GB2487134A

GB2487134A - Means to Protect an Ignition Element of a Burner

Info

Publication number: GB2487134A
Application number: GB1200410.7A
Authority: GB
Inventors: Lamberto Del Grosso
Original assignee: BAXI SpA
Current assignee: BAXI SpA
Priority date: 2011-01-10
Filing date: 2012-01-10
Publication date: 2012-07-11
Anticipated expiration: 2032-01-10
Also published as: ITMI20110005U1; FR2970322A3; ES1076068Y; GB201200410D0; GB2487134B; ES1076068U; HK1168413A1; FR2970322B3

Abstract

The invention is a protective device for an ignition element 19A of a burner 1 for a boiler. The burner has a burner body 3 and a burner lid 5 coupled to each other by at least one of a means of connection 33A, 33B, 33C, and the ignition element is associated with a part of the burner body where a flange (27 fig 3) of the burner lid is fixed. The ignition element is further associated with a plate 43 adapted to overlap at least one of the means of connection so as to prevent the separation of the flange of the burner lid from the burner body before removal of the ignition element. The means of connection may be a nut cooperating with a threaded pin, and the plate may include a protrusion 55 which overlaps the nut, when the ignition element is fitted. The arrangement prevents dismantling of the burner lid from the burner body until the ignition element has been removed, and thus prevents damage to the ignition element.

Description

PROTECTIVE DEVICE FOR AN IGNITION ELEMENT OF A

BURNER FOR A BOILER

This invention relates to a protective device for an ignition element of a burner for a boiler.

Generally, a boiler may be described as a device that transforms the energy of a fuel into heat and makes it available in a circuit containing a heat transfer medium or fluid, such as water or air. This may be so as to distribute the heat into an environment, for example via a water-based space heating system, or to provide hot water.

The boiler typically comprises a burner adapted to burn a fuel such as gas in order to generate the heat necessary to heat the heat-transfer medium or fluid.

Such a burner typically comprises two main parts: a first part attached to the boiler, commonly called a burner body, and a second part coupled to the first part, commonly called a burner lid. The burner body typically has the form of an elongated cylinder, having a cylindrical inner cavity with an opening smaller than the width of the cavity at one end. This end is typically provided with holes for receiving securing means such as threaded pins or bolts for fastening the burner lid (which is connected to an air duct or manifold) and openings for the housing of a suitable ignition element or spark plug and a flame detection device. The burner lid is detachably coupled to the burner body via the securing means (e.g. nuts and threaded bolts) cooperating with holes in a flange of the lid. Similar securing means seoure the spark plugs and the flame detection devices, which are inserted into the corresponding holes or housings in the flange and at the end of the burner body.

However, the arrangement described above presents various problems when it becomes necessary to detach the burner lid e.g. for cleaning the burner. A correct detachment sequence involves: -removing of at least the spark plug; -removing the nuts securing the flange of the lid to the burner body; -decoupling of the flange from the burner body.

Often this sequence is not performed correctly, and the burner body is released from the securing means and the lid is decoupled from the burner body before the spark plug is removed. This incorrect procedure, although faster than the correct one, results in removal of the burner lid with the associated spark plug being more difficult because of the non-linear shape of the electrodes of the spark plug.

In addition, during the steps of decoupling the flange and extracting the spark plug from its housing in the burner body, contact of the electrodes of the spark plug with the walls of the housing can occur. This may result in the possible bending of a protective ceramic element (typically integral to the electrodes) in the spark plug, causing it to crack. Such a crack may mean that the generation of the spark from the spark plug to ignite the flame does not occur at an end of the electrodes (which are positioned side by side) but rather at the crack, causing the failure of the spark plug and the consequent failure of the boiler. As such a crack may be very difficult to detect, a service technician will find it very difficult to attribute the failure of the boiler to the presence of such a crack.

Considering the above, considerable time and maintenance costs will be required due to the long and difficult search for the cause of the failure and may result in the incorrect replacement of non-damaged components (incorrectly considered to be causing the failure) One of the aims of the present invention is to provide a protective device for the ignition element of a burner for a boiler which is capable of resolving at least some of the aforementioned problems.

In particular, the present invention may provide a device which imposes the correct detachment sequence, namely requiring the removal of the spark plug before removal of the burner lid.

These, and other aspects of the invention which will become evident to a person skilled in the art, are achieved by a protective device for the ignition element of a burner according to the appended claims.

According to an aspect of the invention there is provided a protective device for an ignition element of a burner for a boiler, the burner comprising a burner body and a burner lid coupled to each other, the lid being connected to an air duct or manifold, an ignition element, placed adjacent to a part of the burner body where a flange of the burner lid is fixed, through which the removable securing means to said flange being fixed to that ignition element inserted into its own housing; wherein the ignition element is associated with a plate adapted to overlap at least one of said means of connection so as to prevent the separation of the flange of the burner lid from the burner body before the separation from the latter and the flange from said ignition element.

