JPS6387528A - Combustion device - Google Patents

Abstract

PURPOSE:To reduce concentration of gas staying in the vicinity of an ignition rod and to prevent the occurrence of explosive combustion during ignition, by a method wherein, in secondary air feed holes, the size of the feed hole in the vicinity of an ignition rod is made larger than that of the feed hole positioned away from the rod. CONSTITUTION:In the case of ignition, air, the temperature of which is extremely low due to the temperature of the open air, is introduced as primary air into the interior of an evaporating chamber 21, the density is high and the air becomes excessive. According a thin air-fuel mixture is injected through burner ports 25 and 25, and even if spark discharge is effected by means of an ignition plug 26, several seconds are required for ignition, and a delay in ignition occurs. In which case, the size of a secondary air feed port 33 in the vicinity of ignition rods 26A and 26A of the ignition plug 26 is set to 3.5-4mm in diameter, and is made larger than the size of a feed hole 32 formed away from the rods 26A and 26A. By this constitution, even if a delay in ignition occurs, quantities of secondary air is injected through the larger feed hole 33, and the high concentration of air-fuel mixture, staying in the vicinity of the rods 26A and 26A is lowered to prevent the occurrence of explosive combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a combustion device for vaporizing and burning petroleum.

(b) Conventional technology A burner head with multiple flame ports is provided at the tip of the burner body whose interior is a vaporization chamber, and the premixed gas ejected into the combustion chamber from the flame ports of the burner head is stimulated by the discharge sparks of the ignition plug. The burner body was ignited to cause combustion, and secondary air was supplied to the combustion flame from a plurality of secondary air supply ports annularly arranged along the outer periphery of the burner body.
It is known from Japanese Patent Publication No.-2844, Japanese Patent Publication No. 61-18084, etc.

(c) Problems to be solved by the invention In the combustion device disclosed in the above-mentioned Japanese Patent Publication No. 61-2844, etc., the tip of the ignition rod of the ignition plug is located directly in the flame port. If an ignition delay occurs, the premixed gas ejected from the flame port will stagnate near the ignition rod of the spark plug, and this stagnation will ignite the highly concentrated premixed gas, causing an abnormality such as an explosion. Combustion could occur. This abnormal combustion often occurs when re-igniting immediately after extinguishing a fire, but it is especially common in closed or semi-closed combustion devices that discharge combustion exhaust gas from the combustion chamber to the outside through a heat exchanger and exhaust pipe. This explosive combustion is extremely dangerous as it may lead to destruction of parts.

Therefore, the object of the present invention is to prevent explosive combustion from occurring at the time of ignition.

(-) Means for solving the problem To this end, as shown in the embodiments, the present invention has a burner body (18) with a vaporization chamber (21) inside and a plurality of flame ports (25) at the tip. A burner head (24) is provided, and a spark plug (26) having a tip of its ignition rod (26A) (26A) adjacent to the flame port (25) is connected to the burner head (24).
) is ignited and combusted, and secondary air is supplied to the combustion flame from a plurality of secondary air supply holes arranged along the outer periphery of the burner body (18). In the combustion device, among the plurality of secondary air supply holes, the ignition rod (26A) of the spark plug (26) (
The thick awn of the secondary air supply hole (33) located near the ignition rod (26A) is made larger than that of the secondary air supply hole (32) located away from the ignition rod (26A).

(f) Effect When low-temperature air is introduced into the vaporization chamber (21) as primary air during ignition, the primary air in the vaporization chamber (21) has a high density and becomes excess air. A thin premixed gas will blow out from the spark plug (26
) Even if a spark discharge occurs, it takes more than 10 seconds to ignite, resulting in an ignition delay. However, the spark plug (26
) The diameter of the secondary air supply hole (33) near the ignition rod (26A) (26A) is approximately 3.5 to 4 m, and the secondary air supply hole (33) is located away from the ignition rod (26A) (26A). Since it is set larger than the supply hole (32), even if this ignition delay occurs, the large secondary air supply hole (33)
A large amount of secondary air blows out from the ignition rod (26A) (2
6A) The concentration of the highly concentrated premixed gas stagnant in the vicinity becomes low and explosive combustion no longer occurs.

