MH Fluid Cooler
Contents
1. be designed for free drainages of fluid at shutdown Coil shall be warranted against any failure caused by defects in materials and workmanship for a period of eighteen 18 months from the date of tower shipment Convenience and Safety Options Guardrail and Ladder MHF706 and MHF707 models only Add the following paragraph in the Access section The top of the fluid cooler shall be equipped with a sturdy guardrail complete with kneerail and toeboard designed according to OSHA guidelines Guardrails and kneerails shall consist of 42mm O D x 15 gauge gal vanized structural tubing the guardrail of which shall be capable of withstanding a 890N concentrated live load in any direc tion Posts are 51mm x 51mm square structural tubing and shall be spaced on centers of 2438mm or less A 457mm wide aluminum ladder with 76mm I beam side rails and 32mm diameter rungs shall be permanently attached to the endwall casing of the fluid cooler rising from the base of the fluid cooler to the top of the guardrail B For pure resistance to corrosion coupled with the capability to meet stringent fire and building codes there is no substitute for stainless steel No paints or electostatically applied coatings however exotic they may be can match stain less steel s ability to withstand adverse operating conditions B For process fluids that are not compatible with the standard galvanized steel construction stainless steel offers you th2. blade bear ings shall be corrosion resistant molded synthetic bearings Damper blades shall be single skin constructed from G60 galvanized steel Damper frame shall also be manufactured from G60 galvanized steel Damper actuators shall be either pneumatic or electric depending on cus tomer s preference Dampers shall be field installed and actuators shall be wired by others Gear Drive MHF706 and MHF707 models only Replace paragraph 7 1 with the fol lowing Fan s shall be propeller type incorporating aluminum alloy blades and galvanized steel hubs Blades shall be individually adjustable Fan s shall be driven through a right angle industrial duty oil lubricated geared speed reducer that requires no oil changes for the first five 5 years of operation Motor Out of the Airstream MHF706 and MHFO77 models only with gear drive option Add the following to the end of para graph 7 1 The motor shall be mounted outside the casing of the fluid cooler and shall be connected to the gear reducer by a dynamically balanced stainless steel tube and flange drive shaft B Positive closure dampers give you the added security of safe operation in freez ing weather Heat loss data from the coil can be obtained by accessing the Marley UPDATE web based selection software at spxcooling com Pneumatic damper actuators are UL approved totally enclosed with spring return actuators Electric actuators are industrial grade IP56 rate
3. s requirements Marley MH Fluid Cooler Engineering Data Schematic PLAN VIEW wW Use this data for preliminary layouts only Obtain current drawing from your Marley sales representative The Marley UPDATE web based selection software available at spxcooling com provides MH Fluid Cooler model recommendations based on customer s specific design requirements H INSTALLED FLuipour EIGHT mS ACCESS DOOR gt FLUID IN PUMP a Q SIDE ELEVATION AIR INLET ELEVATION Dimensions mm Shipping Weight kg Model Ee Motor Pump A eavies kW kW L WwW H Weight Section MHF702 2769 2565 5182 4237 2699 5 60 11 19 2 24 MHF703 3683 2565 5182 5080 3289 7 46 14 92 3173 MHF704 3683 3632 5817 7824 5162 11 19 22 38 31 3 MHF705 55 12 3632 5817 11782 7743 16 79 33 57 5 60 Marley MH Fluid Cooler Engineering Data Schematic PLAN VIEW Use this data for preliminary layouts only Obtain current drawing from your Marley sales representative The Marley UPDATE web based selection software available at spxcooling com provides MH Fluid Cooler model recommendations based on customer s specific design requirements ACCESS DOOR SIDE ELEVATION INSTALLED HEIGHT FLUID
4. to the by pass circuit the fan motor will run at constant full speed The bypass circuit will not modulate ON and OFF based on fluid temperature The application must be able to handle very cold fluid temperatures while the VFD is in a by pass mode Operator controls shall be mounted on the front of the enclosure and shall consist of start and stop control bypass VFD selection Auto Manual selections manual speed control To prevent heating problems in the fluid cooler fan motor and to assure proper gear reducer lubrication the VFD system shall de energize the motor once 25 motor speed is reached and cooling is no longer required The fluid cooler manufacturer LLa B Marley VFD drive systems are designed to combine absolute temperature control with ideal energy management The fluid cooler user selects a cold water temperature and the drive system will vary the fan speed to maintain that temperature Precise temperature control is accomplished with far less stress to the mechanical equipment components The improved energy management provides fast payback Motors operated on a VFD shall carry a service factor of 1 0 When operating on a VFD the drive parameters should be programmed to limit the current to motor nameplate hp Adjust the Motor specification accordingly Marley MH Fluid Cooler Specifications Options j Specification Value shall supply VFD start up assistance Tower vibration testing throughout
5. water basin is the only part of the tower that is subject to periods of stagnant water concentrated with treatment chemicals and customary contami nants It is also the most expensive and difficult part of any tower to repair or replace For these reasons many customers particularly those who are replac ing older towers choose to specify stainless steel cold water basins B It would also be advisable to change the fill support tubes in Paragraph 8 1 from galvanized structural tubing to 300 stainless steel structural tubing 112 Marley MH Fluid Cooler Specifications Options Specifications Specification Value All Stainless Fluid Cooler Replace paragraph 6 1 with the follow ing Except where otherwise specified all components of the fluid cooler shall be fabricated of heavy gauge series 300 stainless steel The tower shall be capable of withstanding water having a chloride content NaCl up to 750 mg L a sulfate content SO4 up to 1200 mg L a calcium content CaCO3 up to 800 mg L silica SiO2 up to 150 mg L and design operating ranges up to 28 C The circulating water shall contain no oil grease fatty acids or organic solvents Stainless Steel Coil Replace paragraph 4 1 with the follow ing Coil s shall consist of fully welded box headers with serpentine coils All coil components shall be assembled from series 300 stainless steel Maximum operating design pressure shall be 1379 kPa The coil shall
