media installation
Correct Installation of media is vital to ensure the successful
operation of the filter.
| Filter Media Placement | |
| Pattern Test | Before placement a pattern test must be carried out to the satisfaction of all parties. |
| Support Gravels | Great care must be taken with the placement of the first layer of gravel in order to prevent any damage to the filter floor. It is common practice to conduct a second pattern test after the first layer of gravel has been installed and leveled to test for any nozzle breakage. Each support layer is leveled by hand after placement. |
| Sand Filter Media | Initial care should be taken when placing the sand not to disturb the support layer. Any irregularity left in the gravel will remain there for the life of the filter media. The sand layer may be leveled during backwashing. Once clean, the filter is completely drained down to allow for the fines to be scraped from the surface of the layer. The level is the checked and if required topped up. |
| Anthracite Filter Media | Finally the anthracite layer may be installed. This is then backwashed to clean and level the layer. As the top bed of media it is not always necessary to scrape any fines that may remain after backwashing. |
Several Methods of installation are available each with its advantages
and
disadvantages.
| Filter Media Installation | ||
| Media Pump | Special pumps are available which can place all medias, including the support gravels, into the filter | |
| Advantages | ||
| Can place media into a building. | ||
| Uses little water that can be recycled | ||
| Does not require a minimum water pressure | ||
| Clean and dust free | ||
| Can place gravels | ||
| Can accept bulk loads eliminating the need for tote bags | ||
| Quick [30 tonnes/hour] and the most economical for large installations | ||
| Disadvantages | ||
| Requires a specialist company | ||
| Not that economic for very small installations | ||
| Ejector | Again these use water to install the media but without all the advantages of a filter media pump. | |
| Advantages | ||
| Can place media into a building. | ||
| Clean and dust free | ||
| Disadvantages | ||
| Requires a minimum water pressure | ||
| Requires a high volume of water that cannot be easily recycled | ||
| Slower than a pump | ||
| Usually requires a specialist company | ||
| Crane | In some situations a crane may be used to lift tote bags of media into the filter. | |
| Advantages | ||
| A DIY method of installation and may therefore be the cheapest option. | ||
| Disadvantages | ||
| The filters must be open air and within easy reach | ||
| Tote bags have to be used | ||
| Tends to be labour intensive | ||
| May be subject to weather conditions | ||
| Hand Installation | Another DIY method of installation | |
| Advantages | ||
| This method may be economic for very small installations [below 15 tonnes] | ||
| Flexible if on site labour is used. | ||
| Disadvantages | ||
| Manual handling is no longer an safe option. | ||