, extending in the longitudinal direction of the mixture inlet and located behind the mixing pipe, is mounted in an outer casing provided with flame openings. The outer casing forms a feed chamber between its upper wall and the distribution tube chamber itself, which is in fluid communication with the distribution chamber by means of a number of channels extending in the longitudinal direction and provided along the walls of the latter. Such longitudinally extending channels are intended to ensure uniform flow of gas from the distribution chamber to the mixing chamber and, thereby, to ensure uniform distribution of the flame and its profile.

This solution, despite the fact that it contributes to the proper operation of the burner, does not take into account the pressure difference arising in the tubular distribution chamber due to a sudden stop of the mixture flow at the closed end of the distribution chamber itself, opposite the mixing pipe.

In particular, the flow of the mixture in the tubular distribution chamber, created by the release of gas from the corresponding injector, continues in the longitudinal direction from the venturi to the closed end of the distribution chamber itself, where it faces the end closed wall of the latter, which will impede the flow and deflect and bring it into heterogeneous state. For this reason, a non-zero pressure gradient occurs in the distribution chamber, as a result of which the pressure locally increases at the closed end of the distribution chamber and locally decreases at the outlet section of the mixing pipe.

Such a pressure gradient, as one skilled in the art will understand, will cause an uneven distribution of the mixture in the burner and then, even if there is an external supply chamber separated from the above tubular distribution chamber, an uneven distribution of flame and, therefore, an unstable geometric distribution of temperature and heat, generated by the burner.

An attempt to solve this problem was made in international patent application WO 2004/005799, which describes an elongated burner for furnaces containing an elongated tubular distribution chamber of the fuel mixture, which is located behind the mixing tube for mixing gas and primary air with a Venturi effect (Venturi tube). The distribution chamber of the mixture over a certain length, starting from the venturi, is located in fluid communication, with the help of a longitudinal coil, with an external feed chamber provided with flame openings.

The volume of such a coil, formed by two longitudinal ribs inside the burner, placed at a distance from each other in the transverse direction and having a height less than the height of the burner chamber, should form walls designed to transfer part of the mixture flow to the feed chamber located to the side of the tubular distribution chamber, thereby forming a trap for the mixture, which will reach a higher pressure at the flame openings present in the above feed chamber.

Such a higher pressure, which will occur, as indicated above, only at the flame openings of the burner located in the aforementioned supply chamber at a certain length near the venturi, will be sufficient to compensate for the increased pressure arising at the end of the burner opposite the venturi, in which flame openings are directly provided in the distribution chamber and there is no feed chamber, which thus contributes to the regulation of the distribution of the flame of the burner.

The solution described in WO 2004 (005799) was aimed at solving the problem of the existence of a pressure gradient in the mixture inside the distribution chamber of the burner, but, along with the complexity of the practical implementation, it does not allow sufficient uniformity in the local distribution inside the main distribution chamber or inside the supply chamber pressure of the mixture, which can ensure uniformity and uniformity of the flame along the entire length of the burner.

The objective of the invention is to provide a burner for domestic stoves or grills that do not have the known disadvantages of burners for stoves in the prior art. The technical result of this invention is to obtain a uniform flame throughout the longitudinal dimension of the burner itself.

The burner for furnaces contains a venturi tube for mixing fuel gas and primary air and a longitudinally extending distribution chamber located directly behind the venturi tube and providing on its inner side a uniform distribution of the mixture along the entire length of the burner, at least at the respective flame openings.

Another objective of the present invention is to provide a burner for stoves or grills of the above type, which provides a uniform and uniform distributed flame throughout the burner itself.

SUMMARY OF THE INVENTION

The technical result is achieved in the burner for stoves or grill features of an independent claim and the subsequent dependent claims.

The gas burner for furnaces or grills of the present invention comprises a venturi tube for mixing fuel gas and primary air, a main distribution chamber extending in the longitudinal direction of the flow of the mixture and located behind the venturi, and at least one feed chamber located outside the main chamber and provided with openings for discharging a mixture of gas and primary air. The main distribution chamber and the outer feed chamber are hydraulically interconnected, at least in the longitudinal section of the main chamber, with at least one through hole, which has a larger cross section in the section higher in the longitudinal direction of the mixture flow and a smaller cross section in the lower section in the direction of flow of the mixture.

