Overhead Condenser: The Ultimate FAQ Guide

In this guide, you’re going to learn everything about overhead condensers.

Among the things you will learn here include design options, energy balance, calculating residence time, and increasing efficiency, just to mention a few.

Keep reading to learn more.

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What is an Overhead Condenser?

The overhead condenser is a type of heat exchanger that cools down vapors using streams of coolants such as water.

 Overhead condeser system

Overhead condenser system

How Many Design Options of Overhead Condensers are There?

You can arrange the overhead condenser using a series of multiple design options depending on the process objectives.

Here are the main arrangement or design options of an overhead condensing system that you can choose from.

· Boiling Under Reflex Standard Design

In this design, you will include the coil heat exchanger that will lead to an uprising form of condensation.

Here are the main benefits associated with the boiling under reflex standard design.

i. It maximizes the rate of reactors vaporization with minimal subcooling.

ii. It has a coil condenser with very low pressure drops

iii. The coil condenser is also self-baffling and eliminates the flat surfaces for clean in place

iv. It has angle orientation that you can use for restricted height installations

· Boiling Under Reflux Distillation with Tube and Shell Heat Exchangers

In the tube and shell heat exchanger design, you will have similar characteristics in operation as well as benefits of coil style condensers.

You will, however, use this standard design in large condenser or reactor duties.

In addition to that, you can use it for low height requirement options.

· Distillation with Phase Separation Standard Design

You will use this arrangement when you have distillates that form 2 phases just as distillates.

For instance, you can use it in water removal in esterification, heterogeneous, and hydrodistillation azeotropes.

It uses the phase separator to adjust the interphase and separate withdrawal of heavy and light phase.

· Vacuum Distillation Standard Design

Here, the vapors will flow downwards through a condenser thus maximizing subcooling and eliminate distillate revaporization.

You will provide it with additional tubing or piping on the receiver to facilitate multiple cuts under the vacuum.

One of the benefits include the provision of low pressure drop that allows high vacuum levels in the reactors.

· Rectification Standard Design

In this case, you will use a packed column with reflux dividers between the condensers and the reactors.

It will enable the separation of volatile substances with close boiling points through rectification and problems of separation at particular heights.

You will realize the following benefits by using this design:

i. The glass column will allow you excellent visual confirmation of the performance within the column.

ii. The glass surface of packing and column has perfect release characteristics.

How Do You Size the Overhead Condenser?

You will size the overhead condensers through a detailed procedure after defining all the parameters.

In this case, you will size your overhead condenser by looking at the size of the glass lines steel reactor.

In other words, there are different sizes of overhead condensers that you can choose from.

This will, however, depend on the technical specifications or the application requirements.

Which Factors Influence the Cost of the Overhead Condenser?

Overhead condensers are available for you to choose from according to your application requirements.

Since there are different application specifications, you are bound to find different types of overhead condensers.

Apart from that, there are different standard designs of the overhead condensers which also affect the price.

You have the liberty of deciding on the best quality of overhead condenser but that will cost you more.

In general, the cost of overhead condensers will cost you between 20,000 to 250,000 US Dollars.

Which Accessories Do You Use Alongside the Overhead Condenser?

Over head condenser system

Overhead condenser system

You will use the overhead condensers alongside other types of accessories to facilitate proper heat exchange.

Here are the main accessories that you will use alongside the overhead condensers.

  • Reflux Overhead Column
  • Feed Preheater
  • Reboiler Steam Column Bottom
  • Off Gas Overhead Accumulator
  • Distillate Product Overhead Accumulator
  • Colum Feed

What are the Possible Problems that Would Affect the Overhead Condenser?

There are particular disturbances that can affect the smooth operations of the overhead condensers.

Here are the main problems that you should be aware of.

· Fouling of Heat Transfer

There are particular situations when there might be fouling of heat on the surfaces of the overhead condensers.

This might lead to the development of other issues within the overhead condenser units such as leaking problems.

· Loss of Fuel Oil and Gas

You might also experience losses in fuel gas or oil due to a trip in the low fuel gas pressure thus affecting normal functions.

You can sort this by fixing the trip that causes low pressure within the overhead condenser.

Apart from that, you can also check the fuel gas and oil levels then fill them up in case the levels are down.

· Loss of Power Supply

There are situations when you have no power flowing through the overhead condenser thus leading to machine failure.

You should inspect the power system with the help of an electrician to ascertain the source of the problem.

As soon as you get the problem, you should fix it and confirm that the power is flowing to the condenser.

· Pump Failure

You might also note that the pump fails to deliver the gas due to an overload trip, cavitation or loss of power.

In this scenario you should balance the systems to avoid cases of overload trips and then fix the electric supply system.

· Feed Changes

You might see differences in the normal feed supply with excess or lower feed rates, lower boiling components, and contaminations.

Here, you will have to clean the entire system and make it a habit with a proper cleaning and maintenance schedule.

