SALHER - Model Vespa DAF - Dissolved Air Flotation Unit
Salher designs and manufactures the Vespa dissolved air flotation unit to separate suspended solids, grease and oils from wastewater. This system separates the particles in suspension by air microbubbles in a supersaturated concentration. The solids adhere to the microbubbles in their upwards floating path towards the scraping system. The equipment achieves a performance of 50-80% in BOD5 elimination, 60-80% in COD elimination and 90% suspended solids, oils and grease removal. Vespa is a fully modular and compact equipment, with adaptable layouts and deliverable worldwide, fitting perfectly in standard maritime containers.
The main feature of this DAF, compared to others models of the market, is the cylindrical shape of its customized flotator; its height can be customized to adapt to the needs of each client. It also has a leveling system with adjustable supports for uneven grounds.
This DAF is manufactured by Filament Winding system with an innovative material, a GFRP that combines isophthalic resins with basalt fiber, materials that prevent from corrosion and protect from UV radiation, providing the equipment with a total chemical and mechanical resistance to any type of adverse situation.
Metallic elements are all made of AISI 316 stainless steel: a skimmer for floating particles collection, a flexible scraper system and a clarified water collector with adjustable height conforming an equipment easily adaptable to changes of incoming water loads.
This flotator has an upper methacrylate transparent cover to reduce the odors produced as well as to facilitate the visual inspection of the inner part and the maintenance.
As control elements, Vespa has a butterfly valve with pneumatic actuator for the automatic purge of the equipment, a conductive rods probe placed in the clarified water chamber to control the level of operation.
Its recirculated water pressurization system is composed of a centrifuge pressurization pump, a pressure transmitter in the pump drive, a venturi injector where the first water-air mixture is produced, a pressurization tank with pressure measurement and a pre-installed valve kit, pneumatically actuated diaphragm pressurization valves and a pneumatic control box composed of regulating filter (0-8.5 bar), pressure regulator (0-8.5 bar), flow switch and a set of control electrovalves.
The equipment has all the manual valves necessary for the correct operation of the system and safety elements for emergency stop.
The equipment, reference FLC, is the ideal complement for the dissolved air flotation system, Salher brand, reference VESPA, and also for the lamellar settler, reference DE-LA. Its long retention time allows the coagulation and flocculation processes develop under optimal conditions, which greatly increases its yields. The system incorporates in-line inserts for the preparation and control of the flocculation process.
The Salher flocculation system consists of a pipe system made of thermo-welded polyethylene, an internal frame in steel with anti-corrosion paint category C5-M (degree of marine protection), a height regulation and leveling system, sample taking taps, a coagulant and soda injection intake and another flocculation injection intake.
Composed of coagulant dosing pump, coagulant injection kit, 500L reagent storage tank in HDPE, flocculant dosing pump and flocculant injection kit.
The automatic preparation unit of compact Polyelectrolyte, Salher brand, allows the preparation, maturation and dosing of the polyelectrolyte solution continuously and automatically.
It consists of a pH measurement probe with control unit for process automation, a soda dosing pump, a reagent injection kit and a 500L reagent storage tank in PEHD.
The system is supplied fully automated by means of a SIEMENS S7 1200 PLC with a 7 “color touchscreen. The programming of the panel and the dynamic interface of the different screens facilitate the understanding and correct use by the plant operators.