Kobe Steel is one of the leading engineering companies of Fluidized Bed type waste Incinerators in Japan and has plenty experiences for both municipal solid waste and sewage sludge. The maximum capacities of the incinerators constructed by Kobe Steel are 110 t/d (160 t/d x 2 plant is now under construction) for municipal solid waste and 150 t/d for sewage sludge.

Kobe Steel established mixed incineration technology based on such experiences of both waste incineration systems.

[Feeders]

As shown in Fig. 1, MSW is fed to the furnace from the side wall by Kobe's direct refuse feeder, and sludge is fed from the top of the furnace by Kobe's sludge feeder. The sludge is broken into pieces and dispersed unformly to the furnace bed.

Fig. 1 Schematic Flow of Mixed Incineration System of MSW and Sewage Sludge

[Performance]

The incineration is carried out quite smoothly, because of applying advantages of both Kobe's MSW and sludge incinerators. The feed ratio for sludge against MSW can be increased up to 100 % without any damage to stable incineration. In case of high mixture ratio of sludge, auxiliary heavy oil is fed to the sand layer through oil gun. Incombustibles are extracted from the bottom of the furnace. .

Table 1 shows the typical performance data of mixed incineration in the existing incineration facilities which have been constructed by Kobe Steel.

Table 1 Typical Performance Data for Mixed Incineration of Municipal Solid Waste and Sewage Sludge