In addition to that, you will control the supply systems from the control panel and fix leaks in case of any.

What is the Material Balance Loop in Overhead Condensers?

In the overhead condensers, there are material balance loops that affect the whole process.

Here are the main material balance loops that you should pay close attention to.

i. Feed Flow Control Loop

You will use the feed flow control loop to set the throughput such as the rate of production.

ii. Bottom Level Control Loop

Here, you will use the bottom level control loop of the overhead condenser to control column levels.

iii. Accumulator Level Control Loop

You will use the accumulator level control loop to regulate the flow of the products through regulation of the overhead accumulator.

iv. Off Gas Pressure Control Loop

In this case, you will be controlling the column pressure using the off-gas pressure control loops.

What Does the Energy Balance Control Loop Consist Of?

The energy balance control loop consists of control units that you will use to control the energy balance.

Here are the main control systems that you will use for energy balancing.


 Overhead condenser

· Temperature Control Loop

You will use the temperature control loop to control the column bottom temperatures through steam input controls.

· Feed Control Loop

In this case, you will control the feed inlet temperatures using the feed control loops.

· Overhead Condenser Temperature Control Loop

Here, you will use the overhead condenser temperature control loop to control the energy balance within the overhead condenser.

· External Temperature Control Loop

You will use this particular type of control loop to control the temperatures right at the top of the column.

What are the Components of the Overhead Condenser?

The overhead condenser works with the help of the constituent components.

You will depend on the components of the overhead condensers to create the overall effect of condensation.

Here are the main components of the overhead condensers that you have to know about.

· Inlets and Outlets

Inlets are pipes that carry in cooling water and vapor which you intend to cool down.

It also has outlets which are pipes that will carry out the cooled vapor from the system.

The cooling water will also remain in circulation bringing cool water that will absorb the heat.

· Control Loops

You will use the control loops to control the flow of energy such as temperature throughout the overhead condensers.

The control loops will also assist in the control of materials that you need for the whole cooling process of vapor.

· Reflux Drum

You will use the reflux drum to provide the vapors with enough residence time for the water to eliminate the heat.

Reflux drums are available in different capacities capable of handling different amounts of vapor.

· Pressure System

This is the part of the overhead compressor which will control the amount of pressure that the condenser needs.

It is capable of increasing and decreasing the amount of pressure in the overhead condensers to suit the application requirements.

· Electrical Unit

The electrical unit is the part of the overhead condenser that will supply the electric power for operating the machine.

It also has various components that will assist in controlling the electric flow within the overhead condensers.

How Does the Overhead Condenser Work?

Well, overhead condensers are responsible for the elimination of heat from vapors thus cooling them down.

The whole process begins from the top of the distillation columns which will the source of the vapors.

At this point, the vapors are very close to the initial dew points containing both light and heavy components.

Apart from that, the vapors contain a lot of heat that you will eliminate using the overhead condensers.

The vapor will flow straight to the overhead condenser through the inlet section and into the reflux drum.

While in the reflux drum, the vapor will go through a series of cooling and separation with the help of cooling water.

Implying that the overhead condensers have multiple pipes in loops that carry in cooling water for cooling purposes.

While in the reflux drum, the overhead condenser will apply a coolant stream of water that will cool down the vapor.

Since the vapor is very close to the initial dew point, it will start by condensing the heavy component vapors.

The light component within the vapor will still remain in the original vapor phase.

You will then proceed to eliminate the heavy components through the outlet as you proceed with the cooling process.

In case of vapor residues, you will have to recycle the vapor back to the top of the distillation column.

Do You Supply Custom Overhead Condensers?

Absolutely, we do supply custom overhead condensers according to the specifications of the customer.

Implying that you will provide us with the details of the kind of overhead condenser that you would like to have.

After that, we will look at your design and test the applicability of the design and the desired outcomes.

With the help of our designers and engineers, we will make the necessary adjustments after thorough consultation with our customers.

Finally, we will proceed with the manufacturing process of the overhead condensers with the assurance that it will work perfectly.

What is Residence Time in the Overhead Condensers?

Residence time is the period that a particular fluid or substance will spend inside a particular apparatus.

It is the period that the fluid will take inside the apparatus while going through normal continuous processing.

Overhead conderser

 Overhead condenser

How Do You Calculate Residence Time in the Overhead Condenser?

You can calculate the residence time of fluid in the overhead condensers using different calculation methods.

The simplest method that you can use is the division of the fluid volume by the flow rate of the fluid through the vessel.

What is the Significance of Residence Time in the Overhead Condenser?

The residence is very important as it will provide the fluids enough time to complete the whole process entirely.

In the overhead condensers, residence time signifies more time for the vapor to condense and separate into various constituent parts.

The higher the residence time, the higher the degree of separation, conversion, and heat transfer in the overhead condenser.

Apart from that, the high residence time is an indication of bigger equipment and running time thus higher operational costs.

