摘要:
An absorbing tower is provided in its side wall with a gas entrance for introducing a combustion exhaust gas into the absorbing tower, and an absorbing liquid is sprayed from the nozzles of a spray header into the exhaust gas introduced to rise from the gas entrance. A trough is arranged in the side wall of the absorbing tower and above the gas entrance, and a nose having a horseshoe shape in a top plan view and extending into tower is disposed in the tower side wall portion of the gas entrance other than the portion arranging the trough and at the same or at substantially the same height as the portion of the trough. The absorbing liquid, which is sprayed from the nozzle and drops along the absorbing tower wall portion, is rescattered to the center portion of the absorbing tower excepting the entrance of the absorbing tower, so that the gas-liquid contact efficiency is improved while suppressing an increase in pressure loss, thereby to prevent the drift of the gas at the tower wall portion.
摘要:
An absorbing tower is provided in its side wall with a gas entrance for introducing a combustion exhaust gas into the absorbing tower, and an absorbing liquid is sprayed from the nozzles of a spray header into the exhaust gas introduced to rise from the gas entrance. A trough is arranged in the side wall of the absorbing tower and above the gas entrance, and a nose having a horseshoe shape in a top plan view and extending into tower is disposed in the tower side wall portion of the gas entrance other than the portion arranging the trough and at the same or at substantially the same height as the portion of the trough. The absorbing liquid, which is sprayed from the nozzle and drops along the absorbing tower wall portion, is rescattered to the center portion of the absorbing tower excepting the entrance of the absorbing tower, so that the gas-liquid contact efficiency is improved while suppressing an increase in pressure loss, thereby to prevent the drift of the gas at the tower wall portion.
摘要:
An elongated absorber housing, including an inlet duct and an outlet duct, is integrally provided on an upper portion of a circulation tank. The absorber is a self-supporting structure supported by only the circulation tank. At least the furthest upstream spraying stage in a spraying zone in the inlet duct includes spray pipes provided with spray nozzles for spraying an absorbing liquid in a direction cocurrent with gas flow, and at least the furthest downstream spraying stage includes spray nozzles for spraying the absorbing liquid in a direction countercurrent to the gas flow. The absorber is an integral structure in which the upper portion of the circulation tank forms a part of the duct, whereby the absorber is self-supportable and, moreover, is of a simple structure, giving it high strength and eliminating of the need for provision of fitments for supporting the absorber.
摘要:
An absorbing tower provided with plural spray headers (3) which each have a plurality of spray nozzles (5) and are arranged in a multi-stage state in the flow direction of exhaust gas, in which an absorption liquid containing a slurry of limestone or lime is sprayed through the nozzles (5) to absorb and remove sulfur oxide contained in exhaust gas, wherein each spray nozzle (5) is of an annular spray type (a hollow cone type) and the spray nozzles (5) in the neighborhood of the tower wall have such a structure that the fluid is sprayed radially at spray angles of 50 to 80° with the direction counter to the flow of exhaust gas as the center, while the nozzles (5) in the central part of the tower have such a structure that the fluid is sprayed radially at spray angles of 80 to 130° with the direction counter to the flow thereof as the center. According to the invention, the channeling of exhaust gas in the tower can be inhibited by using two kinds of spray nozzles (5) to thereby prevent the desulfurization performance from lowering caused by blow-by of exhaust gas in the neighborhood of the tower wall. Further, an extremely high pressure loss can be inhibited by the flow-regulating effect of sprayed droplets. Thus, a wet-type exhaust gas desulfurizer with a reduced total cost is obtained.
摘要:
An absorbing tower provided with plural spray headers (3) which each have a plurality of spray nozzles (5) and are arranged in a multi-stage state in the flow direction of exhaust gas, in which an absorption liquid containing a slurry of limestone or lime is sprayed through the nozzles (5) to absorb and remove sulfur oxide contained in exhaust gas, wherein each spray nozzle (5) is of an annular spray type (a hollow cone type) and the spray nozzles (5) in the neighborhood of the tower wall have such a structure that the fluid is sprayed radially at spray angles of 50 to 80° with the direction counter to the flow of exhaust gas as the center, while the nozzles (5) in the central part of the tower have such a structure that the fluid is sprayed radially at spray angles of 80 to 130° with the direction counter to the flow thereof as the center. According to the invention, the channeling of exhaust gas in the tower can be inhibited by using two kinds of spray nozzles (5) to thereby prevent the desulfurization performance from lowering caused by blow-by of exhaust gas in the neighborhood of the tower wall. Further, an extremely high pressure loss can be inhibited by the flow-regulating effect of sprayed droplets. Thus, a wet-type exhaust gas desulfurizer with a reduced total cost is obtained.
