Alemite Oil Mist Application Manual

Transcription

1 Alemite Oil Mist Application Manual

2 Oil Mist Application 1 Introduction The Oil Mist principle was developed in the late 1930 s by a European bearing manufacturer. The problem that nurtured this development was the inability to satisfactorily lubricate high-speed spindle bearings on grinders and similar equipment. The speeds of those bearings were too high for grease lubrication, and the heat generated by fluid friction in liquid oil necessitated the use of costly re-circulating systems. Continuous thin-film lubrication with Oil Mist provided a solution, and the purging of bearing housings that accompanies this lubrication produced additional benefits. Stewart-Warner Corporation purchased the rights to Oil Mist in Since then, the Alemite Corporation has developed a broad line of equipment and application techniques to lubricate all kinds of machine elements, from the tiny, ultrahigh-speed parts of dentists drills to the huge gears and bearings of steel rolling mills. With modern demands for more and more complex machines running at higher and higher speeds, and for greater reliability and economy, the list of applications for Alemite Oil Mist Systems grows longer and longer. What it does Oil Mist lubrication is an automatic, centralized system that CONTINUOUSLY delivers fresh, clean oil to multiple, and often widespread, machine elements. There are numerous advantages to Oil Mist, in addition to the improvements in safety, productivity, housekeeping, and lubrication that are achieved by automatic centralized systems in general. particles. This mist is then thrust against a baffle that collects and drops larger particles back into the reservoir. The lighter, airborne particles are then carried by the air stream through the distribution system to the various points of application. The efficiency of an Oil Mist System is dependent upon various designed lubrication fittings that serve as contact points to the parts to be lubricated. These fittings serve two functions. They maintain balanced pressure in the system preventing over or under lubrication of a bearing. They regulate the amount of mist through the fitting orifices into the bearings being lubricated. Continuous delivery, at rates closely approximating actual bearing-surface needs, eliminates the overlubrication that is necessary to insure adequate supply between periodic applications. LUBRICANT CONSUMPTION can often be reduced by as much as 80%. In many cases, continuous lubricant delivery by Oil Mist permits elimination of energy-wasting oil sumps. Reductions in POWER consumption of more than 25% are common. BEARING TEMPERATURES are often lowered dramatically, not by actual cooling, but because most of the power consumption reduction represents heat that is not generated in churning excess lubricant. Pressurization of housings, with continuous outward air flow, extends MACHINE LIFE by helping to exclude dirt and corrosive atmospheres. Oil Mist is even used to protect equipment on standby and in storage. How it does it The heart of the system is the mist generator. Air from normal factory air supply passes over a venturi inside the generator, which accelerates the flow. This creates low pressure and high velocity at the venturi discharge. As air passes through the venturi it draws oil from the generator reservoir into the high velocity air stream. The combination of low pressure and high impact explodes the oil into tiny How to apply it BASIC STEPS TO DESIGN AN ALEMITE OIL MIST SYSTEM 1. DESCRIBE each element to be lubricated and CALCULATE its Oil Mist flow requirement in CUBIC FEET PER MINUTE (CFM). 2. Select APPLICATION FITTING TYPES and determine their PLACEMENT and VENTING provisions. 3. Select the DESIGN MANIFOLD PRESSURE (DMP). 4. Determine FITTINGS SIZES. 5. Select an appropriate Oil Mist GENERATOR. 6. ROUTE and SIZE air and mist distribution PIPING. 7. Select FITTNGS CONFIGURATIONS that will be most convenient to install and connect to distribution system. 8. Select ACCESSORIES. 9. Plan ELECTRICAL CIRCUITRY.

