JPS59176509A - Catalytic burner - Google Patents

Abstract

PURPOSE:To provide a catalytic burner which enables fuel to effect safe and efficient oxidizing reaction even under a wide range of air-fuel ratio, and makes exhaust gas clean, by a method wherein an oxidizing catalyst is located on the upperstream side of a premixture flow and a honeycomb type shielding plate made of a heat-resisting porous ceramic is situated on the downstream side. CONSTITUTION:In a catalytic burner in which a catalyst 12 carriers one or more types of transition-metallic oxides, such as Ni, Co, Fe, Cr, on a carrier, a honeycomb type shielding plate 13, installed at an interval ahead of the catalyst 12, is heated by a radiant heat from the catalyst 12 and is simultaneously heated by a combustion exhaust gas flow, resulting in an increase in temperature to about 800-1,200 deg.C. Thereafter, the catalyst 12 is reversely heated by a radiant heat from the honeycomb type shielding plate 13, and thereby the outer periphery and the front part of the catalyst 12 also hold activating temperature uniformly. Thus, premixture gas is perfectly oxidized on the catalyst 12, and a combustion condition is stablized.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、各種のガス燃料または気化させた液体燃料を
燃焼空気と予混合して触媒体に供給し、２１１−ジ その表面で酸化反応を起こさせて触媒体を発熱させ、発
生する熱を利用する触媒燃焼器に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a method for premixing various gaseous fuels or vaporized liquid fuels with combustion air and supplying the mixture to a catalyst body to cause an oxidation reaction on the surface of the 211-di. This invention relates to a catalytic combustor that generates heat in a catalytic body and utilizes the generated heat.

従来例の構成とその問題点 従来の触媒燃焼器は、第１図に示す通り、燃焼筒１内に
触媒体２を設置１〜ただけで、触媒体２は燃焼筒１およ
び外気との接触で冷却作用を受け、触媒体２の外周部お
よび前面部に活性化温度を下回る低温部が形成されてい
た。従ってこの部分を通過する予混合気は完全には燃焼
しきれず、Ｃ０等を含んだ未燃ガスとして排出される欠
点があった。特に低燃焼量領域で空気過剰率を高くした
場合、この傾向が甚しかった。Conventional structure and its problems As shown in Fig. 1, the conventional catalytic combustor only has a catalyst body 2 installed in the combustion tube 1, and the catalyst body 2 is not in contact with the combustion tube 1 and the outside air. As a result of the cooling effect, a low temperature area below the activation temperature was formed on the outer circumference and front side of the catalyst body 2. Therefore, there is a drawback that the premixture passing through this portion is not completely combusted and is discharged as unburned gas containing CO and the like. This tendency was particularly severe when the excess air ratio was increased in the low combustion area.

発明の目的 本発明はかかる従来の問題点を解消するもので、燃料を
触媒体上で広範囲な空燃比のもとでも安定かつ効率の良
い酸化反応をさせると共に、排気ガスがクリーンとなる
触媒燃焼器を提供することを目的とする。OBJECT OF THE INVENTION The present invention solves these conventional problems, and aims to achieve catalytic combustion in which fuel undergoes a stable and efficient oxidation reaction on a catalyst body even under a wide range of air-fuel ratios, and produces clean exhaust gas. The purpose is to provide equipment.

発明の構成 上記目的を達成するため、本発明では予混合気流の上流
側に酸化触媒を担持した触媒体、下流側に耐熱多孔質セ
ラミックからなるハニカム式遮蔽板を設置した。この構
成により、ハニカム式遮蔽板は燃焼中の触媒体から輻射
熱を受けると共に、燃焼排ガス流により加熱されるため
、８ｏ○〜１２ｏＯ℃程度まで温度上昇する。この時点
で触媒体は、加熱されたハニカム式遮蔽板から逆に輻射
熱を受けるため、触媒体の外周部および前面部も冷却作
用を受けることなく活性化温度を保持する。したがって
、予混合ガスは活性化温度を保持している触媒体により
、完全酸化作用を受け、クリーン々排ガスとして排出さ
れる。この様に、従来よりも高い空燃比に於ても安定燃
焼を行わせることができ、燃焼幅、ひいてはＴＤＲを拡
大することが可能と彦った。Structure of the Invention In order to achieve the above object, in the present invention, a catalyst body supporting an oxidation catalyst is installed on the upstream side of the premixed air flow, and a honeycomb type shielding plate made of heat-resistant porous ceramic is installed on the downstream side. With this configuration, the honeycomb type shielding plate receives radiant heat from the catalyst body during combustion and is heated by the combustion exhaust gas flow, so that the temperature rises to about 80°C to 1200°C. At this point, the catalyst body receives radiant heat from the heated honeycomb shielding plate, so that the outer periphery and front surface of the catalyst body also maintain the activation temperature without being subjected to cooling action. Therefore, the premixed gas is completely oxidized by the catalyst that maintains the activation temperature and is discharged as clean exhaust gas. In this way, stable combustion can be performed even at a higher air-fuel ratio than before, and it has become possible to expand the combustion width and, by extension, the TDR.

