Marley F400 ClearSky Cooling Tower Operation and Maintenance
Contents
1. Intermittent Seasonal Q GPM HW F CW F WB F Condition 1 Good 2 Keep an eye on it 3 Needs immediate attention 1 2 83 Comments Structure Casing Material Structural Material Fan Deck Material Stairway Material Ladder Material Handrails Material Interior Walkway Material Cold Water Basin Material Water Distribution System Distribution System Header Material Manifold Material Branch Arms Nozzles Orifice diameter _ _ inches Heat Transfer System Fill Inlet Face of Fill Eliminators ClearSky Heat Exchangers Use this space to list specific items needing attention 20 inspection checklist Condition 1 Good 2 Keep an eye on it 3 Needs immediate attention Mechanical Equipment Gear Drive Units 2 3 Comments id Manufacturer Model Ratio Oil Level Full LJ Add Immediately Q Low check again soon L Oil Condition Good LJ Contains Water L Contains Metal Q Contains Sludge U Oil Used type Seals Back Lash Fan Shaft End Play Any Unusual Noises No U Drive Shafts Manufacturer Fans Manufacturer Material Yes U Diameter Blade Material Action Required 23 aS Fixed Pitch Q Adjustable Pitch L Number of Blades Hub Material Hub Cover Material Blade Asse2. TOWER PERFORMANCE Keep the cooling tower clean and water distribution uniform to obtain continued maximum cooling capacity The capacity of a cooling tower to cool water to a given cold water temperature varies with the wet bulb temperature and the heat load applied to the cooling tower As the wet bulb temperature drops the cold water temperature also drops However the cold water temperature does not drop linearly with the wet bulb temperature A cooling tower will not control heat load The flow rate of water circulated through the cooling tower will determine the temperature range of cooling in conjunction with a given heat load The hot water and cold water temperatures will increase with higher heat loads ClearSky Plume Abatement System ClearSky towers have the unique ability to vary operation between Maximum Thermal Performance Mode and Maximum Plume Abatement Mode This system variation is achieved by manipulating motor operated control linkages to alter the air paths between heated saturated air or dry ambient air Mechanically actuated Vent Doors located in a horizontal plane just above the mist eliminators at the base of dry air ducts can be opened to permit passage of heated saturated air from the wet section of the cooling tower into dry path air ducts Dry Dampers mounted on the tower s exterior can regulate the amount of dry ambient air passing through the dry ducts and then heated in the ClearSky heat transfer media packs before
3. DAMPERS mi Z Warning Z Warning maintenance Tower Maintenance Always shut off electrical power to the tower fan motor prior to performing any inspections that may involve physical contact with the mechanical or electrical equipment in or on the tower Lock out and tag out any electrical switches to prevent others from turning the power back on Service personnel must wear proper personal protective clothing and equipment Well maintained equipment gives the best operating results and the least maintenance cost SPX recommends setting up a regular inspection schedule to insure effective safe operation of the cooling tower Use the schedule on page 17 to obtain continuously good performance with the least tower maintenance See Cooling Tower Inspection Check List in this manual Keep a continuous lubrication and maintenance record for each cooling tower HOT WATER DISTRIBUTION SYSTEM Keep the circulating water and distribution system piping and nozzles clean and free of dirt algae and scale Algae and scale may clog nozzles eliminators fill and piping and may collect on the equipment served thus reducing its performance An access hatch in the fan deck with ladder to an intermediate platform provides means for inspection of the plenum area above the eliminators Removal of an access hatch at the plenum level allows access to the spray chamber for inspection and maintenance of the nozzles and top of fill Provide surface
4. TOWER fg 3 NON WY FOG AREA f a AIR WITHIN TOWER 1 DRY BULB TEMPERATURE Visible plumes are typically much more dense and persistent in the wintertime than summer This is shown graphically in Figure 1 which relates the characteristics of the plume to the saturation curve of a psychrometric chart In winter operation air enters the tower at condition 1 and leaves saturated at condition 2 On leaving the tower the air reaches equilibrium with the ambient air along line 2 1 In doing so it remains in the supersaturated fog region of the chart for a considerable time Conversely sum mer air enters the tower at condition 3 and exits saturated at condition 4 Returning to ambient conditions along line 4 3 the leaving airstream is never within the fog region This classifies the plume visibility as wispy and short lived often not persisting beyond a few meters above the fan cylinder Although higher heat loads can increase the persistency of summertime plumes they never reach the density of those that form in cooler seasons gt 3 plume characteristics Marley ClearSky provide a means by which the plume leaving the tower can be made less visible or more buoyant or both resulting in reduced ground fogging This is done by reducing the actual grains of moisture in the plenum airstream and at the same time producing a stream of heated dry air that is mixed with the tower s primary saturated airstream prior to its exit from the tower
