GB2194628A

GB2194628A - Gas burner heads

Info

Publication number: GB2194628A
Application number: GB08720075A
Authority: GB
Inventors: Nicco Polidoro
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-08-29
Filing date: 1987-08-26
Publication date: 1988-03-09
Also published as: IT8685593A0; NL8701999A; GB8720075D0; DE3726196A1; IT1205556B; FR2603365A1

Description

1 I GB2194628A 1

SPECIFICATION

Improvements in and relating to gas burner heads The present invention relates to gas burner heads. More especially, the invention concerns gas burner heads formed from a suitably punched sheet.

In our co-pending Italian Patent Application No 85623/A/85, there is described a burner head which essentially comprises an element comparable to a radiator of the type used normally for heating vehicle compartments and which is disposed on one of the walls of a mixing chamber provided in a burner; the gaseous mixture is intended to flow parallel to the lamellae of said element, which thus act as a -support surface- for the flame; a basic feature of the burner is the provision of a hydraulic circuit for the flow of coolant applied between said element or on the surface thereof and designed to remove heat from said lamellae, thus maintaining the temperature of these latter within acceptable limits. These features make it possible to develop a burner whose combustion products contain very low percentages of nitrous products NO., in accordance with the principle of hyperstoichiometric combustion.

In our Italian Patent Application No 85510/A/86, this constructional principle is put into effect in the form of a series of preferred embodiments, one of which provides for the burner head to comprise a series of parallel lamellae, the tube through which the coolant circulates being welded to one of the front surfaces of the lamellar assembly.

An object of the present invention is to pro- vide a design of burner head which yields combustion products containing nitrous products at levels which are substantially below those specified by the relevant standards, particularly those of the European Community, but which at the same time is of much simpler construction both with respect to the devices already mentioned above and with respect to other devices currently in use of a type capable of overcoming the problem asso- ciated with the emission of nitrous products.

In particular, it is an object of the invention to achieve the same or similar results to those achieved by the burner forming the subject matter of our Italian Patent Application 85510/A/86, but using a burner head which is of much simpler construction.

It is a further object of the invention to provide a burner head with a high ratio between ---noload- and ---fullload", for reasons which will be explained below.

According to the present invention, there is provided a gas burner head, comprising a metal sheet in which there is provided close sets of slots arranged in generally parallel rows, a fin projecting between each pair of neighbouring slots of the same row, each said fin upstanding from to the surface of the sheet and being formed from the original surface of the sheet itself, and tubular elements of a cooling circuit for transfering heat from the burner head connected to the surface of the sheet opposite to that from which the fins are upstanding at locations corresponding to gaps provided between adjacent rows of slots.

In practice, the invention provides for the burner head to be formed from a sheet of metal, which is punched without removing any material so as to form a series of adjoining slots disposed in parallel juxtaposed rows, a fin being formed between successive slots; said fin is disposed substantially perpendicularly to the surface and results from the deformation of the originally flat surface of the head.

A suitable coolant circuit similar to that provided in the aforementioned devices is provided level with the lower surface of the head.

The present invention will now be described by way of example only with reference to the accompanying drawings, wherein:

Figures 1, 2 and 3 depict respectively a side view, a plan view and a front view of a burner head in accordance with the invention; and Figures 4, 5 and 6 depict respectively a front view, a plan view and a side view of an enlarged area of the surface of the burner head illustrated in Figures 1 to 3.

As shown in Figures 1, 2 and 3, the burner head comprises a metal sheet 1, including close sets of slots 2 arranged in parallel rows; Figures 1, 3, 4 and 6 show that between each slot 2 and the slot succeeding it there projects a fin 3 disposed substantially perpendicular to the rest of the head surface. Each fin 3 consists of a portion of the original surface of the sheet 1 which has been bent perpendicularly, thereby allowing the formation of the above-mentioned slots.

It is evident that the fins are arranged side by side in generally parallel rows.

In Figures 1 and 3, the various tubular elements 4 of a cooling circuit are illustrated. In the example illustrated, the circuit comprises a pair of manifolds 5 and additional pipes 6 for the inflow and outflow of coolant. The horizontal sections of the tubular elements 4 are secured level with the lower surface of the sheet 1 and, more precisely, so as to correspond with gaps 7 between pairs of adjacent rows of lamellae and fins.

It is also evident from the drawings that the fins 3 are disposed level with that surface of the sheet situated at the actual location where combustion of the gaseous mixture takes place.

The fact that a burner head in accordance with the invention has a high no-load/full-load ratio, together with a lower ratio between 2 GB2194628A 2 0 width and depth of the individual slots, in relation to a perforated sheet from which material has been removed, offers the following advantages: 5 - low resistance to the passage of the gase- 70 ous mixture, - refractory nature in respect of flash-back phenomena. The low flow resistance makes it possible to attain very high specific power which can 75 even exceed 10OKCal/CM2.

Furthermore, compared with a sheet having slots formed by the removal of material and having similar characteristics in respect of con struction material, as well as similar dimen sions and arrangement of the slots them selves, a burner in accordance with the inven tion makes it possible to achieve an increase in the amount of heat transmitted to the pipes through which the coolant circulates, thereby improving the cooling of the -support sur face- for the flame.

The support surface of the sheet 1 may alternatively be of corrugated shape in longitu dinal direction, the troughs and peaks of these corrugations being disposed so as to corre spond with the gaps 7 between the rows of adjoining slots; in this way any solid particles of oxides or the like which may become de tached from the overlying heat exchanger can drop into the troughs in the surface thus formed, thereby preventing the slots from be ing blocked.

Likewise, with a view to avoiding any accu mulation of solid particles on the slots, it is possible to arrange the sheet 1 in such a way that it is not disposed perpendicularly to the flow of fuel mixture.

It is pointed out that a burner head accord ing to the invention can be formed using any punching process of known type, having the essential feature of not involving any removal of material, without thereby departing from the scope of the invention.

Claims

1. A gas burner head, comprising a metal sheet in which there is provided close sets of slots arranged in generally parallel rows, a fin projecting between each pair of neighbouring slots of the same row, each said fin upstand ing from to the surface of the sheet and being formed from the original surface of the sheet itself, and tubular elements of a cooling ci cuit for transfering heat from the burner headton nected to the surface of the sheet opposite to that from which the fins are upstanding at locations corresponding to gaps provided be tween adjacent rows of slots.

2. A gas burner head according to claim 1 wherein each fin is aligned substantially perpendicular to the respective surface of the metal sheet,

3. A gas burner head according to claim 1 or claim 3 wherein the sheet is corrugated shape in the longitudinal direction, the troughs and peaks of the corrugations being disposed so as to correspond with the gaps between adjacent rows of slots.

4. A gas burner head according to any one of claims 1 to 3 wherein the sheet is disposed so as not to be perpendicular to the feed direction of the gaseous mixture.

5. A gas burner head substantially as herein described with reference to Figures 1 to 6 of the accompanying diagrammatic drawings.

Published 1988 at The Patent Office, State House, 66/71 High Holborn, London WC 1 R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.

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