6. IN AIR INLET ELEVATION Dimensions mm Shipping Weight kg Model ENE Motor Pump 4 eavies kW kW L w H Weight Section MHF706 3632 7264 6706 16279 10936 14 92 55 95 2 5 60 MHF 707 4242 7874 6706 18738 12719 22 38 55 95 2 5 60 Marley MH Fluid Cooler Engineering Data Support D AIR INLET ee MODELS MHF702 THRU MHF705 Mew D__ penection MHF702 2515 4 76 MHF703 2515 9 53 MHF704 3581 9 53 MHF705 3581 9 53 MHF706 3432 12 70 MHF707 3737 12 70 Boy on D D MODELS MHF706 AND MHF707 Use this data for preliminary layouts only Obtain detailed support drawings from your Marley sales representative Primary support consists of parallel l beams running the full length of the unit Marley MH Fluid Cooler Engineering Data Freeze Prevention Fluid Cooler Coil When the ambient temperature falls below 0 C heat loss from the coil be substantial even without recirculating water flowing over the coil The process fluid without an applied heat load may be prone to freezing There are various methods to protect against coil freezing Ethylene and propylene glycol solutions are the best means to protect against coil freezing and are recommended for most installations The ap
7. SP Engineering Data amp Specifications gt Marley MH Fluid Cooler Marley MH Fluid Cooler Table of Contents Engineering Data Schematic Single Flow Models Schematic Double Flow Models Support Freeze Prevention Water Quality Specifications Base Base Thermal Performance Performance Warranty Coil Design Loading Construction Mechanical Equipment Fill Louvers and Drift Eliminators Distribution Basin Casing Fan Deck and Fan Guard Access Collection Basin Warranty Specifications Options Stainless Steel Options Stainless Steel Collection Basin Stainless Steel Distribution Basin All Stainless Steel Fluid Cooler Stainless Steel Coil Convenience and Safety Options Guardrail and Ladder Distribution Basin Access Platform Ladder Extension Ladder Safety Cage Access Door Platform Plenum Walkway Interior Mechanical Equipment Access Platform Control Options Fan Motor Starter Control Panel Vibration Limit Switch Basin Heater Fan Motor Variable Speed Drive Miscellaneous Options Dampers Gear Drive Motor Out of the Airstream Premium Efficiency Motor High Temperature Fill Air Inlet Screens FM Approval oa A 10 10 10 11 12 12 12 13 13 13 14 14 15 15 15 16 16 16 16 17 17 17 18 18 19 21 21 21 22 22 22 22 Marley MH Fluid Cooler The Marley MH Fluid Cooler is the most efficient system on the market and your bes
8. acceptable water treatment program must be compatible with the variety of materials incorporated in a fluid cooler ideally the pH of the recirculating water should fall between 6 5 and 9 0 Batch feeding of the chemicals directly into the fluid cooler is not a good practice since localized damage to the fluid cooler is possible Specific startup instructions and additional water quality recommendations can be found in the MH Fluid Cooler User Manual which accompanies the fluid cooler and also is available from your local Marley sales representative For complete water reatment recommendations and services contact your local Marley sales representative Marley MH Fluid Cooler Specifications Base Specifications Specification Value Base Furnish and install an induced draft crossflow type factory assembled galva nized steel closed circuit fluid cooler Unit shall consist of cell s as shown on plans The limiting overall dimensions of the tower shall be wide long and high to the top of the fan guard Total operating kilowatts of all fans shall not exceed kW consisting of kW motor s Tower shall be similar and equal in all respects to Marley Model Thermal Performance Water as the heat transfer fluid The fluid cooler shall be capable of cool ing m hr of water from C to C at a design entering air wet bulb temperature of C Coil pressure drop shall not exceed kPa The thermal performance ra
9. ative to provide for adequate freeze protection Fluid Cooling Recirculating Water When the ambient air temperature falls below 0 C the recirculating water within the fluid cooler can freeze Marley Technical Report H 003 Operating Cooling Towers in Freezing Weather describes how to prevent freezing during operation Ask your Marley sales representative for a copy or download a copy at spxcooling com During shutdown water collects in the basin and may freeze solid You can prevent freezing by adding heat to the water left in the basin or you can drain the tower and all exposed pipework at shutdown Electric Basin Heaters An automatic basin water heater system consisting of the following components e Stainless steel electric immersion heater s Threaded couplings are provided in the side of the collection basin e P56 enclosure containing Magnetic contactor to energize heater Transformer to convert power supply to 24 volts for control circuit Solid state circuit board for temperature and low water cutoff The enclosure may be mounted on the side of the fluid cooler e Control probe in the collection basin to monitor water temperature and level Heat tracing for recirculating water pump The basin heater option is only for freeze protection of the recirculation water in collection basin The basin heater option does not protect the coil during freezing weather Heater components are normally shippe
