Detailed Product Description
Less space Occupying on-line Heat exchanger for Tube MIlls
The completely treated oil / lubricant under pressure, is fed through a check/non-return valve (8), to the heat exchanger (10), through shut off valve (9).The cooled oil from the heat exchanger, finally reaches through shut-off valve (11), the lubricant distribution pipes (12) and (22), meant for serving the two essential requirements of the lubrication scheme, namely for flooding the contacting gear areas before interaction, and for washing away the dirt, heat, and wear debris, after interaction of the gears.Typical details of the seal assembly (16) and (17), for the rotary drum interface with the gear housing (14), is given separately in Fig. G. The rotary drum sealing details are shown in Fig. H, giving the part details and part-sectional view of the arrangement, designed to facilitate effective sealing as segmental assembly, incorporating novel features of flexible labyrinth, air seal, and contacting felt seal as effective combinations. Another view of the girth gear housing(14), assembled in segments, is shown in fig.I. This shows the driving pinion (18), the standing lubricant level (AA), and the baffle arrangements with in the girth gear housing, to contain foaming and air entrapment in to the reservoir. Magnified views of the pipe header assembly (12) and (22), supplying pressurized lubricant to the meshing gears, is illustrated.Fig. J gives the assembly and sectional details of the header/nozzle assembly, for the pressurized loop of lubrication, where through a combination of hole sizes, shapes, pitch, and location, different jet sizes are obtained, with different angular orientations. Suitable combination of hole sizes and orientation, can be selected from outside the housing, to effect the desired change, in the pressure loop of lubrication. This innovative design of the pipe header and nozzle assembly, helps in controlling the flow, pressure, velocity and angular orientation of lubricant jets, as elaborated in the jet nozzle part-sectional details,contained in Figs I and K. Suitable heat exchanger(10), for cooling the lubricant, is added to the lubrication scheme. The heat exchanger design, as detailed in Fig. L, is unique, incorporating multiple, spiral copper tubes to form a flexible coolant circuit, which can be looped-in, depending upon the heat transfer requirements of the lubrication scheme. Typical two-cooler tube assembly, housed in the cylindrical annulus, formed between the walls of the cylindrical housings, is shown in Fig L. The arrangement, economizes the space requirement of the cooler assembly, without sacrificing the efficiency aspects of the cooler. The compactness of the design, together with vertical orientation of the coolers, is ideally suited for the lubrication scheme for girth gear drives, where space
constraints are normally expected for retrofit assemblies. The air-treated, filtered-oil from sump, is then delivered to the heat exchanger(10), through check valve(9).The limitation of floor space and limited accessibility in existing mill drive installations, pose a problem with reference to installation of heat exchanger of right size and capacity. A novel design of heat exchanger is introduced, with the concept of flexible capacity and vertical orientation, to save floor space. Details of heat exchanger design, evolved for girth gear drive installation, is given in Fig L, where the concept is clearly illustrated for a typical two chamber configuration. The required heat exchanging surface, is created by a combination of helical and Archimedean spiral wound, copper tubes, to form a continuous loop of copper tube. This tube assembly is located inside the annulus, formed between two cylindrical housings as shown in the figure L. One more helical, spiral wound copper tube, configured to suit the space, is inserted inside the inner chamber, thus completing the assembly. The flow requirements of the lubricant/coolant, for either of the loops, is controlled from outside, through various measuring gauges, located outside the tube assembly. Depending upon the requirements, the required number of coolers can be looped-in the cooling circuit, with proper inter-connections from outside. Introduction of the varying capacity oil cooler, enable maintenance of oil sump temperature, within limits.