Self-Cleaning Filter Selection: A Practical Industrial Guide

Selecting a self-cleaning filter for an industrial process requires more than choosing a filtration rating.

The correct configuration depends on the liquid being filtered, contaminants, flow rate, operating conditions and the cleaning method.

Here is a practical way to approach the selection.

1. Identify the fluid

Start by identifying the process liquid.

Typical applications may involve:

Industrial water

Cooling water

Wastewater

Process liquids

For some applications, viscosity and corrosiveness should also be considered.

2. Identify the contaminants

Determine what the filter needs to remove.

Common contaminants include sand, sediment, rust, suspended solids and mechanical impurities.

It is also useful to understand the solids loading and physical characteristics of the contaminants.

3. Determine normal and maximum flow

Flow rate should be considered under actual operating conditions.

Both normal and peak flow should be provided when evaluating a filter.

Selecting equipment only according to pipe diameter may result in an unsuitable configuration.

4. Define the filtration requirement

The filtration rating should be related to the particle size that must be removed and the protection required downstream.

A finer rating is not automatically a better choice.

The filtration requirement also needs to work with the selected cleaning mechanism and contaminant loading.

5. Check pressure and temperature

Operating pressure and temperature affect filter configuration, materials and cleaning performance.

These parameters should therefore be established before selecting a specific model.

6. Choose the cleaning mechanism

Different self-cleaning filters use different cleaning methods.

Disc-type filters use a disc-based filtration and cleaning structure.

Scraper filters mechanically remove deposits from the filtration surface.

Suction scanner filters use localized suction to clean the filtration surface.

Automatic backwash filters use reverse flow to remove accumulated contaminants.

The appropriate mechanism depends on the process rather than simply the nominal filtration rating.

In-depth Reading: Self-Cleaning Filter Types

7. Use a selection checklist

Before requesting a self-cleaning filter, it is useful to prepare:

Fluid type

Normal flow rate

Maximum flow rate

Contaminant type

Solids loading

Required filtration rating

Operating pressure

Operating temperature

Viscosity/corrosiveness

Cleaning mechanism

Material requirements

Cleaning control

Connection and installation conditions

This information gives a much better basis for evaluating the filter configuration.

The best self-cleaning filter is not necessarily the largest filter or the one with the finest filtration rating.

It is the configuration that matches the actual process conditions and provides an appropriate filtration and cleaning method.

A more detailed explanation of these parameters and the four main self-cleaning filter technologies is available here: How to Choose a Self-Cleaning Filter