JPH06296873A - Honeycomb heater and exhaust gas purification device using said heater - Google Patents
Honeycomb heater and exhaust gas purification device using said heaterInfo
- Publication number
- JPH06296873A JPH06296873A JP5087408A JP8740893A JPH06296873A JP H06296873 A JPH06296873 A JP H06296873A JP 5087408 A JP5087408 A JP 5087408A JP 8740893 A JP8740893 A JP 8740893A JP H06296873 A JPH06296873 A JP H06296873A
- Authority
- JP
- Japan
- Prior art keywords
- honeycomb
- exhaust gas
- heater
- catalyst
- honeycomb heater
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000746 purification Methods 0.000 title claims description 8
- 239000000919 ceramic Substances 0.000 claims abstract description 20
- 239000013078 crystal Substances 0.000 claims abstract description 8
- 239000003054 catalyst Substances 0.000 claims description 37
- 229910017563 LaCrO Inorganic materials 0.000 claims description 4
- 238000002485 combustion reaction Methods 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 42
- 238000010438 heat treatment Methods 0.000 description 14
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 12
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 8
- 229910002091 carbon monoxide Inorganic materials 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 229930195733 hydrocarbon Natural products 0.000 description 6
- 150000002430 hydrocarbons Chemical class 0.000 description 6
- 230000020169 heat generation Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000003197 catalytic effect Effects 0.000 description 4
- 229910052697 platinum Inorganic materials 0.000 description 4
- 239000000835 fiber Substances 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 230000035939 shock Effects 0.000 description 3
- 230000003584 silencer Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- 241001370313 Alepes vari Species 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- AUFVVJFBLFWLJX-UHFFFAOYSA-N [Mn].[La] Chemical compound [Mn].[La] AUFVVJFBLFWLJX-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- NFYLSJDPENHSBT-UHFFFAOYSA-N chromium(3+);lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Cr+3].[La+3] NFYLSJDPENHSBT-UHFFFAOYSA-N 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000011224 oxide ceramic Substances 0.000 description 1
- 229910052574 oxide ceramic Inorganic materials 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は自動車に使われるガソリ
ンエンジンなど内燃機関の排気に含まれる有害なガス
（ＨＣ、ＣＯ、ＮＯX ）を浄化するための排気ガス浄化
装置、およびこれに用いるハニカムヒータに関するもの
である。Harmful gases present invention relates to a contained in the exhaust of an internal combustion engine such as a gasoline engine used in automobiles (HC, CO, NO X) exhaust gas purification device for purifying, and honeycomb used in this It relates to a heater.
【０００２】[0002]
【従来の技術】自動車が普及すると共に排気ガスによる
環境汚染が問題となり、ガソリンエンジンの排気ガスに
含まれる有害物質である炭化水素（ＨＣ）、一酸化炭素
（ＣＯ）、窒素酸化物（ＮＯX ）の排出規制が強化され
るようになった。わが国では１９７５年からＨＣおよび
ＣＯに対して、さらに１９７８年からはＮＯX に対して
排出が規制されるようになっている。2. Description of the Related Art With the spread of automobiles, environmental pollution due to exhaust gas has become a problem, and hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NO x ) which are harmful substances contained in exhaust gas of gasoline engines. ) Emission regulations have been tightened. In Japan adapted against HC and CO from 1975, more emissions relative to NO X from 1978 is restricted.
【０００３】この規制に対して当初はエンジンの改良
（ＥＧＲ）などで対処していたが、触媒を使ってＨＣ、
ＣＯ、ＮＯX の汚染成分を同時に無害化する方法が開発
され、いわゆる三元触媒と呼ばれる化１のような浄化方
法を利用した排気ガス浄化装置が現在のほとんどの乗用
車に使われている。Initially, this regulation was dealt with by improving the engine (EGR), etc.
A method for simultaneously detoxifying the pollutant components of CO and NO x has been developed, and an exhaust gas purifying apparatus using a purifying method such as chemical formula 1 called a so-called three-way catalyst is currently used in most passenger cars.
【０００４】[0004]
【化１】 [Chemical 1]
【０００５】この三元触媒法は技術的に既に完成された
ものであり、排気ガス中に同時に存在するＣＯおよびＨ
Ｃを還元剤としてＮＯX をＮ2 に還元できる効果的なも
のである。また、上記三元触媒は、図４に示すように一
体成形（モノリス）のコージライト製ハニカム体にアル
ミナをコートしたのち白金（Ｐｔ）などの貴金属の触媒
成分を担持してなるハニカム触媒２０を用いており、こ
のハニカム触媒２０の貫通孔２０ａ中を排気ガスが通過
することによって触媒反応を生じるようにしたものであ
る。This three-way catalyst method has already been technically completed, and CO and H existing simultaneously in the exhaust gas.
