New Chimney Design
New Chimney Design: a new, more economical design for power station chimneys
More and more power stations worldwide use Flue Gas Desulfurization systems. The desulfurized flue gas emitted through the chimney is relatively cool and strongly acidic. The common response has been to use improved, corrosion resistant materials of construction, while sticking basically to the traditional chimney design.
A leading designer of power plant chimneys, FaAA, Dusseldorf, developed a new basic design for FGD chimneys in power stations. This New Chimney Design is a concrete chimney in which the traditional internal flue has been eliminated. Instead, the inside of the concrete shell is protected by a Pennguard® lining, which insulates the shell not only from acidic flue gas, but also from high temperatures and temperature shock. The result: a light and slender FGD chimney suitable for wet and reheated scrubbed flue gas.
Advantages of the New Chimney Design
Lower construction cost – The internal flue / liner and its supports are eliminated, which makes the New Chimney Design 20 % less expensive to build in many cases.
Shorter construction time – Using the example of a 200 m / 656 ft chimney with an 8 m / 26.25 ft internal diameter, the new design would require an all-in construction period of 6 months, while a traditional chimney with an acid resistant brick flue / liner would require 11 months.
Suitable for seismic regions– The elimination of an internal flue / liner leads to a great reduction in mass. The Project Report provides some figures on this.
Lower maintenance requirement – The fue / liner and its supports, thermal insulation, and expansion joints are eliminated, reducing the future requirement for maintenance.
Resistant to acidic flue gas – Borosilicate glass, the basic material of Pennguard® Blocks is one of very few materials that are resistant to sulfuric and hydrochloric acid without any limitation for temperature or concentration.
Suitable for wet stack operation – Pennguard® linings are resistant to unreheated, wet scrubbed flue gas, which makes the design highly suitable for wet stack operation.