Hectron has developed a range of automatic low pressure filters, the AS range, which includes 3 models of filters. These filters are widely used in many fields of applications and are very efficient. Their wide range of filtration thresholds makes them the equipment of choice for long-lasting protection of installations. This range of automatic filters is designed in Nice by Hectron's research and development teams and they are all assembled in its workshops.
Characteristics of the automatic low pressure filters models (AS range by Hectron)
The 3 automatic low pressure filters AS of the company Hectron (AS 200, AS 300, and AS 400) have common technical characteristics.
They are manufactured with a stainless steel casing (of variable size according to the models). They can all admit up to a maximum pressure of 5 bars and have filtration thresholds which go from 6 to 400 microns.
The essential difference between these models lies in their admissible flow rate and therefore their capacity.
For example, an AS 200 automatic low pressure filter can admit a maximum flow rate of 45 m3/h and the AS 300 model allows a maximum flow rate of 120 m3/h.
The AS 400 model has a maximum permissible flow rate of 340 m3/h.
Other differences between these models are the inlet and outlet types and their diameters.
These data are summarized below for the different models of the AS range:
- AS 200: 3" threaded M and 2" threaded F
- AS 300: DN100 and DN150 flanges
- AS 400: DN150, DN200 and DN250 flanges
There are also options available to provide higher pressures, if necessary, (10 bar maximum) and the possibility to have models made entirely in 316 L stainless steel.
How do Hectron automatic low pressure filters work?
Hectron automatic low pressure filters are equipped with a cleaning system by suction ramp which proves to be innovative and economical. This process offers an optimal cleaning quality with a low water consumption.
The cleaning process is triggered automatically when a sensor detects a pressure difference between upstream and downstream. The cleaning phase is therefore carried out at an optimal frequency and only when necessary.
Filtration takes place through a cylindrical sieve. When the sieve is clogged, the pressure difference between the inlet and outlet detected by the pressure switch triggers the cleaning process.
A suction ramp then rotates over the entire surface of the sieve. This action leads to a backwash which is focused essentially on the openings of the ramp.
Once the washing cycle is completed, the remaining material is evacuated by opening a solenoid valve: it then goes outside the filter.
Which membranes to use with the Hectron AS range automatic low pressure filters?
The membranes to be used with an automatic filter are variable according to the required filtration fineness. In the case of these AS range low pressure filters which all have a filtration threshold between 6 and 400 microns, there is only one type of membrane to use: the woven fabric membrane.
It will be of the PETP or nylon (PA 6.6) type. This type of membrane offers long durability and will be suitable for all types of suspended solids. These woven fabric membranes are recommended for mineral and organic matter. However, they are not to be used with polymer flocculants.
Fields of application of Hectron automatic low pressure filters
The AS range of automatic filters of the Hectron brand is essentially dedicated to 3 application possibilities detailed below. This kind of devices is already widely used in these fields and offers very good results, with a reasonable maintenance and a rather long life span of the equipments.
Protection of heat pumps in multi-family buildings
Water-to-water borehole geothermal heat pumps are sensitive, expensive and have components.
This is the case of exchangers which are very sensitive to fouling. This often happens if the water being used is loaded with suspended solids. Especially if the exchanger is not adequately protected.
Over time, the suspended solids agglomerate and settle in the exchanger, clogging its outlets. This greatly impairs the efficiency of the exchanger and can even put it permanently out of service. At the very least, disassembly is then necessary and a complete cleaning must then be performed. These operations are costly and immobilize the equipment.
An automatic low pressure filter is a solution to prevent this risk and avoid these operations. The maintenance of such an equipment will be strongly reduced with a filter of the AS range of the Hectron brand. Their capacity to operate at low pressure allows to install them directly between the pump and the exchanger. The pump is then not oversized and the installation of a pressure maintenance system is useless contrary to a classical automatic filter.
This solution proves to be a modest cost compared to the reduction of maintenance operations to be carried out and the increased longevity of the pump/exchanger assembly.
Water networks are necessary for most industrial sites and of course, they need rigorous and efficient filtration. If these water networks operate at low pressure, they will have proper filtration with the AS automatic low pressure filters. This is the case, for example, for drilling water before filling the tank or also for air cooling towers. The automatic filters are perfectly adapted to these uses thanks to the possibility to select a filtering threshold that is fine enough. The fine filtration threshold proposed by these Hectron filters is particularly well adapted to these industrial installations.
Sea water filtration
For the filtration of sea water, it is necessary to use automatic filters in a special, corrosion-resistant version. This option is available in the AS range of Hectron automatic filters which can be installed in particular on heat pumps running on sea water.