It is effective in reducing NO X to N 2 by using C as a reducing agent. Further, as the three-way catalyst, as shown in FIG. 4, a honeycomb catalyst 20 is obtained by coating a monolithic cordierite honeycomb body with alumina and then carrying a catalyst component of a noble metal such as platinum (Pt). The honeycomb catalyst 20 is used so that the exhaust gas passes through the through holes 20a to cause a catalytic reaction.
【０００６】また、最近では、車両への搭載性などを考
慮して、ステンレスなどを担体としたメタルハニカムも
使われている。[0006] Recently, a metal honeycomb having a carrier such as stainless steel has been used in consideration of mountability on a vehicle.
【０００７】[0007]
【本発明が解決しようとする課題】しかしながら、従来
の排気ガス浄化装置では、三元触媒法は触媒が活性化す
る３００℃以上の温度でなければ機能しない。すなわ
ち、エンジン始動時においては触媒が機能しないままに
排気ガスがハニカム触媒２０中を通過し、ＨＣ、ＣＯ、
ＮＯX がそのまま排出されることになってしまうという
問題点があった。However, in the conventional exhaust gas purifying apparatus, the three-way catalyst method does not function unless the temperature is 300 ° C. or higher at which the catalyst is activated. That is, when the engine is started, the exhaust gas passes through the honeycomb catalyst 20 without the catalyst functioning, and HC, CO,
There was a problem that NO X would be emitted as it was.
【０００８】このコールドスタート時の排気ガスは環境
汚染が深刻化した今日、大きな課題となっており、この
問題解決のためにハニカム触媒２０をバーナーや電気で
加熱する方法が考えられている。ところが、バーナーを
使った加熱は車両に搭載するうえで大きな危険を伴い、
またハニカム触媒２０に触媒機能と電気ヒータ機能を設
けることは極めて困難であった。Exhaust gas at the time of cold start has become a serious problem in recent years when environmental pollution has become serious. To solve this problem, a method of heating the honeycomb catalyst 20 with a burner or electricity has been considered. However, heating with a burner entails a great risk of being installed in a vehicle,
Further, it is extremely difficult to provide the honeycomb catalyst 20 with a catalytic function and an electric heater function.
【０００９】さらに、セラミックハニカム体に発熱抵抗
体を印刷または埋設したハニカムヒータをハニカム触媒
２０の直前に備え、このハニカムヒータに通電して発熱
させ、排気ガスを加熱することも考えられていたが（実
公昭５１−１３６２１号公報等参照）、このような発熱
抵抗体を備えたハニカムヒータは製造が困難であった。
また、上記ハニカム体を導電性を有する炭化珪素質セラ
ミックスで形成し、このハニカム体自体に通電して発熱
させることも考えられていたが（特開昭５７−１１０３
１１号公報等参照）、非酸化物である炭化珪素質セラミ
ックスは９００℃程度の排気ガス中で酸化して特性が劣
化してしまうという問題点があり、結局現在まで実用化
されていなかった。Further, it has been considered that a honeycomb heater in which a heating resistor is printed or embedded in a ceramic honeycomb body is provided immediately in front of the honeycomb catalyst 20 and the honeycomb heater is energized to generate heat to heat exhaust gas. (See Japanese Utility Model Publication No. 51-13621, etc.), it was difficult to manufacture a honeycomb heater having such a heating resistor.
Further, it has been considered that the honeycomb body is formed of conductive silicon carbide ceramics, and the honeycomb body itself is energized to generate heat (Japanese Patent Laid-Open No. 57-1103).
No. 11, etc.), non-oxide silicon carbide ceramics have a problem that they are oxidized in exhaust gas at about 900 ° C. and their characteristics are deteriorated, and they have not been put to practical use until now.
【００１０】[0010]
【課題を解決するための手段】以上のような問題に鑑み
て、本発明は、１０-2〜１０Ω・ｃｍの体積固有抵抗を
有し、ペロブスカイト型の結晶構造を有するセラミック
スによりハニカムヒータを構成したものである。In view of the above problems, the present invention provides a honeycomb heater made of ceramics having a volume resistivity of 10 −2 to 10 Ω · cm and a perovskite type crystal structure. It was done.
