Steam Separators: Types, Working Principle And Advantages

In this article, I will share the function, types, working principles and advantages of using steam separators.

The main function of steam separators is to remove condensate from steam.

You have to note that steam usually contains moisture and that tends to affect many industrial processes in a plant.

Wet steam has a low thermal capacity and this usually decreases the efficiency of its application.

Steam separators are of different types but they all use the same principle.

Without wasting time, let me share what you need to know about steam separators.

Types of steam separators.

1. Baffle-type steam separator.

The Baffle-type steam separator is known for its high separation efficiency.

There is not much to tell about this type of steam separator except that it has baffle plates inside its vessel (separator body), condensate trap, steam inlet and outlet and eventually a vent.

Working principle of baffle-type steam separator

The wet steam enters the baffle-type steam separator under a pressure.

Due to the presence of baffles inside the separator body, the steam won’t be able to move directly to the outlet unless it moves around the baffles inside the vessel.

The movement of the high-pressure steam inside the separator body will cause a sudden change of direction several times.

Water droplets will collect on the baffle plates due to the reduction of speed of the fluid which causes the drop in kinetic energy and also due to the fact that water droplets have greater inertia than steam, will start falling off from the baffle plates.

The steam that is now free of moisture will leave the separator body through the outlet and the condensate will collect at the bottom of the separator body and it will be drained through a steam trap.

2. Cyclonic-type steam separator (centrifugal steam separator).

When it comes to this type of separator, sizing is very critical for it to work to perfection.

Over-sizing will result in poor separation efficiency while under-sizing will result in a high-pressure drop.

So, for the cyclonic-type steam separator to work perfectly the sizing has to be perfect.

Though cyclonic steam separator has great separation efficiencies after baffle steam separator, it has a common problem of wear that one should take into consideration.

This disadvantage makes cyclonic-type steam separators inappropriate in applications where the steam produced is very wet.

Working principle of cyclonic-type steam separator

Inside the separator body, there are a series of fins that generate high-speed cyclonic flow which provides the centrifugal force, and this forces the steam to rotate around the separator body.

As the steam swirl around the separator body heavier water and the one that is suspended on the fins is thrown on the walls of the separator body.

The water from the separator body will flow down the vessel of the separator body and it will be drained to a steam trap that is installed under the unit, while the dry steam will leave the separator body through the outlet.

3. Coalescence-type steam separator.

The coalescence-type steam separator doesn’t have the fancy movements of steam inside the separator body.

It left that to the baffle and cyclonic steam separator.

The coalescence-type steam separator has a demister pad (wire mesh pad) connected to the inlet that is used to trap water molecules from the steam.

This type of steam separator is not that efficient compared to a baffle steam separator, so to enhance efficiency, the coalescence and cyclonic steam separator can be combined.

Working principle of coalescence steam separator.

The working principle of the coalescence steam separator is simple; it only involves a demister pad trapping the water molecules thus leaving the steam dry.

The dry steam will leave the separator body via the steam outlet while the condensate that was initially trapped in the wire mesh pad will drop down the separator body where it will be drained to the steam trap.

Advantages of using steam separators

1. Provides quality steam.

The steam separators are installed on the boiler output to ensure that the steam provided to the turbine or point of application is dry.

As we have seen, steam separators remove moisture from the steam and this clearly tells us that the steam will be dry.

Dry steam is a quality steam since it has high thermal energy compared to wet steam.

Steam separators can increase the overall efficiency of the steam produced by ensuring that the steam supplied to the points of application is dry.

And this is one of the advantages of installing steam separators in your steam boiler.

2. Reduces corrosion of the steam distribution system.

The steam separator removes moisture and leaves the steam dry as it goes to the point of application.

We all know that water is an active agent of corrosion.

By removing the moisture from the steam, steam separators save the steam distribution system from corrosion.

Which ends up prolonging the life of the steam pipelines.

3. Saves water.

The water that is drained to the steam trap can be reused in the preheated and be used in the boiler.

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The small volume of condensate can accumulate to gallons litres of water.

Instead of wasting that water with steam, this water can be of use in the steam generation process.

We can say that steam separators provide the economic usage of water.

Final thoughts

I hope you have learned something about the type of steam separators and how they operate.

It’s important to use steam separators if you want to produce steam of high quality.

I know when you think of the little things that have to be installed along with your steam boiler you are getting tired.

But all this will not be for anything because you will get to achieve the most out of your steam boiler.

If you have any questions about the topic just leave a comment and I will get back to you.

Thanks for reading, see you in my next article.