Hitachi, Ltd.

Babcock-Hitachi Kabushiki Kaisha

Other

Babcock-Hitachi K.k.

Babcock-Hitachi Kabushiki

Hitachi Babcock Kabushiki-Kaisha

Hironobu Kobayashi

Masayuki Taniguchi

Shigeru Azuhata

Kiyoshi Narato

Hirofumi Okazaki

Shigeki Morita

Norio Arashi

Kenichi Sohma

Kenji Kiyama

Tooru Inada

Tadayoshi Murakami

Toshikazu Tsumura

Michio Kuroda

Akira Baba

Hiroshi Miyadera

Kouji Kuramashi

Tadashi Jimbo

Kenji Yamamoto

Miki Shimogori

Yoji Ishibashi

Yasuo Yoshii

Yoshitaka Takahashi

Koji Kuramashi

Shinichiro Nomura

Kunio Hodozuka

Osamu Ito

Shin Tamata

Shuichi Kanno

Kazuyoshi Irie

Takanori Yano

Keizou Ohtsuka

Hisayuki Orita

Toshihiko Mine

Hideo Kikuchi

Kunio Okiura

Shigeto Nakashita

Fumio Koda

Keiji Ishii

Yasuo Iwai

Stephen M Masutani

Osamu Okada

Yukio Hishinuma

Kazutoshi Higashiyama

Akihito Orii

Hiroyuki Kaku

Kazuyuki Ito

Satoshi Tsukahara

Kenichi Ochi

Tadahisa Masai

Satoshi Tadakuma

Noriyuki Hayashi

Ken Amano

Hiroaki Kanemoto

Hidehisa Yoshizako

Yuki Kamikawa

Shigekazu Nishimoto

Noriyuki Ohyatsu

Miki Mori

Noboru Takarayama

Tsuyoshi Kohno

Tsuyoshi Kouno

Toshiyuki Tanaka

Noriyuki Oyatsu

Ken-ichi Sohma

Masakiyo Tanikawa

Kei Kawano

Tatsuzou Enomoto

Shinichirou Nomura

Noriyuki Ooyatsu

Shinji Tsuda

Katsumi Shimohira

Takeru Fukuchi

Hiroshi Yamaguchi

Hitoshi Kikuchi

Kazuhito Sakai

Tadashi Jinbo

Shin-ichiro Nomura

Masao Masutani

Tooru Inata

Isao Koyama

Kenshi Kobayashi

A pulverized coal-fired boiler efficiently supplies air to a central part of a furnace and the neighborhood of a furnace wall, thereby promoting mixture with combustion gas, and reducing both NOx and CO. The main after air ports are structured so as to jet air having a large momentum for enabling arrival at the central part of the furnace, and the sub-after air ports are structured so as to jet air having a small momentum to the neighborhood of the wall face of the furnace, and a sectional center of each of the sub-after air ports is within a range from 1 to 5 times of a caliber of the main after air ports from a sectional center of each of the main after air ports.

Pulverized coal-fired boiler and pulverized coal burning method

The invention provides a combustion apparatus which can inhibit an NOx generation even in the case of promoting a mixing between a high-temperature combustion gas and an air so as to intend to reduce an unburned combustible. In a combustion apparatus provided with a burner burning a fuel within a furnace in a theoretical air ratio or less, and an air port supplying a combustion air for a shortfall in the burner, a supply apparatus for supplying a nitrogen oxide generation inhibiting gas is provided in a mixing region between the both or near the mixing region. Further, the invention provides a wind box which can inhibit an NOx generation even in the case of promoting a mixing between a high-temperature combustion gas and an air so as to intend to reduce an unburned combustible. In a wind box having an air port arranged in a back flow side of the burner and supplying a combustion air for a shortfall in the burner, a supply apparatus for supplying a nitrogen oxide generation inhibiting gas is provided in a mixing region between the both or near the mixing region.