【００１１】ここで、ペロブスカイト型の結晶構造と
は、一般式ＡＢＯ3 で表される複合酸化物のことであ
り、例えばＬａＭｎＯ3 やＬａＣｒＯ3 を主成分とする
セラミックスはそれ自体が１０-2〜１０Ω・ｃｍの体積
固有抵抗を有しており、発熱抵抗体として好適に利用で
きるものである。Here, the perovskite type crystal structure is a complex oxide represented by the general formula ABO 3 , and, for example, ceramics containing LaMnO 3 or LaCrO 3 as a main component are themselves 10 -2 to. It has a volume resistivity of 10 Ω · cm and can be suitably used as a heating resistor.
【００１２】また、本発明は排気ガス浄化用触媒にこの
ハニカムヒータを備えることにより、コールドスタート
時の排気ガス温度を高め、触媒作用を促進させるように
したものである。Further, according to the present invention, the exhaust gas purifying catalyst is provided with this honeycomb heater to increase the exhaust gas temperature at the cold start and accelerate the catalytic action.
【００１３】[0013]
【実施例】以下本発明の実施例を図によって説明する。Embodiments of the present invention will be described below with reference to the drawings.
【００１４】図１に示すハニカムヒータ１は、１０-2〜
１０Ω・ｃｍの体積固有抵抗を持った、ペロブスカイト
型の結晶構造を有するセラミックスからなるハニカム体
２に、軸方向両端部に給電部材３、３を取り付けてなる
ものである。そして、給電線４、４によってハニカム体
２に電圧を印加すると、ハニカム体２自体が抵抗（ジュ
ール）発熱し、貫通孔２ａ中を通過する流体を加熱させ
ることができる。[0014] The honeycomb heater 1 shown in FIG. 1, 10 -2 to
A honeycomb body 2 having a volume resistivity of 10 Ω · cm and made of ceramics having a perovskite type crystal structure is provided with power feeding members 3 at both ends in the axial direction. Then, when a voltage is applied to the honeycomb body 2 by the power supply lines 4 and 4, the honeycomb body 2 itself generates heat by resistance (Joule), and the fluid passing through the through holes 2a can be heated.
【００１５】このような、ハニカムヒータ１を用いれ
ば、ハニカム体２が酸化物であるため高温中でも酸化に
よる特性劣化をすることはなく、貫通孔２ａ中を通過す
る流体を加熱させることができ、以下に示す排気ガス浄
化装置の他、温風ヒータや液体加熱装置などに使用する
ことができる。When such a honeycomb heater 1 is used, since the honeycomb body 2 is an oxide, it is possible to heat the fluid passing through the through hole 2a without deterioration of characteristics due to oxidation even at a high temperature. In addition to the exhaust gas purifying device shown below, it can be used for a warm air heater, a liquid heating device, and the like.
【００１６】次に、このハニカムヒータ１を用いた排気
ガス浄化装置を説明する。図２に示すように、エンジン
１１から排気ガスが排出されるマニホールド１２に接続
して排気ガス浄化装置１０が備えられ、この排気ガス浄
化装置１０の出口管１３は消音器１４へと結ばれ、大気
中に排気ガスを放出するようになっている。また、図３
に示すように、排気ガス浄化装置１０は、金属ケーシン
グ６の内部にハニカムヒータ１を備え、このハニカムヒ
ータ１の直後に三元触媒機能を持つハニカム触媒２０を
載置し、セラミックファイバー等の断熱材７を介して金
属ケーシング６に取り付けたものである。Next, an exhaust gas purifying apparatus using this honeycomb heater 1 will be described. As shown in FIG. 2, an exhaust gas purifying device 10 is provided so as to be connected to a manifold 12 from which exhaust gas is discharged from an engine 11, and an outlet pipe 13 of the exhaust gas purifying device 10 is connected to a silencer 14. It is designed to emit exhaust gas into the atmosphere. Also, FIG.
As shown in FIG. 1, the exhaust gas purifying apparatus 10 includes a honeycomb heater 1 inside a metal casing 6, and a honeycomb catalyst 20 having a three-way catalytic function is placed immediately after the honeycomb heater 1 to heat-insulate a ceramic fiber or the like. It is attached to the metal casing 6 via the material 7.
【００１７】そして、ハニカムヒータ１を成すハニカム
体２の両端部に設けた給電部材３、３間にバッテリー５
より電圧を印加すると、抵抗（ジュール）発熱により数
秒間でハニカムヒータ１は高温に加熱される。すなわ
ち、イグニッションキーを回すと同時にハニカムヒータ
１が加熱し、加熱後にエンジン１１が始動するようにし
ておけば、ハニカムヒータ１を通過することによって加
熱された排気ガスは触媒が活性になる温度までハニカム
触媒２０を加熱することができ、これによって排気ガス
自身が浄化されることになる。もちろん、エンジン１１
始動後３０秒も経過すれば高温の排気ガスがハニカム触
媒２０に送り込まれることになるため、ハニカムヒータ
１を加熱し続ける必要はなくなることから、所定時間経
過後は、ハニカムヒータ１への通電を切るようにすれば
良い。The battery 5 is provided between the power feeding members 3 and 3 provided at both ends of the honeycomb body 2 which constitutes the honeycomb heater 1.
