Abstract:
Secondary sludge produced in the papermaking process is dewatered by adding a material capable of absorbing water together with dry fibers to the secondary sludge, and mixing the secondary sludge with the dried fibers to produce a modified secondary sludge which has sufficient structure and low enough moisture that it may be further dewatered by mechanical means. The preferred fiber adding materials are those readily produced in the papermaking process, particularly dry primary sludge, dried fines and bark and fly ash from boilers.
Abstract:
The present invention provides a method for processing wastes containing a large amount of water and a method for processing leachate from industrial wastes. Specifically, the present invention provides a method which comprises maintaining reduced pressure in the dryer equipped with a stirring means, feeding wastes containing a large amount of water to the dryer, stirring the wastes while blowing refrigerated air at -20.degree. C..+-.5.degree. C. to the dryer, and drying the frozen moisture portion of the wastes by sublimation. Air heated at 80.degree. C.+10.degree. C. can be used instead of refrigerated air to dry water of the wastes by evaporation. The present invention also provides a method for processing leachate which comprises pooling leachate industrial wastes and burned ashes, and utilizing the leachate to absorb wet-type toxic gas, thereby confining the leachate within the waste treatment plant. The present invention therefore make it possible to process wastes containing a large amount of water, which have been a problem in the incineration by the conventional methods, by using the potentioal heat of the waste gas from the incinerater. The present invention also provides an effective means to prevent environmental contamination because leachate is confined in the waste treatment plant.
Abstract:
Hazardous waste is formed into non-hazardous non-leaching aggregate by introducing the material to a rotary kiln where the large solids are at least partially combusted to form a primary aggregate. Gaseous combustion by-products and waste fines from the waste materials are introduced into at least one oxidizer having water-cooled metal walls. Some of the waste fines are melted to form a molten slag-like material that is removed from the apparatus and cooled to form non-hazardous aggregate. The portion of the material in the oxidizer that is not melted, is cooled, neutralized and subjected to a solid gas separation. The solid is reintroduced to the oxidizer with the primary aggregate where they are either melted or entrained within the molten material and become an integral part of the non-hazardous aggregate.
Abstract:
A waste treatment system conditions waste materials for combustion by uniformly drying them to a predetermined moisture level and subsequently incinerating the dried materials in a burner which effects complete combustion of even high moisture content fuels. The system includes the burner, a dryer assembly, and a system of fans which clarifies vapors withdrawn from the dryer and which returns at least part of these vapors to the burner. The system mixes exhaust gasses from the burner and recycled vapors returned by the fans to produce gasses of a suitable temperature for drying the materials. The waste materials and the gasses are then introduced into the dryer, which is designed to use the gasses to dry the material uniformly to the predetermined moisture level without burning them prematurely. The dried materials are then conveyed to the burner, where they are burned to produce more exhaust gasses for drying additional materials. The residual ash in the burners is nontoxic and is suitable for burying. The system can be readily adapted to dry and burn a wide variety of materials by modifying the dwell times of the materials within the individual dryer sections, and/or by changing the dimensions of the dryer.
Abstract:
The present invention provides a tunnel type garbage incinerator, which is characterized that the garbages are first classified into combustible and incombustible materials, then the combustible materials are loaded on a bogie and fed into the incinerating tunnel for incineration, the fore section of the incinerating tunnel is used for drying combustible materials, the middle section of the incinerating tunnel is used for the bleast incineration of the combustible material, the aft section of the incinerating tunnel is used for the cooling and output port of the incinerated materials or ashes. In which, the incinerating tunnel is furnished with blowers, flame igniting device, smoke processing device, and through proper arrangement of the components, the garbages can be completely combusted with minimal fuel oil consumption, furthermore, since the smoke is filtered before it is expelled, it does not produce air pollution.
Abstract:
Moist combustible matter is burned in a fluid bed reactor following a drying treatment in which the combustible matter is brought into contact with hot sand circulated from the fluid bed reactor. The water in the combustible matter is evaporated at a relatively low temperature in the drying treatment, thereby conserving heat in the system. The exhaust vapor from the drying treatment is handled separately from the reactor exhaust gases to condense the vapor therein before subjecting the remaining gas to odor-destroying high temperature.
Abstract:
A method of and an apparatus for the combustion of sludge obtained from a clarifier in the purification of water, wherein the clarifier sludge is passed through a multistage drier above a fluidized-bed furnace in which it is predried with the waste mass of the latter. As the wastes dry, they are comminuted and distributed over the cross section of the fluidized-bed furnace for burning therein.