Preferably, at a continuous distance along the entire continuous portion of the aforementioned main chamber, the through hole between the main chamber and the outer chamber extends throughout the main chamber from the outlet section of the venturi to the substantially end wall of the main chamber opposite the venturi.

This solution provides effective regulation of local pressure in the external feed chamber, forcing the mixture to exit through channels having sections of various shapes and create different load losses in the mixture flow.

In practice, thanks to this invention, load losses will be greater at the through hole between two chambers having a smaller cross section located near the closed end of the burner, and vice versa, will be smaller where the through hole has a larger cross section near the outlet section of the venturi. Thus, the pressure of the fuel mixture will be almost uniform throughout the burner, providing a similar uniform and uniform distribution of the burner flame.

In addition, according to a preferred embodiment of the present invention, the burner comprises two external feed chambers extending in the longitudinal direction along axes parallel to the axis of the main distribution chamber and located on the sides of the latter.

In addition, at least one longitudinal length of the main chamber extends from the area near the outlet section of the venturi to the opposite end of the main chamber.

In a preferred embodiment of the present invention, the burner comprises an upper casing, an intermediate partition and a lower casing, interconnected and forming a venturi and the above main chamber and the outer chambers and an additional compensation chamber located below. The intermediate partition has at least one central concave portion and at least one lateral convex portion, the central concave portion forming with the upper casing a main chamber having longitudinal elongation, and at least one lateral convex portion forms, at least one through hole for the fuel mixture. In such an embodiment, the special shape of the intermediate partition with a concave section and at least one convex section allows you to easily and accurately determine the cross section of the above through holes between the main chamber and the outer chamber or outer chambers of the burner.

In such an embodiment of the burner of the present invention, the venturi is preferably an axial venturi.

Brief Description of the Drawings

The present invention is presented below by drawings, which show:

figure 1 is a perspective top view of the burner according to a specific aspect of the present invention;

figure 2 is a partial side view in section in the burner of figure 1;

figure 3 is another partial side view in section on a burner from the previous figures;

figure 4 is a perspective top view of the intermediate partition in two outer casings forming the burner body of figure 1:

figure 5 is a frontal sectional view of the burner of figure 1 along the line aa of the section of figure 1; and

in Fig.6 is a frontal sectional view of the burner of Fig.1 along the line BB of the section of Fig.1.

Disclosure of invention

In figure 1, the burner 1 of the furnace or grill is formed of the upper casing 5 and the lower casing 6, which are mutually connected and fastened in a known manner and form the outer casing of the burner 1, containing a connecting section 7 for direct or indirect connection of the burner 1 with the inner wall 101 of the furnace or grill, a longitudinally extending element provided in the transverse direction with a plurality of flame holes 4, and a closed end section 8 on the opposite side of the connecting section 7, provided with means for direct or indirect nnogo attachment housing to the other inner wall of the oven or grill.

The casings 5 and 6, between which the intermediate partition 13 is placed (Fig. 4), are mutually connected and, at least partially, form the internal geometry of the burner 1, which contains, starting from the end of the connecting section 7 and ending with the closed section 8, the tube 2 A venturi having an axial structure, a main chamber 3, located after the venturi 2 and continuing coaxially with it in the longitudinal direction, as well as two lateral outer chambers 16, 17 (FIGS. 2 and 3), continuing in the longitudinal direction along parallel axes to the side of axis main to steps 3 and 4 provided with holes.

Figure 2 shows a side section of a part of the burner 1 close to its connecting section 7. The connection between the burner 1 and the inner wall 101 of the furnace or grill can be achieved using the corresponding bracket 100, equipped with known means for mounting the burner 1 at its connecting end 7 and also intended to hold the fuel gas injector 9 in the burner 1 itself while the latter is connected to the bracket 100.