When more voltage is applied, the honeycomb heater 1 is heated to a high temperature within a few seconds due to resistance (joule) heat generation. That is, if the honeycomb heater 1 is heated at the same time as turning the ignition key and the engine 11 is started after heating, the exhaust gas heated by passing through the honeycomb heater 1 is heated to a temperature at which the catalyst becomes active. The catalyst 20 can be heated, which will purify the exhaust gas itself. Of course, the engine 11
After 30 seconds have passed from the start, the high-temperature exhaust gas is sent to the honeycomb catalyst 20, and it is not necessary to continue heating the honeycomb heater 1. Therefore, after a predetermined time has passed, the honeycomb heater 1 is energized. Just cut it.
【００１８】なお、このような通電を行うためには、タ
イマーによる設定や、ハニカム触媒２０の温度を検知し
て一定温度以上になれば通電を止めるようにしておけば
良い。In order to carry out such energization, setting by a timer or detecting the temperature of the honeycomb catalyst 20 and stopping the energization when the temperature exceeds a certain temperature may be carried out.
【００１９】また、エンジン１１が高速運転を続けると
９００℃以上もの高温高速の排気ガスの中にハニカムヒ
ータ１がさらされることになるが、ハニカム体２がペロ
ブスカイト型の結晶構造を持つ酸化物セラミックスから
成るため、耐熱性に優れ、高温中でも特性劣化すること
がない。When the engine 11 continues to operate at high speed, the honeycomb heater 1 is exposed to high-temperature and high-speed exhaust gas of 900 ° C. or higher, but the honeycomb body 2 is an oxide ceramic having a perovskite type crystal structure. It has excellent heat resistance and does not deteriorate in characteristics even at high temperatures.
【００２０】さらに、図３の実施例ではハニカム触媒２
０とハニカムヒータ１を別体としたものを示したが、ハ
ニカムヒータ１自体を触媒とすることもできる。即ち、
図１に示すようなハニカムヒータ１を成すハニカム体２
に直接白金（Ｐｔ）等の触媒成分を担持させれば、この
ハニカムヒータ１自体を触媒とすることができる。この
ような構造とすれば、図３に示すハニカム触媒２０は必
要なくなるため排気ガス浄化装置１０を小型化すること
ができ、しかも発熱効率を良くすることができる。Further, in the embodiment shown in FIG. 3, the honeycomb catalyst 2 is used.
Although 0 and the honeycomb heater 1 are shown as separate bodies, the honeycomb heater 1 itself may be used as a catalyst. That is,
A honeycomb body 2 forming a honeycomb heater 1 as shown in FIG.
By directly supporting a catalyst component such as platinum (Pt) on the honeycomb heater 1, the honeycomb heater 1 itself can be used as a catalyst. With such a structure, since the honeycomb catalyst 20 shown in FIG. 3 is not necessary, the exhaust gas purification device 10 can be downsized, and the heat generation efficiency can be improved.
【００２１】なお、ハニカム体２を成す１０-2〜１０Ω
・ｃｍの体積固有抵抗を有するペロブスカイト型の結晶
構造を持つセラミックスとしては、例えばランタンマン
ガンライト（ＬａＭｎＯ3 ）やランタンクロマイト（Ｌ
ａＣｒＯ3 ）を主成分とするセラミックスを用いれば良
い。これらのセラミックスはそれ自体が１０-2〜１０Ω
・ｃｍの体積固有抵抗を有していることから発熱抵抗体
として好適に用いられ、給電部材３により通電するだけ
で発熱させることができる。さらにＬａの一部をＣａ、
Ｓｒ、Ｂａ等の周期律表第２ａ族元素で置換したり、あ
るいはＭｎ、Ｃｒの一部をＣｏ、Ｆｅ、Ｎｉ、Ｃｅ、Ｚ
ｒ等の元素で置換することでより導電性を高めることも
でき、これらの置換量を調整することでさまざまな抵抗
値を持ったハニカム体２とすることができる。The honeycomb body 2 is formed of 10 −2 to 10 Ω.
