MD Cooling Tower Engineering Data And Specifications

MD cooling towerengineering dataand specifications

MD Steel Cooling TowerMD towers are galvanized steel, factory assembled,counterflow cooling towers, designed to serve airconditioning and refrigeration systems as well as lightto medium industrial process loads on clean water. TheMarley MD evolved from a factory-assembled conceptof towers pioneered by Marley some 85 years ago, andincorporates all of the design advancements that ourcustomers have found valuable. MD towers represent thecurrent state of the art in this cooling tower category.The specifications portion of this publication not onlyrelates the language to use in describing an appropriateMD cooling tower—but also defines why certain items andfeatures are important enough to specify with the intentionof insisting upon compliance by all bidders. The left handcolumn of pages 48 thru 62 provides appropriate text forthe various specification paragraphs, whereas the righthand column comments on the meaning of the subjectmatter and explains its value.2Pages 48 through 54 indicate those paragraphs which willresult in the purchase of a basic cooling tower—one thataccomplishes the specified thermal performance, but whichwill lack many operation—and maintenance-enhancingaccessories and features that are usually desired by thosepersons who are responsible for the continuing operationof the system of which the cooling tower is part. It will alsoincorporate those standard materials which testing andexperience has proven to provide acceptable longevity innormal operating conditions.Pages 55 through 62 provide paragraphs intended toadd those features, components, and materials thatwill customize the cooling tower to meet the user‘srequirements.

MD Steel Cooling TowerAIR MOVEMENT PACKAGE High efficiency fan — wide-chord design for maximum efficiency at low fan tip speeds Eased inlet fan cylinder ensures full area, low turbulent airflow through the cylinder Spherical roller bearings are rated at an L10 life of 100,000 hours TEFC Fan Motor — 1.15 service factor, variable torque, and specially insulated for cooling tower duty The MD Series air movement package including the structural support is guaranteed against failurefor a period of five full years.WATER DISTRIBUTION SYSTEM Pressurized spray system distributes water evenly over the fill Low-clog polypropylene nozzles deliver precise distribution of water over the fill area Marley MC thermoformed PVC film fill assembled into packs for ease of removal and cleaning Marley XCEL TU drift eliminators limit drift losses to no more than .001% of the design flow rateSTRUCTURE Induced-draft, counterflow design may require less plan area than crossflow towers typically use Series 300 stainless steel, 316 stainless steel or heavy mill galvanized steel construction Factory assembled — ensures final field installation will be hassle-free Triple-pass PVC inlet louvers limit splash-out and eliminate sunlight from entering the collection basin3

MD Steel Cooling Tower — Table of Contents4Engineering DataSchematicSupportOutlet ConnectionHoisting InfoWater Quality – Freeze Prevention618202223Specifications / BaseBaseThermal PerformancePerformance WarrantyDesign LoadingConstructionMechanical EquipmentFill, Louvers and Drift EliminatorsHot Water Distribution SystemCasing and Fan GuardAccessCollection s / OptionsStainless Steel OptionsStainless Steel Collection BasinAll Stainless Steel Cooling Tower3030Convenience and Safety OptionsMechanical Access PlatformLadder ExtensionLadder Safety CageMotor DavitMotor and Fan Davit3131313232Control OptionsFan Motor Starter Control PanelVibration Limit SwitchBasin HeaterWater Level ControlFan Motor All Weather Variable Speed Drive3233333334Miscellaneous OptionsEqualizer Flume Weir GatesFan Cylinder ExtensionsBasin Sweeper PipingSplash AttenuationOutlet Sound AttenuationUltra Quiet FanFM ApprovalLow-Clog Film Fill3535353636363737

