DEVELOPMENT OF COMPUTER MODEL AND LABORATORY SCALE EXPERIMENTAL STUDY OF THE FREEZING OF BULK MATERIALS AND FULL SCALE TEST OF COAL FREEZING DURING RAIL TRANSPORTATION
When bulk materials are transported by rail during winter, freezing of the material can occur. This makes the material difficult to discharge from the cars. The mathematical basis of a finite difference computer simulation model of the freezing process is presented. The model can simulate freezing or thawing in three-dimensional rectangular and cylindrical shapes as well as several other miscellaneous container shapes. An insulating material at the inside surface of the container walls may also be specified in the model. Experimental results were also generated with which numerically predicted results could be compared. A copper concentrate and coal were frozen by placing them in a container whose surface was kept at about minus 30 degrees C (minus 20 degrees F). During the test, the surface temperature and the temperature at various points in the material were measured. The measured surface temperature was then used as an input to the computer model and the measured and predicted temperature variations in the material were compared. A test was also undertaken in which the temperature variation in railcars containing coal was measured during a winter journey. A 100-ton Gondola car and Bathtub Gondola car were loaded with coal from a mine in the Crow's Nest Pass area. Thermocouple probes were inserted into the cars and connected to a measuring instrument contained in a caboose between the two cars. The cars were then transported from the mine to Thunder Bay, the journey taking approximately 80 hours. During the journey the temperature in the coal was measured at regular intervals as was the ambient air temperature. Because of the relatively mild temperatures experienced during the journey, the cars were allowed to stand at Thunder Bay for about another week and the coal temperature again was measured. The basic purpose of the test was to provide results that would be used to validate the computer model of the freezing process. Accurate comparison between measured results and those predicted by this model was rendered difficult by the relatively small temperature changes that occurred during the test. However, the general conclusion is that the agreement between the measured and predicted results is satisfactory, which indicates that none of the basic assumptions on which the model is based is radically in error.
Canadian Institute of Guided Ground TransportQueen's University
Kingston, Ontario K7L 3N6, Canada
- OOSTHUIZEN, P H
- Publication Date: 1978-1
- Features: Appendices; Figures; References; Tables;
- Pagination: 150 p.
- TRT Terms: Bulk cargo; Coal; Coal industry; Cold weather; Freezing; Freight traffic; Mathematical models; Open top cars; Operations; Simulation; Tests; Thaw; Unit trains; Validation
- Old TRIS Terms: Bulk materials
- Subject Areas: Administration and Management; Freight Transportation; Railroads;
- Accession Number: 00195072
- Record Type: Publication
- Source Agency: Canadian Institute of Guided Ground Transport
- Report/Paper Numbers: CIGGT Rpt 78-10 Final Rpt.
- Files: TRIS
- Created Date: Jul 31 1979 12:00AM