Examples of ceramics having a perovskite type crystal structure having a volume resistivity of cm include lanthanum manganese light (LaMnO 3 ) and lanthanum chromite (L
Ceramics containing aCrO 3 as a main component may be used. These ceramics are themselves 10 -2 to 10 Ω.
Since it has a volume specific resistance of cm, it is suitably used as a heating resistor, and it can generate heat only by being energized by the power feeding member 3. Furthermore, a part of La is Ca,
Substitution with an element of Group 2a of the periodic table such as Sr or Ba, or part of Mn or Cr is Co, Fe, Ni, Ce, Z
The conductivity can be further enhanced by substituting with an element such as r, and the honeycomb body 2 having various resistance values can be obtained by adjusting the substituting amount thereof.
【００２２】また、その他に、ＢａＴｉＯ3 等も、焼成
条件や添加物によっては上記体積固有抵抗の範囲内とす
ることができる。そして、このような組成のセラミック
ス原料を金型を用いてハニカム形状に押出成形し、焼成
することによって、容易にハニカム体２を得ることがで
きる。In addition, BaTiO 3 and the like can be made within the above range of volume resistivity depending on the firing conditions and additives. Then, the ceramic raw material having such a composition is extrusion-molded into a honeycomb shape by using a mold and fired, whereby the honeycomb body 2 can be easily obtained.
【００２３】なお、このような組成のセラミックスは構
造材料として使われるアルミナや窒化珪素などと比較す
ると耐熱衝撃性がやや劣るが、急加熱されるヒータとし
て実用的に問題のない耐熱衝撃性を持たせるために気孔
率を１０〜３０％とすれば良い。これは、気孔率が１０
％よりも低いと耐熱衝撃性が低くなって急加熱時に破損
しやすくなり、逆に気孔率が３０％よりも高いと機械的
強度が低くなって取扱時等に破損しやすくなるためであ
る。The ceramics having such a composition have a slightly lower thermal shock resistance than alumina or silicon nitride used as a structural material, but have a thermal shock resistance practically no problem as a heater to be rapidly heated. In order to achieve this, the porosity may be 10-30%. This has a porosity of 10
If it is less than%, the thermal shock resistance is low and it tends to be damaged during rapid heating. On the contrary, if the porosity is more than 30%, the mechanical strength is low and it is easily damaged during handling.
【００２４】また、このハニカムヒータ１においてはハ
ニカム体２を成すセラミックスの抵抗値がそのままハニ
カムヒータ１の発熱量として定まることから、排気ガス
を加熱せしめるのに充分な熱量をもとにセラミックスの
抵抗値が決まることになり、１０-2〜１０Ωｃｍの材料
を用いるのがよい。Further, in this honeycomb heater 1, the resistance value of the ceramics forming the honeycomb body 2 is determined as it is as the heat generation amount of the honeycomb heater 1, so that the resistance of the ceramics is determined based on the heat amount sufficient to heat the exhaust gas. Since the value will be determined, it is preferable to use a material of 10 −2 to 10 Ωcm.
【００２５】さらに、ハニカム体２自体の形状や貫通孔
２ａの形状などは、図１に示されたものに限らずさまざ
まなものとできることは言うまでもない。また、ハニカ
ム体２を通過する流体の通過抵抗を小さくするために
は、リブ厚２ｍｍ以下、１平方インチ当たりのセル数を
２００セル以下とすることが好ましい。Further, it goes without saying that the shape of the honeycomb body 2 itself and the shape of the through holes 2a are not limited to those shown in FIG. In order to reduce the passage resistance of the fluid passing through the honeycomb body 2, the rib thickness is preferably 2 mm or less and the number of cells per square inch is 200 cells or less.
【００２６】なお、給電についてはハニカム体２の両端
にメタライズ層を介して給電部材３をロウ付けしたり、
あるいは給電部材３を締めつけてハニカム体２と接合す
るだけでも良い。また、給電部材３は白金（Ｐｔ）等の
高融点金属からなり、耐熱電線の給電線４を用いて電圧
を印加する。Regarding the power feeding, the power feeding member 3 is brazed to both ends of the honeycomb body 2 through the metallized layers,
Alternatively, the power feeding member 3 may be tightened and bonded to the honeycomb body 2. Further, the power feeding member 3 is made of a refractory metal such as platinum (Pt), and a voltage is applied by using the power feeding wire 4 which is a heat resistant wire.