In particular, as shown in figure 2, the internal geometry of the burner 1 provides a first zone 10 located immediately after the connecting section 7 and having the shape of a truncated cone with a tapering section to zone 11, having a cylindrical profile of a reduced section and going to the next zone 12, gradually expanding relative to zone 11 or having an expanding section, essentially in a plane perpendicular to the section from figure 2, as can be seen from figure 1. Zones 10, 11 and 12 extend along a common axis and form a venturi 2 having an axial structure adapted to allow mixing of the fuel gas injected by the injector 9 with the (primary) air drawn in by the venturi 2 itself from the environment outside the burner 1.

As can be seen from FIG. 2, the venturi 2 is partially formed by the lower casing 6, partly by the intermediate partition 13, the latter having a shape that allows it to overlap the same lower casing 6, starting from a given position, and the upper casing 5.

Given the direction of movement of the fuel gas and the mixture in the burner 1 immediately after the exhaust section 14 of the venturi 2, the main chamber 3 is designed to feed the mixture into the burner 1. The main chamber 3 is located in the longitudinal direction coaxially with the venturi 2 and is formed by an intermediate partition 13 and the upper casing 5.

Between the intermediate partition 13 and the lower casing 6, a compensation chamber 15 is also provided, which is in fluid communication with the main chamber 3 through a number of holes 20 (Fig. 4) provided along the lower wall of the intermediate partition 13, and is intended not only to control the flow of the mixture outwardly with the help of several channels 23a, 23b open outward and formed between such a partition 13 and the lower casing 6, but also to ensure optimal flame propagation over several tverstiyam 4 during ignition of the burner 1.

Figure 3 shows a side section of a portion of the burner 1 at the closed end section 8, while the main chamber 3 narrows near the end section 8. In addition, figure 3 shows two holes 16b and 17b formed between the inner ribs of the intermediate partition 13 and the upper casing 5 of the burner 1, forming a through section, which is adjusted to supply the fuel mixture in the direction of one of the side chambers 22b of the supply (see Fig.5 and 6), on which there are open holes 4.

Figure 4-6 shows special forms of the intermediate partition 13 and the upper casing 5, providing the formation of the outer chambers 22a, 22b, which extend laterally with respect to the main distribution chamber 3 along axes parallel to the axis of the latter, and which are in fluid communication with the main chamber 3 using the corresponding through holes 16a, 16b, 17a, 17b, having a cross section with calibrated dimensions in relation to the direction of flow of the fuel mixture.

In a preferred embodiment of the present invention, the through holes 16a, 16b closest to the outlet section of the venturi 2 have a larger cross section than the through holes 17a, 17b provided on the closed end section 8 of the burner 1.

Such a solution, as mentioned above, determines that a part of the fluid flow passing through the through holes 17a, 17b having a smaller cross-sectional area is subject to large load losses (i.e., it will be more difficult for it to reach the corresponding lateral feed chambers 22a, 22b) compared with the loss of stress experienced by the fluid flow passing through the through holes 16a, 16b having a large cross-sectional area.

The different cross-section of the through holes 16a, 16b and 17a, 17b, causing different load losses, essentially compensates for the difference in local pressure that occurs in the inner zone of the burner 1, located next to the closed end section 8, with respect to the inner zone, located directly behind the venturi 2, making the concentration and pressure of the mixture, in the side chambers 22a, 22b, essentially uniform with the subsequent obtaining a uniform flame along the entire length of the burner 1.

Figures 4, 5 and 6 allow a more detailed study of the entire internal profile of the described burner and, in particular, the special shape of the intermediate partition 13 placed between the upper 5 and lower 6 shrouds of the burner 1. Such an intermediate partition 13, clearly shown in the figures, can be made by stamping a metal sheet and contains a lower wall formed to limit the lower zone of the venturi 2 and the main chamber 3 for distribution of the mixture, respectively, as well as the upper wall of the lower compensation chamber mentioned above ry 15. Such a bottom wall, starting from the region of the Venturi tube 2 is substantially concave and provided with a plurality of openings 20 which provide fluid communication between the main chamber 3, located at the top, and the compensation chamber 15 situated below.

