【文章內(nèi)容簡介】
ermal driving force to remove the remaining free water and the keys connected to the water. According to the different heating medium, heating and drying can be divided into two kinds: one is the gaseous state at high temperatures and turbulence flowing Dryer (direct heat), a liquid is heated (usually steam or pressurized of water) transfer heat to the sludge through the dryer heating wall (indirect drying). The purpose of heating and drying is to reach the downstream thermal incineration of sludge with a continuous (usually 30 ~ 35%) or are easy handling and storage of dry sludge (60%). If you want to achieve a long period of stability (a few months), dry solids content should be 90% or more (final dry), and the state of particles is also easy to use (including agricultural applications). Another advantage of the final drying is that it can easily face the ultimate treatment methods, such as agricultural land application, incineration used in cement production, or municipal solid waste incineration. Its disadvantages: first, the high operating costs, especially energy consumption, generally hot dry, each one ton of evaporated water needs 3400MJheat. However, the dewatering step, removing a ton of water as long as the 6MJ (electricity)。 second need more staff to clear the dead in the powder in order to prevent fires. ( 2) Thermal oxidation Burning. Fluidized bed incineration furnace (FBF) on the process performance is concerned, proved to be the best way in the burning of sludge (turbulent way, postbustion of up to 850 degree temperature). And it runs reliably (in the oven without turning section). In 40 years time, Vivendi has built a worldwide dozens of fluidized bed incinerator (such as the European Union, Russia, Turkey). Typically, in a stable state does not require adding extra fuel, the continuity of heat balance can be achieved. If the calorific value of sludge LCV is too low (such as low volatile solids, and / or solid content), exhaust / gas heat exchanger should be large enough to increase the wind room temperature. If you fail (such as extended aeration sludge containing 20% DS), you need to in front of heating and drying. On the dry ash disposal, industrial pollution is not purely for the municipal sludge, heavy metals, not a problem. Because gray is the form of oxides, their permeability is not strong, so it can be reused as cement, used for industrial and road construction. The final step acid byproduct is removed. As the heavy metal pollution, they can only be buried in a special place, but in small quantities. Coincineration of municipal solid waste. In order to reduce investment, urban waste and municipal sewage sludge is usually a burning furnace. Typically, a population equivalent of daily production of 150 to 250 grams of d