How a Crematory Furnace Works: The Complete Guide to Cremation Technology

Cremation is an increasingly widespread process, both for people and for companion animals. However, being a technical and sensitive subject, it is often surrounded by doubts and questions. How does a cremation oven work in detail? It is important to clarify from the outset that this is not a simple oven, but a sophisticated technological system designed to guarantee maximum efficiency, total respect for dignity, and full compliance with environmental regulations.

In this article, we at Fortec, an Italian company leader in the design and construction of cremation and incineration plants, explain the entire process step by step, analyzing the technology behind its operation.

What is a cremation oven and what types are there?

A cremation oven, or more properly a cremation plant, is a high-tech thermal system specifically designed for the reduction of human remains or animal carcasses. Its purpose is to manage a controlled, safe, high-temperature combustion process, at the end of which only inorganic bone remains are obtained.

The technology varies significantly according to its intended use. In fact, there are two main categories of cremation ovens:

• Cremators for human remains: Intended for cemetery use, subject to extremely strict health and emission regulations.
• Cremators for animals: Intended for veterinary clinics, pet cemeteries or specialized centers, with different specifications for the management of companion animal remains.

Although the thermal principle is similar, regulations, dimensions, management software and operational capacities are profoundly different.

The operation of the cremation oven explained in 5 stages

To truly understand how a cremation oven works, it is useful to break the process down into its 5 main operational phases. This allows us to dispel some myths and focus on the technology.

1. Preparation and introduction

Before each cycle, the facility is brought up to an ideal operating temperature (preheating phase). This is essential to ensure a quick, efficient process and, above all, to minimize the production of transient emissions. Once the temperature has been reached, the coffin (or animal remains) is introduced into the primary chamber through an automatic loading system, designed to guarantee operator safety and respect for the deceased.

2. The primary cremation chamber (Combustion)

This is the heart of the process. The primary chamber, maintained at high temperatures (generally between 850°C and 1000°C), initiates the combustion process. It is important to emphasize that the main burners do not burn the body directly, but are designed to keep the chamber at the correct operating temperature. The combined action of heat and oxygen (air blown in a controlled manner) triggers and sustains the combustion.

Modern facilities, such as our Mod. FT cremators, are equipped with advanced software and sensors that automatically manage air intake and burner operation, optimizing consumption and ensuring a perfect process.

3. The post-combustion chamber (Smoke purification)

This is the crucial phase for environmental protection and answers the question: "Do cremation ovens pollute?" The gases produced in the primary chamber are not released into the atmosphere. They are routed to a second chamber, called the post-combustion chamber (or secondary chamber).

Here, the fumes are maintained at even higher temperatures (often above 900°C) for a defined residence time (usually > 2 seconds). This process ensures the total thermal destruction of any volatile organic compound or odor, resulting in emissions into the atmosphere that are clean, odorless, and compliant with the strictest European regulations. Downstream from the afterburner, to complete the purification of exhaust gases, additional abatement systems are installed, such as wet or dry filters, depending on where the plant is located.

4. Cooling and collection of remains

At the end of the primary combustion, what remains are not ashes, but mainly calcified bone remains. The plant initiates a controlled cooling phase. Once a safe temperature is reached, the remains are collected and transferred to a dedicated area or container for the next stage.

5. Final treatment: pulverization

The collected bone fragments are not yet ready for the urn. To obtain the fine consistency commonly associated with "ashes", these remains are processed in a specific piece of equipment: the cremulator, a pulverizer that reduces the fragments into a homogeneous powder, ready to be delivered to the family in the urn.

Key differences: cremation ovens for people vs. animals

Now that we have seen how cremation ovens work in general, it is useful to understand the differences.

• Cremation of human remains: Focused on the dignity of the process, handling one coffin at a time, and complying with strict health and emission regulations. The Fortec Mod. FT facilities are designed for this purpose, with advanced control systems and the potential for energy recovery for district heating.
• Animal cremation: These facilities must offer greater flexibility. The Mod. FIDO animal cremators and FD model cremation ovens, for example, are designed to handle both single cremations (to return the ashes to the owner) and multiple cremations, optimizing management costs for veterinarians and specialized centers.

Fortec technology: efficiency and respect beyond simple operation

Understanding how a modern cremation oven works means addressing advanced software, energy efficiency, remote assistance, and filtration systems. A plant is not only about "heat", but about an integrated system. The advantages of Fortec systems translate into:

• Low consumption: thanks to top-quality refractory materials and management software that optimizes each cycle.
• Reliability and Assistance: remote assistance and monitoring systems allow our technicians to intervene in real time.
• Sustainability: full compliance with environmental regulations and, in the case of cremators for human remains, the concrete possibility of recovering the produced heat.

Frequently Asked Questions (FAQ) about the operation of cremation ovens

How long does a cremation process take?

The combustion phase in the primary chamber generally lasts from 1.5 to 2 hours. The duration varies greatly depending on the type of facility, body size and type of coffin. To this time should be added the pre-heating phase (if the facility is cold), cooling and pulverization.

Do cremation ovens pollute?

No, if they are modern and properly maintained facilities. As explained, the presence of the post-combustion chamber and, where necessary, additional filtration systems eliminate pollutants and odors, making emissions clean and well below legal limits.

What remains after cremation?

Contrary to what one might think, there is no ash (like that from wood or paper). The high temperatures consume all organic matter. What remains are the inorganic components, i.e. calcified bone fragments. These are then reduced to a fine powder by the cremulator.

What temperatures does a cremation oven reach?

Operating temperatures are very high to ensure a rapid and effective process. The primary chamber usually operates between 850°C and 1000°C, while the post-combustion chamber exceeds 900°C to ensure perfect purification of fumes.

Conclusion: technology at the service of respect

Understanding how a cremation oven works reveals a technologically advanced, safe, controlled and environmentally friendly process, far from what people commonly imagine. Today, the real difference is not only made by heat, but by the construction quality, reliability of the control software and full compliance with regulations.

Are you a professional looking for an efficient, reliable and cutting-edge facility? Discover the full range of Fortec cremation ovens or contact our Technicians for advice tailored to your needs.