実施例の説明 本発明による触媒燃焼器の一実施例を第２図に示し、こ
れに従い説明する。DESCRIPTION OF THE EMBODIMENTS An embodiment of the catalytic combustor according to the present invention is shown in FIG. 2 and will be described accordingly.

シーズヒータを埋設した気化予混合筒４内には、金網ま
たはパンチングメタル製の抵抗板６が設置され、気化予
混合筒４後方には、中央に空気口６を有する固定板７が
接合されている。一方、気化予混合筒４の前方には、多
数の噴出孔８を有する噴出板９が、気化予混合筒４と一
体構造を成す様に設置され、さらに耐熱性金属からなる
円筒状の燃焼筒１ｏが接合されている。燃焼筒１０には
、その前方に向かって逆火防止板１１、触媒体１２、本
発明によるハニカム式遮蔽板１３が順次設置されている
。捷た、噴出板９のすぐ前方側には、点火プラグ１４が
燃焼筒１０を貫通した形で設置されている。一方、気化
予混合筒４内に臨んだシャフト１６の先端には、前方に
向は径が犬となる円型台形のコーン１６、回転板１７、
周端に攪拌用小羽根を有する混合板１８が順次固定され
ている。A resistance plate 6 made of wire mesh or punching metal is installed inside the vaporization premixing cylinder 4 in which the sheathed heater is embedded, and a fixed plate 7 having an air port 6 in the center is joined to the rear of the vaporization premixing cylinder 4. There is. On the other hand, in front of the vaporization premixing tube 4, a jet plate 9 having a large number of injection holes 8 is installed so as to form an integral structure with the vaporization premixing tube 4, and a cylindrical combustion tube made of heat-resistant metal is installed. 1o is joined. A flashback prevention plate 11, a catalyst body 12, and a honeycomb type shielding plate 13 according to the present invention are sequentially installed in the combustion tube 10 toward the front thereof. Immediately in front of the spout plate 9, a spark plug 14 is installed so as to pass through the combustion tube 10. On the other hand, at the tip of the shaft 16 facing into the vaporization premixing cylinder 4, there is a circular trapezoidal cone 16 whose diameter is dog-shaped when facing forward, a rotary plate 17,
Mixing plates 18 having small stirring blades at the peripheral ends are fixed in sequence.

また、給油管１９の先端はコーン１６側方に開口する様
に設置されている。Further, the tip of the oil supply pipe 19 is installed so as to open to the side of the cone 16.

次に上記構成による実施例の作用を説明する。Next, the operation of the embodiment with the above configuration will be explained.