5. This results in desaturation of the plume to the point where it does not cross into the fog region on its way back to ambient atmospheric air conditions In other words little or no condensation will occur Visibility reduction is explained graphically in the Figure 2 ClearSky psychrometric diagram The primary airstream leaves the cooling tower s wet section fill at condition 1 and it then passes through the ClearSky heat exchanger where a secondary airstream enters the dry side of the ClearSky heat exchanger cooling the plume airstream and condensing a portion of the moisture moving the airstream condition along the saturation line to condition 2 The dry airstream gains heat but no moisture content and leaves at condition 3 These two airstreams mix together along line 3 2 exiting the tower at condition 4 Returning to atmospheric conditions along line 4 5 the plume is therefore neither dense nor persistent Plume characteristics depend upon the application of the ClearSky heat exchanger modules to the cooling tower In many cases the plume can be made to become invisible within one or two fan diameters above the top of the tower fan cylinder WET BULB OUT OF WET SECTION VISIBLE PLUME seh WET BULB OUT OF CLEARSKY PLUME DESIGN MIX LINE TO AMBIENT POINT S Lc F FAN EXIT POINT aa A M A n DRY BULB OUT OF CLEARSKY MOISTURE CONTENT DRY BULB TEMPERATURE Figure 2 Z Warning Note operation Before Startu
6. added as intermittent or shock treatment only as frequently as needed to control the slime and algae Chlorine and chlorine containing compounds should be added carefully since very high levels of chlorine may occur at or near the point of entry into the circulating water system FOAMING Heavy foaming sometimes occurs when a new tower is put into operation This type of foaming generally subsides after a relatively short period of operation Persistent foaming can be caused by the concentrations of certain combinations of dissolved solids or by contamination of the circulating water with foam causing com pounds This type of foaming can sometimes be minimized by increasing the blowdown but in some cases foam depressant chemicals must be added to the system Foam depressants are available from a number of chemical companies MAINTENANCE OF FILL PERFORMANCE Owner must keep water clean by treatment screening or filtering to avoid the possibility of fill clogging and loss of thermal performance Potential Causes of Fill Clogging Bacteria and or Slime Growth Can control with chlorine or non oxidizing biocides Suspended materials Trash etc Scale Can be sulfates silicates carbonates or oxides Scaling effects can be ac centuated by suspended muds Algae and or Slime Can control with chlorine or non oxidizing biocides A Caution maintenance Possible Sources of Scale Calcium Sulfate From make up and
7. being exhausted through the fan cylinder By closing the Dry Dampers and opening the Vent Doors heated saturated air is permit ted to pass through the ClearSky media passages designed for dry air Thus maximum heated saturated air flow through the fill is achieved producing maximum cooling MAXIMUM THERMAL PERFORMANCE MODE Position the dry dampers in the closed position and position the vent doors in the open position MAXIMUM PLUME ABATEMENT MODE Position the vent doors in the closed posi tion and position the dry dampers in the open position i gt operation In transitioning from maximum thermal performance to maximum plume abate Caution ment the hot and cold water temperatures will rise Care must be exercised to ensure that the water temperatures do not rise above 125 F or a lower limit defined by the user s process PARTIAL PLUME ABATEMENT MODE When managing maximum water tempera tures and reducing plume the tower may be operated in partial plume abatement mode Position the vent doors in the closed position Initially place the dry dampers in the closed position and let the water temperatures stabilize If the water temperatures are too high then open the vent doors for maximum cooling If the water temperatures are below maximum acceptable temperatures adjust the dry dampers incrementally open until either the plume is acceptable or until maximum water temperatures are reached Reference ClearSky Operation Logic Di
