Hungary – Machinery for the treatment of sewage – „Víztelenítő csigaprés beszerzése”

The Contracting Authority wishes to purchase a mechanical dewatering device suitable for dewatering mixed sewage sludge, operating on the screw press (screw press) principle, with the additional task of integrating it into the existing belt press filters in the place of the combined technological building sludge treatment building, on the storage floor of the concentrated sludge, and establishing a process control interface for connection. The sludge dewatering screw press is a mechanical sludge dewatering device that, after polyelectrolyte conditioning, carries out the sludge dewatering with a slowly rotating screw and a rotating body-shaped, perforated steel filter surface surrounding the screw. The filter surface is made of trapezoidal cross-section profiles, the water-draining grooves widen outwards (wedge wire sieve) or another type of filter surface that is capable of achieving at least equivalent results in terms of • filtering capacity, • cake dry matter content, • filtrate water concentration, • specific polyelectrolyte consumption, • tendency to clog, • washing water requirement compared to a device with a “wedge wire sieve” surface. The screw presses must be of the same type as the specified system and must handle digested municipal sludge. The screw gradually advances the sludge inside the filter. The water squeezed out of the sludge exits through the filter surface, while the solid material gradually thickens and exits at the end of the press, regulated by a throttle valve. The system is equipped with a lining. An integrated washing device ensures the periodic cleaning of the filter surface as needed. The screw speed is controlled by automation, typically around 1 rpm. All documents relating to the screw press must contain all purchases, equipment, and work required for operability, as well as compliance with laws, particularly environmental regulations, safety, occupational health and safety, and fire protection regulations. Technological target values: • Daily amount of digested sludge to be processed: 168 m3 (130 – 180 m3) • Incoming sludge quantity: 14 m3/hour • Sludge quality: digested, degassed, • Incoming dry matter content: average: 2.7% • Organic fraction of incoming sludge dry matter (loss on ignition): 70% (68 – 72%) • Daily operating time: 12 hours (in one or more shifts) • Water consumption: max. 1 m3/hour, 20 m3/day (including washing requirement after daily shutdown) • Simultaneous electrical power: max. 10 kW *The dry matter content of the sludge to be dewatered does not exceed 3% in 87% of the samples. The dry matter content of the incoming sludge quantity of 14 m3/hour may decrease above 3%. The parts of the screw press that come into contact with sludge, filtrate, and the vapours derived from them must be made of a material resistant to these corrosive environmental effects. The steel grade must be 304L (1.4307) or equivalent in terms of resistance to the effects of the given environment. The Contracting Authority informs the Bidder that any reference to specific brands, origins, or types of goods in the technical description is made for the purpose of clearly defining the nature of the subject matter, and the Contracting Authority will also accept equivalents, provided that the Bidder proves the equivalence in the bid. The detailed tasks and technical information are contained in the Technical Description and Price List.