10. cou plings and the mechanical equipment support The bear ing assemblies and V belts shall be war ranted for 18 months High Temperature Fill Replace paragraph 8 1 with the follow ing Fill shall be film type thermoformed of 0 51mm thick high temperature PVC with louvers and eliminators formed as part of each fill sheet Fill shall be sus pended from stainless steel structural tubing supported from the tower struc ture Air Inlet Screens Add the following paragraph The air inlet faces of the top module fill area of the fluid cooler shall be covered by 1 mesh hot dip galvanized welded wire screens Screens shall be mounted in galvanized steel U edging and shall be removable FM Approval Add the following paragraph in the Construction section The tower shall include all design and material modi fications necessary to meet the fire rating requirements of Factory Mutual The product proposed shall be listed in the FM Approval Guide latest edition E For process fluid above 57 C B In wooded or windy areas these screens help to keep leaves or blowing debris out of the cooling tower and circulating water system B This could have a very beneficial effect upon your fire insurance premiums Towers not able to meet FM requirements may require the inclusion of a fire protection sprinkler system to achieve a comparable level of insurance premium cost Even if you are not insured by FM this requirement ensures tha
11. d 2 position drive both ways The damper section protrudes from the louver face a minimum of 150mm E The exclusive Marley System5 Geareducer requires no oil changes for five years offering you unmatched reliability and low maintenance B For many years a feature of Marley cooling towers was that the electric motors were located outside the fan cylinders where they were easily accessible and where they were not subjected to the constant humidity that exists inside the tower plenum Although improved motor designs insulation bearings seals and lubricants have now made it feasible for us to locate the motor inside in close coupled proximity to the Geareducer many users still prefer the motor to be located outside the humid airstream If you are among those users or are among those who see the wisdom of their thinking please specify this option Marley MH Fluid Cooler Specifications Options 22 Specifications Specification Value Premium Efficiency Motor Replace paragraph 7 3 with the follow ing The fan and fan drive assembly for each cell shall be supported by a rigid welded hot dip galvanized steel structural support that resists misalignment The mechanical equipment assembly shall be warranted against any failure caused by defects in materials and workmanship for no less than five 5 years following the date of tower shipment This war ranty shall cover the fan speed reducer motor drive shaft and
12. d Cooler Specifications Base Specifications Specification Value of test tolerance then the fluid cooler manufacturer will pay for the cost of the test and will make such corrections as are appropriate and agreeable to the owner to compensate for the perfor mance deficiency Coil Coil s shall consist of fully welded box headers with serpentine coils and hot dip galvanized after fabrication Maximum operating design pressure shall be 1379 kPa The coil shall be designed for free drainages of fluid at shutdown Coil shall be warranted against any failure caused by defects in materials and workmanship for a period of eighteen 18 months from the date of tower shipment Design Loading The structure and anchorage shall be designed to withstand a wind load of 960 Pa on single flow models and 1440 Pa on double flow models while operating The structure and anchorage shall be designed to withstand a seismic load of 11g on single flow models and 18g on double flow models while operating The fluid cooler shall be designed to with stand shipping and hoisting loads of 2g horizontal or 3g vertical The fan deck and hot water basin covers on double flow models shall be designed for 2 42 kPa live load or a 91 kg concentrated load Guardrails where specified shall be capable of withstanding a 890N concen trated live load in any direction and shall be designed in accordance with OSHA guidelines Construction Except wher
13. d separately for installation by others Indoor Storage Tank With this type of system water flows from an indoor tank and back to the tower where it is cooled and recirculated The water flows by gravity from the fluid cooler to the tank located in a heated space At shutdown all exposed water drains into the tank where it is safe from freezing The amount of water needed to successfully operate the system depends on the fluid cooler size and L s and on the volume of water contained in the piping system to and from the tower You must select a tank large enough to contain those combined volumes plus a level sufficient to maintain a flooded suction on your pump Control makeup water according to the level where the tank stabilizes during operation Marley MH Fluid Cooler Engineering Data Water Quality The MH Fluid Cooler can be a very effective air washer Atmospheric dust able to pass through the relatively small louver openings will enter the recirculating water system Increased concentrations can intensity systems maintenance by clogging screens and strainers and smaller particulates can coat system heat transfer surfaces In areas of low flow velocity such as the collection basin sedimentary deposits can provide a breeding ground for bacteria In areas prone to dust and sedimentation you should consider installing some means for keeping the collection basin clean Typical devices include side stream filters and a var
14. dy access to the optional Control System 11 5 11 6 Marley MH Fluid Cooler Specifications Options v Specifications Specification Value Plenum Walkway MHF706 and MHF707 models standard on others Add the following paragraph in the Access section Provide a factory installed heavy gauge galvanized steel walkway with safety grip perforations extending from one endwall access door to the other endwall access door This walkway shall be supported by a galva nized steel framework and the top to the walkway shall be at or above the cold water basin overflow level Interior Mechanical Equipment Access Platform MHF706 and MHF707 models require plenum walk way option Add the following paragraph in the Access section An internal ladder shall extend upward from the plenum walkway to an elevated fiberglass bar grating platform convenient to the care and maintenance of the fluid cooler s mechanical equipment The platform shall be surrounded by a sturdy guardrail and kneerail system Control Options Fan Motor Starter Control Panel Add the following paragraph in the Mechanical Equipment section Each cell of the cooling tower shall be equipped with a UL CUL 508 listed control panel in an IP14 or IP56 outdoor enclosure capable of controlling single speed or two speed motors as required and designed specifi cally for cooling tower applications The panel shall include a main circuit breaker or main fused disc