摘要:
A wet type flue-gas desulfurization apparatus, into which exhaust gas containing mercury goes, includes an upstream absorption tower, an upstream absorbent spray nozzle and a make-up water supply unit on an upstream side of a desulfurization apparatus body in a flow direction of the gas. The upstream absorption tower has a circulation tank reserving absorbent slurry. The make-up water supply unit supplies make-up water into the circulation tank to keep the chloride ion concentration of the absorbent in the circulation tank not lower than 50,000 ppm. Thus, it is possible to provide a wet type flue-gas desulfurization apparatus by which Hg can be prevented from being released again from the desulfurization apparatus, the purity of recovered gypsum can be increased and the usage of industrial water can be reduced.
摘要:
A system is provided that prevents inhibition of adsorption of Hg and other heavy metals by activated carbon or other heavy metal adsorbent due to prior adsorption of sulfur trioxide (SO3) in an exhaust gas containing SO3. As it has been found that while SO3 is adsorbed, the adsorption of SO3 precedes the adsorption of Hg and other heavy metals onto activated carbon, a basic substance injection system is disposed along an exhaust gas flow channel at an upstream side of an activated carbon injection system, thereby attaining effective removal of Hg and other heavy metals from the exhaust gas by adsorption thereof onto surface pores of the activated carbon. The SO3 concentration after removal by basic substance conversion is computed from the SO3 concentration before removal, and the activated carbon injection rate can be controlled based on the concentration after removal.
摘要:
A wet-type flue gas desulfurization method and plant making use of a solid desulfurizing agent in which exhaust gas exhausted from a combustion apparatus such as a boiler is brought into contact with absorbing liquid to absorb sulfur oxide from the exhaust gas into the absorbing liquid followed by neutralization of the absorbing liquid containing the sulfur oxide thus absorbed. The solid desulfurizing agent is selectively retained in an absorbing liquid neutralizing zone and the absorbing liquid, containing water as a main constituent and solid products formed from the absorbed sulfur oxide, is selectively removed from the neutralizing zone. In the neutralizing zone the upward flow of the absorbing liquid, optionally augmented by an upward flow of air or water, forms a fluidized bed of limestone particles, thereby preventing coating of the limestone by gypsum and thereby retaining reactivity of limestone. According to the present invention, coexistence of Al and F in the absorbing liquid seldom deteriorates the desulfurizing performance. Further, it is possible to reduce power and cost required to grind limestone and to achieve a higher desulfurizing performance.
摘要:
A wet-type flue gas desulfurization method and plant making use of a solid desulfurizing agent in which exhaust gas exhausted from a combustion apparatus such as a boiler is brought into contact with absorbing liquid to absorb sulfur oxide from the exhaust gas into the absorbing liquid followed by neutralization of the absorbing liquid containing the sulfur oxide thus absorbed. The solid desulfurizing agent is selectively retained in an absorbing liquid neutralizing zone and the absorbing liquid, containing water as a main constituent and solid products formed from the absorbed sulfur oxide, is selectively removed from the neutralizing zone. In the neutralizing zone the upward flow of the absorbing liquid, optionally augmented by an upward flow of air or water, forms a fluidized bed of limestone particles, thereby preventing coating of the limestone by gypsum and thereby retaining reactivity of limestone. According to the present invention, coexistence of Al and F in the absorbing liquid seldom deteriorates the desulfurizing performance. Further, it is possible to reduce power and cost required to grind limestone and to achieve a higher desulfurizing performance.
摘要:
A system is provided that prevents inhibition of adsorption of Hg and other heavy metals by activated carbon or other heavy metal adsorbent due to prior adsorption of sulfur trioxide (SO3) in an exhaust gas containing SO3. As it has been found that while SO3 is adsorbed, the adsorption of SO3 precedes the adsorption of Hg and other heavy metals onto activated carbon, a basic substance injection system is disposed along an exhaust gas flow channel at an upstream side of an activated carbon injection system, thereby attaining effective removal of Hg and other heavy metals from the exhaust gas by adsorption thereof onto surface pores of the activated carbon. The SO3 concentration after removal by basic substance conversion is computed from the SO3 concentration before removal, and the activated carbon injection rate can be controlled based on the concentration after removal.