Long front arch and secondary air composite structure of lignite-fired traveling grate boiler

Abstract

The invention discloses a long front arch and secondary air composite structure of a lignite-fired traveling grate boiler. The structure comprises a traveling grate stoker, a lignite hopper, a single long front arch, composite secondary air exhaust pipes and a smoke guide arch, wherein the single long front arch is arranged inside a hearth from front to back, the composite secondary air exhaust pipes are arranged on a side wall of the hearth and positioned below the long front arch, and the smoke guide arch is used for guiding high-temperature smoke to an upper hearth. Lignite can be quickly ignited under the action of thermal radiation of the long front arch after being fed into the hearth along with the traveling grate stoker, and flame generated by combustion of the lignite and the high-temperature smoke skim through along an integral lignite bed of the traveling grate stoker from front to back and are discharged from a long front arch outlet positioned at the rear of the hearth, so that the integral lignite bed which is positioned below the long front arch and arranged on the traveling grate stoker is in a high-temperature state, and high combustion efficiency can be realized. Besides, air delivered by an air blower is sprayed into the upper side of the lignite bed positioned below the long front arch via the composite secondary air exhaust pipes, so that high-volatility matters in the lignite are guaranteed against generating black smoke due to oxygen deficiency during combustion.

Description

technical field [0001] The invention relates to the field of boilers, in particular to a combined structure of a long front arch and a secondary air of a lignite-fired chain grate boiler. Background technique [0002] Lignite, also known as firewood coal, is the inferior coal with the lowest degree of coalification. Lignite has high water content, high volatile content, low ignition point, easy to catch fire, low carbon content, and low calorific value. In my country, lignite resources are mainly distributed in eastern Inner Mongolia, Yunnan East, Northeast and South China There are also certain reserves. Due to the above-mentioned combustion characteristics of lignite, at present, boilers can only burn lignite by adopting pulverized coal combustion, fluidized bed and reciprocating grate combustion. The traditional chain grate combustion method adopts a short front arch and a long rear arch. The front arch is higher than the rear arch, and the combined furnace arch stru...

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Problems solved by technology

[0004] Aiming at the problems that the existing chain grate cannot adapt to the combustion characteristics of lignite, which leads to low combustion efficiency and easy generation of black smoke

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