System for Heating Bulk Materials

A system for heating bulk material to remove moisture. The system includes a heat exchanger system in the floor of a bin for receiving moist bulk material. The heat exchanger system is capable of withstanding the weight of the bulk material as well as being stable for the dynamic process of loading and discharging the bulk material. The heat exchanger includes a plurality of spaced beams mounted between a top plate and bottom plate. The spaced beams form conduits for receiving water or other fluids that have been heated by a stove capable of burning wood, coal, biomass material or other energy sources. The stove is capable of providing one million BTUs, or any type of heat exchanger, including existing commercially available units for heat exchange or heat transfer

Modeling of Geometric Change Influence on Blast-Wave Propagation in Underground Airways Using a 2D-Transient Euler Scheme

The impact of methane explosions on mining operations can never be over-emphasized. The safety of miners could be threatened and local ventilation facilities are likely to be damaged by the flame and overpressure induced by a methane explosion event, making it essential to understand the destructiveness and influence range of a specific explosion. In this paper, the attenuation effect of geometric changes, most commonly bends, obstacles, and branches, present in the way of blast-wave propagation and the capability of the selected numerical model were studied. Although some relevant experimental research has been provided, quantitative analysis is insufficient. This paper investigates the attenuation factors of seven bends, three obstacles, and two T-branch scenarios to ascertain a better insight of this potentially devastating event quantitatively. The results suggest that (1) the numerical model used is capable of predicting four of the seven validated scenarios with a relative error less than 12%; (2) the maximum peak overpressure is obtained when the angle equals 50° for bend cases; and (3) the selected numerical scheme would overestimate the obstacle cases by around 15%

Scale Effect of Premixed Methane-Air Combustion in Confined Space Using LES Model

Gas explosion is the most hazardous incident occurring in underground airways. Computational Fluid Dynamics (CFD) techniques are sophisticated in simulating explosions in confined spaces; specifically, when testing large-scale gaseous explosions, such as methane explosions in underground mines. The dimensions of a confined space where explosions could occur vary significantly. Thus, the scale effect on explosion parameters is worth investigating. In this paper, the impact of scaling on explosion overpressures is investigated by employing two scaling factors: The Gas-fill Length Scaling Factor (FLSF) and the Hydraulic Diameter Scaling Factor (HDSF). The combinations of eight FLSFs and five HDSFs will cover a wide range of space dimensions where flammable gas could accumulate. Experiments were also conducted to evaluate the selected numerical models. The Large Eddy Simulation turbulence model was selected because it shows accuracy compared to the widely used Reynolds\u27 averaged models for the scenarios investigated in the experiments. Three major conclusions can be drawn: (1) The overpressure increases with both FLSF and HDSF within the deflagration regime; (2) In an explosion duct with a length to diameter ratio greater than 54, detonation is more likely to be triggered for a stoichiometric methane/air mixture; (3) Overpressure increases as an increment hydraulic diameter of a geometry within deflagration regime. A relative error of 7% is found when predicting blast peak overpressure for the base case compared to the experiment; a good agreement for the wave arrival time is also achieved

Mechanics of dump truck vibrations in high-impact shovel loading operations

The deployment of large machinery for low cost, bulk surface mine production operations has resulted in high-impact shovel loading operations (HISLO). In extreme cases, shovels load large dump trucks with 100-ton (or more) passes generating high-impact forces under gravity. HISLO generates high-frequency shockwaves that cause severe truck vibrations exposing operators to whole body vibrations (WBV). This WBV levels may exceed the recommended International Standards Organization (ISO) limits resulting in longterm lower-back disorders and other health problems. There is a need for fundamental and applied research to determine HISLO vibration levels for heavy mining machinery, their comparisons to ISO 2631 limits and the safety of operators under these conditions. Previous studies have dealt with vibration problems by designing ergonomic seats with no emphasis on the source of machine vibrations. In this study, the mechanics of truck vibrations under HISLO conditions is developed using Lagrangian formulation for a 9-DOF system. The Fehlberg fourth-fifth order Runge-Kutta numerical method is used to solve the corresponding equations of motion. Furthermore, a 3D virtual truck prototype model with 38-DOF is built and simulated in MSC.ADAMS. Simulation experiments are carried out to determine the dynamic characteristics of the truck under the HISLO conditions and to investigate the potential sources of vibration and their propagation. The simulation results show that the vertical RMS accelerations are equal to 3.56 m/s², 1.12 m/s² and 0.90 m/s² for the operator\u27s seat, lower-back and cervical regions, respectively. These values agree with the experimental results by Kumar (1999) in the oil sands operations. The vibration levels also fall within the extremely uncomfortable zone compared to the ISO 2631 limits, which pose severe health threats to truck operators over long-term exposure. This pioneering research initiative has developed comprehensive truck vibration theory, dynamic models and virtual prototype simulation for determining accelerations on critical body parts of a dump truck operator. It advances the heavy mining machinery vibrations frontier and contributes immensely to its body of knowledge. It also provides a foundation and a platform for comparing operator WBV exposures to ISO Limits toward creating a safe working environment that guarantees long-term operator health --Abstract, page iii