15. e otherwise specified al components of the fluid cooler shall be fabricated of heavy gauge steel pro tected against corrosion by Z600 galva nizing After passivation of the galvanized steel 8 weeks at pH 7 8 and calcium hardness and alkalinity at 100 300 mg L each the fluid cooler shall be capable of withstanding water having a pH of 6 5 to 9 0 a chloride content up to 500 ppm as NaCl 300 mg L as CI a sulfate content as SO4 up to 250 mg L a calcium content as CaCO3 up to 500 mg L silica as SiO9 up to 150 mg L B The MH Fluid Cooler coil is suitable for cooling water oils and other fluids compatible with carbon steel in a closed pres surized system Each coil is constructed of all prime surface continuous steel tubing formed into a serpen tine shape and welded into an assembly Tubes are sloped to pro vide free drainage when vented B The indicated design values are the minimum allowables under accepted design standards They give you assurance that the fluid cooler can be shipped han dled hoisted and ultimately operated in a normal cooling tower environment Most MH Fluid Cooler models will withstand significantly higher wind and seis mic loads If your geographic location dictates higher wind load or seismic load values please make the appropriate changes after discussion with your Marley sales representative E In the history of fluid coolers no other coating for carbon steel has ex
16. e ultimate in corrosion resistance and long life The thermal performance rating shall be based on the Cooling Technology Institute certified performance rating adjusted for the thermal prop erties of stainless steel Good maintenance practice requires periodic access to the top of the fluid cooler to inspect the distribution basins as well as the structural integrity of the fan deck fan guard fan cylinder and fan especially the fan blade securing hard ware These models are large enough to accommodate this convenience For the comfort and safety of your operating personnel we recommend that you specify a ladder and guardrail on these models Portable ladders and other make do access means are inappropriate for equipment of this size and com plexity Also fixed ladders without fan deck guardrails invite unsafe maintenance practices and must not be allowed Marley MH Fluid Cooler Specifications Options Specifications Specification Value Distribution Basin Access Platform Add the following paragraph in the Access section Provide an external platform near the top of the louver face for access to the hot water distribution system The platform shall be heavy gauge galvanized steel with safety grip perforations supported by galvanized steel framework attached to the fluid cooler The platform shall be surrounded by a guardrail kneerail and toeboard A permanently attached 457mm wide aluminum ladder with 76 mm I beam s
17. eater Motor s shall be ___ kW maximum Totally Enclosed 1 15 service factor vari able torque and specially insulated for cooling tower duty Speed and electrical characteristics shall be 1500 RPM sin gle winding 3 phase 50 hertz __ volts The fan and fan drive assembly for each cell shall be supported by a rigid galvanized steel structural support that resists misalignment The mechanical equipment assembly shall be warranted against any failure caused by defects in materials and workmanship for no less than five 5 years following the date of tower shipment This warranty is limited to the fan fan shaft bearings sheaves and mechanical equipment support The motor motor components pumps and belt s are warranted by their manufac turer Specification Value B Propeller type fans require only half the operating hp of blower type fans The Marley drive system fea tures all aluminum sheaves matched belts and long life bearings for dependable service To reduce cost some manufacturers may use TEAO motors whose only source of cooling is the flow of air produced by the cooling tower fan They are some times applied at kWs significantly beyond their nameplate rating Unless otherwise specified motor speed will be 1500 RPM 50 Hertz on stan dard models If you prefer the operating flexibility of two speed operation please specify two speed single winding motors which offer full and half speeds for
18. een operational and site related influences Specifying the num ber of cells and the maximum fan hp cell will work to your advantage The benefit of crossflow fluid coolers is that they are inherently easy to operate access and maintain Unlike counterflow fluid coolers crossflow fluid cool ers have a spacious plenum between banks of fill for easy access to all of the tower s internal components and the water distribution system is adjacent to the fan deck E CTI Certification means that the fluid cooler has been tested under operating condi tions and found to perform as rated by the manufacturer under those circumstances It assures the buyer that the tower is not inten tionally or inadvertently undersized by the manufacturer B However CTI certification alone is not sufficient to assure you that the fluid cooler will perform satisfactorily in your situation Certification is established under relatively controlled conditions and fluid coolers seldom operate under such ideal circumstances They are affected by nearby structures machinery enclosures effluent from other sources etc Responsible and knowledgeable bidders will take such site specific effects into consideration in selecting the fluid cooler but the specifier must insist by the written specification that the designer manufacturer guarantee this real world performance Any reluctance on the part of the bidder should cause you some concern Marley MH Flui