8. in the fan and drive assemblies a Fan hub clamp bolts See Marley Fan User Manual for correct torque setting b Fan hub cover bolts c Geareducer and motor mounting bolts d Drive shaft coupling and guard bolts 4 Check Geareducer oil for sludge or water by draining off and testing a sample as outlined in the Geareducer User Manual Check Geareducer oil level at oil level mark on the side of the case Add oil as required The oil level placard must be ad justed so that its full mark is at the same elevation as the full mark on the side of the Geareducer case Check oil lines to be sure there are no leaks See Geareducer User Manual for oil filling procedure and list of recommended lubricants 5 Rotate fan by hand to be sure of free rotation and ample tip clearance See Fan User Manual gt 5 Note Note operation 6 Check motor insulation with a Megger See Maintenance Section of Marley Electric Motor User Manual 7 Lubricate the motor according to motor manufacturer s instructions 8 Test run each fan separately for a short time Check for excessive vibration or unusual noise If either is present see Troubleshooting Guide on pages 18 and 19 of this manual Fan must rotate clockwise when viewed from above Recheck Geareducer oil level 9 Check functioning of make up water supply 10 Make sure the blowdown will carry the proper amount of water 11 Check dry damper linkage to be sure linkage is
9. on the temp range HW CW but is usually from 2 to 5 F Increase dry damper opening by an increment Yes Tower is in maximum plume abatement mode Are dry dampers 100 open 10 Figure 4 operation ClearSky Operation Logic Diagram Notes 1 Assumes maximum cold water CWwax temperature has priority over plume abatement 2 Assumes fans are operating at full speed 3 Assumes vent doors are either all open or all closed Further operational flexibility could be gained by only opening or closing some of the vent doors 4 Assumes dry dampers are closed when vent doors are open 5 CWmax is the maximum allowable cold water temperature established by the user Material temperature limits or process limits may influence this value 6 ACW is a nominal rise in cold water temperature due to closing vent doors from their open position Dry dampers are assumed closed before and after the vent doors are closed 7 Dry damper opening increments may need to be empirically determined as the actuator position is not linear with air flow 8 Maximum thermal performance mode means that no more damper or vent options are available to increase thermal performance to lower the cold water temperature 9 Maximum plume abatement mode means that no more damper or vent options are available to increase plume abatement OPEN VENT DOOR CLOSED VENT DOOR CLEARSKY HEAT EXCHANGERS DRY AIR DUCT DRY
10. sulfates produced by sulfuric acid for pH adjust ment Calcium sulfate should be kept below 1000 ppm expressed as CaCO3 Calcium Carbonate Generally will not form scale in the cooling tower if carbonate scaling does not occur in the condenser Exceptions If make up water contains surplus free carbon dioxide scaling may be inhibited in the condenser but may occur in the tower fill because of COs stripping Silicates and Oxides Silica scale is virtually impossible to remove Silica scale is unlikely if SiOo is held below 150 ppm Oxides such as iron oxide can coat all parts of the system if soluble iron is present in concentrations above 0 5 ppm Iron oxides do not usually develop into thick scales but can accentuate the development of other scales MAINTENANCE OF CLEARSKY PVC HEAT EXCHANGERS Fouling Dust may accumulate in the dry air ducts over time causing reduced heat transfer Do not use high pressure washing equipment on ClearSky PVC heat exchangers Low pressure washing from a municipal or similar water supply system using a hose with a spray nozzle on a shower setting is recommended Do not spray a jet stream directly on the PVC ClearSky heat exchangers Spray water at the top of the ClearSky heat exchangers Leaks Water should not be allowed to accumulate in the dry air ducts except when clean ing Evaporation of water in the dry ducts will reduce plume abatement Furthermore in cold climates ice accumu
11. up water providing none of the solids form scale or are otherwise removed from the system Mg 13 A Caution maintenance The blowdown quantity is normally and most easily achieved using a bleed value acti vated by a measurement of the water s dissolved solids In this way no exact calculation of blowdown GPM is required on an ongoing basis CHEMICAL TREATMENT Chemical treatmentis required to control biological growth in the cooling tower fill basins and piping In most cases chemical treatment of the circulating water is not required if adequate blowdown is maintained In most cases however chemical treatment is required to prevent scale formation and corrosion Sulfuric acid or one of the polyphosphates is most generally used to control calcium carbonate scale Various proprietary materials containing chromates phosphates or other compounds are available for corrosion control When water treatment chemicals are required the services of reliable water treating companies should be obtained Slime a gelatinous organic growth and algae a green moss may grow in the cool ing tower or heat exchangers Their presence can interfere with cooling efficiencies Proprietary compounds are available from water treating companies for the control of slime and or algae however compounds which contain copper are not recommended Chlorine and chlorine containing compounds are effective algaecides and slimicides If used chlorine should be
