| 摘要 |
<p>PURPOSE:To satisfactorily desulfurize the stack gases of heavily fluctuating SO2 concentrations by keeping the rate of drawing from an oxidizing tower to a neutralizing tower constant in conformity with the maximum SO2 load, measuring the basicity at the outlet of the neutralizing tank and controlling the addition of calcium carbonate. CONSTITUTION:A stack gas is introduced into adsorption towers 1, 2, and circulating liquid is conducted to a spray pump tank 3. Thence, the circulating liquid is sent into an oxidizing tower 5, where aluminum sulfite is air-oxidized and the overflowed liquid is put into a pump tank 4 and is recirculated. Part of the circulating liquid is drew continuously at a constant rate from the tower 5 into neutralizing equipment 6, so that it is neutralized down to the prescribed basicity with calcium carbonate. The rate of drawing from the tower 5 into the tank 6 is kept constant in conformity with the point where SO2 load is maximum. The charging of calcium carbonate into the tank 6 is accomplished by measuring the basicity at the outlet of the tank 6 with a basicity meter BM and controlling the charging with a control valve V according to this.</p> |