3 2 Oil Mist Application Details of basic steps - General: For all Systems 1. The DESCRIPTIONS required to CALCULATE the mist requirements of machine elements include type of element, dimensions, and various details of installation and operation. This information is used in simple formulas to calculate cfm of mist required. The formulas are based on the design standard oil/air ratio of 0.4 cubic inch (0.22 ounce) per hour per cfm. They assume that the elements to be lubricated were properly selected for the intended service and properly assembled and protected from contamination. They also assume the use of an oil with the proper misting and lubricating qualities for the intended application. (FORMULAS and other considerations for applying Oil Mist to SPECIFIC TYPES OF MACHINE ELEMENTS are given in a later part of this manual: PAGES 6-10.) 2.APPLICATION FITTING TYPES FITTING SELECTIONS are primarily based on the types of elements to be lubricated, but are often influenced by other factors, such as machine configuration or speed. In general, use SPRAY FITTINGS and SPRAY NOZZLES for ROLLING MOTION elements, such as anti-friction bearings, gears and chains. (SPRAY NOZZLES are just multiples of the largest Alemite spray fitting.) CONDENSING FITTINGS or SPRAY FITTINGS are used for SLIDING MOTION elements, such as plain bearings, slides, and ways. MIST FITTINGS are used only for rolling element bearings operating in closed housings, under particular types of loading, and above a minimum speed. FITTINGS PLACEMENT PLACE SPRAY FITTINGS to discharge close to the lubricated elements, preferably less than one inch away. REMOTE POSITIONING of spray fittings is permissible if their outputs are ducted to and flow through the lubricated elements because of relative positions of fittings and vents, and if passages downstream from the fittings are horizontal or sloped downward toward the elements. TO SPRAY DIRECTLY on elements moving at speeds up to about 1600 linear feet per minute, keep spacing between spray fittings and moving surfaces under 1/20 inch per inch water column manifold pressure. At higher speeds, install spray fittings 1/8 to 1/4 inch from the moving surfaces and use higher mist pressures-40 in. H20 above 2000 lfm and up to 80 in. H20 at much higher speeds. From CONDENSING FITTINGS the oil flows by gravity directly to the grooves supplying the sliding surfaces. The fitting location should be as close to the grooves as possible. MIST FITTINGS may be installed in any location, providing the mist flow envelops or passes through the elements to be lubricated. FITTING DISCHARGE DIRECTION SPRAY and CONDENSING FITTINGS work most efficiently when discharging downward. However, discharge may be in any direction BETWEEN DOWNWARD AND HORIZONTAL. SPRAY FITTINGS may also be installed to discharge UPWARD, in which case the CALCULATED CFM used to select fittings sizes should be DOUBLED. Spray discharge should be approximately perpendicular to the direction of motion of the sprayed surface. MIST FITTINGS may be installed to discharge in any direction. VENTING VENTING must be provided for the escape of carrier air from closed housings. MINIMUM VENT AREA is equal to twice the total flow area of the application fittings supplying flow to that vent. Vent areas of this size will produce housing back pressures equal to about 20% of manifold pressure. Wherever possible, relative POSITIONS of VENTS, APPLICATION FITTINGS, and LUBRICATED ELEMENTS should produce forced flow from application fittings to lubricated surfaces. VENTING can be by means of approximately located DRILLED HOLES or, frequently, by existing ports in the housing. LABYRINTH SEALS will usually provide adequate venting, although a small one might have insufficient clearances for this purpose, and require the addition of a drilled hole. CONTACT SEALS can be notched to provide venting, but this is not recommended because of the likelihood that notching will not be provided when seals are replaced. VENT PORTS can often serve as OIL OVERFLOW OR DRAIN ports. In an oil-sump application the vent can be placed just above the normal sump oil level to provide an overflow path for any excess oil delivered by the Oil Mist system. Such vents should be located so that liquid oil will not splash out through the port. For a dry-sump application the vent can be placed at the bottom of the housing to drain all liquids. VENTS should generally be PROTECTED from outside contaminants. Holes in the sides of housings should slope downward to the outside. Vent ports in the tops of housings should have shielded vent fittings installed. 3. DESIGN MANIFOLD PRESSURE (DMP) is the pressure drop across the application fittings at which the fittings sizes are selected. It is the intended output pressure of the Oil Mist generator. The ALEMITE STANDARD DMP IS 20 INCHES WATER COLUMN. Occasionally, other pressures are recommended to better meet specific application requirements. In general, lower DMP s permit closer oil output control. Higher DMP s are used to produce higher output velocities from spray type application fittings to penetrate air barriers around high-surface speed elements (over 2000 linear feet per minute). Also, spray and condensing fittings operate more efficiently with higher pressure drops across them.

4 Oil Mist Application 3 4. Determine APPLICATION FITTING SIZES from the chart on PAGE 28. A. In the TYPE column, locate the fitting type selected in Step 2. B. In the section for that fitting type, go to the right to the column under the DMP selected in Step 3. C. In the PRESSURE DROP column and type section find the mist flow equal to or nearest to and higher than the requirement calculated in Step 1. D. On that flow line, go to the left to the second column, headed NO., and read the DASH NUMBER that represents the fitting size. E. The columns at the right side of the chart give the minimum vent size for each fitting size. Actually, the sizes given are those of standard drill bits closest to calculated sizes and rounded to nearest thousandth. AN EXCEPTION to the above method of determining fitting type, size and placement is for elements in a closed housing that are lubricated from an oil sump by dipping into the oil or by oil rings, flingers, etc. Gear boxes and pump bearing housings are examples of such equipment to which Oil Mist is often applied to provide purging and to make up oil losses from the sump. In the Hydrocarbon Processing Industries, this is referred to as PURGE-MIST application. Since, in a Purge-Mist application, the Oil Mist system does not actually lubricate the machine elements, and, since sump losses cannot be calculated, there are no calculations to determine application fitting size. Alemite recommends simply starting with a -8 SPRAY FITTING (or -1 spray nozzle) for each housing, and changing sizes as indicated by housing oil levels and/or overflow rates. A 1/8 inch diameter hole at the top of the sump oil level can act as VENT and as overflow to prevent raising sump level. If a CONSTANT LEVEL OILER is used to control sump oil level, it must be modified by drilling an approximately 3/16 inch diameter hole in the side of the surge chamber about 1/4 inch above the operating oil level. This is to provide an overflow for any excess oil delivered by the mist system. To prevent depressing of the sump oil level, the housing must be VENTED to an internal pressure no greater than 1/10 inch water column. An Alemite vent fitting is recommended to accomplish this. 5. Oil Mist GENERATOR selection is based on flow capacity and air heater requirements and, in some cases, on desired reservoir refill interval. The required MIST GENERATING CAPACITY is determined by adding together the flow ratings, at design manifold pressure, of all of the APPLICATION FITTINGS that are to be supplied from the mist generator. Select a generator (see PAGES ) for which this total is within the operating range, preferably near the center of that range. DO NOT plan to operate a system outside the specified flow limits of the mist generator, especially at the low end. Flows less than the minimum specified for a generator will not reliably draw an adequate supply of oil from the reservoir to the mist generating head. If it is necessary to use a mist generator with a higher minimum flow rating than the total of the flow ratings of the application fittings, then that total must be increased. This can be accomplished by using the same fittings at a higher design manifold pressure or by using fittings with higher flow ratings. In most cases, the greater lubricant delivery will not even be noticeable. However, if this approach is objectionable, application fittings can be added to the system, either by lubricating points not included in the original plan, or by discharging spray or condensing fittings into a vented receptacle. Requirements for HEATERS are determined by referring to the chart on PAGE 13. Use of the chart is explained on that page. The lowest two curves indicate whether oil (reservoir) and air heaters are REQUIRED. (Even though they might not be required, these heaters are often used to stabilize the oil/air ratio with widely varying ambient temperatures.) The two curves pertaining to application fittings indicate limits necessitated by the tendency of oils to coat the bores or passages of those fittings. As temperature falls, the coating thickens. At FITTING TEMPERATURES above the limits, the system maintains good balance and output by a rise in manifold pressure, since, for a given input pressure, the mist generator tends to act as a CONSTANT FLOW device. However, at temperatures below the limits, the restrictions become too great for the system to maintain good distribution balance. Systems that are to operate under such conditions should utilize mist generators with Thermo-Aire. The temperature of the application fittings can then usually be kept above the critical levels by insulating the mist distribution system. Occasionally, it might be necessary to provide some HEATING for the FITTINGS. If RESERVOIR REFILL INTERVAL is a matter of concern, consult the chart on PAGE 14. The 0.6 cubic inches of oil per hour per CFM of mist is the approximate maximum oil/air ratio for Alemite Oil Mist generators operating without heaters at normal plant ambient temperatures. Oil/air ratio is a function of the setting of the oil flow adjustment screw in the mist generating head, the type and viscosity of oil used, as well as the air and oil temperatures. If all of these were acting to maximize the oil/air ratio, the required refill intervals could be as short as about one-half of those given on the chart. With all factors combining to minimize oil/air ratio, the intervals could be lengthened to five or six times those shown. However, REMEMBER that changing oil/air ratio also changes lubricant delivery. Reducing the ratio to its minimum means reducing lubrication to about one-fourth of the amount the system was designed to deliver, and adds the danger of a complete loss of lubrication due to a small drop in oil and/or air temperature, or to slightly different misting characteristics of a new supply of oil. All of which means: DO NOT plan to adjust system operating conditions to achieve a desired refill interval. To the extent possible, select a mist generator that will fit into the desired schedule and, if necessary, adjust the schedule or consider using an automatic refill system.