(f) Example An embodiment of the present invention will be described below based on the drawings.

(1) is a hollow cylindrical combustion tube with a combustion chamber (2) inside;
(3) is a heat exchanger connected to the combustion tube (1), and (4) is connected to the heat exchanger (3) through the collection chamber (5) at the negative end, and to the air supply and exhaust tube with a double pipe structure at the other end. (6) are exhaust pipes connected to the respective exhaust pipes. The supply/exhaust pipe (6) penetrates the chamber wall (7) and has its tip protruding outdoors, and the combustion exhaust gas from the exhaust pipe (4) passes through the supply/exhaust pipe (6) to its exhaust port. (8) Easily discharged outdoors. (9) has a burner motor (10
) A turbo-type air supply fan (11) (11
), and the inside of the air supply case (9) is an air supply chamber (13) that communicates with the outdoors via an intake cylinder (12) and an intake/exhaust pipe (6). (14) is a guide vane plate interposed between the two air supply fans (11) (11);
15) is a support plate fixed to the open end inside the air supply case (9), and a primary air supply hole (15) is provided in the center of the support plate (15).
16) has a plurality of communication holes (17) (17) opened at predetermined intervals on the outside. (18> is the insulation material <1
The burner body is attached to the support plate (15) through the burner body, and a vaporization heater (20) is embedded in the peripheral wall of the burner body. A vaporization chamber (21) is formed to which air is supplied.

(22) is a fuel supply pipe (23) connected to a tank (not shown)
The petroleum fuel is atomized by centrifugal force into the vaporization chamber (2).
1), the burner motor 10)
rotated by 24) is the burner body (18).
) is a burner head screwed onto the tip opening of the burner head, and is equipped with a flame port (25) (25) consisting of a large number of radial slits, and the premixed gas of vaporized gas and primary combustion air is passed through the flame port. (25) It is ejected from (25) into the combustion chamber (2). (26) is an ignition plug that is supported through the combustion tube (1), and its pair of ignition rods (26A)<26A)
The premixed gas ejected from the flame port (25) is ignited by causing a spark discharge at the tip of the flame port (25).

The pair of ignition rods <26A) (25A) are in a substantially parallel state, and a suitable place in the middle is connected to the burner body 18.
) side so that the tip faces the flame opening 25>. (27) is the flame mouth (25) (25)
The combustion flame formed in the section <28) is a flame rond that detects the presence or absence of the combustion flame (27).

(29) is a secondary air chamber (
30), the case (29) has its end plate portion <29A) connected to the combustion tube (1) with an insulating backing (31) interposed therebetween. The tip of the end face plate (29A), which is formed by bending the end of the burner case (29) inward, is fixed to the burner body (18) so as to surround the burner body (18). A large number of secondary air supply holes (32
) (33) are bored so as to be arranged in a ring. The size of this secondary air supply hole is the ignition rod (26A
) (26A) are large secondary air supply holes (33) with a diameter of approximately 3° 5-4 m, and the other holes located away from the ignition rod (26A) (26A) are A number of secondary air supply holes (32) have a diameter of approximately 2 to 2.5
It is set as small as 1111. If all of the secondary air supply holes are set to approximately 3.5 to 4 rs, the amount of secondary air supplied will be excessive and the flow rate will be increased, resulting in poor heat exchange efficiency. (34) is a fuel supply pump such as an electromagnetic pump, and (35) is an oil storage tank such as an oil leveler.

Further, a hot air blower is disposed on the back of the heat exchanger (3), and discharges warm air that has exchanged heat with indoor air into the room through an outlet (not shown).

The operation of the above configuration will be explained below.

First, when an operation switch (not shown) is closed, the temperature of the burner body (18) is low, so the vaporization heater (20) is energized and the body (18) is heated. When the burner body 18) eventually reaches the vaporization temperature of the petroleum fuel, the burner motor (10) is started and the air supply fan (11) (u) and the atomizer (22) are operated. Therefore, outdoor air for combustion passes through the supply/exhaust pipe (6) and the supply cylinder (12) to the supply case (
9) into the air supply chamber (13), and this air supply chamber (13)
) is supplied as primary air to the vaporization chamber (21) in the burner body 18), and is also supplied as secondary air to the secondary air chamber (30) in the burner case (29).

