EARLY WARNING TERHADAP INSIDEN KEBAKARAN PADA OVER LAND BELT CONVEYOR PABRIK SEMEN MENGGUNAKAN LINEAR HEAT DETECTION SYSTEM

The cement market is increasingly competitive with the rise of imported cement, which of course must be answered by cement producers among competition. One of the main processes that should not be disturbed is the supply of limestone from quarry to the factory. The safety of people, processes and equipment are certainly necessity for the production process to run smoothly. The problem that can occur in limestone supply is a breakdown on the Overland Belt Conveyor (OLBC) which is caused by a broken roller and causes the belt to tear and potentially fire. For this reason, prevention efforts need to be done with an early warning mechanism to provide alerts to interested parties. Early warning system can be applied to the process because it can detect the beginning of heat so that fires can be prevented. Therefore, it is necessary to install a sensor using optical fiber called a linear heat detector (LHD) on OLBC. Installing the LHD system on OLBC can effectively detect an increase in roller temperature which then becomes an early warning for operators in the control room 24 hours a day to prevent incidents that cause harm to the company due to belt fires or torn belts.

Study on design of temperature - dependence of sublimation transfer roller

Sublimation trasnfer machine's hot roller, a compression type electronic heater, is made of ceramic core which is wrapped with nickel-chromium alloy heater. This roller is insulated with magnesium oxide. When the power is on, the heat is generated. Heat transfers are from high temperature area to low temperature area, and it causes the non-uniform temperature surface and the roller surface distorsion. Such effects always increase with larger diameter of the roller and longer the roller. In order to predict the sublimation transfer machine's roller temperature distribution and validate it, we construct the roller's 3D temperature model and use ANSYS steady state heat transfer analysis module to calculate the power dissipation and simulate it. Final data shall help us to design sublimation transfer machines' roller.

Effects of Preheating and Cooling Durations on Roll-to-Roll Hot Embossing

In this study, we examined the sensitivity of embossed pattern depth to preheat supply and cooling and investigated how the pattern type and density affect the embossed depth. The main factors that affect embossed pattern qualities of roll-to-roll hot embossing, such as roller temperature, roller speed, and applied force, were determined using the response surface methodology. Eight conditions were then added to determine the time-dependent effects of heat transfer with custom-designed preheating and cooling systems. An extended preheat time for the polymethylmethacrylate substrate contributed to the significant change in the embossed depth, whereas the substrate-cooling did not exhibit a clear increasing or decreasing trend. Larger embossed depths were achieved in the horizontal patterns with lower density than in the vertical patterns, and the lower pattern densities showed greater embossed depths in most embossing conditions. We expect that this result will help to understand the effects of the pre- and posttreatment of roll-to-roll hot embossing by employing time duration factors of heat transfer, depending on the mold pattern type and density.

Warping Analysis in Laminated Object Manufacturing Process

This study presents an analysis of warping that occurs in the laminated object manufacturing process. Based on the study of thermal-mechanical behavior of the adhesive and its effect on the laminated materials, the cause of warping, the relationship between temperature and adhesive viscosity, and the adhesive connecting intensity is investigated. A heat transfer mathematical model and finite difference solution algorithm was developed to calculate the intralaminar thermal force induced by the material addition in the processing of laminated object manufacturing. The results of the model prediction were compared to available experimental data. Simulation of intralaminar thermal force and case studies show that the processing parameters, such as roller temperature, speed, and contact pressure, the mechanical properties of laminated material and adhesive will all contribute to the formability and warping of the laminated prototype. An optimal combination of the processing parameters may reduce the undesired warping effect.