WO1994001721A1

WO1994001721A1 - Turbo type blow tube of boiler burner

Info

Publication number: WO1994001721A1
Application number: PCT/KR1993/000031
Authority: WO
Inventors: Jin Min Choi
Original assignee: Jin Min Choi
Priority date: 1992-07-03
Filing date: 1993-04-21
Publication date: 1994-01-20
Also published as: CN1062652C; KR940002548A; CN1080707A; AU4272693A

Abstract

A turbo type blow tube of a boiler burner. This blow tube achieves complete combustion and generates no catching noise. In order to achieve the object, this tube comprises a first tube (1) for carrying out first combustion of fuel and a second tube (2) for carrying out re-combustion of the fuel. The first tube (1) reduces in its diameter such that its outlet (10) has a smaller diameter and shows a bottle-neck outer shape. The second tube (2) is connected to the first tube (1) and provided with a plurality of suction ports (3) for introducing combustion air, which is used for re-combustion of the fuel as well as offset of gas expansion pressure at an initial ignition, into the second tube (2) due to pressure difference between the inside and outside of the second tube (2).

Description

TURBO TYPE BLOW TUBE OF BOILER BURNER

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates in general to blow tubes of boiler burners, and more particularly to turbo type blow tubes which comprises first and second combustion tubes and prevents generation of soot and catching noise in initial ignition, and achieves complete combustion.

Description of the Prior Art

With reference to Fig. 8, a known boiler burner using kerosene or light oil as a fuel generally includes a jet nozzle 11 for injecting the fuel, a blower 15 for supplying combustion air which is to be mixed with the fuel out of the nozzle 11 and a blow pipe or a blow tube 16 for guiding the combustion air of the blower 15 to the nozzle 11 to mix this air with the fuel injected from the nozzle 11. The burner further includes a nozzle support 14 for supporting the nozzle 11 and an ignition rod 12 for igniting the fuel out of the nozzle 11. In order to circulate the combustion ai of the blower 15 in the blow tube 16, a stabilizer 13 is radially provided at the front part of the tube 16. Here, it is conventionall noted that the flame shape of the burner is determined by air circulation accuracy of th stabilizer 13, a distance between the nozzle 11 and th stabilizer 13, and size and shape of the blow tube 16.

However, the known burner has a problem caused by th shape of the blow tube 16. Otherwise stated, this tube 1 has a simple cylindrical shape and this causes unevenness of the flame shape of the burner and generation of flying oil drops caused by lifting phenomenon as depicted in Fig. 8C. The uneven flame shape and the flying oil drops cause incomplete combustion and generation of soot. In this regard, the problem of the known burner is resided in that the burner generates, when it is initially ignited, a catching noise or an explosion noise and becomes sooty.

If described in detail, when the blow tube 16 is constructed to have a simple cylindrical shape as having a uniform diameter throughout its length, the oil fuel injected from the nozzle 11 is evaporated to generate oil particles not burned. These oil particles cause generation of incompletely burned gas due to the lifting phenomenon and this generates CO gas and sulfur dioxide which are known as the cause of environmental pollution. Furthermore, the soot and sludgy easily cover the heat transfer surface of the burner and, as a result, reduce the heat transfer efficiency of this surface and heating efficiency of the boiler. Hence, the using amount of the fuel is increased and this imposes an economical burden on the user. In addition, the soot and sludgy-covered heat transfer surface requires to be often cleaned. These soot and sludgy are exhausted so as to pollute and damage objects, such as the washing hung out to dry, neighboring the boiler. If the inflammable soot and sludgy are not timely removed from the boiler, they cause a fire and makes CO gas not be exhausted to the atmosphere but be introduced into the inside of the room so as to cause gas poisoning. In order to increase the combustion efficiency of the boiler, Korean Utility Model Appln. No. 91-10454 applied by the applicant proposed a blow tube having a narrowing outlet, as depicted in Fig. 8B, for collecting the flame. However, this type of blow tube, while somewhat increasing the combustion efficiency of the burner, nevertheless causes incomplete combustion of the fuel as well as generation of explosion noise in initial ignition.