12. SP USER MANUAL WHERE IDEAS MEET INDUSTRY F400 ClearSky cooling tower OPERATION MAINTENANCE M2012 1248 ISSUED 6 2012 READ AND UNDERSTAND THIS MANUAL PRIOR TO OPERATING OR SERVICING THIS PRODUCT gt Marley Z Warning A Caution Note Note contents The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or to important information concerning the life of the product Indicates presence of a hazard which can cause severe personal injury death or substantial property damage if ignored Indicates presence of a hazard which will or can cause personal injury or prop erty damage if ignored Indicates special instructions on installation operation or maintenance which are important but not related to personal injury hazards These instructions assist in obtaining efficient long life from Marley counterflow cooling towers Direct questions concerning cooling tower operation and main tenance to your Marley sales representative Always include your tower serial number when writing for information or ordering parts Look for this number on the sidewall casing Plume Characteristics 3 Before Startup 5 Starting Procedure 6 Operation 6 ClearSky Plume Abatement System 7 ClearSky Operation Logic Diagram 10 Tower Maintenance 12 Water Usage and Treatment 13 Spare Parts 16 Seasonal Shutdown Instructions 16 Tower Cleaning 17 Troublesho
13. agram and Notes on pages 10 and 11 Note CLEARSKY HEAT EXCHANGERS DRY AIR DUCT WALL REMOVED AT DASHED ok LINES TO SHOW INTERNAL WOKS FEATURES WET AIR DUCT s S VENT DOOR SHOWN OPEN TO AN VENT WET AIR INTO DRY DUCT DRY DAMPER a o WET AIR DUCT Partial section showing the ClearSky plume abatement components Figure 3 HOT WATER DISTRIBUTION SYSTEM Maintain uniform water distribution at the nozzles uniform spray cone The amount of water circulated should approximate the contract requirements and the nozzle pressure should be kept constant Lower pres sures may indicate excessive losses in the piping system and or insufficient pump capacity greater pressures might indicate clogged nozzles and or overpumping If a greatly reduced water flow rate is desired it may be advisable to change nozzle sizes A Caution operation to obtain the desired pressure and maintain proper water distribution An SPX Cooling Technologies engineer can advise minimum and maximum flow rates for even distribution COLD WATER COLLECTION BASIN A suitable depth must be maintained to keep the pumps from pulling air into the line The amount of make up water required to keep the water in the collection basin at the required depth depends upon the evaporation loss and blowdown FAN DRIVE When using two speed motors allow atime delay of 20 seconds minimum after de energizing the high speed winding and before e
14. aintenance schedule General Recommendations more frequent inspection and maintenance may be desirable Stairs Ladders Walkways Doors Guardrails Davits Derricks Hoists ClearSky Dry Dampers and Vent Doors Driveshafts and Guards Structural Members D w 3 fen a ge w fav LL Geareducer Cold Water Basin Hot Water Distribution System Float Valve Control Valves Casing Fan Cylinder Motor ClearSky PVC Heat Exchangers Eliminators Suction Screen Fill e Inspect for clogging Check for unusual noise or vibration nspect keys keyways and set screws ake sure vents are open Lubricate grease Check oil seals Check operating oil level Check static oil level MN Oa AF WN Check oil for water and sludge 10 Change oil 11 Check fan blade tip clearance 12 Check water level 13 Check for leakage 14 Inspect general condition 15 Tighten loose bolts 16 Clean 17 Repaint 18 Rebalance 19 Inspect repair for safe use 20 Inspect and repair before each use D Daily W Weekly M Monthly Q Quarterly S Semiannually Y Yearly R as Required 23 WHERE IDEAS MEET INDUSTRY SPX COOLING TECHNOLOGIES INC 7400 W 129 STREET OVERLAND PARK KANSAS 65213 USA P 913 664 7400 F 913 664 7439 spxcoo
15. ases the quantity of warm water at the air inlet Not recommended for plume control 3 With no heat load on the circulating water icing cannot be controlled Towers must not be operated with reduced water rate and or no heat load during freezing weather If a bypass directly into the cold water basin is used all water must be bypassed Reverse operation of fans is not recommended See Fan Drive for fan speed change precautions INTERMITTENT OPERATION When the unit is operated intermittently during win ter weather it is necessary that the water be drained from the tower piping to insure protection against freezing and possible rupture ClearSky Operation Logic Diagram Wait several minutes Read cold water temp CW Are vent doors open Are dry dampers open Open vent doors Tower is in maximum thermal performance mode Reduce dry damper opening by an increment No action required Is tower pluming Are vent doors open Close vent doors Closing the vent doors will increase CW temp If CW temp is near CWyax then closing the doors may cause the CW temp to exceed CWyax Opening the dry dampers will increase the CW temp further ACW may be determined by operating the tower with the vent doors open and determining the CW temp CWopen Then close the vent doors and measure the CW temp CWciosep ACW CWcioseo CWoren This value will vary depending
