Raw water contaminated with solids is pumped from above into a sand filter. The solids are captured and retained as the raw water flows through the filter bed. The water itself passes through the filter bed and emerges at the bottom end of the sand filter. The treated water (filtrate) flows into a tank. Over time, more and more solids are deposited in the filter bed which increases its flow resistance. This process is detectable by the increasing pressure loss between the sand filter inlet and outlet. The flow through the sand filter decreases. Backwashing with treated water cleans the filter bed and reduces the pressure loss again. The sand filter is equipped with a differential pressure gauge. There are also several pressure measuring points along the filter bed. The pressures are transmitted to tube manometers via hoses and displayed there as water columns. This can be used to plot Micheau diagrams. The flow rate, temperature, differential pressure and system pressure are measured. The flow velocity in the filter bed (filter velocity) can be adjusted. Samples can be taken at all relevant points. A software program is provided to control the operating states and measure data. A process schematic shows the current operating states of the individual components and the measured data. E.g. diatomite can be used to produce the raw water. 1. Specification depth filtration with sand filter, separate supply unit with tank and pump for raw water pump for backwashing the sand filter 10 tube manometers to measure the pressures in the filter bed plotting of Micheau diagrams electromagnetic flow rate sensor, 4 electrically driven shut-off valves measurement of flow rate, differential pressure, system pressure and temperature filter velocity adjustable software with control functions and data acquisition via USB under Windows Vista or Windows 7 2.Technical data Sand filter outer diameter: 120mm inside diameter: 106mm filter bed height: approx. 700mm Raw water pump max. flow rate: approx. 150L/min max. head: approx. 7,6m Backwash pump max. flow rate: approx. 50L/min max. head: approx. 14m Tanks for raw water and treated water capacity: each 180L Measuring ranges flow rate: 0…1300L/h tube manometers: 10x 0…1500mmWC differential pressure: -1…1bar system pressure: 0…2,5bar temperature: 0…100°C filter velocity: 0…70m/h 230V, 50Hz, 1 phase 230V, 60Hz, 1 phase 230V, 60Hz, 3 phases UL/CSA optional Dimensions and weight LxWxH: 1900x790x1900mm (trainer) LxWxH: 1100x790x1100mm (supply unit) Total weight: approx. 250kg Required for operation
