Abstract: This invention provides a flue gas treating system which, though having a basic construction using a small-sized and high-performance gas-liquid contact apparatus comprising the combination of a parallel-flow absorption tower and a counterflow absorption tower, can reduce the ammonia concentration in the treated flue gas to a low level. This system includes a tank (21) for holding an absorbing fluid fed thereto; an inlet side absorption tower (22) of the counterflow type which extends upward from one lateral part of the tank (21) and in which untreated flue gas (A) is introduced from its lower end and brought into gas-liquid contact with the absorbing fluid within the tank (21); and an outlet side absorption tower (23) of the parallel-flow type which extends upward from another lateral part of the tank (21) and in which the flue gas leaving the inlet side absorption tower (22) is introduced from its upper end and brought into gas-liquid contact with the absorbing fluid within the tank (21).

Abstract: The present invention provides a gas-liquid contact apparatus which can make the equipment more compact and reduce the cost while achieving high gas-liquid contact efficiency. In the apparatus of the present invention, an oxidation tank (2) is installed in proximity to an absorption tower (1), and an absorbing fluid (3) is stored in this oxidation tank (2). The level H of the absorbing fluid (3) is determined so as to be above the position of nozzles (7), whereby the absorbing fluid is spouted upward from the nozzles (7). Flue gas is introduced into the absorption tower (1) from a flue gas inlet section (8) and made to flow upward at a high velocity, so that the peaks of the spouted streams are raised above level H. The absorbing fluid (3) is caught by catcher device (11) installed at a position above level H, and returned to the oxidation tank (2) through a circulation pipe (12). An air pipe (20) is connected to the circulation pipe (12) so as to suck in air.

Abstract: An exhaust gas treatment apparatus for the removal of at least a sulfur dioxide gas and ammonia from an exhaust gas by bringing the exhaust gas into vapor-liquid contact with an absorbing liquid comprises an introduction-side tank to which the absorbing liquid is supplied, a parallel-flow type absorption tower positioned above the introduction-side tank; an ejection side tank positioned adjacent the introduction side tank; a counter-flow type absorbing tower positioned above the ejection side tank; a mist eliminator for removing splash mist from the exhaust gas; and a controller for controlling the pH of the absorbing liquid in one of the introduction-side absorption tower and the ejection-side absorption tower.

Abstract: This invention provides a flue gas treating system and process which include a counterflow absorption tower and which can reduce the ammonia concentration in the treated flue gas to a low level.

Abstract: A flue gas treating system including a gas-gas heater and/or a dust collector, and a wet flue gas desulfurization apparatus, characterized in that the flue gas treating system is equipped with addition means for adding an alkaline agent to an absorbent slurry, a pH detector for detecting the pH of the slurry, gas-gas heater operational state detection means, dust collector operational state detection means, and alkaline agent addition control means for controlling the amount of alkaline agent added in response to signals from the pH detector, the gas-gas heater operational state detection means and the dust collector operational state detection means, so that the pH and calcium compound concentration of the absorbent slurry can be controlled.

Abstract: This invention relates to a wet flue gas desulfurization apparatus including: an absorption tower having defined in the lower part thereof a tank for holding a calcium compound-containing slurry fed thereto; a circulating pump for delivering the slurry within the tank to the upper part of the absorption tower in order to bring it into contact with flue gas; air supply member for supplying air to the tank for purposes of oxidation; a withdrawal pump for withdrawing the slurry within the tank in order to recover gypsum formed as a by-product or discharge waste water; falling slurry withdrawal member for withdrawing part of the slurry delivered to the upper part of the absorption tower by the circulating pump and falling through the absorption tower at a position above the liquid surface of the tank; and mixing member for the slurry withdrawn by the falling slurry withdrawal member with the slurry withdrawn from the tank by the withdrawal pump, whereby oxidizing substances produced in the tank of the absorption

Abstract: A desulfurization process which comprises the steps of bringing a combustion exhaust gas into contact with a gypsum slurry containing 1% or less of calcium carbonate in a first absorption tower, and then bringing the combustion exhaust gas into contact with a gypsum slurry containing 1% or more of calcium carbonate in a second absorption tower. SO.sub.x can be removed from a combustion exhaust gas with a high efficiency in accordance with a wet lime/gypsum method.

Abstract: A wet exhaust gas desulfurization apparatus includes a housing, an absorbing solution (3, B) stored in the lower portion of the housing, a flue (1, 2, 11, 12, 21, 25) above the surface of the absorbing solution, and a partition plate (4, 15, 25) for dividing the flue into gas inlet and outlet portions. Exhaust gas is introduced as an untreated combustion gas from a space above an absorbing solution (3) divided by a partition plate (4) into the wet exhaust gas desulfurization apparatus, the lower edge (5) of the partition plate is immersed in the solution, pressure of the exhaust gas lowers the upper level (6) of the solution on the upper side of the plate to a level (6') through which the gas passes and flows under the partition plate in contact with the solution leaving the solution on the other side of the plate and then discharges through a space above the absorbing solution on the other side of the partition plate.