16. cer See Geareducer User Manual If still noisy replace Gears Correct tooth engagement Replace badly worn gears Replace gears with imperfect tooth spacing or form Unusual Fan Drive Vibration Loose bolts and cap screws Tighten all bolts and cap screws on all mechanical equipment and supports Unbalanced drive shaft or worn Make sure motor and Geareducer shafts are in proper alignment and couplings match marks properly matched Repair or replace worn couplings Rebalance drive shaft by adding or removing weights from balancing cap screws See Drive Shaft User Manual Fan Make certain all blades are as far from center of fan as safety devices permit All blades must be pitched the same See Fan User Manual Clean off deposit build up on blades Worn Geareducer bearings Check fan and pinion shaft endplay Replace bearings as necessaly Unbalanced motor Disconnect load and operate motor If motor still vibrates rebalance rotor Bent Geareducer shaft Check fan and pinion shaft with dial indicator Replace if necessary Fan Noise Loose fan hub cover Tighten hub cover fasteners Blade rubbing inside of fan cylinder Adjust cylinder to provide blade tip clearance Loose bolts in blade clamps Check and tighten if necessary Insufficient Cold Water Tower operating in plume abatement mode See ClearSky Operation Logic Diagram on page 10 Plume Insufficient dry air Close vent d
17. is not on all leads at starter make sure overload and short circuit devices are in proper condition Check motor and control connections against wiring diagrams Check nameplate voltage against power supply Check voltage at motor terminals Open circuit in motor winding otor or fan drive stuck Check stator windings for open circuits Disconnect motor from load and check motor and Geareducer for cause of problem Rotor defective Look for broken bars or rings Unusual Motor Noise Motor Runs Hot otor running single phase otor leads connected incorrectly Ball bearings Stop motor and attempt to start it Motor will not start if single phased Check wiring controls and motor Check motor connections against wiring diagram on motor Check lubrication Replace bade bearings Electrical unbalance Check voltages and currents of all three lines Correct if required Air gap not uniform Check and correct bracket fits or bearing Rotor unbalance Cooling fan hitting guard Wrong voltage or unbalanced voltage Rebalance Reinstall or replace fan Check voltage and current of all three lines against nameplate values Overload Check fan blade pitch See Fan Service Manual Check for drag in fan drive train as from damaged bearings Wrong motor RPM Check nameplate against power supply Check RPM of motor and gear ratio Bearings overgreased Remove grease reliefs Run motor
18. lation may cause damage Leaks at casing and or flashing should be resealed Leaks in the PVC heat exchange tubes may be sealed with an adhesive PVC cement is not recommended because it may soften the plastic In the event that the source of the leak can not be identified the wet path of that tube should be plugged A closed cell flexible foam that can be inserted and removed is recommended maintenance Spare Parts SPX Cooling Technologies manufactures and maintains a stock of replacement parts for all cooling tower mechanical equipment Shipment of these parts are normally made within ten days after an order is received If emergency service is necessary contact the local Marley representative for assistance To prevent prolonged shutdown periods in case of damage to the mechanical equip ment it is suggested that the following parts be carried in the owner s stock One fan assembly One Geareducer assembly One drive shaft assembly Be sure to furnish the tower serial number when ordering parts Seasonal Shutdown Instructions Tower Drain all tower piping During shutdown clean the tower and make any necessary repairs Apply protective coating as required to all metal parts Particular attention should be given to mechanical equipment supports drive shaft and drive shaft guards Mechanical Equipment Geareducer shutdown for 3 months or less 1 Each month drain water condensate from the lowest p
19. ling spx com spxcooling com In the interest of technological progress all products are subject to design and or material change without notice ISSUED 6 2012 M2012 1248 COPYRIGHT 2012 SPX Corporation F400 ClearSky cooling tower
