Using a candle filter element guarantees you the following benefits:

Candle Filter Element

• Natural Filtration Media

The surface of a candle filter element consists of perlite and diatomaceous earth precoat.

This precoat forms a cake layer that effectively filters your fluid.

Normally, the filtration process is natural since there is no addition or removal of chemicals and minerals.

• Large Filtration and Dirt Holding Capacity

Most candle filters have a large filtration area as well as a large capacity for holding dirt.

This gives you the benefit of thoroughly filtering your fluid without worrying about clogging the filter element.

The advantage here allows you to filter a large volume of your fluid.

• Easy to Clean

Unlike other filters that you have to stop your application to clean it, a candle filter element easily cleans itself.

This is through backwashing which utilizes the filtration fluid to clean the filter.

Since they are easy to clean, you don’t have a concern about frequently replacing them.

• Compatible

Candle filter elements are compatible with various types of filters such as gravity and pressure filters.

When selecting a candle filter element for your application, you just have to check o the size and number compatibility.

• Efficient Filtration of Pathogens

Candle filters consist of tiny versatile pore structures which are responsible for the efficient filtration of pathogens on the fluid.

This ensures quality filtration of the fluid

• Affordable

Affordability is what you get when selecting a candle filter element.

These candle filter elements are relatively cheap when compare to other types of filter elements.

Structure of Candle Filter Element – Photo Courtesy: STERI TECHNOLOGIES

• Pressure Vessel

The pressure vessel is the outer part of the candle filter.

Its design allows it to hold the fluid under pressure during the filtration process.

• Suspension Feed

This refers to an opening at the bottom of the candle filter.

The suspension feed is the entry point of the fluid during the filtration process.

• Filtrate Outlet

After filtration, the fluid needs to flow out of the candle filter.

The filtrate outlet is there to allow for this flow of the filtrate.

Remember, the location of the filtrate outlet on the sides of the candle filter.

• Compressed Gas Feed

For effective cake discharge, you need to pump either compressed gas or steam through the candle filter.

You can achieve that by using the compressed gas feed which is at the top of the candle filter.

• Solid Discharge Outlet

Cake removal takes place at the solid discharge outlet.

This part is the bottom-most part of the candle filter.

• Filter Candles

A filter candle is a tube-like structure on the inner part of the pressure vessel where actual filtration takes place.

As we shall see later, the filter candles play a crucial role infiltration by allowing the fluid to pass over them.

As the fluid flow, the filter candle holds contaminants thereby filtering your fluid.

• Pressure Transducer

At the top of the candle filter, there is a pressure transducer device whose purpose is to measure the pressure of the gas in the filter.

It is particularly crucial during the cake removal process when you have to pump compressed air into the filter.

Once you know the structure, the working principle of a candle filter element is easy.

Let me take you through this process.

The working process of a candle filter involves six steps.

Working of Candle Filters

• Filling

This is the initial process when you are filtering using a candle filter element. at this stage, the slurry flows from the bottom of the vessel upwards

Moreover, the advantage of this flow is that suspension of the solid takes place which in turn they are deposited evenly on the filter element surface.

• Pre-Coating

In this step, circulation of the suspension takes place through the candle filter elements producing a precoat porous layer.

Precoating takes place under certain circumstances.

First, if the suspension is sticky, a precoat layer forms acting as a barrier that prevents cloth blinding.

At the same time, the layer between the precoat and the cloth separates forcing discharge of the cake.

The process leaves a clean cloth.

Second is if you require the filtrate immediately the filtration process begins.

• Filtration

After the precoating stage, the filtration process begins.

At this step, umping of the slurry into the filter takes place.

The result is cake formation which the candle retains as the fluid continues flowing.

If the solids are slow and fine for filtration, you need to add a body-aid which enhances the cake permeability.

However, you need to remember that adding a body-aid facilitates the solid concentration of the feed.

This in return increases the volume between the candles thereby increasing the quantity of disposal cake.

• Cake Washing

Once the filtration process is complete, there is blowing f gas or air into the filter.

This pushes the cake surrounding the slurry displacing it downwards till it reaches the candle stack bottom.

At this stage, there is an evacuation of any remaining cake back to the tank using a dip pipe. You can locate this pipe at the bottom of the filter.

The evacuation process ensures that the filter is free of any cake.

• Cake Drying

The pumping of air continues passing through the cake until there is a decrease in the moisture level in the cake.

