engleski

Cooling of the plain bearing of ball mill drive in the production of Portland cement

The purpose of this study is to examine the characteristics of industrial shell and tube heat exchanger (MIT05) with fixed tube bundles, 2-pass tube side, for cooling of mineral oil that lubricated plain bearings ball-mill raw material in the production of Portland cement. Through the tube bundle, which consists of 44 copper pipes with the outer diameter of 10 x 1 mm and the length of 404 mm, in two passes, streaming cooling water inlet temperature 21 °C, with volume flow of 1 m3/h. Mineral oil flows inside the shell and around the tube, with volume flow of 8 L/min. The pipes are laid out in a triangular fashion and pitched 13 mm apart. There are 6 baffles inside the shell. The results of examination indicate the laminar flow (Re < Re, c) inside the tubes and shell. Until the oil temperature rises by 5, 5 oC the the available surface area of heat transfer is greater than required and meets the set requirements. As the oil temperature rises up of 5, 5 oC the surface required to exchange heat also rises compared with available surface, while the multi-tube exchanger no longer fulfills the requirements for cooling the mineral oil. By increasing the flow of cooling water is coming to an increase in the tube-side mass flow rate of water and the transition from laminar flow in the transitional area (2300 < Re < 10000). This increases the overall heat transfer coefficient and reduces the required surface heat exchanger to transfer the same amount of heat.

plain bearing, shell and tube heat exchenger, overall heat transfer coefficient, heat transfer surface area

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