20. mbly Hardware Blade Tip Clearance Vibration Level Fan Cylinder Height Mech Eqpt Support Mat Oil Fill amp Drain Lines Oil Level Sight Glass Vibration Limit Switches Other Components Motor Manufacturer Name Plate Data RPM Phase Cycle Volts F L Amps Frame Last Lubrication Date S F Special Info Grease Used Type Any Unusual Noise Any Unusual Vibration Any Unusual Heat Build up No No CoO CoO Action Required Action Required Action Required 21 inspection checklist Actuators Dry Dampers Manufacturer _ Model Ratio Motor Manufacturer Name Plate Data hp RPM Phase Cycle Volts FL Amps Frame S F Special Info Last Lubrication Date Grease Used Type Any Unusual Noise No U Yes U Action Required Any Unusual Vibration No U Yes U Action Required Any Unusual Heat Build up No U Yes U Action Required Actuators Vent Doors Manufacturer Model Ratio Motor Manufacturer Name Plate Data hp RPM Phase Cycle Volts FL Amps Frame S F Special Info Last Lubrication Date Grease Used Type _ SSS Any Unusual Noise No U Yes U Action Required Any Unusual Vibration No U Yes U Action Required Any Unusual Heat Build up No U Yes U Action Required 22 inspection and m
21. nel must wear proper personal protective equipment during decontamination Do NOT attempt any service unless the fan motor is locked out Operators of evaporative cooling equipment such as water cooling towers should fol low maintenance programs which will reduce to an absolute minimum the opportunity for bacteriological contamination Public Health Service officials have recommended that good housekeeping procedures be followed such as regular inspections for concentrations of dirt scale and algae periodic flushing and cleaning and the follow ing of a complete water treatment program including biocidal treatment Visual inspection should take place at least once a week during the operating season Periodic flushing and cleaning should be done at least twice a year Nozzles should be checked for clogging Drift eliminators and easily accessible fill surfaces should be cleaned by use of a moderate pressure water nozzle being careful not to cause physi cal damage A reliable water treatment program should be installed and maintained troubleshooting Trouble Cause Remedy Motor Will Not Start Power not available at motor terminals Wrong connections Low voltage 1 Check power at starter Correct any bad connections between the control apparatus and the motor 2 Check starter contacts and control circuit Reset overloads close contacts reset tripped switches or replace failed control switches 3 If power
22. nergizing the low speed winding Tremendous stresses are placed on driven machinery and motors unless the motors are allowed to slow to low speed RPM or less before the low speed winding is energized COLD WEATHER OPERATION During periods of low temperature operation 35 F to 40 F or below ice will form on the relatively dry parts of the cooling tower that are in contact with the incoming air Primarily this includes the air inlet and adjacent structural framing Your understanding of cold weather operation will be enhanced if you read Operating Cooling Towersin Freezing Weather Marley Technical Report H 003 Ice forming characteristics on any given cooling tower will vary depending on velocity and direction of wind circulating water rate and heat load Excessive ice formation may be controlled by regulating air and water flow through the tower by one or more of the following procedures 1 Shut the fan down This reduces the cooling air rate to a minimum and increases the quantity of warm water at the air inlet to a maximum However normal fan off operation causes reverse air flow by aspiration and may cause water blowout and therefore must be done with caution and monitoring For automatic operation atimer switch can be provided to shut the fan down for a few minutes each hour 2 When a cooling tower has two speed motors operate the fans at half speed forward This reduces the cooling air rate heat transfer and incre
23. oint of the Geareducer and its oil system Check oil level and add oil if necessary Operate to recoat all interior surfaces with oil 2 At start up drain water condensate and check oil level Add oil if necessary Refer to Geareducer User Manual for maintenance and lubrication instructions Geareducer shutdown for 3 months or more 1 If the motors have space heaters operate mechanical equipment one hour each month 2 If the motors do not have space heaters operate mechanical equipment one hour each week Z Warning maintenance 3 At startup operate mechanical equipment one hour or until oil is warm then shut the equipment down Drain the oil and refill with new oil Refer to Geareducer Manual for instruction on changing oil Refer to Downtime Instruction Manual for downtime exceeding six months Electric Motors 1 Do not start motor without determining that there will be no interference with free rotation of the fan drive 2 Refer to the Marley Motor User Manual 3 If shutdown period is longer than seasonal contact your Marley sales representative for additional information ClearSky Plume Abatement System Close dry dampers to prevent foreign objects from entering the dry ducts Cooling Tower Cleaning Any evaporative type cooling tower must be thoroughly cleaned on a regular basis to minimize the growth of bacteria including Legionella Pneumophilla to avoid the risk of sickness or death Service person
