Conditioning Rotor-Recycle Process with particle conditioning - a simple and effective process for the gas cleaning downstream waste incinerators

摘要

Following to the tightening of emission limit values in Europe between 1980 and 1990, complex, multi-stage plants have been installed for the gas cleaning systems downstream of waste incinerators. As a result of the extremely high investment and operating costs, a waste incineration was no longer economical. Due to the consistent advancement of semi-dry procedures, high-efficient cleaning systems could be developed, with reliable observance of the requested emission limit values at considerably lower investment and operating costs. The Conditioning Rotor - Recycle Process with particle conditioning offers such a procedure. It mainly comprises the component parts for additive powder injection (CaO/Ca(OH)_2, AC), reaction chamber with conditioning rotor, fabric filter and multiple particle re-circulation with wetting of recycled particulate prior to reinjection into reactor. This system allows the simultaneous separation of particles, heavy metals, incl. mercury and mercury compounds, acid crude gas components such as HF, HCI, SO_x as well as dioxins/furans. The approx. 50fold particle re-circulation combined with the wetting of the recycled particulate grants the high effectiveness of this system with regard to the separation capacity and the additive powder consumption. The efficiency is described on the basis of several application examples from the field of waste incinerators. The presentation includes among other things the degrees of separation and the emission limit values in comparison with definitely more complex scrubbing systems. The process is also provided with an up-to-date control device for the additive powder injection. Based on crude gas measurements of the acid crude gas components, HCI and SO_x, as well as on measurements of the volume flow, the additive powder is injected in dosed quantities in accordance with a given stoichiometric factor. The control concept is explained by means of a practical example. Furthermore, results will be presented, showing the advantages of the Conditioning Rotor - Recycle Process with particle conditioning relating to the expenses for consumable supplies, compared to a conventional spray sorption for the separation of acid crude gas components, as used for many plants in the USA. A comparison of the emission limit values for waste incinerators in the USA and Europe shows, that the presented process is also suited for the American market and offers cost advantages for the operators of waste incinerators.