Ashing is the process of expelling organic material from a sample before it is analyzed. For ashing to take place, complete combustion of the sample is critical to yield accurate results, and this requires the use of an ashing furnace. However, because there are many different applications of ashing, there is no standard model for ashing furnaces and they often have to be purpose-built.

Key Aspects of Ashing Furnace Design

Ashing furnaces are used to quantify the change in weight from a sample as one or more components are burned away. When choosing an ashing furnace, it is necessary to consider if it will be used in one specific process or if it will also be used for general heat treatment applications. Some ashing furnaces will also need to adhere to strict testing standards or be exposed to fumes which could damage the furnace or create a health hazard. The furnace must also be chosen with sample size and potential contamination risk in mind.

Ashing furnaces employ controlled airflows and high-temperature heating elements, making them well-suited to burning samples in air at controlled rates. This helps them to precisely calculate the volume of incombustible compounds which are present. This means the heating chamber atmosphere must be meticulously controlled by the use of air metering and exhaustion to allow for numerous air changes per minute.

The ashing furnace’s consist heating element is used to combust material inside an enclosure and often a weighing scale which are used for weighing materials before, during and after combustion.

Ashing Furnace Applications

There are many industries in which understanding the incombustible content of a sample is of critical importance. Ash content can be employed in nutritional evaluation of food goods and it is also frequently used in the petroleum industry. As they are being used for quality control and compliance and in these applications, ashing furnaces are an optimal analytical solution.

In the food science industry, ashing furnaces are used to estimate the mineral composition of food samples as an initial step in further elemental analysis. A sample is put in the heating chamber of an ashing furnace and heated to temperatures of around 600 C (1112°F) in a flow of oxygen. Whilst the sample burns, the incombustible elements convert to oxides and sulfates. This means that the mineral concentrations can be quantified based on the content of dry-weight ash.

In the petroleum industry, ashing furnaces are used to test petroleum-based products and crudes. These products are intended to be combusted in their application, so incombustible contents are not desirable. Compounds that are incombustible may be harmful to equipment or possibly pollutive to the atmosphere.

At Thermcraft, our ashing furnaces are designed to offer ideal conditions for complete combustion of test samples. Our furnaces are customizable with optional upgrades such as the inclusion of profile programming, data acquisition and communications in the SmartControl. Our ashing furnace also has an adjustable air flow meter which can be used to reduce or increase air flow rate along with many other options which are available on request. If you have any questions, contact us today.