Combustion apparatus and wind box

A catalytic exhaust gas decomposition spirals an exhaust gas containing therein a substance to be decomposed and a reactant gas, rectifies the spiral flow, and lets the substance to be decomposed react with the reactant gas after the spiral flow has been rectified. For rectifying the spiral flow of the exhaust gas and the reactant gas, a plate-like baffle wall has therein a through hole at a portion near its center. The spiral flow is allowed to pass through the through hole so as to be centralized temporarily. The spiral flow then passes through an enlarged section of a flow path downstream of the through hole before being introduced into the catalyst bed. The method helps minimize variations in gas velocity of the exhaust gas flowing into the catalyst bed, thereby allowing a desired decomposition rate to be obtained substantially consistently.

Catalytic exhaust gas decomposition apparatus and exhaust gas decomposition method

The catalytic exhaust gas decomposition apparatus spirals an exhaust gas containing therein a substance to be decomposed and a reactant gas, rectifies the spiral flow, and lets the substance to be decomposed contained in the exhaust gas react with the reactant gas after the spiral flow has been rectified. This arrangement rectifies the spiral flow of the exhaust gas and the reactant gas with a plate-like baffle wall having therein a through hole at a portion near the center thereof. The spiral flow is allowed to pass through the through hole so as to be centralized temporarily. The spiral flow then passes through an enlarged section of a flow path downstream of the through hole before being introduced into the catalyst bed.

Solid fuel burner and method of combustion using solid fuel burner

The invention provides a boiler provided with low cost means which can reduce a concentration of CO, an unburned matter, an attached ash and the like near a side wall and maintain a combustion state well with a simple structure. In a boiler having a combustion chamber formed by front and rear walls (burner walls) provided with a plural stages of burners and on at least one of them and opposing to each other, and side walls and crossing to said burner walls and , a gas port containing no fuel for making a pressure of a gas near said side walls and within said combustion chamber higher than a pressure of a gas at a center portion of said combustion chamber is provided between an outermost burner and the side walls and within a range of a height of said burner stages and . A combustion gas can not come close to the side walls and due to the jet of the gas.

Boiler

A boiler has a combustion chamber formed by front and rear walls and a side wall extending between the front and rear walls. Plural stages of burners are placed on at least one of the front and rear walls. In the front and rear walls are opposing gas jets for making a pressure of the gas near the side wall within the combustion chamber higher than the pressure of the gas at a center portion of the combustion chamber. The gas jet ports are disposed at a height within a range of the height of the burner stages. The burner stages supply the pulverized coal, the air for transferring the pulverized coal and the air for burning. A part of the air for transferring the pulverized coal or the air for burning is supplied in a branched manner to the gas jet port and injected into the combustion chamber. Further, the air is preferably injected from the gas jet ports in a direct gas flow, not a swirling flow.

A burner for burning fine coal powder comprising: a fine coal powder nozzle,for injecting a mixture of the fine coal powder and air; and air nozzles,for injecting air: wherein the sufficient amount of air for complete combustion of the fine coal powder is supplied from the air nozzles; a reducing flame at a high temperature is formed by consuming oxygen rapidly with forming a flame at a high temperature by igniting the fine coal powder rapidly in the vicinity of the outlet of the burner; and an oxidizing flame having an uniform distribution of gas composition in radial direction to the central axis of the burner is formed by mixing the air injected from the air nozzle in the downstream of the reducing flame at the high temperature.

Fine coal powder combustion method for a fine coal powder combustion burner

A combustion burner includes a mixture nozzle (,) defining a mixture fluid passage through which a mixture fluid (,) containing pulverized coal and conveyor gas flows toward a furnace, secondary and tertiary air passages surrounding the mixture nozzle (,), through which secondary air (,) and tertiary air (,) for combustion purposes flow, respectively; and air injection nozzles (,) provided in the vicinity of an outer periphery of a distal end of the mixture nozzle (,). The air (,) is injected from the air injection nozzles (,) toward the axis of the mixture nozzle, so that the high-temperature gas in the vicinity of the outer periphery of the distal end of the mixture nozzle (,) is drawn into the mixture fluid (,) in the vicinity of the outer periphery of this distal end.