According to another aspect of the invention there is provided a protective device for an igniticn element of a burner for a boiler, wherein the burner comprises: a burner body and a burner lid detachably coupled by securing means to each other, the lid preferably being connected to an air duct or manifold; an ignition element, inserted into a housing located at a part of the burner body where a flange of the burner lid is fixed; and wherein the protective device comprises a plate with which the ignition element is associated, the plate being adapted to overlap at least one of the securing means so as to prevent the separation of the flange of the burner lid from the burner body before removal of the ignition element.

The invention extends to methods and/or apparatus substantially as herein described with reference to the accompanying drawings.

Any apparatus feature as described herein may also be provided as a method feature, and vice versa -As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method to aspects may be applied apparatus aspects, and vice versa.

The invention will now be described, purely by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partial perspective view of a burner provided with a protective device according to the invention; Figure 2 is a partial perspective view of the body of the burner; Figure 3 is a perspective view of the burner lid; and Figure 4 is a perspective view of the spark plug arrangement according to the invention.

Figures 1 to 4 show a burner 1 comprising two main parts: a first part or burner body 3 and a second part detachably coupled to the first part indicated as burner lid 5.

Figure 2 shows the burner body 3 having, in this example, a cylindrical shape, with a cylindrical internal cavity 7 where a flame is generated in a known manner (which will not be described); the burner body 3 has an opening 9 whose width is smaller than that of the cavity 7, said opening being provided at a front end section 11 of burner body 3. Front end section 11 has a plurality of securing means comprising threaded pins 13, on one surface 12, an opening 15 (communicating with the cavity 7) adapted to enable the connection to the burner of a normal duct (not shown), and openings l7A and 17B (communicating with the cavity 7) adapted to house a spark plug 19A and a flame detection device 19B, respectively.

Figure 3 shows the burner lid 5, which is detachably coupled to the burner body 3, and which comprises mainly a flange 27, adapted to be directly secured to the burner body 3, and to which an air duct or manifold may be connected. Flange 27 has generally a circular shape, with holes 31

S

adapted to receive the securing means 13, the latter cooperating with nuts 33A, 33B and 330 so as to secure the lid 5 to the burner body 3. Lid 5 also has a central hole (not shown in the figures), adapted to house the manifold 29, and holes 37A and 37B adapted to secure the spark plug ISA and the flame detection device 19B, respectively. Flange 27 also has a cutaway section 39 adapted to enable the securing of the aforementioned duct (not shown in the figures) to the opening 15 of the burner body 3.

Manifold 29 is secured to the flange 27 by means of screws or bolts 41.

Figure 4 shows the spark plug iSA mechanically fixed (so as to form a single body), via an interference fit to a plate 43; the spark plug comprises a pair of electrodes 45 and 63, which are connected to electrical contacts 51 and 49, respectively. The electrode 63 has a ceramic coating 61 to provide electrical isolation.

Plate 43 comprises holes 53 adapted to house screws 54 for the securing of the spark plug ISA to the flange 27 and a protrusion 55 located at its lateral end section 57. The latter has an S-shaped folded portion 59 adapted to enable the protrusion to be positioned immediately above a nut 33A in order to block and prevent the removal thereof without removing the spark plug 19A and the plate 43 associated thereto.

As a result, it is then envisaged that the plate 43 associated with the spark plug 19A should both be removed in order to remove one of the nuts (33A) which connect the lid 5 to the burner body 3 and separate the latter. This avoids the inconveniences of the known solutions and an incorrect method of separation of the parts.

Obviously, a plate similar to the plate 43 may also be associated to the spark plug 19A or the plate 43 may have a different shape such as, for example, to hold more nuts 33A and 338. Other such variations are to be considered to fall within the soope of the following claims.

It will be understood that the invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

Each feature disclosed in the description, and

(where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.

The abstract is repeated here for completeness: A protective device for an ignition element (l9A) of a burner (1) for a boiler, the boiler comprising a burner body (3) and a burner lid (5) coupled to each other, the lid (5) being connected Jo an air duct or manifold, an ignition element (19A) placed at a part of the burner body where it a flange (27) of the burner lid (5) is fixed, through which the removable securing means to said flange being fixed to said ignition element (19A) inserted into its own housing. Associated to this ignition element is a plate (43) adapted to overlap at least one of the said securing means so as to prevent the separation of the flange (27) from the burner body before the separation from the latter and the flange of said ignition element (l9A)