Reducing the Cost of Pumping High Viscosity Fluids for Jordanian Industry

Abstract

All industrial facilities have a network of piping that carries liquids. The frictional power required is dependent on rate of flow, pipe size (Diameter), overall length of pipe, pipe characteristics (surface roughness, material, etc.) and properties of the liquid being pumped. Heating high viscosity liquids leads to drop in their viscosity. As a result,    pressure loss resulting from friction deceases, and these pressure losses result in low cost of pumping. But nevertheless, the heating operation demands additional cost that increases progressively with the increase of    heating temperature degree. This paper aims to find out the effect of heating temperature degree on cost of pumping and heating, and eventually on the total cost (heating plus pumping). In addition, the paper aims to confirm whether there is an optimal heating degree t_opt appropriate to the minimum total cost ?C_min, and to see what the values and facts affecting the value of the minimum cost are. For this purpose, a commuter program has been prepared based on the flow chart of the operation procedure overviewed in this paper. Calculations carried out by the computer show the effect of price change of electrical energy $/(kW.h) on the optimal heating temperature degree, and the  effect of the price of steam generation  demanded   for the heating operation,  $/kg on the optimal heating temperature degree as well , in addition to the effect   of flow rate change of  the liquid which will be pumped, kg/s. The results also show that the heating optimal degree occurs at the transitional moment from laminar to turbulent flow. When checking the effect of diameters of the used pipe on the optimal heating degree, the results have given a new concept that is termed as “the critical diameter”, the exceeding of which makes the heating operation a factor that contributes to increase of total cost, ?C but not the opposite. The optimal heating degree appropriate to the minimum total cost (heating plus pumping) only occurs when diameters of the pipes used are less than that of the critical diameter. The study carried out  on sugar syrup shows that the critical diameter of pipes is d_cr=0.046 m, the  exceeding of which will not cause  decrease in the expected total cost of   the heating operation , and the   optimal heating degree  can not be achieved. When the diameter of the pipes used is  less than that of the critical diameter by 15mm, the total cost drops 1.5 $/hour with the heating temperature degree  increases from 20-29°C when the   liquid flow rate is   6 kg/sec ,  the electrical energy price is  0.081 $/kW/h , and the demanded steam price is 0.0055 $/kg. The effect of the liquid flow, electrical energy price, and diameters of the pipes used on the  optimal heating degree and the critical diameter  are overviewed in this paper.