JPS5870816A - Method for collecting dust - Google Patents

Abstract

PURPOSE:To prevent a phenomenon wherein dust adhered on a heat conductive surface in a dust containing gas side in re-scattered to an other gas side and the concn. of dust is increased in other gas. CONSTITUTION:The part of a treated waste gas is induced from a duct prior to a chimney 7 by a blower 8 and introduced into a dust removing region 9 arranged in a rotary regenerative type heat exchanger 4 under pressure. Dust adhered on the heat conductive surface in the dust removing region is rescattered into a treated waste gas and the treated waste gas containing re-scattered dust is issued from the rotary regenerative type heat exchanger 4 and the part or the whole thereof is introduced into a dry or a semi-dry desulfurization apparatus 10 to remove sulfur oxide therein to be returned to the duct prior to the chimney while subjected to dust collection in a dry dust collector 11. In addition, the part or the whole thereof can be again returned to the suction side of the blower 8 in order to be subjected to dust removel on the heat conductive surface and bad effect due to the re-scattering of dust is prevented and most of conveying-in and leakage is eliminated and dust is collected.

Description

【発明の詳細な説明】 本発明はばいじん゛を含むガスと他のガスとの熱交換を
回転蓄熱式熱交換器により行う場合の集塵方法に関する
ものであり、峰にばいじんを含むガス側で伝熱面上に付
着したばいじんが他のガス側で再飛散し、他のガス゛の
ばいじん濃度を増大させることを防止する新規なる集塵
方法を提供するものである。[Detailed Description of the Invention] The present invention relates to a dust collection method when heat exchange between a gas containing soot and other gas is performed using a rotary regenerative heat exchanger, and the present invention relates to a dust collection method when a gas containing soot and dust is exchanged with other gas using a rotating regenerative heat exchanger. To provide a new dust collection method that prevents soot and dust adhering to a heat transfer surface from being re-scattered on the other gas side and increasing the soot and dust concentration of other gases.

最近省石油の見地から石炭燃料の使用は時代の要求であ
る。石炭燃焼ボイラーより排出される排煙には多くの硫
黄酸化物が含有されており、これを脱硫する為に脱硫装
置が設置される。即ち、第１図に見る如くボイラー１よ
りの排煙は空気予熱器２へ導かれ、熱回収が行なわれる
。その後、電気集塵機３により排煙中のダストの集塵が
行なわれた後、ガス−ガス熱交換器４、通風機５を経て
、湿式脱硫装置６へ導かれ、スクラバ一方式による′脱
硫と集塵が同時に行なわれた後、再びガス−ガス熱交換
器４を経て、煙突７より大気中へ放出される。このガス
−ガス熱交換器４は湿式脱硫装置による排煙の温度低下
によって起こされる白煙を防止し、かつ、排煙の拡散効
果の向上をはかることを目的として排煙加熱するもので
、燃焼式加熱装置の適用は低硫黄重油を使用しても再び
硫黄酸化物が発生する。Recently, from the viewpoint of oil conservation, the use of coal fuel is the demand of the times. The flue gas emitted from coal-fired boilers contains a lot of sulfur oxides, and desulfurization equipment is installed to desulfurize this. That is, as shown in FIG. 1, exhaust smoke from a boiler 1 is guided to an air preheater 2, where heat is recovered. After that, the dust in the flue gas is collected by an electric precipitator 3, and then passed through a gas-gas heat exchanger 4 and a ventilator 5 to a wet desulfurization device 6, where it is desulfurized and collected by a single-type scrubber. After the dust is removed at the same time, it passes through the gas-gas heat exchanger 4 again and is discharged into the atmosphere from the chimney 7. This gas-gas heat exchanger 4 heats the flue gas for the purpose of preventing white smoke caused by the temperature drop of the flue gas caused by the wet desulfurization equipment and improving the diffusion effect of the flue gas. Even if low sulfur heavy oil is used in the application of the type heating device, sulfur oxides are generated again.

又硫黄を含まない灯油又はガス燃料を採用すると運転費
が大となる問題があるため、ガス−ガス熱交換器が採用
され、多くの場合その形式は回転蓄熱式熱交換器であり
、その代表例が回転子を有するユングストローム形熱交
換器である。In addition, if kerosene or gas fuel that does not contain sulfur is used, there is a problem of high operating costs, so a gas-to-gas heat exchanger is used, and in most cases, the type is a rotary regenerative heat exchanger. An example is a Ljungström heat exchanger with a rotor.

