Vol. 11 No. 2 (1996)

This paper concerns with comparison of various heat transfer equations which can be used in the design of a shell and tube heat exchanger for combustion gas and air. A computer programme which also includes the thermodynamics properties of the gas and air was made for that purpose. Characteristics of the heat exchangers are then compared with the existing industrial heatexchanger. It was found that the overall heat transfer coefficient equation proposed by Babcock & Wilcock gives the best results.

The existing software of pinch technique provide only the tool for the heat exchanger network design. To improve the reliability of the software, in particularly for retrofitting the existing system, several additional aspects need to be included. In this paper, an algorithm to determine the optimum condition of heat exchangers for a specified allowable head loss is proposed. With this new method, the retrofit design of an existing system can be done even by taking into consideration of using the existing fluid circulation systems (i.e. pumps and compressors). The proposed method of heat…

This paper presents research on the development of semi automation technique for balancing machines. Using this technique, rotational speed of rotors, data acquisition process, and amplitude and phase of vibration calculations could be performed by a computer. Consequently, faster and more accurate balancing process can be achieved. The effectiveness of the proposed control method was verified using experimental results. In this test, the rotor speed was measured by and compared to the results obtained from software, a digital oscilloscope, a digital tachometer and a Multi Channel Spectrum…

This paper deals with the development of direct balancing method that uses no trial mass. This activity is the continuation work of the previous research on semi automation of balancing machine that has been performed at the Dynamics Laboratory IUC-ES ITB. This method has been developed by using Frequency Response Function (FRF) data of a balancing machine as a function of frequency and rotors masses that will be balanced. These FRF data are used as aconversion factor of voltage, which is the output of velocity transducer, to unbalance flzrce. Using this method, the balancing process can be…

A 5 cm diameter spouted-bed reactor has been applied for solid-liquid reaction, paddy ash and NaOH producing Na-silicate. Hydrodinamics of spouted-bed reactor was studied by using paddy ash-water system. Correlation for minimum superfisial spouting (Ums) was determined and follows the equation. ( in cgs unit)The spouted bed (SB) operates under transition regime i.e. Reynold number particle range 7-25 or Re number fluid ranging from 19 to 254. The mass transfer is the controlling step for this system as for all solid-liquid reactions are very fast. So, a model of mass transfer has been…