At the lateral ends of such a concave lower wall of the intermediate partition 13 only behind the venturi 2, according to the direction of the flow of the fuel mixture for some extent, there are upward and longitudinally extending ribs 18a, 18b and 19a, 19b, which are formed by convex protruding sections of the sheet containing the intermediate the partition 13, and which are designed to form, respectively, the above calibrated through holes 16 a, 16 b and 17 a, 17 b for supplying the mixture from the main chamber 3 to the outer chamber at 22a. 22b.

Such ribs 18a, 18b and 19a, 19b protrude to different heights starting from the bottom wall of the intermediate partition 13 to form a number of first through holes 16a, 16b for a mixture having a larger cross section than a section of a number of second through holes 17a, 17b located before the first of the two named.

It should be noted that in the particular embodiment shown here, the through holes 16a, 16b formed by the ribs 18a and 18b, as well as the through holes 17a, 17b formed by the ribs 19a, 19b, have the same cross section.

Since the burner 1 has a narrowing in the closed end section 8, the ribs 19a, 19b, also intended for functional connection with the upper casing 5 of the burner 1, near such a closed end section 8 have a decreasing height relative to the lower wall of the intermediate partition 13, so that the through holes 19a, 19b had substantially the same cross section.

In addition, on the outer sides of the ribs 18a, 18b and 19a, 19b, the intermediate partition has two essentially flat side walls, forming respectively with the upper casing 5 the outer chambers 22a, 22b for supplying the fuel mixture with the corresponding holes 4, 4a, 4b, 4c, 4d and with the lower casing 6, the lower compensation chamber 15 with the corresponding calibrated channels 23a, 23b.

And finally, at the end section 8 of the burner 1, the intermediate partition has an end wall 21 protruding upward, like the ribs 18a, 18b and 19a, 19b, and designed to close the main distribution chamber 3 of the burner 1.

It should be noted that, although up to now, a description has been given of a furnace or grill burner equipped with a main distribution chamber, two lateral external supply chambers and a lower compensation chamber, formed by connecting the upper casing with the lower casing and placing a profiled intermediate partition between them, any other burner design of a furnace or grill having at least one main chamber and at least one external feed chamber connected to the main chamber by potassium Combined through holes for the fuel mixture having a larger cross section higher in the direction of flow of the mixture and a smaller cross section lower in the direction of flow of the mixture are part of the present invention.

Similarly, although the embodiment of the present invention has been described above, confirming essentially the presence of two longitudinal sections on each side of the main distribution chamber, along which are two calibrated through holes of different sections, respectively, despite the same length, any other configuration due to the constant reduction of the cross-section, which also allows to obtain the above effect, i.e. a smaller cross-section for supplying fluid from the main chamber to each feed chamber at the closed end section of the burner is part of a group of possible embodiments of the present invention.

The burner 1 of the oven or grill described above operates as follows. After connecting the burner 1 with the injector 9 and fixing the burner 1 at the connecting section 7 to the bracket 100 attached to the wall 101 of the furnace or grill, the flow of fuel gas through the injector 9, initiated by a user using a valve of a known design, creates a gas stream passing through the tube 2 Venturi first to zone 10 having a tapering section, then to zone 11 having a reduced section, and finally to zone 12, with an expanding section of the venturi 2. As is well known, the narrowing-expanding shape of the venturi 2 causes, in turn, due to the passage of fuel gas, the formation of a low pressure region near zone 11 with a reduced cross section; in such a reduced pressure region, the (primary) air is sucked in from the environment and the fuel gas mixes with the primary air, which ends in zone 12 with an expanding cross section.

Then, the fuel mixture formed passes into the main distribution chamber 3 and from there it partially enters the lower feed chamber 15 by means of the holes 20 provided on the concave lower wall of the intermediate partition 13, and partially into the lateral outer chambers 22a, 22b, passing through the calibrated holes 16a, 16b and 17a, 17b, respectively, formed, as could be seen, using ribs or bulges 18a, 18b and 19a, 19b of the intermediate partition 13 itself.

