Journal La Multiapp

Efficiency and Performance Analysis of the Design and Construction of a 30 Kg/Hour Coffee Grinding Machine

Thu, 16 Apr 2026 00:00:00 +0700

This study aims to evaluate the performance of a disk mill coffee grinding machine with a design capacity of 30 kg per hour for small and medium scale coffee processing. The machine was developed as a practical gasoline powered grinder to support coffee processing activities, particularly in areas where access to electricity may be limited. A performance test was conducted using roasted coffee beans with three input loads, namely 500 g, 750 g, and 1000 g. The observed parameters included grinding time, grinding capacity, product yield, residual material, material loss, material conversion efficiency, energy efficiency, and grinding quality based on particle size distribution. The results show that the machine achieved an average grinding capacity of 29.68 kg per hour, which is close to the intended capacity of 30 kg per hour. The average product yield and material conversion efficiency reached 94.55 percent, while the average material loss was 1.11 percent. However, residual material remained at 4.00 percent, indicating that the grinding chamber and discharge system still require improvement. The energy efficiency was reported at 73.8 percent, although the engine power specification needs further clarification. In terms of grinding quality, 70 percent of the particles were within the desired range of 500 to 700 micrometers. These findings indicate that the machine is technically feasible for small scale coffee production, but further refinement is needed to improve material discharge, reduce residual particles, and strengthen particle size consistency.

Thermal Effectiveness Analysis of Lube Oil Cooler Fan with Capacity of 40.332 Kg/S with Pressure of 5 Bar

Wed, 29 Apr 2026 13:55:09 +0700

The Lube Oil Cooler Fan is an essential component in the lubrication system of a gas turbine because it maintains lubricating oil temperature within a safe operating range. This study aims to analyze the thermal performance and effectiveness of the Lube Oil Cooler Fan on Gas Turbine GT 1.1 at PT XYZ. The study employed a descriptive quantitative approach using field observation data and heat transfer calculations. The analysis was conducted through the Log Mean Temperature Difference method and heat exchanger effectiveness approach by considering fluid temperature changes, mass flow rates, thermophysical properties, flow characteristics, convective heat transfer coefficients, overall heat transfer coefficient, heat transfer rate, and thermal effectiveness. The results show that the lubricating oil temperature decreased from 61°C to 49°C, while the cooling air temperature increased from 32°C to 53.5°C. The tube side heat transfer coefficient was 40.71 W/m²°C, the shell side heat transfer coefficient was 308 W/m²°C, and the overall heat transfer coefficient was 30.61 W/m²°C. The calculated heat transfer rate was 992.57 W or approximately 0.993 kW. The lubricating oil was identified as the minimum heat capacity fluid, with a heat capacity rate of 33.13 kW/°C. The thermal effectiveness of the Lube Oil Cooler Fan was 41.4%, indicating that the cooler was able to perform its cooling function, although its performance remained moderate. Routine monitoring, stable airflow control, and periodic cleaning are recommended to improve thermal performance.