【００２７】さらに、ハニカムヒータ１全体を絶縁した
い場合は、絶縁性のガラスやセラミックスをハニカム体
２表面にコーティングする必要があるが、通常はハニカ
ムヒータ１を耐熱性の無機（セラミック）ファイバー等
で包み込み、金属ケーシング６に固定すれば容易に外部
との絶縁や断熱が可能となる。Further, when it is desired to insulate the entire honeycomb heater 1, it is necessary to coat the surface of the honeycomb body 2 with insulating glass or ceramics, but normally the honeycomb heater 1 is made of a heat-resistant inorganic (ceramic) fiber or the like. If it is wrapped and fixed to the metal casing 6, insulation and heat insulation from the outside can be easily performed.
【００２８】実験例 ここで実際に図１に示すハニカムヒータ１を試作してそ
の効果を調べる実験を行った。 Experimental Example Here, an experiment was carried out to actually test the honeycomb heater 1 shown in FIG. 1 and examine its effect.
【００２９】ハニカム体２は外径１２０ｍｍ、長さ３０
ｍｍの円筒状のもので、ＬａＣｒＯ3 を主成分とする原
料に有機バインダー等を添加混練し、ハニカム形状に押
出成形し焼成して、気孔率２０％のものを得た。しかる
のちハニカム体２の両端に白金（Ｐｔ）の給電部材３を
介して給電線４を取り付けた。The honeycomb body 2 has an outer diameter of 120 mm and a length of 30.
A cylindrical body having a diameter of mm, a raw material containing LaCrO 3 as a main component, an organic binder and the like were added and kneaded, and extruded into a honeycomb shape and fired to obtain a porosity of 20%. Then, the power supply lines 4 were attached to both ends of the honeycomb body 2 via the platinum (Pt) power supply member 3.
【００３０】また、上記ハニカム体２を成すＬａＣｒＯ
3 のＬａやＣｒの一部を他の元素で置換することによ
り、ハニカム体２の体積固有抵抗値を１０-2〜１０Ω・
ｃｍの範囲内で調整し、給電線４にバッテリ電圧（１２
Ｖ）を印加した時の発熱量が表１に示すように毎分１〜
８０ｋｃａｌの発熱量が得られるような、１０種類のハ
ニカムヒータ１を用意した。また、それぞれについて１
平方インチ当りのセル数が１００、２００、３００、ま
たリブ厚みが１、２、３ｍｍと異なるハニカムヒータ１
を用意した。The LaCrO forming the honeycomb body 2 is also used.
By substituting a part of La and Cr of 3 with another element, the volume resistivity value of the honeycomb body 2 is 10 -2 to 10 Ω.
Adjust the voltage within the range of cm, and supply the battery voltage (12
The amount of heat generated when V) is applied is 1 to 1 minute as shown in Table 1.
Ten types of honeycomb heaters 1 were prepared so as to obtain a heating value of 80 kcal. Also, for each
Honeycomb heater 1 having different number of cells per square inch of 100, 200, 300 and rib thickness of 1, 2, 3 mm
Prepared.
【００３１】[0031]
【表１】 [Table 1]
【００３２】図３に示すように、これらのハニカムヒー
タ１の直後に三元触媒機能を持つハニカム触媒２０を載
置し、セラミックファイバーの断熱材７を介して金属ケ
ーシング６に取り付けた。この金属ケーシング６の入口
管は図２に示すように４サイクル２０００ｃｃガソリン
エンジン１１から排気ガスが排出されるマニホールド１
２に接続し、出口管１３は消音器１４へと結ばれてい
る。As shown in FIG. 3, a honeycomb catalyst 20 having a three-way catalytic function was placed immediately after these honeycomb heaters 1 and attached to the metal casing 6 via a ceramic fiber heat insulating material 7. The inlet pipe of this metal casing 6 is a manifold 1 from which exhaust gas is discharged from a 4-cycle 2000cc gasoline engine 11 as shown in FIG.
2, the outlet pipe 13 is connected to a silencer 14.
【００３３】このような本発明のハニカムヒータ１を内
蔵した排気ガス浄化装置１０と、ハニカムヒータを内蔵
しない従来の排気ガス浄化装置を用いて、それぞれ空燃
比を１４．６％とした時の排気ガスの成分濃度を測定
し、触媒効率を調べた。その結果、図５に示すようにエ
ンジン始動直後のＨＣ、ＣＯ、ＮＯX の量に大きな違い
が生じるが、エンジン始動３０秒後の排気ガス濃度では
両者の差がなかった。したがって、排気ガスが冷やされ
た状態で触媒に注がれると浄化されることなく排出され
てしまうが、本発明のハニカムヒータ１を使って触媒直
前で一旦加熱すると触媒の浄化作用が得られることがわ
かった。Exhaust gas when the air-fuel ratio is set to 14.6% by using the exhaust gas purifying apparatus 10 having the honeycomb heater 1 of the present invention and the conventional exhaust gas purifying apparatus having no honeycomb heater, respectively. The gas component concentration was measured to examine the catalyst efficiency. As a result, as shown in FIG. 5, the amounts of HC, CO, and NO x immediately after the engine was started differed greatly, but there was no difference in the exhaust gas concentration 30 seconds after the engine was started. Therefore, if the exhaust gas is poured into the catalyst in a cooled state, it is exhausted without being purified. However, if the honeycomb heater 1 of the present invention is once heated immediately before the catalyst, a purifying action of the catalyst can be obtained. I understood.