24. oors and incrementally open dry dampers See ClearSky Operation Logic Diagram on page 10 Duty more difficult than design Tower will plume Configure for maximum plume mode See ClearSky Operation Logic Diagram on page 10 SAFETY FIRST The tower has been designed to provide a safe working environment while either operating or shut down The ultimate responsibility for safety rests with the Operator and Owner When flow to the tower is shut off or when portions of the tower require maintenance temporary safety barricades may be required around openings and other safety precautions such as safety harnesses should be utilized where appropriate for compliance with OSHA regulations and standards and good safety practices Routine periodic maintenance must be performed on all personnel access and material handling accessories in accordance with the following schedule Ladders Stairways Walkways Handrails Covers Decks and Access Doors Davits Derricks and Hoists Inspect for General Condition Semi annually Semi annually Inspect and Repair for Safe Use Yearly Inspect and Repair Before Each Use As Required inspection checklist Date Inspected Owner Owner s Tower Designation Inspected By Tower Manufacturer Process Served by Tower Design Conditions Number of Fan Cells Location Model No Serial No Operation Continuous
25. oting 18 Safety 19 Inspection Checklist 20 Inspection and Maintenance Schedule 23 Figure 1 MOISTURE CONTENT plume characteristics Because of the evaporation that takes place in a cooling tower the leaving airstream is saturated with water vapor This plume of saturated air can be highly visible because it is usually warmer and contains considerably more moisture than the surrounding atmosphere As it cools to reach equilibrium with the ambient air its excess water vapor condenses because cold air is incapable of assimilating as much moisture specific humidity as warm air This condensed plume of moisture becomes visible as fog The cooling of this plume also decreases its buoyancy its ability to rise In many cases particularly in adverse wind conditions cooling plumes will remain at very low levels until they dissipate often reinforcing ground level fogging This is unacceptable in the vicinity of airports and is of serious concern when the density and persistency affects road visibility The density persistency and buoyancy of this visible plume is a function of the total amount of heat extracted from the water by evaporation the temperature at which the heat is extracted and the temperature of the ambient atmospheric air The greater the difference between the temperature of the warm exhaust air and the cool ambient air the more visible the plume x VISIBLE PLUME amp FOG AREA S iS X S MIXING AIR ABOVE
26. p Among other sources outbreaks of Legionnaires disease have reportedly been traced to cooling towers Maintenance procedures that prevent amplification and dissemination of Legionella and other airborne bacteria should be formu lated and implemented BEFORE systems are operated and continued regularly thereafter to avoid the risk of sickness or death CLEANING New installations should be cleaned and treated with biocides by a water treatment expert before startup Remove any dirt and trash which has accumulated in the cold water basin Remove any sediment from the cold water collection basin sump and screens Use a water hose to flush cold water collection basins OPERATE WATER SYSTEM Start the circulating water pumps Increase the flow of circulating water gradually to match design water flow rate Circulate water over the cooling tower continuously for several days before starting the mechanical equipment and placing the cooling tower into continuous operation When starting in cold weather follow procedures outlined in Cold Weather Operation INSPECTION It is imperative that all operating assemblies be inspected before they are placed in operation The following is a list of components to be checked before starting the tower 1 Check drive shaft alignment Realign if necessary See Marley Drive Shaft Service Manual 2 Check tightness of bolts in fan cylinder joints 3 Check tightness of the following bolted joints