On the other hand, a pre-purge is performed, and after approximately 20 seconds have elapsed since the start of the burner motor (10), the fuel supply pump (34) is driven and the spark plug (26) starts spark discharge. Therefore, the pump (34) can completely supply fuel to the rotating atomizer (22) through the fuel supply pipe (23), and the atomized fuel is instantaneously vaporized in the vaporization chamber (21) and It mixes with air to become a premixed gas, which flows from the flame port (25) of the burner head (24) to the combustion chamber (2).
Squirt inside. At this time, the plug (26) is ignited by spark discharge to form a combustion flame (27) and combustion begins. In addition, the secondary air in the secondary air chamber (30) is ejected from the secondary air supply holes (32) and (33), creating a combustion flame (27).
is supplied to promote secondary combustion. After this combustion starts,
The burner body (18) is heated by the combustion flame (27) and h-dupak is performed, so the power to the vaporization heater (20) is stopped, and the ignition plug (26) is also set to a built-in timer for about 15 to 30 minutes after starting. Stops driving after 20 seconds,
Combustion continues.

By the way, when air with extremely low temperature is introduced into the vaporization chamber (21) as primary air due to the influence of outside temperature etc. at the time of ignition, the primary air in the vaporization chamber (21) has a high density and becomes excess air, causing the flame nozzle. (25) A thin premixed gas is ejected from (25), and even if a spark discharge occurs at the ignition plug (26), it takes more than ten seconds to ignite, resulting in an ignition delay. However, the secondary air supply hole (3) located near the ignition rod (26A) (26A) of the spark plug (26)
3) is set to have a diameter of about 3.5 to 4 ann, which is larger than the secondary air supply hole (32) located away from the ignition rod (26A), so even if this ignition delay occurs, the A large amount of secondary air blows out from the large secondary air supply hole (33), and the concentration of the highly concentrated premixed gas stagnant near the ignition rod (26A) becomes low, causing explosive combustion. There isn't.

Therefore, the connection between the burner case (29) and the combustion tube (1), the connection between the combustion tube (1) and the heat exchanger (3), and the connection between the heat exchanger (3) and the gathering chamber (5). etc. will not be damaged by explosion or combustion.

In addition, the numerous secondary air holes (32) (32) located away from the ignition rods (26A) (26A) are still small in diameter, approximately 2 to 2.5 m, so the amount of secondary air increases. Therefore, the flow rate of the combustion exhaust gas through the combustion tube (1) and the heat exchanger (3) does not become extremely high, and the heat exchange efficiency does not decrease significantly.

(G) Effects of the Invention As described above, the present invention can prevent abnormal combustion such as explosion due to ignition delay, and therefore can provide a highly safe combustion device. However, the many secondary air supply ports located far from the ignition rod of the spark plug remain the same, so they are particularly limited to closed and semi-closed types that discharge combustion exhaust gas outdoors via a heat exchanger and exhaust pipe. In a closed type combustion device, the heat exchange efficiency does not decrease significantly.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along the line AA' in FIG. 2, FIG. 2 is a front view of the combustion device, and FIG. 3 is a vertical sectional view of a main part of the combustion device. (1)... Combustion tube, (18)... Burner body,
(21)... vaporization chamber, (24)... burner head, (25)... flame port, (26)... spark plug, (26A) (26A)... ignition rod, (32 )
(33)...Secondary air hole. Applicant: Sanyo Electric Co., Ltd. and 1 other representative Patent attorney Takuji Nishino and 1 other person Figure 1 ql-111,

Claims (1)

[Claims] (1) A burner head having a plurality of flame ports is provided at the tip of a burner main body with a vaporizing chamber inside, and a spark plug with the tip of its ignition rod located in the flame port allows the premixed gas to be ejected from the flame port. In a combustion device that ignites and burns the burner and supplies secondary air to the combustion flame from a plurality of secondary air supply ports arranged along the outer periphery of the burner main body, the plurality of secondary air A combustion device characterized in that, among the air supply ports, the size of the secondary air supply port located near the ignition rod of the ignition plug is larger than the size of the secondary air supply port located away from the ignition rod.