Combustion burner and combustion device provided with same

A combustion method utilizing a pulverized coal combustion burner which is provided with a pulverized coal nozzle for jetting a fluid mixture of pulverized coal and air and an air nozzle for jetting air. In the method, a combustion flame formed by the pulverized coal combustion burner forms a first zone of a gas phase air ratio of one or less at a radially central portion of the flame and a second zone of a gas phase air ratio of more than one outside of the first zone adjacent the coal nozzle, and a third zone of a gas phase air ratio of one or less at a downstream side from said first and second zones.

Pulverized coal combustion burner and combustion method thereby

A pulverized coal burner includes a pulverized coal nozzle for jetting a mixture of pulverized coal and primary air, a secondary air nozzle and a tertiary air nozzle, concentrically arranged around the outer periphery of the pulverized coal nozzle, and a tube expanded portion at the end of a partition wall separating two adjacent air nozzles. A flow shift means such as a guide plate for shifting the secondary air in the secondary air nozzle so as to flow along the tube expanded portion is provided. The secondary air is jetted outwardly by the guide plate, and mixing of the secondary air and the tertiary air with pulverized coals is delayed, whereby an amount of NOx is decreased.

Pulverized coal burner

A pulverized coal burner includes a venturi for contracting a flow of a mixture of pulverized coal and primary air toward a central axis of a fuel nozzle 2. A spindle having a cone is provided coaxially with the central axis and gradually expands from an upstream side to a downstream side to cause the mixture to impinge thereon and diffuse. A column extends from the cone and is parallel to the central axis of the fuel nozzle, and a cone extends from the column and gradually narrows from an upstream side to a downstream side. A flow path divider, having a cone gradually narrowing coaxially with the central axis on the downstream side of the spindle, and a cylinder extending from the cone and being coaxial and parallel with the central axis of the fuel nozzle 2, coaxially divides the flow path.

To provide a pulverized coal burner capable of reducing the NOx concentration at the time of a low load, a pulverized coal burner includes a secondary air nozzle and a tertiary air nozzle concentrically positioned about the outer periphery of a fuel nozzle carrying a pulverized coal with a primary air, and two swirling flow generators are included at least one of these nozzles with a positional relation parallel to a flow of air. One of the swirling flow of the two swirling flow generators can be set strongly. And, under a condition of low air flow rate, air can be supplied from one swirling flow generator alone. Since the swirling strength of the combustion air can be increased, the concentration of NOx produced by the combustion of the pulverized coal can be reduced. Also, because the swirling strength at the time of low load can be increased, the NOx concentration can be reduced by keeping the pulverized coal flame stable.

Pulverized coal burner and method of using same

When at least one of a distribution of gas composition and distribution of temperature inside a furnace is estimated by dividing the region inside the furnace into two-dimensional or three-dimensional cells, and calculating a gas flow rate, a gas reaction amount, a coal combustion rate, a radiant heat transfer rate in each of the cells, based on design data including furnace dimentions and operational data including a coal supply rate and an air supply rate, an air ratio of gas phase--gas composion table is referred to, thereby to simplify the gas reaction amount calculation and reduce drastically time required for the calculation.

Furnace inside state estimation control apparatus of pulverized coal

A pulverized coal combustion burner includes a pulverized coal nozzle, and secondary and tertiary air nozzles provided in concentric relation to the pulverized coal nozzle. A flame stabilizing ring is provided at an outlet end of the pulverized coal nozzle. A separation wall is provided within the pulverized coal nozzle to divide a passage in this nozzle into two passages. A pulverized coal/air mixture flows straight through the two passages, so that recirculation flows of the pulverized coal/air mixture are formed in proximity to the outlet end of the pulverized coal nozzle. As a result, the ignitability of the pulverized coal, as well as a combustion rate, is enhanced, thereby reducing the amount of discharge of NOx.

Pulverized coal combustion burner

Growing community of inventors

Hitachi, Japan

Hironobu Kobayashi