19. hibited the success and longevity of galvanization in exposure to the normal cooling tower water quality defined at left No paints or electrostatically applied coat ings however exotic they may be can approach galvanization s history of suc cess If extended longevity of the fluid cooler is required or unusually harsh operat ing conditions are expected consider specifying stainless steel as either the base construction material or the material utilized for specific components of your choice See Stainless Steel Options on page 12 Marley MH Fluid Cooler Specifications Base and design operating ranges up to 28 C The circulating water shall contain no oil grease fatty acids or organic solvents The specifications as written are intend ed to indicate those materials that will be capable of withstanding the above water quality in continuing service as well as the loads described in paragraph 6 1 They are to be regarded as minimum requirements Where component materi als unique to individual tower designs are not specified the manufacturers shall take the above water quality and load carrying capabilities into account in the selection of their materials of manufac ture Mechanical Equipment Fan s shall be heavy duty axial flow design Fan s shall be driven through an industrial grade system of V belts pul leys and tapered roller bearings Bearings shall be rated at an L4 life of 40 000 hours or gr
20. ide rails and 32 mm diameter serrated rungs shall extend from the base of the tower to the top of the guardrail Ladder Extension Add the following to the end of para graph 11 2 Provide a ladder extension for connection to the foot of the ladder This extension shall be long enough to rise from the roof grade level to the base of the fluid cooler The installing contractor shall be responsible for cut ting the ladder to length attaching it to the foot of the fluid cooler ladder and anchoring it at its base Ladder Safety Cage Add the following paragraph in the Access section An aluminum safety cage shall surround the ladder extending from a point approximately 2m above the foot of the ladder to the top of the guard rail surrounding the fan deck or platform Access Door Platform Add the following paragraph in the Access section There shall be an access platform at the base of the fluid cooler extending from the vertical ladder to the endwall access door The platform shall be galvanized steel bar grating supported by galvanized steel framework attached to the fluid cooler The platform shall be surrounded by a guardrail kneerail and toeboard E Periodic inspection and maintenance of a fluid cooler distribution system is fundamental to preserving maximum cooling system efficiency All fluid coolers crossflow or counterflow are subject to clogging to varying degrees by water borne contaminants such as pi
21. iety of filtration media Blowdown Blowdown or Bleedoff is the continuous removal of a small portion of the water from the open recirculating 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 on the cooling range the difference between the hot and cold water temperatures of the closed circuit and the composition of the makeup water The MH Fluid Cooler is equipped with a blowdown line with metering valve connected directly to the overflow Specific blowdown adjustment instructions and additional blowdown information can be found in the MH Fluid Cooler User Manual A CAUTION The fluid cooler must be located at such distance and direction to avoid the possibility of contaminated discharge air being drawn into building fresh air intake ducts The purchaser should obtain the services of a Licensed professional Engineer or Registered Architect to certify that the location of the fluid cooler is in compliance with applicable air pollution fire and clean air codes Water Treatment To control the buildup of dissolved solids resulting from water evaporation as well as airborne impurities and biological contaminants including Legionella an effective consistent water treatment program is required Simple blowdown may be adequate to control corrosion and scale but biological contamination can only be controlled with biocides An
22. le of supporting the loads imposed in maintenance They will therefore tell you that it is really unnecessary for you to ever go to the top of their towers and if you do have to that it is better for you to work from the top of a portable ladder B Manufacturers who use materials other than heavy gauge steel for fan decks may be unable to meet your specified loading requirements Fan decks on the larger models MHF706 and MHF707 are designed to be used as a working platform mi Ro ie i Marley MH Fluid Cooler Specifications Base 13 Specification Value Access A large galvanized hinged steel access door 711mm wide and 1066mm high shall be located on both endwalls for entry into the cold water basin and fan plenum area Access doors shall be oper able from inside as well as outside the tower Collection Basin The collection basin shall be heavy gauge galvanized steel Suction connections shall be equipped with galvanized debris screens A factory installed float operat ed mechanical makeup valve and waste water blowdown line shall be included A 4 diameter PVC drain and overflow shall be provided in each cell of the tower The basin shall include a depressed sec tion into which accumulated silt can be flushed to permit cleaning The basin floor adjacent to the depressed section shall slope toward the depressed section to prevent buildup of silt under the coil area Reci
23. less steel electric immersion heaters installed in threaded couplings provided in the side of the basin A IP56 enclosure shall house a magnetic contactor to energize heaters a transformer to provide 24 volt control circuit power and a solid state cir cuit board for temperature and low water cut off A control probe shall be located in the basin to monitor water level and temperature The system shall be capable of maintaining 5 C water temperature at an ambient air temperature of___ C E Unless specified otherwise a Marley M 5 vibration switch will be provided The requirement for manual reset assures that the fluid cooler will be visited to determine the cause of excessive vibration E The Marley basin heater components described at left represent our recommen dation for a reliable automatic system for the prevention of basin freezing They are normally shipped separately for installation at the jobsite by the installing contractor When purchased in conjunction with the enhanced Control System option however they are customarily factory mounted and tested Submerged in basin water in which zinc ions are present copper immersion heaters must not be used Insist upon stainless steel The ambient air temperature that you insert in the specifications should be the lowest 1 level of winter temperature prevalent at site Marley MH Fluid Cooler Specifications Options Specification Value Fan Motor Variable Speed Dri
