Description of Process Flow
(1) This process is designed for mainly sludge from paper mill, residua from furfural factory, dejecta from breeding field and thickened sludge from municipal sewage disposal works.
(2) The common points of the above materials are. containing organic substance of 25%~45%, higher moisture content, bulky granule and containing fiber. Thereby first ferment raw materials in order to reduce materials, moisture, increase organic substance and kill zyme. During fermenting raw materials, add organic components and nutrients necessary for aerobic ferment, thereby generate high temperature which can synchronously kill zyme, vapor moisture and decompose fiber-type substances.
(3) After the above process step, the moisture of the materials can reach below 35% and the organic substance can increase by above 5%. Use special Organic Substance Pulverize to pulverize the materials to make the material granule diameter reach below 1,5mm which can meet the requirements for granulating.
(4) After being metered, the powdery inorganic materials such as N.P.K and fillers (mainly including bond) etc. go into mixing process-step synchronously together with the powdery organic substances. The materials mixed evenly are conveyed into Granulator by belt conveyor. During granulating, properly control the proportion between the moisture and fillers, which can efficiently control the bulk and strength of the granules and ensure a final product rate of 70%~95% (final product rate is dependent on granulating way).
(5) Although the materials after granulating have come into being granules, the granules at this time have a quite high moisture, which can't meet the requirements of packaging and shipping. Thus, the materials are conveyed to rotary drier by belt conveyor for drying, the temperature of the materials coming out of drier is quite high, and then the materials are sent to rotary cooler for cooling to further increase the granule strength and reduce the moisture. And then, the cooled granules are coorse-sieved and fine-sieved to separate large granules and fine powder. finally, final products are achieved.