Quartz sand for filters is the most widespread filter material. It is caused by the fact that it is essentially free of clay and impurities that can be leached into the water passing through the filter material.It differs from ordinary sand due to its monomineral features, uniformity of structure, low intergranular porosity. This feature makes quartz sand indispensable for swimming pools and various industries as it has a high retained capacity, durability and mechanical and chemical influences.
The main sphere of quartz sand activity is chemical water purification from salt manganese or iron. Before quartz sand for mechanical filters is suitable it must be purified by calcination. It removes dirt and impurities from the sand and gives the opportunity to get the material corresponding to all the norms and standards. For water purification quartz sand of different fractions is used. It depends on the size of a filter and its power.
The lifetime of high-quality sand for filters can be up to 8 years on condition that the filter is properly installed. In addition if it is cleaned in time you can extend the lifetime of the sand.
(Other factions can be made according to an individual order)
Packaging: Multilayer sealed bags of 25 kg. Delivery of materials carried in bags on pallets, wrapped with several layers of polyethylene strapped with steel cables. Pallet -1200 kg (48 sacks of 25 kg each).
Multilayer sealed big bags of 1000 kg.
Minimum batch: 25 kg bag
Maximum batch: unlimited
Quartz sand for filtration systems and pool filters is the most common filter material. This is largely due to the fact that it practically does not contain clay and impurities that can be washed out into the water passing through the filter material. It is distinguished from ordinary sand by monominerality, uniformity of structure, and low intergranular porosity. This feature makes quartz sand indispensable for swimming pools and in various industries, as it has high dirt capacity, resistance and mechanical and chemical influences.
The service life of high-quality sand for filters can be up to 8 years, provided that the filter is configured correctly. In addition, if you clean it in time, you can extend the life of the sand.
One of the methods for purifying water from suspended and colloidal impurities is to filter it through a porous granular medium. Filtering facilities can be used both as a post-treatment of water after sedimentation tanks or clarifiers with suspended sediment, as well as stand-alone facilities.
The physicochemical nature of reagent clarification and bleaching of water during the filtration process is the adhesion (adhesion) of suspended and colloidal particles to the grain surface of the filter material or to previously adhered particles. The precipitate formed in the loading pores has a fragile structure, which is destroyed by the hydrodynamic forces of the stream. In each
clarification of water occurs until the detachment forces of the particles begin to prevail over the forces of adhesion and autohesion (interactions between particles in the adherent layer).
Detached sediment particles are transferred to subsequent layers and are retained there.
In addition to clarification of surface waters, with the help of granular filters, iron removal, softening (ion-exchange granular filtering materials), fluorination (fluorite sand), defluorination (granular aluminum oxides), water stabilization (marble chips) are carried out.
Depending on the nature and type of the filter layer, the following types of filters are distinguished: granular ( filter layer – quartz sand , expanded clay, expanded polystyrene, etc.); mesh (the filtering layer is a mesh with a mesh size of 20-60 microns); fabric (filter layer – cotton, linen, cloth, glass or nylon fabrics); alluvial (the filtering layer is wood flour, diatomite, asbestos chips and other materials washed in the form of a thin layer on the frame of porous ceramics, metal mesh or synthetic fabric).
Granular filters made of quartz sand used to purify household drinking water and industrial water, from fine suspension and colloids ; mesh – to detain coarse suspended and floating particles; fabric – in field water supply; alluvial – for the purification of low-turbid waters at stations of low productivity (for settlements, swimming pools, etc.).
Granular filters are most widely used for water treatment in public and industrial water supply . According to the filtration speed, they are divided into slow (filtering speed 0.1-0.2 m / h), half-speed (0.2-5.0 m / h), fast (5.0-15 m / h) and ultra-fast ( 15-25 m / h).
Depending on the grain size of the filter layer, silica sand granular filters are divided into fine-grained (for example, slow filters with a grain size of the upper sand layer of 0.3 – 0.5 mm), medium-grain (for example, quick filters with the grain size of the upper sand layer is 0.5 – 0.8 mm) and coarse-grained (in particular, preliminary filters with the grain size of the upper sand layer 1 – 2.5 mm).
If the loading of the filter layer is uniform in density and differs only in grain size, then these types of filters are called single-layer (for example, quick filters loaded with quartz sand) . Filters loaded with a non-uniform loading by density and grain size are called multilayer filters (for example, two-layer fast filters, in which the lower layer is quartz sand, the upper one is anthracite).
In the direction of the flow of water during filtering, granular filters are single and multi-flow, with vertical , horizontal and radial water flow directions.
Depending on the pressure supply created after cleaning, the filters are classified as pressureless, pressure head and combined.
By type of load, there are filters with heavy granular (grain density of which is greater than the density of water) and with floating loads, which are able to stay unlimited time in water in a floating state.
The first include filters with quartz and anthracite loading, with loads of crushed and uncrushed expanded clay, burned rocks, volcanic slag, activated carbon, marble chips, ion-exchanged natural and artificial granular materials.
The second group includes filters with granular polystyrene foam , polyurethane foam , fluoroplastic, and other loads. Closed-cell waterproof shungizite, redoxide, fiberglass, granulated slag granules, crushed waste from foam boards and the like can also be used as floating or semi-floating filtering materials.
The estimated filtration rates and the washing regime are specified in the process of technological surveys carried out on the water of a particular water source.
Coarse-grained (coarse-grained filters)
Coarse-grained (coarse-grained filters) are used for partial clarification of water intended for technical purposes, if the turbidity of the water in the water supply does not exceed 150 mg / l. They hold up to 50-60% of suspended solids contained in water. Their main purpose is to detain suspended matter larger than 0.05 mm, capable of settling in areas of cooling systems with reduced water speeds.
Coarse filters are designed to be pressure or open. Coarse pressure filters should be counted on the maximum pressure loss in the filter load and drainage up to 15 m, open – 3-3.5 m. In open filters, it is necessary to provide a layer of water above the load level of 1.5 -2 m.
silica sand or other granular materials with appropriate mechanical strength and chemical resistance are used as filter media.
Devices for supplying and discharging washing water should provide the following mode: loosening the filter load with water with an intensity of 6-8 l / (cm2) – 1 min, air-water washing with an intensity of 3-4 l / (cm2) of water and 15-25 l / ( cm2) of air – 5 min, washing with water and hydraulic sorting of the filter load with a water flow rate of 6-8 l / (cm2) – 2 min.
The area of coarse filters F is calculated by the formula:
𝐹 = 𝑄, м2 (4.7.1)
где Q – useful filter performance, м3/d; Т—station operating time during the day, h;
𝜈р – estimated filtering rate, m/h;
n – the number of rinses of all filters per day;
𝜔1 · 𝑡1 – intensity in l/(sm2) and duration in h of loosening the filter layer;
𝜔2 · 𝑡2 – water flow rate in l/(sm2) and duration in hours of air washing;
𝜔3 · 𝑡3 – intensity in l/(sm2) and duration in h washing; t4 – filter downtime due to flushing in hours.