Description of system components
1. Settling tank (ST)
The tank sits below the upper edge of the terrain and can be accessed via an access opening (1.3) for control and maintenance purposes. Entry into the tank is not necessary for servicing.
PVC KG pipe is normally used for the supply line (1.1) and discharge line (1.2). Concrete (min. B45) or plastic (PE) is used as the tank material, depending on the design. The shaft covers are without ventilation openings, but are not gas-tight.
All tanks approved by the DIBt and meeting the requirements of DIN 4261 can be used as STs. This is especially beneficial when existing tanks are to be used, assuming they are in proper structural condition and offer the minimum volume.
Technical data ST:
Minimum volumes: 4.00 m³
Diameter of the access opening: DN 600
2. Membrane reactor (MR)
The MR, like the ST, sits below the upper edge of the terrain. The MR can be accessed via an access opening. But entry into the tank is not necessary for servicing. The MR is connected to the ST above the ST's drain via a PVC KG pipe (2.1).
The MR is filled through this pipe. Concrete (min. B45) or plastic (PE) is used as the tank material, depending on the design. The shaft covers are without ventilation openings, but are not gas-tight.
Technical data MR:
Diameter: 1.00 m
Usable volume: 1.20 m³
Diameter of the access opening: DN 600
3. Filtration module
The filter module is especially designed to meet the requirements of the application. It is a plate module in which 12 membrane plates and two outer plastic plates are arrayed in parallel and sealed on the side. This results in a compact unit.
Two collecting channels are attached above and below on the front side. Connected together, they form the filtrate outlet. The hose for the filtrate pump is connected to the upper end of the outlet, while at the lower end, the module can be emptied by opening a ball valve. Filtrate The membrane module is placed on a ventilation and upstream channel and fixed to it with a holding bar.
The module is removed by lifting it, together with the ventilation unit, vertically out of the MR. The module is then emptied completely via the drain valve. The holding bar is pulled out by loosening a cotter-pin, and the module simply removed.
Technical data for the plate module:
Membrane material: PVDF
Pore size: 0.2 µm
Membrane surface: 7.1 m²
Dimensions (W x D x H): 190 x 315 x 1090 mm
Weight when empty: 10 kg
4. Switch cabinet and switch cabinet components
The switch cabinet can be placed in a nearby dry, well-ventilated room (basement, garage, etc.), as the customer wishes. It is also possible to set up an outside switch cabinet in the immediate proximity of the small purification unit. Electrical supply of 230 V is all that is necessary. A DC version is available upon request.
Besides the control unit, the blower, pump and solenoid valve are placed in the switch cabinet. The connections for the air and filtrate hoses as well as the electrical connections for the float switch are located on the outside.
4.1. Control unit
On the rear of the control unit are located the outlets for connecting the voltage source, compressor, solenoid valves and filtrate pump as well as the inlets for connecting the float switches. Also on the rear of the control unit are the fuse receptacles for visible type fuses, which protect each individual channel from overload. The control unit is supplied with voltage of 230 V. A DC version is available upon request.
The control unit can be extended via a CAN bus. The control unit can be remotely controlled by modem through a serial interface. Through this interface, operating conditions and logs can be transmitted from the control unit to any PC.
4.2. Blower
A free-piston compressor is used to supply air. This blower type has proven itself to be especially low maintenance and reliable in operation. It is also frequently used for ventilating fish ponds and has been a standard component of a large number of small purification units for years.
Technical data:
Operating pressure: 180 mbar (max. 250 mbar)
Displacement: 6 m³/h
Electrical power rating: 0.13 kW
Dimensions: 408 x 210 x 232 mm (L x B x H)
4.3. Filtrate pump
A vane-cell pump with a displacement of 100 l/hour is used as the filtrate pump. The pump is a positive displacement pump and virtually wear-free, since the rotor works without contact. It is self-priming up to a displacement height of 2 m.
The pump has proven itself with small flow channels in test systems and has been used there for several years.
Technical data:
Displacement flow: 100 l/hour
Displacement height: 10 bar
Intake pressure: Up to 800 mbar
Electrical power rating: 0.12 kW
Dimensions: 300 x 150 x 155 mm (L x W x H)
4.4. Valve
The solenoid valve is located in a modular design inside the switch cabinet. It is used to switch over the air from MR ventilation to the compressed air lifter. The path for MR ventilation is freely open.
The path to the compressed air lifter is opened when demanded by a solenoid valve. Due to the higher pressure resistance of the ventilation, the air then flows completely to the compressed air lifter.
The valves have proven themselves in many fixed-bed and SBR small purification units for years.
Technical data:
Connection size: G1/2
Operating pressure: 0 up to 0.4 bar
Nominal width: 11 mm
Inside material: 1.4401
5. Compressed air lifter
The displacement device for feeding the MR works according to the principle of a compressed air lift system. To operate the compressed air lifter, the blower in the switch cabinet is switched together with the corresponding solenoid valve.
The compressed air lifter is connected by a hose to the hose nozzles on the switch cabinet. Normally, the hoses are laid below ground (To simplify installation, the hoses are pulled through an empty pipe). PVC pipe (b) and HT pipe (a) as well as fasteners made of stainless steel 1.4301 are used as materials.
Technical data:
Volume flow rate at 0.4 m displacement height: 0.8 m³/hour
6. Ventilation
Two rubber membrane pipe vents are used, which are supplied with air via a ¾" distribution line. They are integrated into the upstream channel and can be screwed out individually.
Two vents with an overall length of 0.5 m are built in. They are pressurised with 6.0 m³/hour of air. This creates a fine-bubbled ventilation with a favourable oxygenation capacity.
The pipe vents have proven themselves in many fixed-bed and SBR small purification units for years.
7. Float switch
The fill level in the ST and MR is registered by means of float switches. They are fastened to the walls. The float switch cable is guided through the empty pipe together with the air hoses and connected via a PG union to the switch system.
This type of float valve has proven itself in many SBR small purification units for years. The float switch is made completely of PE; the cable is made of TPK.
Protection type: IP68