従来、ユングストローム形の如き回転蓄熱式熱交換器で
は回転子内に包含されたガスが回転子の回転により他方
のガス内に搬入される欠点があった。Conventionally, rotary regenerative heat exchangers such as the Ljungström type have had the disadvantage that the gas contained in the rotor is carried into the other gas by the rotation of the rotor.

即ち、第１図においてガス−ガス熱交換器４に於て、若
干量の未処理排煙が漏洩し、これらは、後置の脱硫装置
６による集塵が行なわれないまま処理排煙に含有されて
、煙突から大気中へ放出されるので大気汚染発生の原因
となる。然してこの対策としては、回転数の低減など種
−々の対策がとられてきた。That is, in FIG. 1, a small amount of untreated flue gas leaks from the gas-gas heat exchanger 4, and these are contained in the treated flue gas without being collected by the downstream desulfurization device 6. It is then released into the atmosphere from chimneys, causing air pollution. However, various measures have been taken to counter this problem, such as reducing the number of revolutions.

一方、近年石炭燃焼ボイラが漸増しつつあるが、これの
排煙中に含まれるばいじん濃度は重油燃焼の場合のそれ
と比較してはるかに大きく、この多量のばいじんが回転
蓄熱式熱交換器の伝熱面上に付着し、第１図においては
、伝熱面が処理排煙側に回転した際、伝熱面上のばいじ
んが再飛散して処理排煙中に混入し煙突７の手前のばい
じん濃度が増大する事例が見られ、前記の回転子の回転
による搬入漏洩によるばいじん濃度の増大と相まってこ
れが無視できない値となる場合がある。On the other hand, although the number of coal-fired boilers has been gradually increasing in recent years, the concentration of soot and dust contained in the flue gas is much higher than that of heavy oil combustion, and this large amount of soot and dust is transferred to the rotary regenerative heat exchanger. In Fig. 1, when the heat transfer surface rotates toward the processing flue gas side, the soot and dust on the heat transfer surface is re-scattered and mixed into the processing flue gas, and the soot and dust in front of the chimney 7 is There have been cases where the concentration has increased, and in combination with the increase in soot and dust concentration due to the leakage caused by the rotation of the rotor, this may reach a value that cannot be ignored.

又、将来に於けるばいじんの排出基準の強化や微細粒子
ばいじんに対する規制強化の見地からも、煙突７の手前
でのばいじん濃度の低減は極めて重要な技術的１ＩＩＮ
である。本発明はかかる技術的課題を解決する新規なる
回転蓄熱式熱交換器の集塵方法を提案するものである。In addition, from the perspective of stricter soot and dust emission standards and stricter regulations regarding fine particulate dust in the future, reducing the soot and dust concentration before the chimney 7 is an extremely important technical point.
It is. The present invention proposes a novel dust collection method for a rotary regenerative heat exchanger that solves these technical problems.

本発明の実施例を第２図及び第３図に夫々示す。An embodiment of the invention is shown in FIGS. 2 and 3, respectively.

煙突７の手前のダクトより通風機８により処理排煙の一
部を誘引、加圧して回転蓄熱式熱交換器４に配設された
除塵域９へ導入する。A part of the treated flue gas is drawn through a duct in front of the chimney 7 by a ventilator 8, pressurized, and introduced into a dust removal area 9 disposed in a rotary regenerative heat exchanger 4.

除塵域内の伝熱面上に付着したばいじんは導入された処
理排煙中に再飛散し、再飛散ばいじんを含んだ処理排煙
は回転蓄熱式熱交換器４を出て第２図の実施例に於ては
、その一部又は全部を乾式又は半乾式脱硫装置１０によ
り硫黄酸化物を除去して後、乾式集塵機１１により集塵
されて後、煙突７の手前のダクトにもどされる。又、再
循環用ダクト１２にょ抄その一部又は全部を再び伝熱面
上のばいじん除去に供するために通風機８の吸込側へも
どすこともできる。The soot and dust adhering to the heat transfer surface in the dust removal area is re-scattered into the treated flue gas that has been introduced, and the treated flue gas containing the re-splattered dust exits the rotary regenerative heat exchanger 4 and is transferred to the embodiment shown in FIG. In this case, some or all of the sulfur oxides are removed by a dry or semi-dry desulfurization device 10, the dust is collected by a dry dust collector 11, and then returned to the duct in front of the chimney 7. Further, part or all of the recirculation duct 12 can be returned to the suction side of the ventilation fan 8 in order to use it again to remove dust from the heat transfer surface.

