Industrial Engineering

Different types of furnaces 

A furnace, often known as a heater, is a device that uses the combustion of a fuel source to produce thermal energy in a controlled manner. This thermal energy is used to heat rooms, buildings, and other structures. In addition, some are employed to process specific materials in industrial and commercial settings.

It is mostly employed in central heating systems as a significant component. They are installed to supply heat to the interior space by the use of an intermediary fluid, such as air, steam, or hot water. In some regions, electric resistance heating is used, particularly if electricity costs are low or where the primary goal is air cooling.

A normal gas furnace is roughly 80% efficient, and modern furnaces can be up to 98 percent efficient and operate without a chimney. One thing to keep in mind about furnaces is that they come in a range of sizes, and not all of them are appropriate for all purposes.

industrial furnace

In this article, you’ll learn about 20 various types of furnaces used in industries today.

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Types of Furnaces

The various types of furnaces include:

  • Natural gas furnace
  • Oil furnace
  • Electric furnace
  • Propane furnace
  • Waste oil furnace
  • Wood burning furnace
  • Dual Fuel Furnace
  • Modulating furnace
  • Single-stage furnace
  • Two-stage furnace
  • Bell furnace
  • Box furnace
  • Forging furnace
  • Pit furnace
  • Quenching furnace
  • Rotary furnace
  • Salt bath furnace
  • Tempering furnace

Natural gas furnace

Natural gas furnaces are the most prevalent and oldest type of furnace. The major source of fuel is a naturally occurring gaseous mixture of carbon (C) and hydrogen (H). Because these furnaces do not wear out frequently, they are substantially less expensive to maintain. With proper care, it can endure up to 25 years.

Natural gas furnaces in your home save money on energy since they use the cheapest fossil fuels. Because it is the cleanest variety, pollution is reduced. It can also provide a lot of heat when burned, helping you to heat your home with fewer resources.

Oil furnace

An oil furnace, as the name implies, burns oil as a fuel source. The users of these types of furnaces must have a location to keep the oil and must also fill the tank regularly. The furnace will not operate if the tank runs out of oil.

While the furnace is simple to maintain, the accumulation of dirt and soot makes it expensive to run. These furnaces, on the other hand, have a 30-year lifespan and are less expensive than gas furnaces. Although current oil furnaces must have an AFUE rating of between 80 and 90 percent, they are not ecologically friendly.

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Electric furnace

Because electric furnaces do not require a gas line, they are the most common type of furnace. Electric furnaces are more expensive to run than gas or oil furnaces. Despite this, for a variety of reasons, these are more helpful to both customers and the environment. It’s also a more cost-effective and efficient option.

It usually comprises a cabinet that houses a blower motor and a heating coil (heat strips). An electric current travels through the heating coils when the thermostat calls for heat, causing them to become extremely hot. These can be found in the engineering, food, chemical, and laboratory industries, among other places.

Propane furnace

In a propane type of furnace, the heat is transferred to a heat exchanger by converting liquid propane into a gas in a propane furnace. Because propane does not require a gas line and can be used practically anyplace, it is the most popular variety. They’re a terrific option because of their advantages, such as being safer, more cost-effective, and warmer.

It can be set to use natural gas as an alternative in the event of a propane scarcity or a severe price hike. Propane provides more heat than other fuels when burned. As a result, it swiftly heats a home.

Waste oil furnace

For user convenience, waste oil types of furnaces utilize waste oil and convert it into efficient, free heat. Waste oil, such as discarded vegetable oil or automobile oil, is utilized in these furnaces because it can no longer be used for its original function.

As a result, it is regarded as a very environmentally beneficial gadget, as it recycles oil for disposal. These types reduce the expense and danger of transferring old oil away from your home. They also conserve space on the floor and might help you achieve a high return on investment.

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Wood burning furnace

Wood-burning furnaces are ideal for households, places where there is a plentiful supply of firewood. A solid metal closed firebox, often lined with firebrick, and one or more air controls are typical components of a furnace (manually or automatically).

In the same way, as gas furnaces emit heat, wood types of furnaces burned in a firebox emit heat that flows through the ductwork. However, even if you use wood pellets, these are of limited value because they must be physically fed and cared for regularly. They’re inconvenient, especially if there’s no one around when the furnace is on.

Dual Fuel Furnace

To improve comfort and economy, a dual fuel type of furnace combines an electric heat pump with a gas furnace and alternates between the two fuel sources. These furnaces are incredibly practical, as they can be used as gas furnaces in the winter and as heat pumps in the summer.

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These are known to be highly efficient in terms of energy use and cost-effectiveness once you get beyond the initial upgrading and installation costs. One disadvantage is that switching from a single-fuel furnace to a dual-fuel furnace may incur additional costs.

Modulating furnace

Even though modulating furnaces are more expensive, most people think they are worth it because they provide you more flexibility over your temperature settings and help you save energy. It regulates the amount of gas burned to ensure that the temperature on the thermostat is met.