Research and Engineering Solution for Dump Tuck Vibration Problems in High-Impact Shovel Loading Operations

The deployment of large machinery for low cost, bulk surface mine production operations has resulted in high-impact shovel loading operations (HISLO). In extreme cases, shovels load large dump trucks with 100-ton (or more) passes generating high-impact forces under gravity. HISLO generates high-frequency Shockwaves that cause severe truck vibrations exposing operators to whole body vibrations (WBV). Current research study in this area has established that the vibration levels affecting the operator\u27s seat, lower-back, lumbar and cervical regions fall within the extremely uncomfortable zone compared to the ISO 2631 comfort zone. These results pose health threats to truck operators over long-term exposure to these vibrations. In this paper, the authors will examine engineered solutions to mitigate these health threats

Lagrangian Formulation and Numerical Solutions to Dump Truck Vibrations under HISLO Conditions

Heavy mining machinery has exposed the human body to extreme vibrations that may limit the performance of operators and further impact the overall system performance. Large capacity shovels and dump trucks have been deployed in surface mines to achieve economic, bulk production operations. The high-impact shovel loading operation (HISLO) causes severe truck vibrations that expose operators to whole-body vibrations (WBV) levels that may exceed ISO standards. The effects of these shockwaves on the human body are severe resulting in long-term lower-back disorders and other health problems. There is a need for fundamental and applied research to determine HISLO vibration levels, their comparisons to ISO 2631 limits, and the safety of operators under these conditions. A fundamental research has been carried to model these HISLO shockwave generation and propagation through the truck body and attenuated via the suspension mechanism and within the rollover protective structures (ROPS) cabin. The Lagrangian mechanics technique has been used to formulate the equations of motions governing the HISLO problem. The Fehberg fourth-fifth order Runge-Kutta (RKF45) numerical method in maple environment (maple classic Version 10.00, 2006, Maplesoft, a division of Waterloo Maple Inc., Waterloo, ON, Canada) is used to solve the equations of motions symbolically. The Lagrangian formulation and the RKF45 solutions provide efficient solutions to complex functions with stability, convergence, and minimum errors. The results of this analysis show that the vertical root mean square (rms) accelerations are equal to 3.56, 1.12, and 0.87 m/s² for the operator\u27s seat, lower-back, and cervical regions, respectively. These vibration levels also fall within the extremely uncomfortable zone compared to the ISO 2631-1 comfort zone (less than 0.315 m/s²), which pose severe health threats to truck operators over long-term exposure to these vibrations

Virtual Prototype Simulation of Truck Vibrations in High-Impact Shovel Loading Operations

Virtual prototyping has dramatically increased in the past decades due to powerful computing tools and environment. Moreover, companies are under pressure to reduce development and optimization time for their future products. With virtual prototyping, engineers can explore the performance and behavior of various design alternatives without investing time and money required to build actual prototypes. Also, in dangerous applications, human factor can be analyzed in a virtual prototype without compromising their health and safety. This paper highlights the development of a 3D virtual prototype simulator for truck vibrations under High-Impact Shovel Loading Operations (HISLO) conditions. It contains a complete methodology and procedure for building the complex dynamic model, with multi-degrees of freedom that best captures the actual truck under the HISLO conditions. The detailed steps and methodologies for building the virtual model using MSC.ADAMS are also discussed in this paper. The constraints, dimensions and control environments of this virtual model are described. This study also focuses on the methods used in MSC.ADAMS to build the complex dynamic model, and their limitations for developing and simulating the virtual prototype simulators

Intelligent Machine Monitoring and Sensing for Safe Surface Mining Operations

The creation and maintenance of a healthy surface mining environment require advanced research initiatives for developing powered excavation and haulage technologies. The shovel-truck system is widely used in surface mining due to flexibility, economics and maintainability. Advances in technology have resulted in large shovels and trucks for economic, bulk operations. These advances have resulted in high-impact shovel loading operations (HISLO), which cause significant vibrations and affect an operator\u27s health. Dump truck operators also face challenges in interacting with mine layouts, which include limited vision due to extensive “blind” areas and truck stability in difficult conditions. This paper contains a summary on frontier research on truck control, vision and collision avoidance and vibrations and their effects. Dynamic modeling is used to capture truck-road interactions. Intelligent sensing and collision avoidance system is used to develop an integrated system for a 360° vision. Theoretical models are also used to capture the effects of vibrations from HISLO. Virtual simulators are used to simulate the response of the integrated system to HISLO vibrations. This research is significant because it will provide a strong basis for developing technologies to improve shovel-truck haulage safety in surface mines and construction sites