Introduction
Inside metals manufacturing, furnaces are extensively used to heat substances to high temperatures. This then enables the chemical reaction of the metal materials to take place as needed. Furnaces come in different shapes and sizes and use different ways of providing heat energy. Many furnaces require an oxygen supply to function. An oxygen enriched atmosphere within the furnace is essential for raising the combustion temperature in the furnace. In smaller furnaces, the oxygen which is introduced is usually done through the combustion of natural gas, petrol or light diesel. This, however, needs careful consideration when selecting the pipe size, oxygen output, ignition type and locations to resolve the issue of providing sufficient oxygen for complete combustion.
This article will focus on providing an overview of the different ways in which oxygen can be supplied to a rotary furnace and an assessment of which of the approaches is best suited to the goals of achieving sufficient oxygen exchange and efficiency. The paper analyzes the pros and cons of each of the available oxygen supply systems, providing a critical evaluation of each of the various approaches.
Combustion Gases
The combustion gases approach is the most commonly used when providing oxygen in furnaces. This is the least expensive and simplest way of supplying oxygen to the furnace. The approach works through the burning of hydrocarbon fuels and a sufficient amount of air in the combustion chamber of the furnace. The combustion of the fuel produces a mixture of nitrogen, oxygen and carbon dioxide. The amount of oxygen produced is directly proportional to the amount of fuel used, with more fuel burning producing more oxygen. The hot gases produced are usually around 800–1000°C and are directed towards the furnace where the heat energy is used to heat the materials. This approach is best suited for both small and large furnaces, and can be easily adjusted to provide a specific oxygen concentration and fluxes in the furnace.
The advantages of this approach include its low cost and flexibility in terms of adjusting the oxygen levels to meet specific needs. It is also relatively easy to implement and maintain. The main disadvantages are that it produces large amounts of heat, which can be a problem in smaller furnaces, and can cause energy losses due to the hot gases. In addition, the process produces large amounts of nitrogen and can be difficult to control in terms of output.
Liquid Oxygen
The second approach to providing oxygen is through the use of liquid oxygen. This is generally only used in larger furnaces as it is more expensive than the combustion gases approach and requires a specialized delivery system. The delivery system works through the delivery of cryogenic liquid oxygen from tanks to a set of pumps which limit the flow rate, distribution flow rate and pressure for adding oxygen to the furnace.
The main advantage of this system is its high efficiency, as it delivers precise and consistent amounts of oxygen to the furnace. It also produces little heat and has very low energy losses. The main disadvantages are that it is more expensive to implement than the combustion gases approach and also requires specialized knowledge and equipment to set up and maintain.
Gas Injection
Gas injection is another option for providing oxygen to a furnace. This approach is generally used in larger furnaces and consists of the delivery of a mixture of nitrogen, oxygen and helium. This mixture is injected into the furnace at a set rate and pressure which is controlled by a set of valves. The advantage of this system is that it can provide precise oxygen delivery with very little heat and energy losses. The main disadvantages are that it requires complex equipment and is more expensive than other methods.
Sanosil
Sanosil is a system that has been developed to provide oxygen to furnaces in an automated, precise and economical way. It consists of a control panel which is connected to a sensor that detects the oxygen concentration in the furnace. This information is then used to activate the delivery system, which consists of a nozzle designed to inject oxygen directly into the furnace.
The advantage of this system is that it is highly automated and requires no manual intervention. It provides precise oxygen delivery with very low energy losses and is highly efficient. The main disadvantage is that it is more expensive to implement than other systems.
Conclusion
Providing oxygen to a rotary furnace is an important part of ensuring efficient and effective combustion. The different methods outlined above each have their own pros and cons, and which option is best suited depends on the specific needs of the furnace. The combustion gases approach is the least expensive and simplest way of supplying oxygen to the furnace but it produces large amounts of heat and is not as efficient as the other methods. Liquid oxygen and gas injection are more efficient but require specialized knowledge and equipment to set up and maintain. Sanosil is the most efficient and automated approach but is more expensive to implement.