You can use hot steam as an alternative to hot air for drying the cake.

• Cake Discharge

Cake discharge involves opening the filter outlet and back blowing or vibrating the candle stack to remove the cake.

You need to ensure that there is an interlocking of the outlet with a pressure sensor.

This prevents the opening of the outlet under high pressure.

After the cake discharge, you need to backwash the filter element with water.

The purpose of this is to ensure the filter element is clean of any adhered contaminants for further filtration of your fluid.

Selecting a candle filter can be a difficult task especially if you are not an expert.

However, you don’t have to panic

Here are a few things to check out when purchasing a candle filter for your application.

Candle Filter – Photo Courtesy: CENTRASEP

• Particle Characteristics

A unique characteristic of a candle filter is its ability to filter microparticles.

However, when selecting a candle filter, you need to check on particle characteristics of the filtration fluid.

This will assist you in picking the correct candle filter for your application.

• Maximum Flow Rate

Another consideration you have to make is the flow rate of your application.

Flow rate affects the filtration process by ensuring that there is a maximum filtration of the contaminants.

• Operating Pressure

You need to select a candle filer that will handle the pressure of your application without breaking the filter element.

Also, your candle filter needs to maintain the pressure of the fluid for efficient filtration.

Selecting a candle filter with less pressure may result in poor filtration since there will be no force for your fluid in the filter itself.

• Pressure Drop

Pressure drop is the decrease in the pressure of the fluid as it flows through the filter.

Forcing the fluid through the filter element causes the fluid to change direction.

The effect of this is that there is a resistance to the fluid flow causing a decrease in pressure after the fluid flows through the filter.

Factors that cause [pressure drop include a filter element, contaminants, and the flow rate.

An increase in pressure drop causes quick cake formation which will have an impact on your filtration process.

To minimize this, always ensure that you select a candle filter element that has a corresponding pressure drop with your application.

• Operating Cost

In as much as these filters are cheaper than others, you still have to check on the overall operating cost before selecting one.

The operating cost includes the cost of purchasing and maintenance including repair.

These costs need to be within your affordability range.

There are various applications where the candle filter element plays a critical role.

Among the major applications of candle filters include the following.

Chemical Processing Industry

1.Water Treatment Plants

The use of the candle filter element is gaining popularity in water treatment plants due to its efficient filtration.

Treatment plants utilize candle filters to remove contaminants and pathogens from the water thus making it safe for use.

The tiny pores of the candle filter element make it ideal for the filtration of micro-contaminants from the water.

2. Chemical Industry

Chemical manufacturing industries need a filtration system capable of filtering the poisonous elements they produce.

That is where candle filter elements come in handy since they can filter hazardous gases before being released into the environment.

This ensures the waste is safe for humans.

3. Pharmaceutical Industry

Another area of application of candle filter elements is in the pharmaceutical industry.

Here, candle filter elements play a critical role in filtering elements that are not useful in the manufacturing of drugs.

The importance of this is the quality manufacturing of drugs that are safe for human and animal use.

4. Oil Industry

The oil industry is yet another area of application of candle filter elements.

Here, the use of these filters is in the refinery of crude oil.

Filtration allows you to remove unwanted particles from the crude oil.

Also, candle filter elements are crucial in ensuring adequate separation of the different gases and oils present in crude oil.

5. Food Industry

Consumption of safe food is key to our survival.

There is a wide area of the food industry that uses candle filter elements that ensures this.

For instance, in the manufacture beverage manufacturing industry, the candle filter element plays a role infiltration of unwanted particles.

These particles may be the used raw materials like barley in beer production.

Such contaminants may temper the quality of the product hence the need for removal.

Removal of these contaminants ensures that we have safe and quality foods.

6. Automobile industry

The latest technology enables the fitting of these filters in automobiles which helps in the filtration of automobile oil.

The effect of this is it ensures the quality filtration of the engine oil thereby reducing the amount of carbon monoxide emission.

It also improves the performance of the vehicle thereby guaranteeing your efficiency as well as a long-lasting car.

Now you are best equipped in candle filters.

To achieve maximum filtration using these filters, ensure that you check on the specifications when selecting them.

Also, you can easily install these filters on your application by simply following the guidelines.

Moreover, you need to buy your candle filter from a reputable manufacturer.

This will ensure that you get quality candle filters and in case of malfunctioning, they can help you out.

Get in touch with us today for professional assistance on candle filter elements.