【００３４】次に、ハニカムヒータ１の発熱量と加熱時
間との関係を図６に示すように、発熱量の違いによって
ハニカムヒータ１が触媒の機能温度である３００℃まで
到達する時間が異なってくるが、発熱量が２０ｋｃａｌ
／分であれば５秒以内で昇温でき充分実用的であること
がわかった。もちろん、エンジン始動に要するまでの時
間をより短くしたい場合は発熱量の大きなハニカムヒー
タ１を使えばよいが、大きな発熱量のハニカムヒータ１
を用いるほど消費電力が増え、バッテリの容量も増大し
なければならない。Next, as shown in FIG. 6, the relationship between the heating value of the honeycomb heater 1 and the heating time is shown in FIG. 6, and the time required for the honeycomb heater 1 to reach the catalyst functional temperature of 300 ° C. varies depending on the heating value. But the calorific value is 20 kcal
It was found that the temperature could be raised within 5 seconds if it was / minute, which was sufficiently practical. Of course, if it is desired to shorten the time required to start the engine, the honeycomb heater 1 having a large heat generation amount may be used, but the honeycomb heater 1 having a large heat generation amount may be used.
The more power consumption is used, the more battery capacity must be increased.
【００３５】さらに、ハニカム体２のセル数やリブ厚と
エンジンの出力との関係を表２に示すように、ハニカム
体２のリブ厚が２ｍｍより大きいか、またはセル数が１
平方インチ当たり２００セルを超えると、排気ガスの圧
力損失が急激に高まってしまい、エンジンの出力低下を
まねくため好ましくないことがわかった。したがって、
ハニカム体２のリブ厚は２ｍｍ以下でかつセル数をい平
方インチ当たり２００セル以下としたものが良い。Further, as shown in Table 2 for the relationship between the number of cells or rib thickness of the honeycomb body 2 and the output of the engine, the rib thickness of the honeycomb body 2 is larger than 2 mm or the number of cells is 1.
It has been found that when the number of cells exceeds 200 cells per square inch, the pressure loss of the exhaust gas rapidly increases, which leads to a reduction in engine output, which is not preferable. Therefore,
The rib thickness of the honeycomb body 2 is preferably 2 mm or less and the number of cells is 200 cells or less per square inch.
【００３６】[0036]
【表２】 [Table 2]
【００３７】なお、以上の実験はガソリンエンジンのみ
で行ったが、ディーゼルエンジンなど他の内燃機関であ
っても同様の効果を得らることができる。Although the above experiment was conducted only with a gasoline engine, the same effect can be obtained with other internal combustion engines such as a diesel engine.
【００３８】[0038]
【発明の効果】以上のように、本発明によれば、１０-2
〜１０Ω・ｃｍの体積固有抵抗値を持ったペロブスカイ
ト型の結晶構造を有するセラミックスから成るハニカム
体に給電部材を取り付けてハニカムヒータを構成したこ
とによって、この給電部材に通電するだけで発熱させる
ことができ、高温中でも使用可能なハニカムヒータを容
易に製造することができる。As described above, according to the present invention, 10 -2
By forming a honeycomb heater by attaching a power feeding member to a honeycomb body made of ceramics having a perovskite type crystal structure having a volume resistivity value of 10 Ω · cm, it is possible to generate heat only by supplying current to the power feeding member. It is possible to easily manufacture a honeycomb heater that can be used even at a high temperature.
【００３９】また、このハニカムヒータを触媒の直前に
設置して排気ガス浄化装置を構成したことによって、エ
ンジンスタート直後の排気ガスを加熱し、触媒の機能を
促進させることができ、クリーンな排気ガスとすること
ができる。Further, by configuring this exhaust gas purifying device by installing this honeycomb heater immediately before the catalyst, it is possible to heat the exhaust gas immediately after the engine is started and to promote the function of the catalyst, so that a clean exhaust gas can be obtained. Can be
【図１】本発明のハニカムヒータを示す斜視図である。FIG. 1 is a perspective view showing a honeycomb heater of the present invention.
