Thickener (Pre-Filtration)
Thickener is classified as a pre-filtration equipment, the product (waste or concentrated) with low solids density coming to the filtration unit at the outlet of the plant is supplied to the thickener before coming to the equipment (press filter, belt filter, vacuum belt filter, vacuum drum filter, vacuum disc filter, etc.) in the filter section and high solids density is provided. In this way, the solids content of the material increases that will come into the filter group. The material with a high solids content ensures both the performance of the filters and the smaller capacity selection when selecting the filter capacity.
Capacity and Calculation Criteria
There are three main criteria for capacity calculation of thickener; flow of incoming material and product features. Following the laboratory studies, the diameter of the thickener is determined by considering these three criteria.
Drive Group and Scraper Comb Mechanism
They are the most important parts of thickeners. The product collapsing to the base of the thickener is directed to the bottom taper outlet at the center with the help of the scraper comb mechanism. In this way, the product moves to the next stage(filtration) with homogeneous solids density. The scraper is determined by taking into account the rotation speed of the drive group and designed to withstand mechanical stress caused by sludge, It aims to keep the product density at the output homogenous by moving up and down as well as rotational movement. This feature is also used as a safety for scraper combs.
Control System
Thanks to the software of the system, the load on scraper combs can be seen on the touch screen of the electric panel as digital data. When the sludge load from the scraper combs reaches its maximum limits, the scraper combs system in the main drive group is activated and scraper combs moves upwards. In this way, the scraper is prevented from being exposed to unwanted forces, at the same time the resulting product is obtained in homogeneous density. The dense solid material formed on the bottom taper is directed to the filters to pass to the filtration stage.