シーズヒータ３に通電され、気化予混合筒４の内壁面が
所定の温度に到達すると、ファン、電磁ポンプ（共に図
示せず）に通電され、空気および５．２ 液体燃料の供給が開始される。液体燃料は給油管１９に
よって回転中のコーン１６上に送られ、コーン１６のテ
ーパに沿って回転板１７に達すると、その回転力により
円周方向に微粒子として飛散し、定温状態の気化予混合
筒４の壁面に衝突し、直ちに気化する。一方、ファンに
よって取り入れられた空気は、空気口６から気化予混合
筒４内に送入され、混合板１８により気化した液体燃料
と均一に混合され予混合ガスとなる。予混合ガスは抵抗
板６、噴出板９を通過したところで、通電によりスパー
クを発している点火プラク１４で点火される。この状態
で火炎からの輻射熱、燃焼筒１ｏからの伝熱を受けて、
触媒体１２て活性化温度に到達する。しかるのち、一旦
燃料の供給を停止して火炎を消滅させ、ついで燃料の供
給を再開すると、予混合ガスは火炎を形成することなく
、活性化温度を保っている触媒体１２上で無炎燃焼が開
始される。この時、触媒体１２の前方に設置されたハニ
カム式遮蔽板１３は、触媒体１２から輻射熱を受けると
共に、燃焼排ガス流により加熱され、６７−ｓ・ ８００〜１２００℃程度まで温度上昇する。こののち触
媒体１２は、ハニカム式遮蔽板１３から逆に輻射熱を受
けるため、触媒体１２の外周部および前面部も一様に活
性化温度を保持する。したがって、予混合ガスは触媒体
１２上で完全酸化され、燃焼状態は安定化する。When the sheathed heater 3 is energized and the inner wall surface of the vaporization premix cylinder 4 reaches a predetermined temperature, the fan and electromagnetic pump (both not shown) are energized and the supply of air and liquid fuel is started. . The liquid fuel is sent onto the rotating cone 16 through the fuel supply pipe 19, and when it reaches the rotating plate 17 along the taper of the cone 16, it is scattered as fine particles in the circumferential direction due to the rotational force, and is vaporized and premixed at a constant temperature. It collides with the wall of cylinder 4 and immediately vaporizes. On the other hand, the air taken in by the fan is sent into the vaporization premix cylinder 4 through the air port 6, and is uniformly mixed with the vaporized liquid fuel by the mixing plate 18 to become a premix gas. After the premixed gas has passed through the resistance plate 6 and the ejection plate 9, it is ignited by the ignition plaque 14, which generates a spark when energized. In this state, receiving radiant heat from the flame and heat transfer from the combustion tube 1o,
The catalyst body 12 reaches the activation temperature. After that, once the fuel supply is stopped to extinguish the flame, and then the fuel supply is restarted, the premixed gas burns flamelessly on the catalyst body 12 that maintains the activation temperature without forming a flame. is started. At this time, the honeycomb type shielding plate 13 installed in front of the catalyst body 12 receives radiant heat from the catalyst body 12 and is heated by the combustion exhaust gas flow, and the temperature rises to about 67-s/800 to 1200°C. Thereafter, the catalyst body 12 receives radiant heat from the honeycomb shielding plate 13, so that the outer circumference and front surface of the catalyst body 12 maintain the activation temperature uniformly. Therefore, the premixed gas is completely oxidized on the catalyst body 12, and the combustion state is stabilized.

本発明の触媒燃焼器による効果を実証するデータとして
、第１図に示した従来例、第２図に示した本発明の実施
例の各々を用いた場合の燃焼特性の相違を第３図に示し
た。なお、ハニカム遮蔽板１３の使用以外は、従来例、
本発明の実施例共に同一仕様とした。触媒体１２、ノ・
ニカム遮蔽板１３共にＺｒＯ２を母材としふ媒体１２の
酸化触媒としてＮｉＯを数チ担持し、燃料は灯油を用い
た。As data demonstrating the effects of the catalytic combustor of the present invention, Figure 3 shows the differences in combustion characteristics when using the conventional example shown in Figure 1 and the embodiment of the present invention shown in Figure 2. Indicated. In addition, except for the use of the honeycomb shielding plate 13, the conventional example,
Both embodiments of the present invention had the same specifications. Catalyst body 12, no.
Both of the nicum shielding plates 13 were made of ZrO2 as a base material, supported on several layers of NiO as an oxidation catalyst for the sulfur medium 12, and kerosene was used as the fuel.

図中、黒丸が本発明の実施例、白丸が従来例を示し、上
方の曲線が燃焼上限、下方の曲線が燃焼下限を示してい
る。燃焼上限の定義は、空気量を絞ってＣ０２濃度を増
大させていった場合に、逆火防止板１１後方に火炎を形
成し、もはや無炎燃焼し得なくなる限界のＣ０２濃度（
逆火限界）、燃焼下７、 限の定義は、空気量を増加させてＣＯ２濃度を低下させ
ていった時に、排ガス中にＣｏが発生し始める限界のＣ
Ｏ２濃度（吹き飛び限界）を示し、両限界の差を燃焼幅
と定義した。In the figure, black circles indicate the embodiment of the present invention, white circles indicate the conventional example, the upper curve indicates the upper limit of combustion, and the lower curve indicates the lower limit of combustion. The combustion upper limit is defined as the limit CO2 concentration at which flame is formed behind the flashback prevention plate 11 and flameless combustion is no longer possible when the CO2 concentration is increased by restricting the amount of air.
The definition of combustion limit is the limit at which Co begins to be generated in the exhaust gas when the amount of air is increased and the CO2 concentration is decreased.
The O2 concentration (blown-off limit) is shown, and the difference between the two limits is defined as the combustion width.