5 4 Oil Mist Application 6. PIPING refers to the systems used to supply air to the Oil Mist generator and to distribute the Oil Mist from the generator to the application fittings. It includes piping, tubing, hose, and connectors. In GENERAL, air and mist piping should be free of dirt, scale, or other contaminants. Internal diameters should be of sufficient size to avoid excessive pressure drop. Materials should be compatible with internal fluids, and resistant to external abuse, chemical attack and ambient temperature. For AIR PIPING, galvanized or copper pipe; copper, stainless steel or anodized aluminum tubing; rubber hose or synthetic tubing are recommended. The TABLE at the TOP of the PAGE 15 gives pressure drops, at various air flows, through 100 feet of pipe. The plant main supply pipe must be larger than the branch supplying air to the Oil Mist generator. The plant supply pipe pressure, at the inlet to the branch, must be at least equal to the sum of the generator regulated air pressure and the pressure drop through the branch and the air accessories, such as air solenoid valve, water separator, and air pressure regulator. If the strainers in the water separator and the air regulator become clogged, the pressure drop will increase. For MIST PIPING, any manifold material meeting the GENERAL requirements above can be used. Black pipe and plain steel tubing can be used if protected from external corrosion by paint. The bore of black pipe should be coated with preservative oil to prevent corrosion prior to the introduction of Oil Mist. Mist piping should permit mist flow with minimum wetting out of oil, and provide for drainage of any oil that is deposited, without creating obstructions to the mist flow. Since the mist system operates at very low pressure, the use of pipe dope or other thread sealants is not necessary and not recommended. Improperly used, these sealants can contaminate the mist piping. Flushing of the manifold is recommended during installation to eliminate scale and dirt which can plug the small bores of the application fittings. MIST PIPING SIZES are selected primarily to limit mist flow velocity. The TABLE at the BOTTOM of PAGE 15 shows the CFM that a given pipe, tube, or hose size carries at various flow velocities. The MAXIMUM VELOCITY of mist in the distribution system should be 24 fps (feet per second). Higher velocities will cause excessive wetting out of oil from the mist. The GENERAL RECOMMENDATION is to select distribution piping sizes to limit flow velocity to fps. This will keep wetting out of oil to an acceptable minimum and will permit some increase in system flow, if required, without exceeding the maximum rate. For ROLLING MILL application, 15 fps should be the maximum flow velocity. For systems designed to operate at manifold pressures between 16 inches and 6 inches water column, use 12 fps as design velocity. The use of OVERSIZE mist lines is PERMISSIBLE but UNDERSIZE piping should NOT BE USED. In some installations, drain lines are provided to carry reclassified oil away from housings. If such lines are also acting as vents, they should follow the same criteria as mist distribution piping, regarding flow velocity and avoidance of traps. In ROUTING MIST PIPING, the main consideration is AVOIDANCE OF TRAPS - low spots in which oil could collect. All parts of the distribution systems MUST DRAIN by gravity. The main manifold should be sloped downward toward the Oil Mist generator wherever possible. It is especially important to slope the first part of the main manifold toward the generator for a distance equal to 300 times the pipe ID, since most of the oil wetting-out occurs within that distance. The TABLE at the TOP of PAGE 16 shows the RECOMMENDED SLOPE of manifold for proper drainage back toward the generator. Branch lines, if sloped toward the main manifold, should be connected to the top or sides of the manifold, to avoid liquid oil traps. Where drainage provisions allow liquid oil and mist to flow in the same direction, horizontal runs do not require any slope. Horizontal runs which are not sloped should have drainage points not farther apart than 300 times the manifold ID. The drainage may be to points of lubrication, or to a standpipe or sump having provision for periodic dumping of collected oil. Where oil traps are unavoidable, a 3/64 inch diameter hole or a -3 spray fitting should be provided at the lowest point of the trap to drain oil. If dripping is objectionable, run a drain tube to a suitable receptable, vented with a 1/16 inch diameter hole. 7. Select APPLICATION FITTINGS CONFIGURATIONS that will be most convenient to install. Refer to types and sizes previously determined (Step 4), and select from fittings described on PAGES 17-21, and in Oil Mist Catalog. The complete fitting part number consists of a six-digit number, designating type and style, followed by the dash number, indicating size. 8. ACCESSORIES The basic Oil Mist system components are: a. An air line filter/water separator to assure a clean air supply to the Oil Mist generator. (INCLUDED with some models of Alemite Oil Mist generators, purchased separately for others). b. An air pressure regulator to control the atomizing air pressure to the generator - the BASIC SYSTEM ADJUSTMENT. (INCLUDED with some models of Alemite Oil Mist generators, purchased separately for others). c. An Oil Mist generator which includes a venturi nozzle, oil life tube, reservoir, and oil flow adjusting screw. d. Mist distribution system to convey the Oil Mist to the application fittings.

