School of Chemical and Metallurgical Engineering University of the Witwatersrand, Johannesburg CHMT 2023/4A Assignment 3 Answer ALL questions. You are not allowed to consult anybody while completing this assignment. The lecturer and tutor will help with the theory involved but will not give specifics for the assignment. Read the problem below and understand as much as possible before logging in to Ulwazi. Make sure you know how to do this problem BEFORE attempting to submit. You will have 1 hour once you log into Ulwazi (Quizzes) and 1 hours to submit on Gradescope. Once you click in Ulwazi, you will have to submit (only one submission allowed). Further clarification instructions may be given in the dedicated discussion. Look there before asking. Water flows through a 30 cm rotameter (Type A) with an internal diameter of 22 mm at the top and 18 mm at the bottom. The float has a diameter of 18 mm, a volume of 7.5 cm3 and a specific gravity of 5. The flow through the rotameter is 500 l/hr. a) Calculate the area of the annulus assuming CD is 0.98 and A2/A1 =0 [3] b) Recalculate the area of the annulus when A2/A1 <> 0; DO NOT assume a constant CD value. What value of CD did you use in the calculation. [6] c) What error (as an absolute percentage) do you find when comparing your answers above – (a) vs (b)? [1] Give your answer in (a) and (b) square millimetres Use a value of 9.81 for the gravitational constant and 1000kg/m3 and 1 cP respectively for the density and viscosity of water.
