Build it from the parts:
鼓 (gǔ, to drum/blow) +
风 (fēng, wind) +
炉 (lú, furnace) — literally 'wind-blowing furnace', i.e. forced-air furnace. In modern industrial Chinese, the more usual term is
高炉 (gāolú, lit. 'tall furnace') for a steel-mill blast furnace;
鼓风炉 covers the broader category and historical/smaller furnaces.