又、第３図の実施例に於ては、その一部を乾式又は半乾
式脱硫装置１０により、硫黄酸化物を除去して後、乾式
集塵機１１により集塵されて後、その一部又は全部を再
び伝熱面上のばいじん除去に供するために、通風機８の
吸込側ダクトにもどされる。In the embodiment shown in FIG. 3, a part of the sulfur oxide is removed by a dry or semi-dry desulfurization device 10, and then part or all of it is collected by a dry dust collector 11. is returned to the suction side duct of the ventilator 8 in order to again remove dust from the heat transfer surface.

尚、一般的に第１図に示すように煙突７の手前の排煙の
性状は、湿式脱硫装置６により排煙中に水分が多くなる
ため乾式の集塵機は使用できないと考えられていたが、
第１図の煙突７の入口に於ける排煙の測定調査によれば
、水分が１０Ｖｏ１％（Ｄ　ＲＹ　）、ＳＯｘ濃度が１
０ｐｐｍである。又、８０ｘ中にＳ０３は湿式脱硫後で
あるため、はとんど含まれていない。すなわち、煙突７
の入口の排煙の温度は露点以上である。又、採取したば
いじんはさらさらの乾燥状態のものであった。以上より
本発明の実施例を示す第２図、及び第３図の如く煙突７
の手前の排煙に乾式集１１１を設置することが十□分可
能である事が判明した。従って本発明の第２図及び第３
図の実施例においては、該乾式集塵機は、集塵率の高い
ものが要求されるため、乾式電気集嘆機又はろ過集塵機
であるバグフィルタ−を適用する。It should be noted that, as shown in Fig. 1, it was generally thought that a dry dust collector could not be used due to the nature of the flue gas in front of the chimney 7 due to the wet desulfurization device 6 causing a large amount of moisture in the flue gas.
According to the measurement survey of the flue gas at the entrance of the chimney 7 in Figure 1, the moisture content is 10Vo1% (DRY), and the SOx concentration is 1%.
It is 0 ppm. Furthermore, S03 is hardly included in 80x since it has been subjected to wet desulfurization. That is, chimney 7
The temperature of the flue gas at the inlet is above the dew point. In addition, the collected soot and dust was in a smooth dry state. From the above, as shown in FIG. 2 and FIG. 3 showing the embodiment of the present invention, the chimney 7
It was found that it is possible to install a dry collection 111 in front of the smoke exhaust. Therefore, FIGS. 2 and 3 of the present invention
In the illustrated embodiment, since the dry dust collector is required to have a high dust collection rate, a bag filter, which is a dry electric dust collector or a filtration dust collector, is used.

バグフィルタ−は電気集塵機との集塵原理の違いにより
、図中６で示す電気集塵機で集塵できなかった微細ばい
じんや再飛散ばいじんを、このバグフィルタ−で集塵で
きる効果がある。Due to the difference in dust collection principle between the bag filter and an electrostatic precipitator, the bag filter has the effect of being able to collect fine dust and re-splattered dust that could not be collected by the electric precipitator shown at 6 in the figure.

又、第２図及び第３図の実施例において、除塵域９を通
過するガスが再循環されたガスである場合、再び除塵域
を通過することＫより硫黄慣化物が更に加わり、その濃
度が増加することになる。従ってこれを避けることを目
的として、該ガスの一部又は全部を脱硫装置１０により
脱硫するものである。尚、脱硫装置１０に後置される集
塵機１１０安定的運転を確保するために、脱硫装置１０
は乾式又は半乾式とし、湿分の増加を極力抑制するのが
よい。In addition, in the embodiments shown in FIGS. 2 and 3, if the gas passing through the dust removal zone 9 is recycled gas, more sulfur inertia will be added to the gas as it passes through the dust removal zone again, and its concentration will increase. will increase. Therefore, in order to avoid this, some or all of the gas is desulfurized by the desulfurization device 10. In addition, in order to ensure stable operation of the dust collector 110 installed after the desulfurization device 10, the desulfurization device 10
It is best to use a dry or semi-dry method to suppress increase in moisture as much as possible.

