WET-TYPE PLANT FOR DESULFURIZATION OF FLUE GASES AND METHOD OF USE OF SOLID DESULFURIZING SUBSTANCE Russian patent published in 1999 - IPC

FIELD: methods and plants for flue gas desulfurization. SUBSTANCE: flue gas coming from combustion apparatuses such as boiler comes in contact with absorbing fluid for absorption of sulfur oxide. Particles of limestone with large diameter are left selectively in zone where absorbing fluid is neutralized. Absorbing fluid containing main components in form of water and gypsum formed by sulfur oxide are selectively withdrawn from neutralization zone to bring it again in contact with treated gas. During this time, absorbing fluid brought in contact with treated gas contains main component in form of water so that quality of desulfurization may be considerably impaired due to change of boiler load, etc. For regulation of outlet concentration of SO₂ within the preset values, regulated is more than one parameter taken from such parameters as flow velocity of circulating absorbing fluid subject to be supplied for contacting the flue gases, amount of solid desulfurizing substance, subject for introduction into absorbing fluid, diameter of particles of solid desulfurizing substance and velocity of motion of desulfurizing substance in zone of neutralization. In addition, said parameters include boiler load, content of sulfur in fuel burnt in boiler, flue gas flow velocity, inlet concentration of SO₂ in desulfurization plant, or value of pH of absorbing fluid in zone of neutralization, or loss of pressure in zone of neutralization, torque of mixing device, concentration of solid substance in absorbing fluid, density of absorbing fluid and its viscosity. EFFECT: higher degree of controllability by variation of amount of treated gas or concentration of SO₂ in it. 9 cl, 27 dwg