図より、従来例の場合は、燃焼下限が高い位置にあり、
特に低燃焼量領域でこの傾向が甚しく々っている。す々
わち高い空燃比に於ける燃焼が極めて不安定であること
を示している。これに対１〜本実施例では、８００〜３
２００　Ｋ　ｃａｌｌ　／　ｈまで比較的安定した燃焼
幅（３，ｏ〜３．９　ｖｏ１％）を保持しており、従来
例と比べ、高い空燃比に於てもかなり安定燃焼が可能で
あることを示している。From the figure, in the case of the conventional example, the lower combustion limit is at a high position,
This tendency is particularly severe in the low combustion amount region. This shows that combustion at high air-fuel ratios is extremely unstable. In contrast, 1 to 800 to 3 in this example.
It maintains a relatively stable combustion width (3.0 to 3.9 vo1%) up to 200 K call/h, and compared to conventional examples, it has been shown that fairly stable combustion is possible even at high air-fuel ratios. It shows.

発明の効果 本発明の触媒燃焼器によれば、次に列記する効果が得ら
れる。Effects of the Invention According to the catalytic combustor of the present invention, the following effects can be obtained.

（１）予混合気流の上流側に酸化触媒を担持した触媒体
、下流側に耐熱多孔質セラミックからなるハニカム式遮
蔽板を、各々一定の間隔を置いて設置したことにより、
ハニカム式遮蔽板が保熱板の役割を果たし、触媒体全体
を活性化温度に保持するため、予混合ガスは完全酸イヒ
され、クリーンな排ガスを得ることができる。(1) By installing a catalyst body carrying an oxidation catalyst on the upstream side of the premixed airflow and a honeycomb type shielding plate made of heat-resistant porous ceramic on the downstream side, each of them was installed at a certain interval.
The honeycomb type shielding plate plays the role of a heat retaining plate and maintains the entire catalyst at the activation temperature, so the premixed gas is completely oxidized and clean exhaust gas can be obtained.

（２）上記構成により、低燃焼量領域に於ても、従来よ
り高い空燃比での安定燃焼が可能となり、結果的に幅広
い燃焼幅を得ることが可能となった。(2) The above configuration enables stable combustion at a higher air-fuel ratio than before even in the low combustion amount region, and as a result, it becomes possible to obtain a wide combustion width.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は従来の触媒燃焼器の縦断面図、第２図は本発明
による触媒燃焼器の一実施例の縦断面図、第３図は従来
例と本発明実施例とを使用した場合の比較を示した図で
ある。 １２・・・・・・触媒体、１３・・・・・ノ・ニカム式
遮蔽板。FIG. 1 is a longitudinal sectional view of a conventional catalytic combustor, FIG. 2 is a longitudinal sectional view of an embodiment of a catalytic combustor according to the present invention, and FIG. 3 is a longitudinal sectional view of a conventional catalytic combustor and an embodiment of the present invention. It is a figure showing a comparison. 12...Catalyst body, 13...No-nikum type shielding plate.

Claims (1)

【特許請求の範囲】 ０）　ガス燃料または気化させた液体燃料を燃焼空気と
予混合気流の上流側に、酸化触媒を担持した触媒体を、
下流側に耐熱多孔質セラミックからなるハニカム式遮蔽
板を、各々一定の間隔を置いて設置した触媒燃焼器。 （２）触媒体は担体上にＮｉ、　Ｇｏ、　Ｆｅ、　Ｃｒ
　　等の遷移金属酸化物のうち一種類以上を担持した特
許請求の範囲第１項記載の触媒燃焼器。 （■　ハニカム式遮蔽板の温度がＳＯＯ〜１２ｏ。 ℃程度となる様に、ハニカム式遮蔽板と触媒体との間隔
を設定した特許請求の範囲第１項記載の触媒燃焼器。[Scope of Claims] 0) A catalyst body supporting an oxidation catalyst is placed on the upstream side of a premixed airflow of gaseous fuel or vaporized liquid fuel with combustion air,
A catalytic combustor with honeycomb shielding plates made of heat-resistant porous ceramic installed at regular intervals on the downstream side. (2) The catalyst has Ni, Go, Fe, Cr on the carrier.
The catalytic combustor according to claim 1, wherein the catalytic combustor supports one or more types of transition metal oxides such as the following. (2) The catalytic combustor according to claim 1, wherein the distance between the honeycomb shielding plate and the catalyst body is set so that the temperature of the honeycomb shielding plate is about SOO to 12°C.