Plant Waste Drying in an Isothermal Model

The paper highlights advantages of using furnaces for processing vegetable waste, including the absence of condensation, minimal ash production, stable coolant temperature, and efficient heat exchange. To improve this machine and intensify the drying process, it is necessary to gather data on the heat and mass transfer characteristics during high-temperature drying of moisture-laden particles. Due to the inherent challenges of studying the drying process in a real furnace, the experiment was conducted using an isothermal (cold) model under laboratory conditions closely resembling real-world processes. (Research purpose) The research aims to assess the effectiveness of the proposed aerodynamic models for drying plant waste and validate the mathematical model for drying particles in a suspended bed. (Materials and methods) The study employs two suspended bed models with distinct vortex flow aerodynamics (flare and cyclone) in combustion chambers. The study investigates the drying kinetics of two specific fractions of sunflower husks, each with an equivalent particle diameter of 0.25 and 1.5 millimeters, and initial moisture levels of 15 and 18 percent. At various time intervals, measurements were taken for both the temperature and humidity of the husk particles, in addition to recording the temperature and relative humidity of the drying agent as it exited. The drying process operated in a cyclical mode. (Results and discussion) When the sunflower husk particles had an initial moisture content of 15 percent, two phases of increasing drying rates were observed, while at an 18 percent moisture content, three such periods were identified, with the first period displaying a constant rate. The results suggest that when the husks start with an initial moisture content of 15 percent, the drying curves exhibit minimal linear segments. This observation implies that the process is occurring as the drying rate decreases. (Conclusions) The experiment reveals the most effective drying mode in terms of intensity. It becomes evident that both the flarevortex and cyclone-vortex aerodynamic modes facilitate particle drying, with the cyclone-vortex mode delivering a notably more intense drying process. When transitioning from a model to a real-world process, it is essential to undertake a comparison of estimated processes with practical operational conditions, as exemplified by the particle drying model in a suspended bed.

1. Golobokov S.V., Mukhamed’yarova N.K., Lesin I.A. Tekhnologii pererabotki i utilizatsii otkhodov derevoobrabotki [Reproduction and utilization technology of woodworking waste] Inzhiniring i Tekhnologii. 2019. Vol. 4. N2. 32-37 (In Russian). DOI: 10.21685/2587-7704-2019-4-2-5. EDN: MDZTSJ.

2. Sudakova I.G., Rudenko N.B. Poluchenie tverdykh biotopliv iz rastitel’nykh othodov (obzor) [Obtaining of solid biofuels from plant waste (Review)]. Zhurnal Sibirskogo federal’nogo universiteta. Seria: Khimiya. 2015. Vol. 8. N4. 499-513 (In Russian). DOI: 10.17516/1998-2836-2015-8-4-499-513.

3. Shayakhmetova A.H., Timerbaeva A.L., Borisova R.V. Sravnitel’nye kharakteristiki pellet iz luzgi podsolnechnika i drevesnykh pellet [Comparative characteristics of sunflower husk and wood pellets]. Vestnik Kazanskogo tekhnologicheskogo universiteta. 2015. Vol. 18. N2. 243-246 (In Russian). EDN: TJLTKL.

4. Alithawi W.K.A. Production of biofuel from wood. Eastern European Scientific Journal. 2014. N3. 206-218 (In English). DOI: 10.12851/EESJ201406C06ART04. EDN: TXUDHH.

5. Drincha V.M., Tsench Yu.S. Fundamentals and prospects for the technologies development for post-harvest grain processing and seed preparation. Agricultural mashinery and technologies. 2020. Vol. 14. N4. 17-25 (In English). DOI: 10.22314/2073-7599-2020-14-4-17-25. EDN: QCBKWJ.

6. Manigomba J.A. Prospects for biomass energy use in the republic of Burundi. J.A. Manigomba, N.D. Chichirova, et al. International Journal of Mechanical Engineering and Technology. 2019. Vol. 10. N1. 1371-1382 (In English). EDN: EOSTDB.

7. Lyubov V.K., Tsypnyatov I.I. Povyshenie effektivnosti energeticheskogo ispol’zovaniya biotopliva [Improving the efficiency of energy use of biofuels]. Izvestiya vysshikh uchebnykh zavedeniy. Lesnoy Zhurnal. 2023. N1(391). 172-185 (In Russian). DOI: 10.37482/0536-1036-2023-1-172-185.

8. Arshadi M., Gref R., Geladi P., et al. The influence of raw material characteristics on the industrial pelletizing process and pellet quality. Fuel Processing Technology. 2008. Vol. 89. N12. 1442-1447 (In English). DOI: 10.1016/j.fuproc.2008.07.001.

9. Dadyko A.N. Modelirovanie aerodinamiki fakel’no-vikhrevogo rezhima v topke dlya rastitel’nykh otkhodov [Mode ling of aerodynamics of flare and vortex mode in a fire chamber for vegetable waste]. Sel’skokhozyaystvennye mashiny i tekhnologii. 2016. N2. 32-35 (In Russian).

10. Lobachevsky Ya.P., Pekhal’skiy I.A., Pavlov S.A. Raschet izotermicheskoy sushki zerna [Calculation of isothermal drying of grain]. Sel’skiy mekhanizator. 2019. N8. 22-23 (In Russian). EDN: OQXPPO.

11. Golubkovich A.V., Belen’kaya L.I., Dadyko A.N., Lovkis V.B. Opyt szhiganiya rastitel’nykh otkhodov v topochnom bloke TBR-2.0 [Experience in vegetable waste burning in furnace block TBR-2.0]. Sel’skokhozyaystvennye mashiny i tekhnologii. 2017. N1. 37-41 (In Russian). https://doi.org/10.22314/2073-7599-2017-1-37-41.

12. Pavlov S.A., Pekhal’skiy I.A., Kynev N.G. Osobennosti sushki semyan pri szhiganii tverdogo topliva peremennogo kachestva [Specifics of seed drying during combustion of variable-quality solid fuel]. Vestnik VIESH. 2018. N3. 81-85 (In Russian). EDN: SKEWYZ.

13. Sosin D.V., Litun D.S., Ryzhiy I.A., et al. Opyt szhiganiya luzgi podsolnechnika v pyleugol’nykh kotlakh Kumertauskoy TETs [Experience of burning sunflower husks in the Kumertau CHP pulverized coal-fired boilers]. Teploenergetika. 2020. N1. 15-22 (In Russian). DOI: 10.1134/S0040363619120099. EDN: ZNJRBS.

14. Izmailov A.Yu., Golubkovich A.V., Pavlov S.A., Dadyko A.N. Usloviya raboty zernosushilki s topochnym blokom na rastitel’nykh otkhodakh [Operating conditions of the grain dryer with a combustion space on the vegetation residues]. Vestnik rossiyskoy sel’skokhozyaystvennoy nauki. 2017. N4. 69-72 (In Russian). EDN: ZXIYQD.

15. Shchetkin B.N. Matematicheskaya model’ processa sushki dispersnykh materialov vo vzveshennom sostoyanii [Mathematical model of the drying process of dispersed materials in suspended state]. Sciences of Europe. 2021. N1. 45-50 (In Russian). DOI: 10.24412/3162-2364-2021-85-1-45-50. EDN: LXYVVA.