Which Factors Affect the Residence Time in an Overhead Condenser?

There are quite a number of factors that affect the residence time in different applications.

Here are the main factors which you should know about as you talk about residence time.

· Vessel or Equipment Size

You will realize that the bigger the size of the vessel, the higher the residence time the fluid spends in the vessel.

· Shape of the Vessel

In this case, the higher the irregularities I shape of the overhead condenser, the more the residence time.

· Flow Pattern

Here, you will look at the flow pattern of the fluid within the overhead condenser.

Radial flow patterns take a shorter period within the vessel while swirling flow patterns increase the residence time.

What is the Difference Between a Partial Overhead Condensation and a Total Overhead Condensation?

Well, you can use the overhead condenser to perform two main forms of separation or condensation.

In other words, you can either have partial overhead condensation or total overhead condensation.

Partial overhead condensation occurs when you separate the heavy components of vapor from the lighter components.

As soon as the heavy components are separate from the light components you will send the mixtures to the reflux drum.

You will perform this function using the partial overhead condensers.

On the other hand, you will condense vapor completely separating the components into lighter and heavier components.

As soon as the separation and condensation is complete, you will take them out as two distinct products.

At that point, the vapor that remains in the overhead compressor unchanged will go back to the distillation column.

You will perform this function entirely using a total overhead condenser.

Apart from the Overhead Condenser, What Other Types of Heat Exchangers are There?

There are quite a lot of mediums that you can use in the transfer of heat from hot fluids to cold fluids.

Just like the overhead condenser, you will use other types of heat exchangers to help in the process of heat transfer.

Here are the main types of heat exchangers that perform similar functions as the overhead condenser under varying circumstances.

  • Plate and Frame Exchangers
  • Spiral Heat Exchangers
  • Plate-fin Heat Exchangers
  • Air Coolers
  • Double Pipe Exchangers
  • Tube and Shell Exchangers

How Does the Overhead Condenser Compare to the Reflux Accumulator?

You can use the overhead condenser and the reflux accumulator for the purpose of cooling and separating different fluids.

Despite the similarity, there is a difference between the two in terms of working principles.

Here is a comparison between the overhead condenser and the reflux accumulator.

· Overhead Condensers

Overhead condensers are types of air-cooled fin-fan heat exchangers that cool overhead gases and condense the steam to form water.

· Reflux Accumulators

On the other hand, the reflux accumulator is a type of separator that you will use to separate acid gases from condensed water.

It will accumulate and return the water back to the striper as one of the bi-products as reflux.

What Can You Do to Increase the Efficiency of the Overhead Condenser?

Well, there is a very elaborate procedure that you can follow in o0rder to increase the efficiency of the overhead condenser.

Among the daily operations, here are a few things that you must perform to increase the efficiency of overhead condensers.

· Proper Performance Record Keeping

You will keep records on the performance of the overhead condensers on a daily basis.

In case of a problem with the overhead condenser, you will be able to identify it through the records.

You will also know the things that you can perform in a bid to increase the efficiency of the overhead condensers.

· Inspecting the Overhead Condensers

In addition to that, you must also inspect the overhead condensers on a regular basis.

Frequent inspection means checking out every part of the overhead condenser in order to identify faults.

As you insect the machine, you should note the key areas that will require proper maintenance when the time comes.

· Cleaning and Maintaining the Machine

Yu must have a cleaning and maintenance schedule where you will clean all the parts of the overhead condenser well.

Apart from that, you will perform routine maintenance of lubricating the moving parts in order to reduce friction.

You must also fill the oil and water reservoirs to ensure constant supply of the said resources.

· Treating the Fluids

You will also ensure that you treat the fluids on a regular basis to get rid of the contaminants.

Getting rid of the contaminants will mean getting rid of the possibility of mold growth within the pipes and tanks.

How Do You Choose a Good Overhead Condenser?

You will choose a good overhead condenser by looking at the key specifications of the overhead condensers.

Here are some of the factors that you will look at when choosing an overhead condenser.

Overhead condeser

Overhead condenser

· Capacity of Operation

You will look at the capacity that the overhead condensers can comfortably handle.

In this case, you must match the capacity of the overhead condensers with application requirements.

· Type of Materials

You will choose your materials through a proper examination of the properties of the material.

The materials must have the capability of withstanding high pressure and temperature.

In addition to that, it must have the capability to resist corrosion as overhead condensers work with sensitive fluids.

· Dimensions of the Overhead Condensers

In this case, you will look at the dimensions in terms of the size of the overhead condensers.

In case you have a big scale of operation, you will have to purchase an overhead condenser that is big enough.

· Temperature and Pressure Ranges

You must also look at the temperature and pressure range that you will be working with in your specific operations.

In this case, you must choose an overhead condenser that is capable of containing the wide pressure and temperature ranges.

Depending on your specific needs, FilSon Filters offers a range of overhead condensers with varying performance.

Contact us today for all your overhead condenser needs.

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