A different cross-section of such calibrated holes 16a, 16b and 17a, 17b, larger near the venturi 2 and smaller near the closed end section 8 of the main chamber 3, determines different “ease” of reaching the side chambers 22a, 22b by the flow of the fuel mixture (i.e., the flow subjected to various load losses), which causes a substantially uniform distribution of the fuel mixture and its local pressure inside the outer chambers 22a, 22b, despite the tendency, as a result of closing the end section 8 of the main chamber 3, to establish a higher fuel pressure implicit mixture near the end section 8 of the burner 1.

The fuel mixture is discharged from the external supply chambers 22a, 22b, as well as from the compensation chamber 15 through the flame openings 4a, 4b, 4c, 4d, respectively, and through calibrated channels 23a, 23b, providing, after ignition of the burner 1, the appearance of a uniform and uniformly distributed flame along the entire outer length of the burner 1.

Claims (11)

1. A gas burner (1) for stoves or grills, containing a venturi tube (2) for mixing fuel gas and primary air, a main distribution chamber (3), continuing in the longitudinal direction of the mixture flow and located behind the venturi (2), and at least one supply chamber (22a, 22b) located outside the main chamber (3) and provided with openings (4; 4a, 4b, 4c, 4d) for discharging a mixture of gas and primary air; moreover, the main chamber (3) and at least one outer chamber (22a, 22b) are hydraulically interconnected at least along the longitudinal length of the main chamber (3) using at least one through hole (16a, 16b, 17a, 17b), characterized in that at least one through hole (16a, 16b, 17a, 17b) has a relatively larger section in the upstream section and a smaller section in the downstream section relative to the longitudinal direction of the flow of the mixture at least one longitudinal length of the main chamber (3). 2. The burner according to claim 1, characterized in that it contains two chambers (22a, 22b) located outside the main chamber (3) and provided with holes (4; 4a, 4b, 4c, 4d) and are hydraulically interconnected with the main chamber ( 3) using two corresponding through holes (16a, 16b, 17a, 17b) for the fuel mixture, and through holes (16a, 16b, 17a, 17b) respectively provided for at least one corresponding longitudinal length of the main chamber (3) and have a relatively larger section in the upstream section with respect to the longitudinal direction of the flow of the mixture; and enshee section at the downstream portion, at least one longitudinal length of the main chamber (3). 3. A burner according to claim 2, characterized in that at least two outer chambers (22a, 22b) have a longitudinal elongation in the direction of flow of the mixture and are located along axes parallel to the axis of the main chamber (3). 4. The burner according to claim 1 or 2, characterized in that it contains an upper casing (5) and an intermediate partition (13), which when connected form at least partially the main chamber (3), at least one an outer chamber (22a, 22b) and at least one through hole (16a, 16b, 17a, 17b) for the fuel mixture. 5. The burner according to claim 4, characterized in that it comprises a lower casing (6) connected to the upper casing (5) and to the intermediate partition (13), and the lower casing (6) forms the lower compensation with the intermediate partition (13) camera (15). 6. A burner according to claim 4, characterized in that the intermediate partition (13) has at least one central concave section and at least one lateral convex section (18a, 18b, 19a, 19b), the central concave the section forms with the upper casing (5) a main chamber (3) having a longitudinal extension, and at least one lateral convex section (18a, 18b, 19a, 19b) forms at least one through hole (16a, 16b , 17a, 17b) for the fuel mixture. 7. The burner according to claim 6, characterized in that it comprises a lower casing (6) connected to the upper casing (5) and to the intermediate partition (13), and the lower casing (6) forms the lower compensation chamber with the intermediate partition (13) (fifteen). 8. The burner according to claim 4, characterized in that the intermediate partition (13) partially has openings (20). 9. The burner according to claim 1, characterized in that at least one longitudinal length of the main chamber (3) extends from the area near the outlet section (14) of the venturi (2) to the opposite end (8) of the main chamber (3) . 10. The burner according to claim 1, characterized in that the through hole (16a, 16b, 17a, 17b) has a section that decreases by part of the length or along the entire length. 11. The burner according to claim 1, characterized in that the venturi tube (2) is made in the form of an axial type.

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