Industrial Basket Strainer

We are very well aware of the fact that physical contaminants can be the biggest disaster in food manufacturing industries, this is the reason why food technologists/engineers install devices like a sifter, magnet trap, basket strainers, disc filters in process for eliminating foreign bodies that not only helps in achieving food safety goals but also reduces maintenance cost and downtime by protecting valuable equipment like flow meters, heat exchangers, valves, cooling towers, spray nozzles, pumps, valves, pasteurized, etc. from the damage associated with nuts, bolts, metal shavings, etc. But to achieve removal of the foreign bodies from the pipeline system conveying process fluids, basket strainer becomes the most preferred choice among the available options as it can remove both- metallic and non-metallic contaminants up to specific particle size. 

1. Sanitary Basket Strainers

These are closed vessel consisting of wire mesh screens which trap solid debris from the process fluids. Installation of basket strainers in food industries is considered good practice for removing contaminants, regulating product size, or bettering product quality. The mesh is designed in many sizes and shapes and is either woven or welded together. These screens are tightly woven to provide an adequate training material that is capable of filtering material that is either 100 microns or larger.

2. Types of Strainers-

A] On the basis of the size of the mesh

Strainers are broken down into three main filtering categories:

1. Coarse Strainers – for large particles
2. Medium Strainers – for particles 75 to 1905 microns
3. Fine Strainers – for particles down to 5 microns

B] On the basis of mode of operation

1. Simplex Filter:

 These are single-chambered equipment installed in pipeline systems that remove the particles and debris from the flowing fluid in pipeline systems. These kinds of strainers are not useful for the continuous process, as it requires the process to shut down for a certain period to replace/clean the basket strainer. We can easily determine when the basket is clogged by comparing the pressure at the inlet and outlet.

 

2. Duplex Filter:

It is a twin basket filter with two identical simplex filters which are connected via pipe and valves. These have two independent basket strainer chambers having common inlet and outlet ports and are very essential for the processes that are required to be operated under continuous mode. The major benefit of a duplex strainer is that there is no need to shut them off when they become clogged and have a butterfly valve that directs flow through either side without shutting off the flow.

3. Self-Cleaning Basket Filters:

It is the advanced form of basket strainers which are also known as an automatic self-cleaning strainer. In this strainer, fluid will flow via inlet to the self-cleaning strainer and then to the outlet. The strainer element will strap the contaminants to a point where it is clogged. Once the differential pressure exceeds a specific threshold, the process of clog removal immediately initiates. The system will then backwash the strainer element. During this time, it will block the inlet pipe while opening another valve through which the dirt particles leave the filter system. They basically offer two main advantages:

1. Reduction in downtime as you do not require baskets to uninstall for cleaning thus saving maintenance cost.
2. A worry-free maintenance costs.

 

3. Components

Basket strainers are an assembly of different components and parts which are discussed below:

1. Industrial Basket Strainer Housing: It is the outer covering of the strainer in which basket assembly rests.
2. Filter Element: It is a cleanable screen with, built-in basket strainer to allow filtering of larger particles or dirt in the pipe system. The basket straining element is either made of straight or staggering perforated plates.
3. Handle: It is ergonomically designed to handle for easy removal/installation of the basket assembly.
4. Internal Cylinder: It closes the inlet and outlet for replacement of dirty elements by turning position.
5. Vent Valve: Used for pressure relief.
6. Clogging Indicator: It indicates when the filter element requires replacement.
7. Blow off Valve: It removes dirt particles and helps strainer bodies to clean.
8. Inlet Port: It is the point from where contaminated process fluid enters the strainer element.
9. Outlet Port: It is the point from where clean fluid exits the strainer element.

4. Designing Parameters for Basket Filter

 

1. Material of Construction of Removable Basket Assembly: Beverage and food strainers are manufactured from stainless steel mesh (304l/316L), but other corrosion-resistant alloys can be used for processing highly corrosive fluids.
2. Type of Process: It is critical for model selection to understand that if the process has to operate under batch or continuous mode.
3. Nature of Fluid: It is Paramount to know if the fluid is liquid, gaseous, abrasive, corrosive in nature.
4. Process Parameters: Whenever you are buying an industrial basket strainer to install in a piping system, ensure that the system parameters like working pressure, temperature, flow rate, etc. must match with the strainer’s standard specifications.
5. Easy to Clean: Low surface roughness makes basket strainers extremely easy to clean, which is important for maintaining product safety. Any corrosion could lead to bacterial growth that causes contamination and potential health issues for consumers.
6. Flow Rate: It is important to know the process flow rate as it decides whether the model of basket filter will be able to withstand it or not.
7. Mesh Size: Mesh Size indicates the particle retention by the cleanable screen.
8. Fabrication: The industrial welded simplex basket strainers manufacturers use either bolts or welding to join various components. But still, fully welded strainers are better than the casted ones as they offer zero leakage and superior cleanability.
9. Location of Installation: As per standard engineering practices, strainers are employed in pipelines to protect downstream mechanical equipment such as condensers, heat exchangers, pumps, compressor, meters, spray nozzles, turbines, steam traps, etc. from the detrimental effect of sediment, rust, pipe scale or other extraneous debris.

Basket Strainers are now no longer confined to a simple cast body with a wire mesh screen but are a technical, highly refined, carefully designed piece of equipment. So, before you buy any basket strainer, ensure you understand every detail mentioned above. More importantly, identify a trusted and reliable manufacturer for purchase of it.