Figs. 9A to 9D show variation of a flame of the known burner having the blow tube disclosed in the above Korean U.M. Appln. from a time of an initial ignition to a time of a normal combustion. With reference to these drawings, the burner is instantaneous y ignited, at a first step of Fig. 9A, since it is maintained in pre-purge state where the inner pressure of the combustion chamber of the burner is lower than a predetermined level. However, when the fuel oil injected from the nozzle is ignited at a second step, the inner pressure of the combustion chamber is rapidly increased since the oil ignition causes a momentary ga expansion and this generates so-called catching phenomeno where the flame can not normally go to the boiler chimne because of disturbance of the increased inner pressure o the combustion chamber but be momentarily pushed back to th burner as depicted in Fig. 9B. Hence, there generates pulsation between the flame and the inner pressure with a explosion noise "pop". Thereafter, a small flame i generated, at a third step of Fig. 90, thanking for th pressure of combustion air supplied by the blower (no shown). At a fourth step, this small flame is enlarged t be a normal flame before the normal combustion of the burne is achieved as depicted in Fig. 9D. Here, th aforementioned catching makes the nozzle, the ignition rod, a diffuser and the blow tube be continuously covered with the soot. This mainly causes malfunction of the burner, such as bad ignition or ignition failure, besides generation of large explosion noise due to the pulsation between the flame and the inner pressure of the combustion chamber. This explosion noise gives feelings of uneasiness and unpleasantness to the user, and furthermore, occasionally causes separation of the chimney from the boiler.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a turbo type blow tube for a boiler burner in which the aforementioned problems of incomplete combustion and generation of explosion noise can be overcome, and which includes first and second combustion tubes for combustion and re-combustion of the fuel, respectively.

The aforementioned object can be accomplished by providing a turbo type blow tube of a boiler burner comprising a first tube for carrying out first combustion of fuel and a second tube for carrying out re-combustion of the fuel. The first tube reduces in its diameter such that its outlet has a smaller diameter and shows a bottle-neck outer shape. The second tube is connected to the first tube and provided with a plurality of suction ports for introducing combustion air, which is used for re-combustion of the fuel as well as offset of gas expansion pressure at an initial ignition, into the second tube due to pressure difference between the inside and outside of the second tube. BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention _. wi11 be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a perspective view of a turbo type blow tube in accordance with an embodiment of this invention;

Fig. 2 is a side view of the blow tube of Fig. 1; Fig. 3 is a view corresponding to Fig. 2, but showing another embodiment having rectangulai—shaped suction ports;

Fig. 4 is a view corresponding to Fig. 2, but showing another embodiment having a simple cylindrical outer shape;

Fig. 5 is a view corresponding to Fig. 2, but showing another embodiment having a cylindrical bottle-neck outer shape;

Fig. 6 is a sectioned view of the blow tube of Fig. 1; Fig. 7 is a sectioned view of a burner combined with the blow tube of Fig. 1 and shows operation of the blow tube;

Figs. 8A to 80 show a construction of a known blow tube, respectively, in which:

Fig. 8A is a schematic view showing the construction; Fig. 8B is a front view of a stabilizer of the blow tube; and

Fig. 80 is a schematic view showing the flame shape; Figs. 9A to 9D show variation of a flame of the known burner having the known blow tube of Figs. 8A to 8C from a time of an initial ignition to a time of a normε-J combustion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to Fig. 1 showing a primary embodiment of the present invention, the turbo type blow tube of this invention preferably has a generally cylindrical outer shape. This tube preferably varies its diameter such that the diameter is gently enlarged so as to be larger at the outlet 1a of the tube. This tube includes a plurality of suction ports 3 which are arranged in a line at its circumferential surface. As sectional ly represented in Fig. 6, the tube comprises a first tube 1 which is adapted for first combustion of the fuel. This first tube 1 is provided with a flange 6 at its inlet and has a bottle-neck shape at its outlet. This first tube 1 is connected to a second tube 2 which is adapted for re-combustion of the fuel and welded to the first tube 1 under the condition that it is inserted onto the erect portion of the tube 1.

This second tube 2 varies its diameter such that the diameter is gently enlarged toward the outlet 2a of the tube 2 and, as a result, the enlarged outer shape of the blow tube will be achieved. The suction ports 3 are formed on circumferential surface of the second tube 2.

In accordance with another embodiment of this invention, the second tube 2 may have a simple cylindrical outer shape as depicted in Fig. 4 or a cylindrical bottle¬ neck outer shape as reducing its diameter such that the diameter at the outlet is smaller as represented Fig. 5.

It is preferred to form about 10 - 40 of suction ports 3 on the second tube 2 and to arrange these port 3 so as to be aligned with the distal end of the outlet 1a of the first tube 1.

Each of the suction ports 3 preferably has a small circular shape as represented in Fig. 2, however, this port 3 may be formed to have a rectangular shape as represented in Fig. 3.

It is preferred to manufacture the first and second tubes 1 and 2 separately, and thereafter, weld the second tube 2 to the first tube 1 as described above. However, please note that the first and second tubes 1 and 2 of this blow tube may be integrally molded at the manufacturing process of the blow tube.

In the drawings, the reference numeral 4 denotes mounting holes for mounting this blow tube on the burner body 10 using set screws, the numeral 5 denotes an outside air suction port and the numeral 13 denotes a diffuser.

