Patent ID: 8707912
Filing Date: 2014-04-29
Classification: F22B

Abstract:
1. A furnace of a boiler for a power plant, comprising: an outer water tube section adapted to allow a bottom portion thereof to receive water from the outside and heat the water into hot water and steam while allowing the water to be moved upwardly; an inner water tube section disposed within the outer water tube section, the inner water tube section being adapted to allow a bottom portion thereof to receive the hot water and steam from the outer water tube section and heat the hot water into steam while allowing the hot water to be moved upwardly; a downcomer tube adapted to supply hot water and steam moved to a top portion of the outer water tube section to the bottom portion of the inner water tube section; a steam collecting chamber adapted to receive the heated steam moved to a top portion of the inner water tube section along the inner water tube section; a first lower water collecting chamber adapted to receive water from the outside and supply the received water to the outer water tube section; an upper water collecting chamber adapted to collect the hot water and steam moved to the top portion of the outer water tube section and supply the collected hot water and steam to the downcomer tube; a second water collecting chamber adapted to collect the hot water and steam fed downwardly along the downcomer tube and supply the collected hot water and steam to the bottom portion of the inner water tube section, wherein the outer water tube section comprises a first lower header disposed at a lower portion thereof and adapted to receive water from the first water collecting chamber; an outer water tube wall adapted to receive the water introduced into the first lower header from the first lower header and heat the introduced water into hot water and steam while allowing the water to be moved upwardly along a plurality of water tubes; a first upper header disposed at an upper portion thereof, the first upper header being adapted to collect the hot water and steam moved upwardly along the outer water tube wall and supply the collected hot water and steam to the upper water collecting chamber, wherein the inner water tube section comprises a second lower header disposed at a lower portion thereof and adapted to receive the hot water and steam from the second water collecting chamber; an inner water tube wall adapted to receive the hot water and steam introduced into the second lower header from the second lower header and heat the introduced hot water into steam while allowing the water to be moved upwardly along a plurality of water tubes, and a second upper header disposed at an upper portion thereof, the second upper header being adapted to collect the heated steam moved upwardly along the inner water tube wall and supply the collected steam to the steam collecting chamber, wherein a membrane is disposed between two adjacent water tubes of each of the inner water tube wall and the outer water tube wall, such that a plurality of membranes are circumferentially arranged in parallel with one another, so that the membranes and the respective water tubes are jointly connected with each other by parallel welding so as to form a circular wall, such that a fire ball or flame is prevented from forming inside the inner water tube wall and forming between the inner water tube wall and the outer water tube wall, wherein the downcomer tube is disposed within the inner water tube section through a central space surrounded by the inner water tube wall, wherein the upper water collecting chamber and the second water collecting chamber are connected by the downcomer tube, wherein each of the steam collecting chamber, a first lower water collecting chamber, the upper water collecting chamber, and the second water collecting chamber is disposed vertically along a direction of the downcomer tube.