Updated: July 2002

1. Outline of system

Having made efforts to realize energy savings and labor savings in the field of sludge treatment, our company has had many achievements since it delivered the first energy-saving type sludge flow incineration plant in Japan. (Fig.1) Besides incineration equipment, our company has also grappled actively with the improvement of the efficiency of sludge transfer equipment, sludge drying equipment, etc. In addition, our company has already completed the development of a Circulating fluidized bed furnace in which clean exhaust gas complying with the recent mandatory control reinforcement has been realized, and furthermore, low cost has been achieved.

Fig. 1 Sludge treatment equipment

2. Characteristics

(1) Sludge transfer equipment:
In place of the conventional belt conveyor, our company has adopted the dewatering cake forced feed system for long-distance transfers, realizing efficient and clean transfers (Fig.2). In the case of the (Mitsubishi dewatering cake forced feed system) forced feed pump, the single cylinder type piston pump for small-capacity transfers in addition to the double cylinder type piston pump for a large capacity are lined up (Fig.3).
(2) Sludge drying equipment
With the adoption of the indirect heating type drying system, high thermal efficiency and compactness have been realized. Furthermore, our company has developed a new system drying equipment for the indirect type heat pump system consisting of circulating steam and exhaust steam. (Super-efficient drying system)
(3) Sludge incineration equipment
In addition to the bubble type flow furnace which is in the mainstream at present, our company has completed the development of a circulating fluidized bed furnace in which high temperature circulating sand disperse in the furnace. The new type high-performance flow furnace has excellent merits in that it has achieved both energy savings and more cleanness of exhaust gas at the same time by increasing the combustion efficiency in the furnace through the division of high temperature sand.

Fig. 2 Flow sheet for forced feed process

Fig. 3 Single cylinder type piston pump

3. Performance

Table 1 shows the scale of the sludge treatment equipment. It the case of the sludge incineration equipment, our company has delivery performance extensively ranging from the small-scale equipment with a capacity of 5 t/d to the large-scale equipment with a capacity of 300 t/d.

Table 1. Scale of sludge treatment equipment

4. Applicability and objectives

(1) Applicability: sludge treatment
(2) Objectives: sewage sludge (wastes with a high water content)