6 Oil Mist Application 5 e. Mist, spray or condensing application fittings to meter and reclassify the Oil Mist at each lubrication point. ACCESSORY Oil Mist system components include: a. An air supply on-off valve. A solenoid valve is often used and is INCLUDED with some models of Alemite Oil Mist generators. The use of a solenoid valve permits remote control or the interlocking of mist system operation with that of the lubricated machine. b. An oil heater to maintain the oil in the generator reservoir at the proper viscosity for good mist generation (INCLUDED with all generators supplied with air heater and with some sales models of most other generators.) c. An air heater ( Thermo-Aire ) to stabilize oil/air ratio, at varying ambient temperature, or to mist heavy oils which will not properly atomize at the prevailing ambient temperature. INCLUDED with some sales models of all generators for which available. NOT AVAILABLE for 12 ounce or one gallon generators). d. An oil level switch to signal low oil level in the reservoir and/or to control automatic reservoir refill. e. A mist manifold pressure gauge (manometer) for visual indication of manifold pressure. Although not necessary for system operation, it is STRONGLY RECOMMENDED that a mist pressure gauge be included in every Oil Mist system. It simplifies and improves the accuracy of system adjustment and provides valuable information on system operation, especially during start-up and if trouble shooting is required. f. A mist manifold pressure switch to signal high or low manifold pressure. SHOULD BE INCLUDED IN THERMO-AIRE SYSTEMS, wired to shut off air heater under alarm conditions, to protect heater element. See circuit diagrams in section 9. g. An Oil Mist detection unit ( Mist Monitor ) to signal high or low density of oil particles in the mist. With reservoir oil level, manifold pressure, and air temperature all within normal limits, it is still possible that a mist generator will not produce mist, due to improper oil in the reservoir or to blockage of oil flow to the mist head. The Mist Monitor continuously monitors mist density, photoelectrically, and signals any serious deviation from the calibration level. 9. Some suggested ELECTRICAL CIRCUITS are shown on PAGES Terminal or wire numbers for electrical components are given on PAGE 22. Of course, the user may use these components as desired, within their ratings. NOTE that circuits involving Thermo-Aire (air heaters)interlock the heater with the mist pressure switch. This is to protect the heater by preventing application of power without air flow through the unit.

7 6 Oil Mist Application Applying Oil Mist to specific types of machine elements ROLLING ELEMENT BEARINGS MODERATE SERVICE CFM = 2x1/40=0.05 CFM CALCULATIONS Moderate Service Heavy Service Rolling Mill Service Where D = Shaft diameter in inches cfm=dr/40 cfm=dr/20 cfm=dr/14 R = Number of rows of rolling elements The HEAVY SERVICE formula is used for: All constantly thrust loaded bearings. All preloaded bearings All bearings on shafts transmitting more than 40 horsepower. All bearings subjected to high inertial loads, either by frequent hard starting and stopping or by unbalanced shaft designs. The ROLLING MILL SERVICE formula is used for work roll and backup roll bearings in ferrous and non-ferrous rolling mills. MODERATE SERVICE is any not included in the other service definitions. SPRAY FITTINGS OR NOZZLES are preferred for rolling element bearings. MIST FITTINGS are used for moderate service rolling element bearings in closed housings where it is not practical to place a spray fitting close to each bearing. Because most of the output of a mist fitting will remain air-borne until carried into the turbulent region of a bearing, mist fittings can be installed remotely from the bearings they are to lubricate. Several bearings in a housing can be served by one mist fitting. To utilize the output from mist fittings, bearings must be operating at speeds no lower than 200 linear feet per minute and preferably above 1000 lfm, at the mean diameter of the bearing. VENTS must be positioned and sized to proportion positive mist flow through each bearing. AN EXCEPTION to the forced flow principle of inlet and vent location is used advantageously on single row, moderate service, ball bearings on shafts under four inches in diameter, operating over 200 lfm. Bearings in this category, mounted in the wall of a machine housing containing a mist atmosphere, can be mist lubricated if BOTH SIDES of the bearing are freely exposed to the mist. A drilled hole or undercut with a minimum area of square inches in the outer race support is used to expose the outboard side of a bearing in a blind wall mounting to the mist in the housing. The windage created by the rotating parts of the bearing assembly will create sufficient flow of mist through the rolling elements. The cfm requirement for each such bearing should be included in the calculated mist input for the housing. For radially mounted bearings designed to carry THRUST LOADS (Heavy Service), such as angular contact ball or tapered roller bearings, spray fittings and vents should be located so the flow through the bearing is opposite to the direction of thrust from the shaft. This is not necessary if an oil sump or bath is maintained. TAPERED ROLLER BEARINGS, operating with light preloads, are best lubricated from the small end of the rollers. On HEAVILY PRELOADED tapered roller bearings, two spray fittings per row can be used to advantage, especially in critical applications such as precision machine tool spindles. For these installations use the HEAVY SERVICE or even the MILL SERVICE formula. On the upstream side of the bearing use a spray fitting sized to deliver about one-third of the calculated requirement, and on the vent side use a spray fitting that will deliver about two-thirds of the calculated value. On the vent side, place the fitting as close as possible to the bearing and try to direct its output toward the bearing and away from the vent. VENTS and APPLICATION FITTINGS should generally be located so the calculated cfm for each row of rolling elements in HEAVY SERVICE flows through that row before exhausting through the vent. For bearings in MODERATE SERVICE, such forced flow can be through two consecutive rows, if necessary. With the EXCEPTION noted previously, forced flow through bearings is necessary when using mist fittings. In direct spray applications, with spray fittings discharging close to lubricated elements, the vents and fittings need not be on opposite sides of the bearings. OIL SUMPS are recommended for ALL HEAVY SERVICE BEARINGS and for all moderate service bearings mounted on shafts four inches or larger in diameter. A DEPTH of oil sufficient to cover the inside diameter of the bearing cup is recommended for tapered roller bearings. For other bearing types the depth of oil should be to the mid-height of the rolling element at the bottom of the bearing. Vent locations can be used to maintain the proper oil level. For high speed bearings, vents used to control the sump level should be located so the churning effect of the rolling elements does not throw sump oil out of the vent ports. Bearing housings with DOUBLE LIP SEALS require spray inlets and vents located to maintain an oil sump in the area between the contacting lips. The CFM seal requirement is equal to a row of elements on the same shaft in moderate service (cfm=d/40). Means of sighting sump oil level are recommended.

