Pressure drop in the granular zone of a blast furnace is 300 mm of water per meter of the bed height. The bed permeability is 0.8 𝑚4. 𝑁-1. 𝑠-1. The volumetric flow rate of gas per unit area through the bed [in (𝑚3. 𝑠-1). 𝑚-2, rounded off to the nearest integer] is ______ . Assume Darcy’s law is applicable and g = 9.8 𝑚. 𝑠-1. Density of water = 1000 𝑘𝑔. 𝑚-3.