27. properly functioning Actuate dry dampers to make sure they open and close 12 Check dry duct vent doors to see that linkage is properly functioning In cold weather if possible inspect doors for snow and ice that may freeze doors shut Tower may need to operate with heat load to melt snow and ice prior to operating vent doors Actuate dry duct vent doors to make sure they open and close Starting Procedure WATER SYSTEM Fill the cold water collection basin and circulating water system until the operating water level is reached See Operation Section below Prime and start the circulating water pumps Increase the flow of circulating water gradually to design water flow rate to avoid water hammer which could damage the distribution piping system Clean the sump screens several times during the first weeks of operation After this clean sump screens weekly When starting in cold weather follow procedures outlined in Cold Weather Operation STARTING FAN Startthe fan After 30 minutes of operating time to permit Geareducer oil to come up to operating temperature check motor load with watt meter or take operating volt and ampere readings and calculate motor hp Refer to Marley Fan User Manual for instructions Pitch fans to pull correct contract horsepower when circulating design water rate at design hot water temperature A Caution operation Operation Entering water temperature in excess of 125 F may result in fill deformation
28. protection before walking on the fill DRIFT ELIMINATORS Eliminators should be kept clean Do not walk or step on the eliminators without planking and safety harness Number of Concentrations 1 5X 2 5X 3 0X 4 0X 5 F 2 78 C 78 38 25 18 11 10 F 5 56 C 1 58 78 51 38 25 15 F 8 33 C 2 38 1 18 78 58 38 20 F 11 11 C 3 18 1 58 1 05 78 51 25 F 13 89 C 3 98 1 98 1 32 98 64 Cooling Range Multipliers are based on drift of 0 02 of the circulating water rate COLD WATER COLLECTION BASIN supplied by others Inspect collection basin occasionally for leaks and repair if necessary Keep cold water outlets clean and free of debris Makeup and circulating water controls must operate freely and maintain the desired water quantity in the system maintenance DRIVE SHAFT Check drive shaft alignment and condition of couplings every six months See the Drive Shaft User Manual for correcting misalignment balancing or replacing parts ELECTRIC MOTOR Lubricate and maintain each electric motor in accordance with the manufacturer s instructions If repair work is necessary contact the nearest repre sentative of the motor manufacturer See Warranty Section of Marley Electric Motors User Manual FAN Inspect fan blade surfaces every six months For detailed maintenance informa tion refer to Marley Fan User Manual GEAREDUCER Make weekly and monthly oil checks Inspect in
29. ternal parts during seasonal oil change Refer to the Geareducer User Manual for detailed maintenance instructions DRY DAMPERS Inspect linkages adjust and lubricate as needed VENT DOORS Inspect linkages and bearings adjust and lubricate as needed PAINTING Periodically clean and if necessary recoat all metal parts subjectto corrosion Water Usage and Treatment BLOWDOWN Blowdown or bleed off is the continuous removal of a portion of the water from the circulating system Blowdown is used to prevent the dissolved solids from concentrating to the point where they will form scale The amount of blowdown required depends upon the cooling range the difference between the hot and cold water temperatures the composition of the make up water water added to the sys tem to compensate for losses by blowdown evaporation and drift and the amount of condensed water returned from the ClearSky heat exchanger modules The follow ing table shows an approximate amount of blowdown required to maintain different concentrations with various cooling ranges these numbers are reduced by the of condensed water at a given weather condition BLOWDOWN OF CIRCULATING RATE EXAMPLE 7000 GPM circulating rate 15 cooling range To maintain 4 concentra tions the required blowdown is 38 or 0038 times 7000 GPM which is 26 6 GPM If tower is operated at 4 concentrations circulating water will contain four times as much dissolved solid as the make
30. up to speed to purge excessive grease Rotor rubs stator bore Wrong lubricant in bearings If not poor machining replace worn bearing Change to proper lubricant See motor manufacturer s instruction One phase open Stop motor and attempt to start it Motor will not start if single phased Check wiring controls and motor Poor ventilation Clean motor and check ventilation openings Allow ample ventilation around motor Winding fault Bent motor shaft Insufficient grease Deterioration of or foreign material in grease Check with Ohmmeter Straighten or replace shaft Remove plugs and regrease bearings Flush bearings and relubricate Bearings damaged Replace bearings Incorrect fan blade pitch See Fan Service Manual for blade pitching instructions Voltage too low at motor terminals because of line drop Check transformer and setting of taps Use higher voltage on trans former terminals or reduce loads Increase wire size or reduce inertia Motor Does Not Come Up To Speed Broken rotor bars Look for cracks near the rings A new rotor may be required Have motor service man check motor 18 troubleshooting Trouble Cause Remedy Wrong Rotation Motor Wrong sequence of phases Change any two of the three motor leads Geareducer Noise Geareducer bearings If new see if noise disappears after one week of operation Drain flush and refill Gearedu
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