Purifying and recovering energy from boiler flue gases by condensation, involves adding contaminated part of condensate to flue gases from boiler

摘要

At least a fraction of the contaminated part of the condensate is added to the flue gases from the boiler (2). Water is added to the flue gases from the boiler in order to achieve cooling and increase the moisture content of the gases, then the gases are condensed to a liquid in order to recover energy from them, and then the liquid is purified and separated into a purified liquid part comprising purified water and a contaminated liquid part comprising contaminated water. At least a fraction of the contaminated part of the condensate is added to the flue gases from the boiler. An independent claim is are also included for the boiler flue gas purification and energy recovery apparatus, comprising a quench unit (1) for receiving the flue gases from the boiler and adding water to these gases; a condenser unit (9) for receiving the flue gases from the quench unit and condensing them to a liquid; a purifying unit (10) for receiving the liquid from the condenser unit, purifying it and separating it into purified part and contaminated parts; and a means (18) for supplying at least a fraction of the contaminated part of the liquid to the quench unit, the latter also including a means (4, 5) for adding this contaminated part to the flue gases.