Calculate the clean bed head loss for the given conditions: temperature = 10 °c, flow rate = 4 mm/s, media is sand with sphericity of 0.8, fixed bed porosity of 0.43 and total depth = 0.90 m. use kozeny equation, but check to ensure that the reynold’s number is acceptable. assume uniform porosity with depth (a good assumption) and thus, the depth of each layer is proportional to the weight fraction.