また、回転蓄熱式熱交換器４の除塵域９の実施例を第４
図に示す。放射状に配置された仕切板１３をもち伝熱エ
レメントを内蔵する回転子１４が１５の如く回転移動し
、未処理排煙側と処理排煙側とを仕切るよう配設された
扇状の摺動板１６のほぼ中央部に備けられた開口部２８
の位置に至った場合、該開口部より通風機８により導か
れた処理排煙が１７の如く圧入し仕切板１３により囲ま
れた扇状空間１８内の伝熱面上に付着したばいじんを吹
落して再飛散させ１９の如く通過し、再飛散ばいじんを
伴って２０の如く反対側の摺動板１６の開口部より２０
の如く排出される。かくして回転子の回転に従い伝熱面
は常時圧入する処理排煙により連続的に清浄される。尚
、シール板２７で除塵用処理排煙の漏洩を防ぐ。In addition, the embodiment of the dust removal area 9 of the rotary regenerative heat exchanger 4 is shown in the fourth example.
As shown in the figure. A rotor 14 having partition plates 13 arranged radially and containing a heat transfer element rotates as shown in 15, and is a fan-shaped sliding plate arranged to partition the untreated smoke exhaust side and the treated smoke exhaust side. An opening 28 provided approximately in the center of 16
When the position is reached, the treated exhaust gas guided by the ventilator 8 from the opening is pressed in as shown in 17 and blows off the soot and dust attached to the heat transfer surface in the fan-shaped space 18 surrounded by the partition plate 13. The dust is re-scattered and passed through as shown in 19, and the dust is passed through the opening of the sliding plate 16 on the opposite side as shown in 20 with the re-splattered dust.
It is discharged as follows. In this manner, as the rotor rotates, the heat transfer surface is continuously cleaned by the treated exhaust gas that is constantly pressurized. Note that the seal plate 27 prevents leakage of the treated flue gas for dust removal.

本発明によれば回転蓄熱式熱交換器の伝熱面上に付着し
たばいじんの再飛散による悪影響を防止できるのに加え
、前述の搬入漏洩の大部分も掃気され集塵機により集塵
することも可能となる等優れた効果を有している。According to the present invention, in addition to being able to prevent the negative effects of dust adhering to the heat transfer surface of a rotary regenerative heat exchanger due to re-scattering, it is also possible to scavenge most of the aforementioned leakage and collect it with a dust collector. It has excellent effects such as.

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

第１図は、従来の排煙処理法を示す系統図（ダンパーな
どは省略）、第２図及び第３図は、本発明の集塵方法の
１実施例を示す系統図（ダンパーなどは省略）である。 第４図は、回転蓄熱式熱交換器の関係部分の断面図（一
部展開図を含む）である。 尚、図中の主要部の符号は次の通りである。 １・・・・・・ポイ２−２・・・・・・空気予黙器５・
・・・・・通風機　　　　　　　６・・・・・・湿式脱
硫装置７・・・・・・煙　突　　　　　　　８・・・・
・・通風機９・・・・・・除塵域を配設した回転蓄熱式
熱交換器１０・・・・・・乾式又は半乾式脱硫装置１１
・・・・・・除塵機　　　　　　　１２・・・・・・再
循環用ダクト１５・・・・・・回転子の回転方向　　１
６・・・・・・摺動板１７・・・・・・除塵用の処理排
煙の　１８・・・・・・扇状空間流れ方向 １９・・・・・・除塵中の処理排煙の　２０・・・・・
・除塵後の処理排煙の流れ方向　　　　　　　　　流れ
方向 ２１・・・・・・未処理排煙の流れ方向　２２・・・・
・・処理排煙の流れ方向２３・・・・・・未処理排煙ダ
クト２４・・・・・・処理排煙ダクト特許出願人 ガデリウス株式会社 ９４−Fig. 1 is a system diagram showing a conventional flue gas treatment method (dampers, etc. are omitted), and Figs. 2 and 3 are system diagrams showing one embodiment of the dust collection method of the present invention (dampers, etc. are omitted). ). FIG. 4 is a sectional view (including a partially exploded view) of related parts of the rotary regenerative heat exchanger. Incidentally, the symbols of the main parts in the figure are as follows. 1... Poi 2-2... Air silencer 5.
... Ventilator 6 ... Wet desulfurization equipment 7 ... Chimney 8 ...
... Ventilator 9 ... Rotating regenerative heat exchanger 10 equipped with a dust removal area ... Dry or semi-dry desulfurization device 11
... Dust remover 12 ... Recirculation duct 15 ... Rotation direction of rotor 1
6... Sliding plate 17... 18... Fan-shaped space flow direction 19... 20... For processing exhaust gas during dust removal.・・・・・・
・Flow direction of treated flue gas after dust removal Flow direction 21...Flow direction of untreated flue gas 22...
... Flow direction of treated flue gas 23 ... Untreated smoke flue duct 24 ... Treated smoke flue duct Patent applicant Gadelius Co., Ltd. 94-