As a result, it can more accurately indicate temperature. These types of furnaces likewise have lower energy requirements, yet they still provide adequate heat. In comparison to single-stage and two-stage furnaces, the modulating furnace is less efficient. Even so, it’s a great option for homes in places where winters are longer.

Single-stage furnace

A single-stage furnace, as the name implies, simply has an “on” setting. This type of furnace provides for a higher rate of gas flow and is meant to run at a steady speed. It is usually noisy. In terms of monthly cost reductions, it does not provide much heating.

These are ideal for lighter locations because they work at an annual fuel efficiency of 80%, which is sufficient to keep your home warm. However, because there is less technology involved in the process, it is less expensive to implement. Because these are so long-lasting, just minor furnace maintenance is required.

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Two-stage furnace

The two stages simply suggest that there are two levels of heat production: high for chilly days and low for mild days. Because it allows you more control over the flow of gas, it has more alternatives than a single-stage furnace.

It can adjust the power to the heating load’s demand and run at a 90 percent yearly fuel efficiency. The thermostat will send a signal when it cools down, which will automatically open the valve and start the furnace at full power. These types of furnaces have a prolonged heat cycle, which means hot air is distributed throughout your home to make it more comfortable.

Bell furnace

It’s an industrial-style furnace that’s often utilized for batch or intermittent procedures. This furnace type is utilized for heat treatment, but it can also be used for low-temperature sintering procedures. During vacuum or controlled atmosphere processes, the hood of this furnace can be raised and lowered repeatedly.

Tempering, annealing, normalizing, and stress relieving parts manufactured of steel plates are all done in this sort of furnace. This tool can be used with a variety of bases while still providing a secure seal. Bell furnaces have the advantage of being a safe and cost-effective heat treatment technology.

Box furnace

A vertical lift or swing-out door on a box furnace allows different-sized goods to be placed within. They are utilized in high-temperature thermal processes such as heat treatment, calcining, curing, annealing, stress relief, preheating, tempering, and others.

The box furnace can be used with either gas or electricity as a fuel source. Box furnaces are used in the laboratory and industrial settings to treat large quantities of material consistently. It comes in tight seal designs that provide excellent pressure management, allowing you to get the most out of your burners.

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Forging furnace

Forging types of furnaces are open-hearth furnaces that are primarily used for preheating and act similarly to a pizza oven. They use radiation to deliver heat to metals so that they may be forged or hardening processes can be stopped.

In heavy-duty forging furnaces, blooms, steel ingots, and other items are typically reheated. They can also be purchased in a forging box. The load charge and discharge may be easily adjusted in certain of these furnaces.

Pit furnace

A pit furnace is primarily used to harden and evenly heat metals such as steel. It’s also employed in metallurgical procedures when low temperatures are required. One of their distinguishing advantages is the ability to produce a variety of temperatures inside a safe and controlled work environment.

These come in a variety of sizes and can be used with either gas or electricity. These furnaces are commonly found in the fabrication of automobile and aerospace parts, as well as machine manufacturing, wind power, and mining.

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Quenching furnace

It’s an enclosed heating chamber that keeps low-temperature processes like phase transitions at bay. The main goal of this furnace is to prevent uneven heating and overheating, however after quenching, tempering techniques can be employed to increase hardness.

These types of furnaces provide stiff materials with rapid, controlled cooling. These furnaces are commonly used to process bearings, gears, fasteners, and agricultural machinery components. Electric and gas-powered versions are also available.

Rotary furnace

Rotary furnaces are batch furnaces with oxy-fuel burners that produce a limited quantity of off-gasses. During the heating process, these are usually installed on a barrel-rotating drive with a steel-welded barrel lining.

These types of furnaces provide heat homogeneity and good material contact since they are incredibly heated efficient and easy to press. They are available as gas or electricity, with the compressed combustion gasses flowing in the opposite direction. These are extensively used in calcination and oxidation processes.

Salt bath furnace

A salt bath furnace is a ceramic or metal container filled with molten salt in which work is heated or cooled. To obtain speedy results in metals, they use incredibly fast heating. Typically, these are electric, although they can also be gas-powered or heated outside using an electric unit.

They’re utilized for surface treatment that doesn’t involve carburization or salt nitriding, simple surface cleaning, or temperature changes that aren’t extreme. When necessary, the furnace may reach 2,350 degrees Fahrenheit.

Tempering furnace

It’s a sort of industrial oven used to harden ferrous metal products by heating them. Heat treatment of high-strength materials can alter the alloy’s formation and energy absorption.

To achieve a balance of flexibility and strength, tempering furnaces are used in conjunction with quenching furnaces. To accomplish the appropriate physical qualities, these furnaces maintain a constant temperature throughout the chamber. These types of furnaces can be of both gas and electric heating and can provide indirect fuel contact.

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Conclusion

Furnaces are mostly employed in central heating systems as a significant component. They are installed to supply heat to the interior space by the use of an intermediary fluid, such as air, steam, or hot water. The common types of furnaces have been explained above. I think that is all for this article, where the various types of furnaces are being discussed. I hope you get a lot from the reading, If so, kindly share with other students. Thanks for reading, see you around!