8 Oil Mist Application 7

9 8 Oil Mist Application PLAIN BEARINGS CFM CALCULATIONS Moderate Service Heavy Service Heavy Service, High Loss Where D = Shaft Diameter in Inches L = Sleeve Length in Inches MODERATE SERVICE BEARINGS are: cfm=ld/100 cfm=ld/60 cfm=ld/30 Rotating bearings on horizontal shafts where the load zone is always in the lower half of the bearing. Bearings mounted in any position where the oil is retained in the bearing by contact type seals. Bearings with porous bushings or synthetic frictionless sleeves. HEAVY SERVICE BEARINGS are: Oscillating bearings on horizontal shafts where the load zone is always in the lower half of the bearing. Unsealed bearings subjected to shock loading where the load zone constantly shifts, but boundary lubrication is permissible, such as king pins and spring pins on trucks. Small rotating bearings not mounted on horizontal shafts. HEAVY SERVICE, HIGH OIL LOSS BEARINGS are: Rotating bearings or bearings oscillating rapidly where the load zone shifts more than 180, such as crankshaft and crankarm bearings. Applications where these bearings operate over 600 lfm should be referred to the factory. Large bearings without seals that are not mounted on horizontal shafts. CONDENSING OR SPRAY FITTINGS are recommended for plain bearings with 360 sleeves. SPRAY FITTINGS are recommended for half-sleeve bearings. On 360 bearings, fittings are installed so their outlets are above the bearing housing. On HALF BEARINGS, spray fittings are installed to spray on the shaft near its line of entry into the bearing. The following general RULES FOR GROOVE LOCATIONS in Oil Mist lubrication bearings are consistent with accepted grooving practice for oil lubricated plain bearings, regardless of the method of oil application: A. Grooves should be located so that 90% of the surface area of the ungrooved surface (usually the shaft) passes over one oil groove during each cycle of motion. This rule is best represented by a longitudinal groove extending 90% of the sleeve length in a rotating bearing. Following this rule, OSCILLATING BEARINGS may require several longitudinal grooves. In small oscillating bearings these primary grooves can be connected by a circumferential secondary groove with a single application fitting supplying all grooves. On large bearings of this type, a fitting should be used for each longitudinal groove. B. Groove volumes should be kept to a minimum. With a constant source of lubricant input, large volume grooves, acting as reservoirs, are not required. Large volume grooves can be a disadvantage on machine start-up, if oil has completely drained from the groove volume during a shutdown period. For this reason, application fittings should not be spaced further than FIVE INCHES apart in bearings over five inches long. C. All groove edges or housing parting line edges facing the oncoming sliding surface should be rounded or chamfered to prevent scraping the oil from the shaft. D. Grooves should be in the unloaded zone of hydrodynamically lubricated bearings. On large bearings of this type the groove should be close to the area where the shaft enters the load zone. The RULES FOR VENTING plain bearings are: A. Grooves are also used to vent plain bearings. For this purpose, longitudinal grooves should extend to within 1/4 from the end of the sleeve in horizontal bearings. Circumferential grooves in vertical sleeves should be in the upper third of the sleeve and a longitudinal groove extending upward from this groove to the END of the sleeve is preferred for venting and should be opposite the application fitting inlet. B. Bearings with very close tolerances or with contact seals require a vent passage connected to the top of the internal grooving. The inlet and vent passages may be combined. SLIDES AND WAYS CFM CALCULATIONS Application fittings installed in SLIDE: cfm=a/800 Application fittings discharging ONTO WAYS: cfm=a/400 Where A = TOTAL contact area in square inches Generally, CONDENSING FITTINGS are used to deliver lubricant through holes in slides. SPRAY FITTINGS are used to supply oil to ways. For SLIDES, provide at least one application fitting for each six inches of slide width and four inches of slide length, or fractions thereof. Thus, a slide seven inches wide by nine inches long should carry six application fittings - two across by three lengthwise. Fittings should discharge into TRANSVERSE GROOVES extending 90% of slide width. Grooves should be VENTED or inlets and vents may be combined as illustrated for plain bearings. For WAYS, provide at least one application fitting for each six inches of contact width. Where MULTIPLE FITTINGS are used, DIVIDE the calculated CFM EQUALLY among them.