Claims (1)

【特許請求の範囲】 １）ばいじんを含むガスと他のガスとの熱交換を行う回
転蓄熱式熱交換器において、ばいじんを含むガス側の伝
熱面被曝域と他のガス側の伝熱面被曝域との間に除塵域
を配設し、該除塵域において伝熱面上に付着したばいじ
んを流体を用いて除去し、該除去されたばいじんを含む
流体の一部を脱硫装置により硫黄酸化物を除去して後集
塵機により集塵することを特徴とする集塵方法。 ２）＠熱面上に付着したばいじんを除去する手段として
用いる流体が、前記熱交換器の加熱側ガス又は被加熱側
ガスであることを特徴とする特許請求の範囲第１項記載
の集塵方法。 乙）伝熱面上に付着したばいじんを除去する手段として
用いた流体の一部又は全部を再び伝熱面上のばいじん除
去に供するため循環させることを特徴とする特許請求の
範囲第１項又は第２項記載の集塵方法。 ４）前記除塵域において除去されたばいじんを含む流体
を集塵する手段として用いる集塵機が、電気式集塵機又
はろ過式集塵機であることを特徴とする特許請求の範囲
第１項、第２項又は第６項記載の集塵方法。 ５）前記硫黄酸化物を除去する脱°硫装置が乾式−１又
は半乾式脱硫装置であることを特徴とする特許請求の範
囲第１項、第２項、第５項又は第４項記載σ集塵方法。 ６）前記集塵機が乾式集塵機であることを特徴とする特
許請求の範囲第１項、第２項、第３項、第４項又は第５
項記載の集塵方法。 ７）前記除塵域において除去されたばいじんを含む流体
の一部を脱硫装置により硫黄酸化物を除去して後集塵機
により集塵して後その一部又は全部を再び伝熱面上のば
いじん除去に供するため循環させることを特徴とする特
許請求の範囲第１項、第２項、第３項、第４項、第５項
又は第６項記載の集塵方法。[Claims] 1) In a rotary regenerative heat exchanger that exchanges heat between a gas containing soot and other gases, an exposed area of a heat transfer surface on the gas side containing soot and dust and a heat transfer surface on the other gas side. A dust removal area is provided between the exposed area and the dust attached to the heat transfer surface is removed using a fluid in the dust removal area, and a part of the fluid containing the removed dust is oxidized by sulfur using a desulfurization device. A dust collection method characterized by removing objects and collecting dust using a post-dust collector. 2) The dust collector according to claim 1, wherein the fluid used as a means for removing dust adhering to a hot surface is a heating side gas or a heated side gas of the heat exchanger. Method. B) Part or all of the fluid used as a means for removing soot and dust adhering to the heat transfer surface is circulated again to remove soot and dust from the heat transfer surface, or The dust collection method described in Section 2. 4) Claims 1, 2, or 4, characterized in that the dust collector used as a means for collecting the fluid containing the dust removed in the dust removal area is an electric dust collector or a filtration type dust collector. Dust collection method described in Section 6. 5) The desulfurization device for removing sulfur oxides is a dry type-1 or semi-dry type desulfurization device, σ as described in claim 1, 2, 5, or 4. Dust collection method. 6) Claims 1, 2, 3, 4, or 5, wherein the dust collector is a dry dust collector.
Dust collection method described in section. 7) A part of the fluid containing soot and dust removed in the dust removal area is used to remove sulfur oxides by a desulfurization device, and then collected by a dust collector, and then a part or all of it is used again to remove dust from the heat transfer surface. A dust collection method according to claim 1, 2, 3, 4, 5, or 6, characterized in that the dust collection method is performed by circulating the dust for use.