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Manganese Sand Tank Filter and Wedge Wire Filter Element

JOHNSON SCREEN

We provide the filter element in the manganese sand tank (filter) – Wedge Wire Filter 

Due to the erosion of carbonic acid, the influence of organic matter on iron and the reduction of trivalent iron oxide, a lot of iron in the earth’s crust will enter into groundwater.

According to the health standard of drinking water in China, iron content ≤ 0.3mg/l, manganese content ≤ 0.1mg/l, long-term drinking water with high iron and manganese content is harmful to human body.

In textile, papermaking, brewing, food and other industries, excessive iron and manganese will affect the quality of products, make the products produce spots, and also corrode the equipment.

The common iron removal filter is that the underground water containing iron (manganese) flows through the manganese sand or special quartz sand filter layer after aeration to oxidize, solidify and remove the iron (manganese).

Manganese sand filter is a pressure vessel, which is equipped with Johnson screen (wedge wire) filter element, and it is a horizontal or vertical cylinder structure.

The flow enters from one end, and evenly distributes the flow to the inner surface of the wedge wire filter element.

After filtration by wedge wire filter element, the material will flow out of the filter element, collect to the water collecting type, and then flow out through the water collecting type filter.

After a period of operation, if the quality of effluent water drops or the filtration resistance is too large, it should be cleaned, which can greatly improve the practical life of manganese sand filter material, save energy consumption and ensure production water.

The V-shaped wire structure of the wedge wire filter makes it difficult to block and clean, which is the reason why the manganese sand tank chooses it as the filter element.

The cleaning of manganese sand filter should pay attention to the following problems

PH value

In the process of removing iron and manganese from groundwater, pH value is the key factor affecting the removal of iron and manganese.

The higher the pH value, the faster the oxidation rate of Fe2 + and Mn2 +, and the easier the removal of Fe and Mn.

When the pH value is higher than 5.5, the oxidation rate of Fe2 + will increase by 100 times when the pH value is increased by 1.0, and the oxidation rate of Mn2 + will also increase obviously when the pH value is higher than 9.

Backwash strength

The phenomenon of “saturation” or “passivation” of manganese sand is common in the practical process of iron and manganese removal filter, which greatly reduces the capacity of manganese removal.

The main cleaning method is backwashing, and the backwashing method is air water combined backwashing.

The backwashing water flow intensity is 10-12l / s · m2, and the backwashing duration will vary according to the specific use conditions, generally about 30 minutes.

The principle is to observe the backwashing water, when the water flow gradually becomes clear or near the end of the backwashing process with clear water.

It can also be repeatedly rinsed with regenerant for three times, and finally rinsed with tap water to neutral, and then reused.

Chemical Cleaning

During the operation of manganese sand filter, impurities are distributed unevenly in the filter layer, and the penetration depth of impurities is different. Moreover, it is impossible to fully remove the sludge attached to the filter material and smash the large particles in each backwash. At the same time, when the manganese sand filter is filtering or backwashing, the hydraulic conditions of the filter layer are also uneven, so that a large number of impurities are retained when impurities penetrate the surface of the deep filter layer , the filter layer forms “mud felt”, which causes the filter material to harden. At this time, chemical cleaning is required, and special cleaning agent is used for soaking circulation to remove colloid and organic particles, scale and metal oxide, so as to recover the normal treatment effect of filter material.

 

Wedge filter element for filtration equipment

Manganese Sand Tank Filter
Diatomaceous Filter