24. maximum energy savings Incidentally two speed motors are a far better choice than separate pony motors which simply double the problems indicated above The value of a 5 year mechanical equipment warranty speaks for itself a Marley MH Fluid Cooler Specifications Base Fill Louvers and Drift Eliminators Fill shall be film type thermoformed of 0 38 mm thick PVC with louvers and eliminators formed as part of each fill sheet Fill shall be suspended from galva nized structural tubing supported from the tower structure Coil louvers and eliminators shall be film type thermoformed of 0 43mm thick PVC and shall be easily removable for access to tube bundle Fill and coil drift eliminators shall be tri ple pass and shall limit drift losses to no more than 0 005 or less of the design water flow rate of the recirculating water The air inlet face of the tower shall be free of water splash out Distribution Basins An open basin above the fill with remov able interchangeable polypropylene noz zles installed in the floor of the basin shall provide full coverage of the fill by gravity flow Basin shall be installed and sealed at the factory and shall be equipped with removable galvanized steel covers A redistribution basin below the fill with polypropylene nozzles installed in the floor of the basin shall provide full cover age of the coil at a flow rate sufficient to ensure complete wetting
25. ne shall be included A 4 diameter PVC drain and overflow shall be provided in each cell of the tower The basin shall include a depressed section into which accumulated silt can be flushed to permit cleaning The basin floor adjacent to the depressed section shall slope toward the depressed section to prevent buildup of silt under the coil area All steel items which project into the basin coil supports anchor clips etc shall also be made of stainless steel Stainless Steel Distribution Basin Replace paragraph 9 1 with the follow ing An open stainless steel basin above the fill with removable interchangeable polypropylene nozzles installed in the floor of the basin shall provide full cover age of the fill by gravity flow Basin shall be installed and sealed at the factory and shall be equipped with removable stain less steel covers capable of withstanding the loads described in paragraph 5 1 All components of these basins with the exception of the nozzles and redistribu tion piping shall be stainless steel Replace paragraph 9 2 with the follow ing A redistribution basin below the fill with removable interchangeable polypro pylene nozzles installed in the floor of the basin shall provide full coverage of the coil at a flow rate sufficient to ensure complete wetting of the coil at all times All components of the basin with the exception of the nozzles shall be stainless steel Specification Value E The cold
26. nt temperature of the cold water The drive design shall be operated as a stand alone system without the need for a BMS system Operator controls shall be mounted on the front of the enclosure and shall consist of start and stop control bypass VFD selector switch Auto Manual selector switch manual speed control and solid state temperature controller An emer gency bypass selector switch internal to the panel allowing the fluid cooler fan motor to be run at full speed shall be furnished To prevent heating problems in the fluid cooler fan motor and to assure proper gear box lubrication the VFD system shall de ener gize the motor once 25 motor speed is reached and cooling is no longer required The VFD shall include de icing logic with auto canceling and adjustable time Speed Marley MH Fluid Cooler Specifications Options 21 Specifications Specification Value in De Ice mode shall not exceed 50 motor speed The fluid cooler manufacturer shall supply VFD start up assistance Tower vibration testing throughout the speed range is required to identify and lockout any natural frequency vibration levels which may exceed CTI guidelines Miscellaneous Options Positive Closure Dampers Add the following paragraph in the Coil section Provide positive closure actuat ing dampers to prevent air from flowing through the coil section when the damp ers are closed All linkage and axles shall be stainless steel and the
27. of the coil at all times Casing Fan Deck and Fan Guard The casing and fan deck shall be heavy gauge Z600 galvanized steel panels The top of the fan cylinder s shall be equipped with a conical non sagging removable fan guard fabricated of weld ed 8mm and 7 gauge rods and hot dip galvanized after fabrication B Louvers integral with the fill keep the B Drift rate varies with design water Specification Value flowing water within the confines of the fill The separate external lou vers used by others permit water to escape the fill and form ice or pro duce an unsightly situation adjacent to the tower If you plan to use your tower in the wintertime particularly for free cooling integral louvers will put your operating concerns to rest loading and air rate as well as drift eliminator depth and number of directional changes A drift rate of 0 001 is readily available on many standard models If a lower rate is required please discuss with your Marley sales representative B Gravity flow distribution basins are a feature of the MH Fluid Cooler resulting in operating pump heads less than that encountered in fluid coolers with pres surized spray systems Also these basins are out where they can be easily inspected even maintained while the fluid cooler is in operation Spray systems are extremely awkward to access and maintain Also the plastic basin covers offered by some manufacturers are incapab
