How Does a Sand Filter Work?
Sand filters have a fine particulate bed that can trap and remove large pieces of sediment and other contaminants from water. In many systems, water flows through the system and exits from the bottom, ready for use or additional filtration and purification processes.
Companies across a wide range of industries use sand filters as a critical component of purifying and treating water, either as a standalone option for non-potable water or as a way to reduce strain on more sensitive filtration membranes and processes.
At Holliston Sand, we supply sub-rounded NSF-61-certified sand from our natural deposit is used to fill and refill sand filters. Learn more about the different types of systems and how to keep them in peak condition.
Different Types of Sand Filters
Sand filters are commonly used in water treatment systems, but there are many different types to choose between, each one using a different method and a different type of filter:
- Rapid sand filters use chemicals to speed up the treatment to maintain a faster water flow as water moves through the sand filter
- Upward flow sand filters have a moving media bed and can continuously backflush to remove solids
- Slow sand filter, in which water is poured over a relatively deep sand bed with a support gravel base
Sand filters are considered “depth filters” as the water moves through the entire vertical bed of loose sand grains. They might be paired with surface filters, centrifuges, or other additional filters.
Sand Filter Care and Maintenance
Sand filters use relatively simple principles to treat water: the sand granules are loosely or tightly packed to allow water to flow through them and leave behind any solids too big to move through the sand. However, these filters require ongoing maintenance to ensure they operate safely and at required performance levels. Ongoing tasks include:
- Backwashing the filter to remove sediment and buildup caught in the media. While it’s best to routinely clean the system, operators can also monitor pressure levels and flow rates to note when the filter is getting too dirty
- Replenishing the sand media. The amount of water processed, the condition of the raw water, and the degree of filtration demanded will all determine how often the sand must be removed and replaced.
- Monitoring conditions. Operators need to continuously monitor the filter pressure level to ensure there isn’t a risk of overflow or breakage. They should also monitor the top of the sand filter to check for excessive organic growth, such as algae.
Sand Filter Cost
Commercial and industrial sand filtration systems can cost thousands or tens of thousands of dollars. Factors such as the size of the filter and its anticipated usage, whether it needs to integrate with additional filtration solutions, and the condition of the input water will all impact the price. But while the initial investment can be high, organizations can keep the costs low and predictable with a consistent maintenance process.
Proactive and preventive maintenance can help your operators catch repair needs before they develop into severe problems, allow you to replenish the filtration media on time, and keep pressure levels within safe ranges.
In addition to the costs of labor and time, consider other variable costs, such as the type and fineness of your filtration media and the complexity of the monitoring systems.
Request a Quote From Holliston Sand Company, Located in Slatersville, Rhode Island
Replenishing the sand in your sand filter is a vital part of maintenance, as it allows you to keep your sand filters cleaner, block unwanted solids, and regulate pressure levels over time.
At Holliston Sand Company, we offer a wide range of sub-round and subangular sand varieties for use in different filtration solutions. Contact us today to learn more and to order one-time or recurring units of sand.
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