10 Oil Mist Application 9

11 10 Oil Mist Application GEARS CFM CALCULATIONS Spur, bevel, helical, etc: unidirectional cfm = F(D 1 + D 2 + D )/160 reversing cfm = F(D 1 + D 2 + D )/110 Worm gears, unidirectional cfm = F(2D 1 + D 2 )/160 reversing cfm = F(2D 1 + D 2 )/110 Where F = Gear face width, in inches D 1 = Pitch diameter of small gear or worm, in inches D 2 = Pitch diameter of large gear, in inches D 3, etc = Pitch diameters of additional gears, in inches If D 2, D 3 or any gear is LARGER THAN 2D, (except worm), in place of that larger gear USE 2D1. SPRAY FITTINGS OR NOZZLES are used to spray directly on gears. Provide a spray fitting for each TWO INCHES OF FACE WIDTH or fraction thereof. Where MULTIPLE FITTINGS are used across a WIDE GEAR FACE, DIVIDE the calculated CFM EQUALLY among them. For moderately loaded GEAR TRAINS, sprays directed at every second or third gear in the train will generally suffice. Using the formula, calculate the total cfm requirement for the train. Proportion this by eyeball estimate to the lubrication points selected. Use more or larger fittings on larger gears or on those with more mesh points. For HEAVILY LOADED GEAR TRAINS, provide sprays for all mesh point, estimating proportioning to determine number or sizes of fittings. For UNIDIRECTIONAL operation, direct spray at load side of gear teeth. For REVERSING service, direct spray toward gear axis: CHAINS CFM CALCULATIONS ROLLER Chain, power transmitting cfm = PDR 320 cfm = WD S 3 SILENT Chain 600 (100 ) Where P = Pitch of chain or sprocket, in inches D = Pitch diameter of small sprocket, in inches R = Number of rows of chain rollers W = Width of chain in inches S = rpm of small sprocket CONVEYOR Chain cfm = 3DW + 0.1LW 500 Where D = Diameter of drive sprocket, in inches W = Width of chain, in inches L = Length of chain, in inches SPRAY FITTINGS are used for chain lubrication. S 3 (100) For ROLLER and CONVEYOR chains, direct spray onto edges of link plates. For single strand roller and for conveyor chains, apply about one-half of the calculated cfm to each row of link plates. For MULTIPLE STRAND roller chain, divide the calculated cfm by the number of rows of rollers to find the spray FITTING SIZE for the inner rows of link plates. For the two outer rows of link plates, divide calculated cfm by two times the number of roller rows. For SILENT chain, provide one spray fitting for each 1/2 inch of width, starting 1/4 inch from outside edges. To SIZE fittings, divide calculated cfm by twice the chain width. For best results, position fittings to spray on the INSIDE OF THE SLACK STRAND. If spraying the SLACK STRAND, direct the spray slightly AGAINST the chain motion. If spraying the WORKING STRAND, point the spray slightly in the direction of chain motion.

12 Oil Mist Application 11 MIST GENERATOR FLOW CHARACTERISTICS

13 12 Oil Mist Application MIST GENERATOR FLOW CHARACTERISTICS

14 Oil Mist Application 13 SELECTION OF Oil Mist GENERATING COMPONENTS TO OBTAIN OIL/AIR RATIO OF 0.4 CUBIC INCH OIL/HOUR/CFM AIR The minimum ambient temperature and the oil viscosity for any intended application are used to locate a point on this chart. The location of this point provides information used to determine the Oil Mist equipment requirements for the intended application. CERTAIN OIL ADDITIVES CAN AFFECT THE OIL/AIR RATIO, OR STOP THE GENERATION OF MIST. OIL VISCOSITY RATING VS. ESTIMATED MINIMUM AMBIENT TEMPERATURE

15 14 Oil Mist Application RESERVOIR REFILL INTERVAL The chart relates mist flow and intervals at which various Alemite Oil Mist reservoirs will require refilling. Curves are based on a mist density of 0.6 cubic inches of oil per hour per cfm of mist. Curves are labeled with nominal reservoir capacities, but are based on actual usable cubic inches from FULL mark to nozzle starvation. Ranges covered by curves are those available with Alemite standard reservoir and mist head combinations.

16 (cfm) 2 2 Oil Mist Application 15 AIR PIPING 1/8 1/4 3/8 1/2 3/4.269 I.D..364 I.D..493 I.D..622 I.D..824 I.D PRESSURE DROP PER 100 FEET OF PIPE-psi PIPE SIZE MIST PIPE SIZING MIST FLOW SCFM SIZE ID-in 1/4 tube /8 tube /2 tube /8 pipe /4 pipe /8 pipe /2 pipe /4 pipe pipe /4 pipe /2 pipe pipe /2 pipe pipe /16 hose /4 hose /8 hose /2 hose /4 hose hose /4hose /2hose

17 16 Oil Mist Application Table Notes: SLOPE OF MIST MANIFOLD TOWARD GENERATOR OIL VISCOSITY MINIMUM AMBIENT OR MANIFOLD TEMPERATURE 0F 32F 50F 75F 100F *PERCENT SLOPE OF MANIFOLD *2% slope equals 2 drop every 100 of manifold 1. Table is for manifold where condensed oil flow is opposite the mist flow. 2. Table is for installations in continuous operation. For systems operating one or two shifts daily, divide slope in Table by 2.