28. onnect with an external operating handle lockable in the off posi tion for safety Full voltage non reversing magnetic starter shall be controlled with a thermostatic or solid state temperature controller Door mounted selector switch es shall be provided to enable automatic or manual control and wired for 120VAC control Control circuit to be wired out to terminal blocks for field connection to a remote vibration switch overload trip alarms and remote temperature control devices The temperature controller shall be adjustable for the required cold water temperature If a thermostatic controller mi E A galvanized steel walkway enables easy access to inspect collection basin items such as the coil coil eliminators sump screen and make up valve and provides a dry working area to view and access the drive system E An elevated fiberglass bar grating service platform with aluminum ladder pro vides a permanent working surface to inspect and maintain the mechanical equipment components B If it is your opinion that the control system for the fluid cooler be part of the fluid cooler manufacturer s responsibility we are in wholehearted agreement with you Who better to determine the most efficient mode and manner of a fluid cooler s operation and to apply a system most compatible with it than the designer and manufacturer of the fluid cooler Marley variable speed drives are also available for the ultimate in temperature cont
29. pe scale and sediment Therefore safe and easy access to these components is of significant value to the operator Access can be provided in a number of ways including portable ladders or scaffolding but for maximum safety and convenience a field installed Marley access platform with guardrails is available to make this task as safe and user friendly as possible Further its location on the side of the tower does not add to the height of the unit preserving architectural integrity It also saves the owner time and money in that maintenance personnel may devote their time to inspection rather than searching for ladders or erection of portable scaffolding E Many fluid coolers are installed such that the base of the unit is 610 mm or more above the roof or grade level This makes it difficult to get up to the foot of the attached ladder The ladder extension alleviates this problem Marley ladder extensions are available in standard 1 5m and 3 4m lengths B To meet OSHA guidelines towers whose fan decks are 20 0 6 096m or more above roof or grade and which are equipped with ladders should have safety cages surrounding the ladders but with approximately 2m clear head room B Where fluid coolers are installed on an elevated grillage or piers it is often diffi cult to get to and through the access door conveniently This platform provides easy safe and comfortable access to that door It also extends beyond the door to provide rea
30. propriate concentration of ethylene or propylene glycol should be determined based on the required protection from low ambient temperatures If the use of an industrial antifreeze solution is not compatible with the system another accepted method of preventing coil freezing is to maintain a sufficient flow rate and heat load on the process fluid The fluid exiting the coil must be maintained at or above 7 C at the full process flow rate If the process load does not yield such a heat load it may be necessary to apply a supplementary heat load to the process fluid Draining the coil is not considered to be an acceptable means of protection against freezing Introducing air to the interior of the bundle will promote corrosion of the heat exchanger coil In an emergency this alternative can be used in the event that the process fluid drops below 45 F the ambient temperature is below freezing and the coils are not protected with industrial antifreeze Cycling of the recirculating water pumps should not be used to control process flow temperatures Coils may be used for seasonal dry operation followed by seasonal wet operation but not for frequent cycling of the recirculating water pump Such operation may lead to an excessive scale buildup resulting in a decrease in efficiency A CAUTION Freezing ambient conditions could cause significant damage to the heat exchanger coil of the MH Fluid Cooler To avoid possible damage it is imper
31. rculation pump s shall be mounted to the collection basin in conjunction with a suction assembly Recirculation piping shall be schedule 40 PVC A blowdown line with metering valve shall be con nected directly to the tower overflow Warranty The fluid cooler shall be free from defects in materials and workmanship for a period of eighteen 18 months from the date of shipment B Access doors on other manufacturer s towers may be 18 wide or smaller which is unreasonably small for a human being Specifying the size of the door will cause those bidders to take exception alerting you to a potential mainte nance headache Two doors are standard on all MH Fluid Coolers one in each endwall The removable standpipe type of overflow is valuable because it provides a way to achieve flush out cleanability Other drains may be as little as 25mm diameter making flush out cleaning impractical at best Location of the coil in the lower portion of the MH Fluid Cooler makes it much easier to access for cleaning and inspection Marley MH Fluid Cooler Specifications Options Stainless Steel Options Stainless Steel Collection Basin Replace paragraph 12 1 with the follow ing The cold water basin shall be heavy guage series 300 welded stainless steel Suction connections shall be equipped with stainless steel debris screens A fac tory installed float operated mechanical makeup valve and waste water blowdown li
32. rol energy management and mechanical equipment longevity Marley MH Fluid Cooler Specifications Options Specifications Specification Value is used it shall be mounted on the side of the tower with the temperature sens ing bulb installed in the cold water basin using a Suspension mounting bracket If a solid state temperature controller is used the controller will be door mounted on the control panel The solid state temperature controller will display two temperatures one for outgoing water and the other for set point Water temperature input shall be obtained using a three wire RTD with dry well in the outlet water piping and wired back to the solid state temperature controller in the control panel Vibration Limit Switch Add the following paragraph in the Mechanical Equipment section A single pole double throw vibration limit switch in a IP56 housing shall be installed on the mechanical equipment support for wiring into the owner s control panel The purpose of this switch will be to interrupt power to the motor in the event of exces sive vibration It shall be adjustable for sensitivity and shall require manual reset Basin Heater Add the following paragraph in the Cold Water Basin section Provide a system of electric immersion heaters and con trols for each cell of the tower to prevent freezing of water in the collection basin during periods of shutdown The system shall consist of one or more stain