【図２】本発明の排気ガス浄化装置を用いたエンジンの
排気部を示す概略図である。FIG. 2 is a schematic diagram showing an exhaust portion of an engine using the exhaust gas purifying apparatus of the present invention.
【図３】本発明の排気ガス浄化装置を示す一部破断面図
である。FIG. 3 is a partial cross-sectional view showing an exhaust gas purification device of the present invention.
【図４】一般的なハニカム触媒を示す斜視図である。FIG. 4 is a perspective view showing a general honeycomb catalyst.
【図５】本発明の排気ガス浄化装置の触媒効率を示すグ
ラフである。FIG. 5 is a graph showing the catalyst efficiency of the exhaust gas purification device of the present invention.
【図６】本発明のハニカムヒータの昇温特性を示すグラ
フである。FIG. 6 is a graph showing temperature rising characteristics of the honeycomb heater of the present invention.
１：ハニカムヒータ ２：ハニカム体 ３：給電部材 ４：給電線 ５：電源 ６：金属ケーシング ７：断熱材 １０：排気ガス浄化装置 １１：エンジン １２：排気マニホールド １３：出口管 １４：消音器 ２０：ハニカム触媒 1: Honeycomb heater 2: Honeycomb body 3: Power supply member 4: Power supply line 5: Power supply 6: Metal casing 7: Insulation material 10: Exhaust gas purification device 11: Engine 12: Exhaust manifold 13: Outlet pipe 14: Silencer 20: Honeycomb catalyst
Claims (3)
スカイト型の結晶構造を持ち、かつ１０-2〜１０Ω・ｃ
ｍの体積固有抵抗値を有するセラミックスから成るハニ
カム体に給電部材を取り付けてなるハニカムヒータ。1. A perovskite type crystal structure such as LaMnO 3 or LaCrO 3 and having a concentration of 10 −2 to 10 Ω · c.
A honeycomb heater in which a power feeding member is attached to a honeycomb body made of ceramics having a volume resistivity of m.
の排気ガス浄化用触媒の直前に備えて成る排気ガス浄化
装置。2. An exhaust gas purifying apparatus comprising the honeycomb heater according to claim 1 immediately before an exhaust gas purifying catalyst for an internal combustion engine.
関の排気ガス浄化機能を有する触媒成分を担持させて成
る排気ガス浄化装置。3. An exhaust gas purification apparatus comprising the honeycomb heater according to claim 1 carrying a catalyst component having an exhaust gas purification function of an internal combustion engine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5087408A JPH06296873A (en) | 1993-04-14 | 1993-04-14 | Honeycomb heater and exhaust gas purification device using said heater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5087408A JPH06296873A (en) | 1993-04-14 | 1993-04-14 | Honeycomb heater and exhaust gas purification device using said heater |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06296873A true JPH06296873A (en) | 1994-10-25 |
Family
ID=13914059
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5087408A Pending JPH06296873A (en) | 1993-04-14 | 1993-04-14 | Honeycomb heater and exhaust gas purification device using said heater |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06296873A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002080271A (en) * | 2000-05-31 | 2002-03-19 | Corning Inc | Diesel engine exhaust gas filter |
| JP2011230999A (en) * | 2010-04-09 | 2011-11-17 | Ibiden Co Ltd | Honeycomb structure and exhaust gas cleaning device |
| JP2014054935A (en) * | 2012-09-13 | 2014-03-27 | Ngk Insulators Ltd | Heater |
| JP2014054934A (en) * | 2012-09-13 | 2014-03-27 | Ngk Insulators Ltd | Heater |
| JP5850858B2 (en) * | 2010-12-24 | 2016-02-03 | 日本碍子株式会社 | Honeycomb structure |
-
1993
- 1993-04-14 JP JP5087408A patent/JPH06296873A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002080271A (en) * | 2000-05-31 | 2002-03-19 | Corning Inc | Diesel engine exhaust gas filter |
| JP2011230999A (en) * | 2010-04-09 | 2011-11-17 | Ibiden Co Ltd | Honeycomb structure and exhaust gas cleaning device |
| JP5850858B2 (en) * | 2010-12-24 | 2016-02-03 | 日本碍子株式会社 | Honeycomb structure |
| JP2014054935A (en) * | 2012-09-13 | 2014-03-27 | Ngk Insulators Ltd | Heater |
| JP2014054934A (en) * | 2012-09-13 | 2014-03-27 | Ngk Insulators Ltd | Heater |
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