Research On Stone Machining Sewage Treatment Process And Filter Equipment

In the stone cutting and polishing process, it will produce massive high turbidity sewage, which will cause the waste of water and environmental pollution. Based on the experiment and numerical simulation of combining, the subject puts forward a new type of dewatering system for small-sized and medium-sized stone material enterprise. According to the sequence of sewage flocculent, precipitation, concentration and solid-liquid separation, the subject designs an economic treatment process and dewatering equipment. This new system will promote the development of stone sewage treating technology, and guide the related stone recycling industries. It conforms to the development trend of the circular economy.Learning from the mature treatment technology of the general industrial and domestic sewage processing industry, the subject proposes an overall planning of sludge dewatering system according to the enterprise's requirements and convenience to upgrade, including the processing craft, feeding system, dehydration systems and auxiliary system. On the basis of one stone enterprises sewage production status in Rizhao city, the sedimentation tank was redesigned, the parameter design was accomplished, and a set of complete process was put forward in this paper.The subject conducted the experimental study of sludge resistance which is part of stone inherent characteristic. The resistance a changes significantly when the sludge concentration is lower than 0.20g/ml, unobvious when over the value. Its filtration time and the moisture content has greatly improved when choosing polymerization AlCl3 (PAC) and polyacrylamide (PAM) as additives. The specific resistance is 0.77×107cm /g when PAM solution is 10ml, PAC solution is 7ml which was added in accordance with the ratio, which decreased 55.2% than the case without adding flocculant and 30% than the case adding PAM solution only. It improves the flocculation, and provides a reference for improving the treatment process and filtering parameters further.Flow field of the three-dimensional entity filtering model was established using PRO/E, and the model was meshed with GAMBIT. Using discrete phase model and combining the Euler model, voltage force, velocity field distribution of 0.7×0.7×0.03 meters-filter chamber were simulated in FLUNT based on k-factor turbulence model. According to the analysis of turbulence effect on pulp separation speed on the different conditions, it obtained the ideal filter parameters, offering guidance for selecting the specific model of equipment and enriching filtration theory.It designs a set of perfect sludge dewatering equipment, determines the basic structure of pressure filter; chooses polyester filter cloth as the filter medium, which have filter mesh between 300 to 400. It chooses pneumatic diaphragm pumps as new material feeding equipment, estimates the pump's specific models and realizes the matching relations between the pump and filter press. The conveyor belt, reservoir mud boxes and auxiliary equipment were designed, PLC control system was introduced and the design of control system was completed. Facing the 1～10 sets scale enterprise, it series the sludge dewatering system, evaluates the system operation cost and social benefits. Analysis shows that the system satisfies sewage treatment technology requirements of stone enterprises.