Circulating Cooling Tower Water Filtration Automatic Sand Filter
Rapid sand filters use relatively coarse sand and other granular media to remove particles and impurities that have been trapped in a flocthrough the use of flocculation chemicals-typically alum. The unfiltered water flows through the filter medium under gravity or under pumped pressure and the floc material is trapped in the sand matrix.
Mixing, flocculation and sedimentation processes are typical treatment stages that precede filtration. Chemical additives, such as coagulants, are often used in conjunction with the filtration system.
The two types of rapid sand filter are the gravity type (e.g. Paterson's filter) and pressure type (e.g. Candy's filter).
A disinfection system (typically using chlorine or ozone) is commonly used following filtration. Rapid sand filtration has very little effect on taste and smell and dissolved impurities of drinking water, unless activated carbon is included in the filter medium.
Rapid sand filters must be cleaned frequently, often several times a day, by backwashing, which involves reversing the direction of the water and adding compressed air. During backwashing, the bed is fluidized and care must be taken not to wash away the media.
Rapid sand filters are typically designed as part of multi-stage treatment systems used by large municipalities. These systems are complex and expensive to operate and maintain, and therefore less suitable for small communities and developing nations.
Working principle
For the by-pass filtration, the filter is installed in the main circulating pipeline to filter all the circulating water, but a part of the circulating water flows from the main circulating pipeline is filtered, which is a repeated circulating interception step by step to filter the impurities within the system and finally remove the impurities by the necessary backwash out of the system. Installing a by-pass filter in the circulating water system can prevent the terminal pipe of device from sludge blocking and remove the impurities in the system with chemical dosing.
By-pass filtration is used to reduce the turbidity of the water circulation system, exactly, to reduce slime and prevent its deposition in the heat exchanger, so that the effect of agent will be better.
Generally speaking, if your filter is a quartz sand filter, it usually has two main functions:
1. To reduce suspended solids (turbidity). Otherwise, as the system is running, suspended solids increases, which will exacerbate the deposition and other problems.
2. Degreasing. Especially the oily turbid circulation, such as steel rolling and continuous casting, has high oil content and is easy for breeding microorganism and blocking the nozzles.
Technical description of by-pass filter for the industrial circulating water
Flow filter flow is designed according to 5% to 10% of the total circulation volume (the by-pass filter flow of the cooling water is designed by 10 % of the circulation volume and the by-pass filter flow of chilled water is designed by 5% of the circulation volume) and the filtration rate is designed by 20 - 3Smih according to water quality of the system. Specific to corrosive suspended solids of the circulating water system as well as the control, our technical support team has designed a variety of manual/automatic by-pass filtrating equipment in line with customer demand.
The characteristics of the filtration system
1. Manual or automatic control is available;
2. Water distributor is simple, uniform and reliable;
3. Finished water collector has high strength and long service life;
4. Easy to install. Only connect the inlet and outlet to the waste pipe when installing;
5. Less water consumption in backwash: A homogeneous filter is used, so that backwash cycle is extended and the total backwash water volume is greatly reduced;
6. High backwash efficiency: An advanced water collector is used, ensuring efficient backwash effect.
Technical parameters sheet for Shallow Sand Filter (Bypass Filtration Sand Filter)
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