18 Oil Mist Application 17 MIST APPLICATION FITTINGS Mist fittings are metering orifices which deliver mist, with minimum condensation, to machine elements. The mist must be converted to liquid oil by the machine element. The fittings are made of brass. Color - black. The air flow graph shows average output. INLET 1/8 NPTF (FEMALE) INLET 1/4 OD TUBE FTG ORIFICE OUTLET OUTLET OUTLET DIAMETER LENGTH FLOW 1/8 PTF* (m) 1/4 NPTF (m) 1/8 PTF* (m) AREA *SAE Special Short. PREFERRED ARRANGEMENT. INLET AND OUTLET CAN BE INTERCHANGED WHERE NECESSARY. PART NO. INCLUDES: ,-4,-6,-10, OR -16 FTG COMP. NUT COMP. SLEEVE

19 18 Oil Mist Application CONDENSING APPLICATION FITTINGS Condensing fittings are metering elements which convert mist to liquid oil within the fitting. The condensed oil flows by gravity to the machine element. The fittings are made of brass. Color - silver. The air flow graph shows average output. INLET 1/8 NPTF (f) INLET 1/4 OD TUBE FTG ORIFICE (BAFFLED) OUTLET 1/8 PTF * (m) OUTLET 1/8 PTF *(m) SIZE LENGTH FLOW AREA SLOT.014 R SLOT.020 R SLOTS.020 R SLOTS.020 R SLOTS.020 R SLOTS.020 R *SAE Special Short. PREFERRED ARRANGEMENT. INLET AND OUTLET CAN BE INTERCHANGED WHERE NECESSARY.

20 Oil Mist Application 19 SPRAY APPLICATION FITTINGS Spray fittings are metering orifices which convert a high percentage of mist to an oil spray. The fittings are made of brass. Color - olive drab. The air flow graph shows average output. INLET 1/8 NPTF INLET 1/4 OD TUBE FTG ORIFICE OUTLET 1/8 NPTF OUTLET 1/8 NPTF DIAMETER LENGTH FLOW AREA

21 20 Oil Mist Application SPRAY NOZZLE APPLICATION FITTINGS Spray nozzles contain one or more metering orifices which convert a high percentage of mist to an oil spray. The capacity of each metering orifice is nearly equal to that of one -8 spray fitting. The nozzles are made of brass. ONE END THREADED BOTH ENDS THREADED 1/2 NPTF (m) 3/4 NPTF (m) 1/4 NPTF (m) 1/2 PTF*(m) *SAE Short NO. OF ORIFICES.067 DIA LG. TOTAL FLOW AREA SQ. IN

22 Oil Mist Application 21 SPRAY NOZZLE APPLICATION FITTINGS (continued) Dash number for each curve indicates number of.067 diameter orifices in nozzle and is used as suffix of nozzle part number. The flow through one.067 diameter orifice is.56 cfm at a pressure drop of 60 inches water column, and.68 cfm at 80 inches water column. The nozzle air flow graph shows average output.

23 22 Oil Mist Application BASIC OIL MIST GENERATOR ELECTRICAL INTERCONNECTION DIAGRAM CODE SOL A TS-2 OH HPS LPS LLS TS-1 TS-3 AH **CAP. RSS SOL R COMPONENT TABLE OF COMPONENTS SOLENOID AIR SHUT-OFF VALVE OIL HEATER THERMOSTAT OIL HEATER MIST HIGH PRESSURE SWITCH (NO.2) MIST LOW PRESSURE SWITCH (NO.1) LOW LEVEL SWITCH ON THERMO-AIRE GENERATORS ONLY AIR HEATER THERMOSTAT LOW AIR TEMPERATURE SWITCH AIR HEATER CAPACITOR REFILL AND SIGNAL SWITCH SOLENOID OIL REFILL VALVE AUTOMATIC REFILL KIT NOTES: 1. This is the interconnection diagram for Oil Mist generators, but most models do not incorporate all the electrical components. 2. Terminal boxes having the same terminal strip numbering are recommended for Modular Design Generators. 3. These terminal numbers are used in the recommended elementary diagrams (in this section) for all Oil Mist Units, even though most models do not incorporate all the electrical components. 4. The recommended elementary diagrams in this section are intended to be representative of the majority of desired hookups. Where feasible, likely alternatives are shown. 5. Some circuits will require removal of jumpers 2-5, 5-6 and/or **High volume Thermo-Aire Generators only.

24 Oil Mist Application 23 RECOMMENDED ELEMENTARY WIRING DIAGRAMS FOR OIL MIST SYSTEMS WITHOUT OIL HEATERS These wiring diagrams are recommended for Oil Mist systems integral with a single machine. CR relay (5) can be used to interlock machine start and stop with Oil Mist system operation. DS-1(1) can be omitted if machine is equipped with a power disconnect. Sequence of Operation (upper diagram): 1. Manually closing DS-1 (1) energizes the air solenoid (4), allowing air to flow to the Oil Mist generator. Closing DS-1 also energizes the red light (6) and CR(5); therefore, CR contact (2) is open, and machine cannot be started. 2. When sufficient manifold pressure is attained, LPS (5) opens, de-energizing CR and the red light. The machine can now be started by closing PB-1. Function of CR Contacts: 1. With CR contacts in location #1, machine cannot be started without Oil Mist system, and will shut down when there is low oil level, low manifold pressure, or high manifold pressure. 2. With CR contacts in location #2, machine cannot be started without Oil Mist System, but once machine is started, failure of the Oil Mist system will energize red light, but will not shut down the machine. Sequence of Operation (lower diagram): 1. Manually closing DS-1(1) starts the Oil Mist system simultaneously with the machine, and failure of the Oil Mist System will only energize the red light (5).

