Grit classifier



The grit classifier ICES type is a combination of a grit classifier ES type and a hydro cyclone ICS type. This union allows to treat large water flow rate with low grit concentrations. This is the case in which its use is recommended.

The main components of the machine are: hydro cyclone made of a water inlet volute, a truncated conical body, a lower flanged pipe connection for the grit outlet, an upper flanged pipe connection for the grit-free water outlet. All that is assembled on the grit classifier tank through a bolted supporta shaftless screw, forged and turned from a high quality and high thickness steel bar. The screw inclination is about 25°. The special manufacturing of the screw aims at a considerable increase in hardness and strength of the steel and normal, silent operation;a tank with a suitable shape, volume and surface to allow a good separation of the grit from the water, while preventing the separation of organic substances;The tank is supplied with a hydro cyclone inlet and outlet spout with a flange and an adjustable grit-free water systema U-shaped laying canal of the screw with a bolted cover and a with lower inner part lined with replaceable wearresistant material;at the upper end, the same canal is supplied with a threaded connection for the inlet of the grit washing water and a square pipe suitable for the discharge of the grit into a disposal container;gearmotor suitable for slow rotation of the screw, of the hollow slow shaft type, through a special hub which is splined to the hollow slow shaft of the gearmotor on the one hand and screwed firmly to the screw on the other hand.

In wastewater treatment plants, the grit extracted from the grit removers by means of electric pumps or AIR LIFT, still contains not only an organic content, but also a large amount of water, usually around 90-95%. The grit classifier ICES type has been designed to wash these grit, classify them according to their diameter and dewater them up to a water content less than 10%. This process is made possible in the ICES machine by a long-lasting full-scale experimentation. Since 1975 up to nowadays, this experimentation has never stopped, and it will continue in the next years in order to obtain a top-quality product with high performances. The grit mixed with water and organic substances arrive at the classifier ICES type via a pressure pipe through the grit removers and enter the hydro cyclone. The inlet water in the volute, whose direction is perpendicular to truncated. conical body axis, separates from the grit due to the different centrifugal thrust. The grit, that is heavy, remains on the side walls of truncated conical body, going down by gravity toward the classifier tank; while the water, that is light, rises towards the outlet under the dynamic thrust of the incoming water. The tank shape allows a further separation of the water still present in the grit and the separation of the grit free of organic substances. While the water, which is rich in organic substances and free of grit, goes out of the tank by means of a special system with adjustable multi-canals, the grit settles on the bottom. The rotating screw picks up the grit from the bottom of the tank and transport them upwards. Immediately outside the water surface of the tank, the grit can be washed of the organic residues it contains thanks to the service water. After the washing, the grit is still transported upwards with a linearrotational motion suitable to permit the maximum drainage water. The drained grit, which has arrived at the highest part of the classifier, falls through the square discharge pipe into the disposal container. The abrasion effect of the grit on the screw canal is eliminated by the cover, which is made of replaceable panels of highly abrasion-resistant plastic material.The advantages of this machine are precise, such as its high inlet flow rate, simple construction and high efficiencyin separating perfectly washed grit, with low installation and maintenance. costs