33. t choice for industrial and HVAC applications By keeping the process fluid in a clean closed loop and combining the function of a cooling tower and heat exchanger into one system they provide superior operational and maintenance benefits The specifications portion of this publication not only relates the language to use in describing an appropriate MH Fluid Cooler but also defines why certain items and features are important enough to specify with the intention of insisting upon compliance by all bidders The left hand column of pages 9 thru 22 provides appropriate text for the various specification paragraphs whereas the right hand column comments on the meaning of the subject matter and explains its value Pages 9 thru 13 indicate those paragraphs which will result in the purchase of a basic fluid cooler one that accomplishes the specified thermal performance but which will lack many operation and maintenance enhancing accessories and features that are usually desired by those persons who are responsible for the continuing operation of the system of which the fluid cooler is part It will also incorporate those standard materials which testing and experience has proven to provide acceptable longevity in normal operating conditions Pages 14 thru 22 provide paragraphs intended to add those features components and materials that will customize the fluid cooler to meet the user
34. t each cell will contain any fire that may occur without losing the ability of limited opera tions and capacity SP SPX COOLING TECHNOLOGIES 3 KNIGHTSBRIDGE PARK WAINWRIGHT ROAD WORCESTER WR4 9FA UNITED KINGDOM 44 0 1905 750 270 info uk spx com spxcooling com In the interest of technological progress all products are subject to design and or material change without notice 2011 SPX uk_MHF TS 11
35. the speed range is required to identify and lockout any natural frequency vibration levels which may exceed CTI guidelines Marley Premium VFD System Add the following paragraph in the Mechanical Equipment section when VFD is used as a stand alone system A complete UL listed Variable Speed Drive system in a IP52 indoor or IP54 outdoor enclosure shall be provided The VFD shall use PWM technology with IGBT switching and integrated bypass design VFD output switching shall not cause mechanical issues with gearbox teeth or drive shafts The VFD shall catch a fan spinning in the reverse direction without tripping The panel shall include a main disconnect with short circuit protection and external operating handle lockable in the off position for safety The system shall include a solid state PI tem perature controller to adjust frequency output of the drive in response to the tower fluid temperature The temperature of the fluid and set point shall be displayed on the door of the control panel The bypass shall include a complete magnetic bypass circuit with capability to isolate the VFD when in the bypass mode Transfer to the bypass mode shall be automatic in the event of VFD failure or for specific trip conditions allowing safe transfer of utility voltage to the motor Automatic bypass with an earth ground condition is not allowed The bypass contactor shall be cycled on and off while operating in bypass to main tain the set poi
36. ting shall be Certified by the Cooling Technology Institute Aqueous glycol solution as the heat transfer fluid The fluid cooler shall be capable of cool ing m hr of water from C to C at a design entering air wet bulb temperature of C Coil pres sure drop shall not exceed kPa The thermal performance rating shall be based on the Cooling Technology Institute certified performance rating adjusted for the thermal properties of the aqueous glycol solution used Performance Warranty CTI Certification notwithstanding the cooling tower manufacturer shall guaran tee that the fluid cooler supplied will meet the specified performance conditions when the tower is installed according to plans If because of a suspected ther mal performance deficiency the owner chooses to conduct an on site thermal performance test under the supervision of a qualified disinterested third party in accordance with CTI or ASME standards during the first year of operation and if the tower fails to perform within the limits mi B Your specification base establishes the type configuration base material and physical limitations of the fluid cooler to be quoted During the planning and lay out stages of your project you will have focused your attention on a fluid cooler selection that fits your space allotment and whose power usage is acceptable Limitations on physical size and total operating horsepower avoid the introduc tion of unfores
37. ve Marley All Weather ACH550 System Add the following paragraph in the Mechanical Equipment section when VFD is used with customers Building Management System A complete UL listed Variable Speed Drive system in a IP10 indoor IP52 indoor or IP54 outdoor enclosure shall be provided The VFD shall use PWM technology with IGBT switch ing and integrated bypass design VFD out put switching shall not cause mechanical issues with gearbox teeth or drive shafts The VFD shall catch a fan spinning in the reverse direction without tripping The panel shall include a main disconnect with short circuit protection and external oper ating handle lockable in the off position or safety The VFD system shall receive a speed reference signal from the Building anagement System monitoring the tower fluid temperature As an option to receiving he speed reference signal from a build ing management system the drive must have the capability to receive a 4 20 ma emperature signal from an RTD transmitter The VFD shall have an internal PI regula or to modulate fan speed maintaining set point temperature The drive s panel display shall be able to display the set point tem perature and cold fluid temperature on two separate lines The bypass shall include a complete magnetic bypass circuit and with capability to isolate the VFD when in the bypass mode Transfer to the bypass mode shall be manual in the event of VFD failure Once the motor is transferred
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