Chemical treatment apparatus for heating apparatus, appliances and installations; apparatus for the treatment of combustion products, effluents, exhaust products, flue gases and pollutants from boilers, burners, furnaces and incinerators; apparatus for reducing the concentration of pollutants in the combustion products, effluents, exhaust products and flue gases from boilers, burners, furnaces and incinerators; apparatus for the introduction of chemical agents into the combustion products, ef...