This blow tube having the aforementioned construction is mounted on a bracket in a combustion chamber arranged at a lower part of the burner body 10 as represented in Fig. 7.

Hereinafter, the operational effect of this turbo type blow tube will be described in conjunction with Fig. 7.

Here, since most of the elements of the burner of this invention except for the blow tube are common with those of the prior art of Fig. 8A, and therefore, those elements common to both the prior art and this invention will carr the same reference numerals.

In operation of the burner, a blower (not shown) of th burner is driven to supply the outside air to the nozzle 11.

At this time, an electronic oil pump (not shown) is drive to cause the oil to be injected from the nozzle 11 and, a the same time, the ignition rod 12 ignites the oil out o the nozzle 11. Hence, a flame is generated at the distal end of the nozzle 11 and goes toward the outlet 1a of the fi rst tube 1.

This flame continues its combustion state due to the combustion air introduced from the burner body 10 to the inside of the blow tube and moves from the first tube 1 to the second tube 2. At this time, this flame causes a momentary gas expansion in the same manner as the prior art. However, this turbo type blow tube is provided with the plurality of suction ports 3 on the second tube 2 and, in this respect, causes no pulsation differently from the prior art. Otherwise stated, when the flame is pushed to the outlet 2a of the second tube 2, the air remaining in the combustion chamber of the boiler is sucked into the tube 2 due to the pressure difference between the inside and outside of the tube 2. In result, no pulsation is generated in the tube 2 and this allows the flame to simply go to the chimney and does not generate explosion noise or catching noise. It is thus possible to carry out normal combustion with no explosion noise.

The flame at this normal combustion heats the second tube 2 to a temperature higher than 800 ^*C. In addition, the inner pressure of the blow tube lower than the outer pressure of the tube causes the air remaining in the combustion chamber to be continuously introduced into the second tube 2 through the suction ports 3 and be used for completely burning the incompletely burned oil in the tube 2. Hence, this blow tube achieves complete combustion of the fuel . As described above, the present invention provides a turbo type blow tube for a boiler burner which comprises first and second combustion tubes which are connected to each other and adapted for combustion and re-combustion of the fuel, respectively. The second tube is provided with a plurality of suction ports for introducing the air remaining out of the second tube in the combustion chamber into the second tube due to pressure difference between the inside and outside of the second tube. Thanking for such a construction of this blow tube, the air introduced from the outside of the tube to the inside of the tube offsets gas expansion pressure in the blow tube at the initial ignition of the burner and, as a result, achieves the ignition with no explosion noise or catching noise. This invention thus provides a burner of high reliability which scarcely generates soot and does not cause malfunction such as bad ignition or ignition failure. In addition, the combustion air is naturally introduced into the second tube through the suction ports at the normal combustion of the burner so that the incompletely burned oil in the second tube is completely burned. This blow tube thus achieves complete combustion of the fuel oil so that it increases the combustion efficiency of the burner and, as a result, reduces the using amount of fuel. This turbo type blow tube prevents generation of soot and poisonous gases and this makes maintenance of boiler be easy and prevents envi onmental pollution.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

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Claims

WHAT IS CLAIMED IS:

1. A turbo type blow tube of a boiler burner comprising: a first tube for carrying out first combustion of fuel, said first tube reducing in its diameter such that the outlet of said first tube has a smaller diameter and showing a bottle-neck outer shape; and a second tube for carrying out re-combustion of the fuel, said second tube being connected to said first tube and provided with a plurality of suction ports for introducing combustion air, which is used for re-combustion of the fuel as well as offset of gas expansion pressure at an initial ignition, into said second tube due to pressure difference between the inside and outside of said second tube.

2. A turbo type blow tube according to claim 1, wherein said second tube has such enlarged diameter that the outlet of said second tube has a larger diameter.

3. A turbo type blow tube according to claim 1, wherein said second tube is welded to said first tube as inserted onto said first tube.

4. A turbo type blow tube according to claim 1 , wherein said second tube is integrally formed with said first tube.

5. A turbo type blow tube according to claim 1 , wherein said second tube has a simple cylindrical shape of a unifor d i ameter .

6. A turbo type blow tube according to claim 1, wherein said second tube has such reduced diameter that the outlet of said second tube has a smaller diameter and shows a bottle-neck outer shape.

7. A turbo type blow tube according to claim 1, wherein said suction ports of the second tube are arranged to be aligned with a distal end of said outlet of the first tube.

8. A turbo type blow tube according to claim 1, wherein each of said suction ports has a rectangular shape.

9. A turbo type blow tube according to claim 1, wherein the number of said suction ports is ranged from about 10 to about 40.