Low-Cost Radiant Heater for Rapid Response, High-Temperature Heating

High-temperature processing has an irreplaceable role in many research and industrial applications. Despite remarkable development spanning over a century, the pursuit of even higher thermal flux density and more rapid thermal transients has not slowed down. As part of the ongoing energy evolution, many industrial applications are transitioning from direct combustion of fossil fuels as primary energy sources to increasing electrification, capable of adapting to renewable power grids. Thus, there is an emerging need for electrical heaters that can replace burners and supply the heat demand, especially at the highest temperatures. In this study, we report on a radiant heater design that can achieve cyclic heating/cooling rates of up to 400 K min–1 and a temperature range in excess of 1,800 K, comparable to those of commercial infrared gold image furnaces, at high surface and volumetric power densities. The heater consists of a modular unit of incandescent tungsten filament and is enclosed in an evacuated ceramic envelope, chemically inert, tolerant of thermal shock, and impervious to gasses. The material and manufacture cost of such heaters, which is estimated at ∼$0.05/W, is less than 0.03% of that for infrared gold image furnaces, which is at >$2/W. Tests of more than 10,000 demanding cycles (high temperature and high heating/cooling rate) over 350 h of total operational time and in different temperature ranges confirm the robust performance of radiant heater prototypes. The design is widely applicable to high-temperature reactor and furnace designs. In thermochemistry research and practice, these radiant heaters could offer multiple benefits compared to solar simulators, lasers, infrared gold furnaces, ceramic heaters, or direct concentration of solar input.

Evaluating Radiant Heater Performance Using Chick Thermal Preference and Spatial Analysis

HighlightsRadiant heaters from different manufacturers with the same power output do not produce the same radiant distribution.Heater net usable area is influenced by heater elevation and chick preferences for radiant flux.Radiant heaters should be operated at manufacturer specified elevations to minimize potential reductions in performance.Abstract. Radiant heaters are the most common method of providing supplemental heat in broiler houses, but little is known about how efficiently they create a suitable thermal environment for brooding chicks. This study investigates the net usable area (NUA), or the total floor area within the range of radiant flux preferred by chicks, for six round radiant heaters with a nominally rated power output of 11.72 kW. NUA was calculated for all heaters at three manufacturer specified heights 1.52, 1.83, and 1.98 m and at a distance 0.3 m below manufacturer specified height (1.22 m). NUA ranged from 11.6 ± 0.7 m2 to 59.4 ± 19.7 m2 and increased with heater mounting elevation. Results indicate that radiant heaters from different manufacturers with the same power output do not produce the same NUA. NUA was also shown to be higher at 8 d than 1 d for all heaters and was attributed to the decrease in chick preference for level of radiant flux during the first week of brooding. NUA gross radiant coefficient (GRC), or the proportion of the heat energy in the fuel that reached the floor and was within the thermal comfort range of the chicks, did not exceed 0.37 for any heater and decreased with heater elevation. Operating a heater below the manufacturer specified mounting elevations led to reduced NUA and an overall less efficient use of fuel. Keywords: Broiler chicks, Brooding, Net usable area, Radiant heaters, Thermal preference.

Failure Analysis of Tube Radiant Heater Hot Oil in Refinery Industry

Heater, known as a furnace or fired heater is used to heat the oil which flows through tubes around a flame. When the tubes are failed, the fired heater reliability is affected. This paper investigates the probable cause/ causes of the radiant tube failure in the fired heater. In that context, depth analysis is conducted as part of the investigative studies, involve visual observation and dimensional measurement, metallographic examination, and chemical analysis. Finally, it has been concluded that the tube radiant has mainly failed due to crevice corrosion. In the other side, spherodization and external corrosion are also found as other failure contributors.