Thermal System Design for Sulfuric Acid Dilution Device - A Case of Awash Melkassa Aluminum Sulphate and Sulfuric Acid S. Co

Abstract

Preparation of the diluted sulfuric acid not only causes chemical burns, but also secondary thermal burns because of dehydration. However, the domestic acid company only supply the (98-98.5 percentage) of concentrated sulfuric acid to the customer. Thus, customers have no choice, and manually dilute the concentrated sulfuric acid at home while they face the problem of strong acid dilution hazards. In response to this problem, the main objective of this thesis is to design an acid dilution system of capacity that delivers (1 97 ⁄%) diluted acid concentration. The main components of the system are pipelines, heat exchanger, storage tanks, pumps, mixing device, valves and fittings. The method used for developing the overall conceptual design of the acid dilution system is inferring the existing worldwide acid dilution system experience using solid work 2016 for modelling and mathematical investigation, and M.S Excel 2016 for iteration. The required flow rate of both concentrated sulfuric acid and diluent water is calculated for each output concentration, and the heat load as well as final temperature during dilution is determined and validated. Considering the allowable velocity and surface roughness for each material as the design variable with two conflicting objectives of pressure drop and pipe diameter over each output concentration, among the seven recommended concentrated sulfuric acid pipe materials the carbon steel is selected. Moreover, stainless steel is used for diluent and cooling water piping and the appropriate dimension of the pipe is determined. In addition, the size of tank capacity per day with time is determined using a simple finite difference method. Moreover, other auxiliary system equipment’s, like pump, static mixer, valve is selected as per requirement.