MD Steel Cooling Tower — Operational and Environmental AwarenessSYSTEM CLEANLINESSTYPICAL APPLICATIONSCooling towers are very effective air washers. Atmospheric dustable to pass through the relatively small louver openings will enterthe circulating water system. Increased concentrations can intensifysystem maintenance by clogging screens and strainers—and smallerparticulates can coat system heat transfer surfaces. In areas of lowflow velocity—such as the cold water basin—sedimentary depositscan provide a breeding ground for bacteria.The MD tower is an excellent choice for normal applicationsrequiring cold water for the dissipation of heat. This includescondenser water cooling for air conditioning, refrigeration, andthermal storage systems, as well as their utilization for free-coolingin all of those systems. A low-clog fill option provides a high degreeof clog resistance and makes the MD tower ideal for dirty waterapplications. The MD can also be used in the cooling of jacket waterfor engines and air compressors, and are widely applied to dissipatewaste heat in a variety of industrial, power and manufacturingprocesses.In areas prone to dust and sedimentation, you should considerinstalling some means for keeping the cold water basin clean. Typicaldevices include side stream filters and a variety of filtration media.WATER TREATMENTTo control the buildup of dissolved solids resulting from waterevaporation, as well as airborne impurities and biological contaminantsincluding Legionella, an effective consistent water treatment programis required. Simple blowdown may be adequate to control corrosionand scale, but biological contamination can only be controlled withbiocides.An acceptable water treatment program must be compatible withthe variety of materials incorporated in a cooling tower—ideally thepH of the circulating water should fall between 6.5 and 9.0. Batchfeeding of chemicals directly into the cooling tower is not a goodpractice since localized damage to the tower is possible. Specificstartup instructions and additional water quality recommendationscan be found in the MD User Manual which accompanies the towerand also is available from your local Marley sales representative. Forcomplete water treatment recommendations, consult a competent,qualified water treatment supplier.5Choosing the all stainless steel construction option, the MDcan be confidently applied in unusually corrosive processes andoperating environments. However, no single product line can answerall problems, and selective judgement should be exercised in thefollowing situationsAPPLICATIONS REQUIRING ALTERNATIVE COOLINGTOWER SELECTIONSCertain types of applications are incompatible with any coolingtower with film fill — whether MD or a competitive tower ofsimilar manufacture. Film fill is subject to distortion in high watertemperatures, and the narrow passages are easily clogged by turbidor debris-laden water. Some of the applications, which call foralternative tower designs are: Water temperatures exceeding 135 F—adversely affects theservice life and performance of normal counterflow PVC fill.Higher temperature fill materials are available. Ethylene glycol content—can plug fill passages as slime andalgae accumulate to feed on the available organic materials.CAUTIONThe cooling tower must be located at such distanceand direction to avoid the possibility of contaminateddischarge air being drawn into building fresh air intake Fatty acid content—found in processes such as soap anddetergent manufacturing and some food processing—fattyacids pose a serious threat for plugging fill passages. Particulate carry over—often found in steel mills and cementducts. The purchaser should obtain the servicesplants—can both cause fill plugging, and can build up topotentially damaging levels on tower structure.of a Licensed Professional Engineer or Registered Pulp carry over—typical of the paper industry and foodArchitect to certify that the location of the coolingtower is in compliance with applicable air pollution,fire and clean air codes.processing where vacuum pumps or barometric condensers areused. Causes fill plugging which may be intensified by algae.ALTERNATIVE SELECTIONSIn addition to the MD, SPX Cooling Technologies offers a fullscope of products in various designs and capacities to meet thespecial demands of specific applications.spxcooling.com—visit us on the web for a complete list ofproducts, services, publications and to find your nearest salesrepresentative.

MD Steel Cooling Tower — Engineering Data: Schematic6MD50066' x 8.5' Nominal Cell SizeDESCRIPTION — MODEL SUFFIXUse this data for preliminary layouts only.Obtain current drawing from your Marley salesrepresentative.UPDATE web-based selection software,available at spxcooling.com/update provides MDmodel recommendations based on customer'sspecific design requirements.LAYOUT CONFIGURATIONSINGLE CELL — 1LTWO OR MORE INLINE CELLS — 2L TWO CELLS BACK-TO-BACK — 2BSingle cell arrangement shown.Multicell inline standard spacing 2.5".Multicell back-to-back standard spacing 4".Water inlet location can be on either faceexcept motor face.5'-11 7/8"CLPLAN1 3/8"8'-5 1/2"1'-10 3/8"4 1/4"6" INLETMOTORHASIDE ELEVATIONEND ELEVATION

MD Steel Cooling Tower — Engineering Data: Schematic Data7MD50066' x 8.5' Nominal Cell SizeTable Data Per CellModelNominal Tonsnote 2note 6PAF1L16615DimensionsH note 4A10'-51 8"7'-21 8"11'-51 8"12'-51 8"DesignOperatingWeightlbShipping WeightlbWeight/CellHeaviest Section5103288016318'-21 8"5299307516319'-21 8"560033771738Standard Layout Configuration Adds Per CellDescriptionSINGLE CELLTWO OR MORE INLINE CELLSTWO CELLS BACK-TO-BACKDimensionsModel Suffixnote 2H note 4ADesignOperatingWeightlbShipping WeightlbWeight/Cell1L––––2L 4"4"29292B4"4"2929NOTE1 Use this bulletin for preliminary layouts only. Obtain currentdrawings from your Marley sales representative. All table data isper cell.2 Last two characters of the model number indicate number of cellsand cell configuration.3 Nominal tons are based upon 95 F HW, 85 F CW, 78 F WB and3 gpm/ton. The Marley UPDATE web-based selection softwareprovides MD model recommendations based on specific designrequirements.4 Models with an Ultra Quiet Fan option require a taller fan cylinder,add 1'-111 2" to this dimension for correct height.

MD Steel Cooling Tower — Engineering Data: Schematic8MD50088.5' x 9' Nominal Cell SizeUPDATE web-based selection software,available at spxcooling.com/update provides MDmodel recommendations based on customer'sspecific design requirements.LAYOUT CONFIGURATIONDESCRIPTION — MODEL SUFFIXUse this data for preliminary layouts only.Obtain current drawing from your Marley salesrepresentative.SINGLE CELL — 1LTWO OR MORE INLINE CELLS — 2L TWO CELLS BACK-TO-BACK — 2B8'-5 1/2"Single cell arrangement shown.Multicell inline standard spacing 2.5".Multicell back-to-back standard spacing 4".Water inlet location can be on either faceexcept motor face.CLPLAN1 3/8"8'-111/2"1'-10 3/8"51/2"8" INLETMOTORHASIDE ELEVATIONEND ELEVATION