25 24 Oil Mist Application RECOMMENDED ELEMENTARY WIRING DIAGRAMS FOR OIL MIST SYSTEMS WITH OIL HEATERS AND SIGNALS These wiring diagrams are recommended for Oil Mist systems integral with a single machine. CR relay (3) can be used to interlock machine start-and-stop with Oil Mist system operation. An alternate relay CR-2(7) can be wired in series with DS-3, and CR omitted. Where DS-1(1) is operated just prior to machine start, the oil heater should be wired upstream of DS-1. DS-1 can be omitted if machine is equipped with a power disconnect. Sequence of Operation (upper diagram): 1. Manually closing DS-1(1) energizes the oil heater (2) and the red light(5) indicating power on. 2. Manually closing DS-2(8) energizes the air solenoid, allowing air to flow to Oil Mist generator. 3. When sufficient manifold pressure is attained, LPS(4) de-energizes the green light (4) and optional relay coil CR(3). 4. If CR is used, machine can now be started. Also, DS-3(6) may now be closed to lock in howler H for annunciation of system fault. Sequence of Operation (lower diagram): 1. In diagram below, WS Light Signal unit is used in place of the individual red and green lights above. In case of malfunction, the red light and howler H, if used, will be energized. Sequence of operation is the same, except there is no indication when DS-3 can be closed without energizing the red light and howler. Also, there is no indication of power-on when DS-1 is closed to energize the oil heater; instead, the green light indicates the air solenoid is energized.

26 Oil Mist Application 25 RECOMMENDED ELEMENTARY WIRING DIAGRAMS FOR OIL MIST SYSTEMS WITH AIR AND OIL HEATERS AND SIGNALS These wiring diagrams are recommended where Oil Mist is lubricating a machine segment of a multiple-machine operation. Malfunction of the Oil Mist system energizes the warning signals, but does not stop the machine. WS alarm signal units are interchangeable in either circuit arrangement. Upper circuit shows air heater on same power input as control circuits. Lower circuit shows air heater on separate power input. Upper circuit can include 2CR relay (4) for interlocking machine start with proper Oil Mist system operation. When 2CR is used, 2CR contacts in start circuit are normally open. Upper circuit, as shown, is for MODULAR SERIES Thermo-Aire generators. For HIGH VOLUME units (2000 watt air heater), replace TS-1 and AH(3)with Heater Control Relay (HCR) coil, and connect TS-1, AH and HCR contacts as shown in lower diagram. Sequence of Operation (upper diagram): 1. Power across the input lines energizes the oil heater (1). 2. Manually closing DS-1(2) starts the Oil Mist system. 3. When Oil Mist system is stabilized, DS-2(6,8) is closed to lock in WS alarm, (Light Signal ), H Howler , and optional 2CR relay. Sequence of Operation (lower diagram): WS light signals (lamp 60 watts maximum) are shown in place of the alarm circuit shown above, and DS-2 is not required. 2CR relay cannot be used in circuit below, unless the WS alarm system shown in upper diagram is used. 1. Manually closing DS-1(1,5) starts the Oil Mist system. 2. When the Oil Mist system is stabilized, all warning lights are de-energized.

27 26 Oil Mist Application RECOMMENDED WIRING DIAGRAMS FOR OIL MIST SYSTEMS WITH OIL AND AIR HEATERS AND INDIVIDUAL SIGNALS This wiring diagram is recommended where Oil Mist is lubricating a machine segment of a multiple-machine operation, and neon pilot lights are used (with master warning signals) to indicate the cause of malfunction. Malfunction of the Oil Mist system energizes the warning signals, but does not stop the machine. The circuit shows air heater on a separate power input. The circuit can include 4 CR relay (15) for interlocking machine start with proper Oil Mist system operation. When 4 CR is used, 4 CR contacts in the start circuit are normally open.

28 Oil Mist Application 27 TYPICAL OIL-MIST SYSTEM PIPING SCHEMATIC

29 28 Oil Mist Application NOTES ON USE OF APPLICATION FITTING SELECTION CHART 1. Basic Design Manifold Pressure is 20 inches water column. 2. Minimum recommended vent area equals twice the application fitting orifice area. 3. Minimum recommended manifold pressure for mist fittings is 2 H Minimum recommended manifold pressure for spray fittings is 8 H Minimum recommended manifold pressure for condensing fittings is 12 H Design manifold pressure of 40 H20 is recommended for: a. Direct spray applications over 2000 fpm. b. Applications where the ambient temp. at the fittings is close to the minimum recommended. APPLICATION FITTING ORIFICE APPLICATION FITTING SELECTION CHART APPLICATION FITTINGS STANDARD CFM PRESSURE DROP-- INCHES WATER MIN. VENT TYPE NO. SIZE LENGTH FLOW AREA DIA. AREA DIA DIA MIST DIA DIA DIA ?? -05 SLOT.014R SLOT.020R SLOTS CONDENSING SLOTS SLOTS SLOTS CONDENSED 6 SLOTS &.38 SPRAY DIA DIA SPRAY DIA FITTING DIA ?? DIA ?? DIA D(1) D(2) D(3) D(4) D(5) D(6) SPRAY D(7) NOZZLE D(8) D(9) D(10) ? D(11) ??? D(12) ??? G(13) D(14)