Heat Transfer Characteristics of Shuttle Kilns

Category: Industry News

Release Date: 2026-04-16

Summary: Inside a flame kiln, the products of combustion transfer heat to the articles primarily through convective and radiative heat transfer. 1) Convective heat transfer: the rate of heat transfer is directly proportional to the temperature difference between the flue gases and the articles, and to the 0.8 power of the flue gas velocity within the kiln;

Within a flame kiln, the products of combustion transfer heat to the articles being fired through convective and radiative heat transfer.
1) Convective heat transfer: the heat transfer rate is directly proportional to the temperature difference between the flue gas and the product, and to the 0.8th power of the flue gas velocity inside the kiln;
2) Radiative heat transfer: It is proportional to the difference in the fourth powers of the absolute temperatures of the flue gas and the product.
① From a heat-transfer perspective, increasing the temperature difference between the flue gas and the product is beneficial for enhancing heat-transfer efficiency;
However, it is detrimental in terms of creating a temperature difference between the interior and exterior of the product.
② Increasing the flue gas velocity can ensure that all the products in the kiln are heated uniformly and rapidly.
By employing high-speed, temperature-adjustable burners, the temperature difference between the flue gases and the products is minimized, while the flue-gas velocity within the kiln is increased by approximately tenfold compared with conventional burners. This not only ensures superior firing quality but also enhances heat-transfer rates, enabling the fastest possible firing cycle compatible with product specifications.
③ Modern intermittent shuttle kilns are equipped with high-speed, temperature-adjustable burners that inject combustion products into the kiln at extremely high velocities—exceeding 100 meters per second. As a result, the convective heat-transfer rate of the combustion products is significantly enhanced throughout the entire firing process;
Even during the high-temperature stage, convective heat transfer plays a significant role.
④ However, when using high-speed modulating burners, the product stack must be arranged in such a way as to leave a flame passage of 100–400 mm between stacks; typically, the width of this passage increases with the increasing width of the kiln.
It is preferable to establish a swirling airflow within the kiln to prevent high-velocity flames from directly impinging on localized areas of the ware, which could disrupt flame dynamics and lead to significant temperature gradients.

Keywords: Heat Transfer Characteristics of Shuttle Kilns

Related Information

Company News

Industry News

Previous entry: Characteristics of Tunnel Kilns

Next: Energy-Saving Methods for Shuttle Kilns

Submit