SAHIPPO-WORLD’SSAFESTSUBMERSIBLEPUMPFORUNDERGROUNDMINING

Coalminingaccidentscausedbygasandcoaldustexplosionsaccountforthemostfatal mining disasters around the world. However, dangerousMethane gas ispresentatmostundergroundminesaswellandnotonlyincoalmines.Thiswas,onceagain,confirmedwhenafatalmethanegasexplosionoccurredundergroundattheZAPOLYARNYNickleMineinNorthernRussiaon7July2017,claiming4liveswhenabuild-upofmethanegasignited.

ThemostrecentwasacoalmineinKashmirthatcollapsedon7August2017afteragasexplosiontookplaceattheSeriDarravillagenearMuzaffarabadkillingfiveminers. Thesitehasbeenshutdownuntil furthernoticeandsixofficialsof theminingcompanywerearrestedforfailingtoobservesafetystandards.

Aphotoofanundergroundminingtunnelthatcollapsedduetoagasexplosion

InJune201713minersthatdiedatcoalmineintheCucunubadistrictofColombiainamethanegasexplosionandthe35minerswerekilledinasimilarwayattheEMESTSNYURTCoalMineinIranon4May2017.

Duringthepastfourmonths57minerswerekilledinundergroundgasexplosions.AtthePIKERIVERCoalMine intheWestCoastRegionofNewZealand’sSouthIslandamethaneexplosionoccurredunderground1500metersfromthemine’sentranceandkilling29minerson19November2010.

AtthePIKERIVERCoalMinetheventilationshafthadbeentotallyblownaway.Coaldust,ifnotsufficientlysuppressed,couldcontributetofatalexplosionsandall equipment installed must duly comply with the IEC 60079-1 flameproofrequirements.

Atsomeopencastmines,theviewistakenthatnoprecautionsneedtobetakentopreventthebuild-upofmethanegasassufficientventilationshouldexist topreventexplosions.Thepossibility,however,existsthatpocketsofmethanegasandcoaldustispresentwhichcouldigniteandcauseexplosionssuchasin2004attheBlairAtholCoal(BAC)locatedinCentralQueensland,Australiawhencoaldustandgassesexploded.

Theextendoftheseveredamagecausedtodraglinesaswellasnearbytruckswhengasandcoaldustexplodedinanopenmineoperation.

The worst coal mine disaster ever occurred on 26 April 1942 at the Benxihucolliery,intheHomelikecoalmine,Chinacausingthelossof1,549lives.

Thefatalundergroundexplosionwascausedbyamixtureofgasandcoaldustsettingalightandthisundergroundfireexplodedoutofthemineshaftentrancewhichissituatedabovegroundlevel.Theventilationsystemwasshutoffandthepitheadwassealedbythemineoperatortodeprivetheundergroundofoxygen

topreventthefirefromfurtherdamagewhichcouldcauseatotalcollapseofthemine.Carbonmonoxidepoisoningduetotheclosureof theventilationsystemwasreportedtohavecausedmostofthedeaths.

Theimpactofagasandcoaldustexplosionisclearlyshownwhereitthereachestheshaftentranceaboveground.

Excessgroundwaterplaysamajorroleinthesafetyoftheminesandithasasamajor effect on production underground should the pumping system beinadequate and flooding would occur. In most underground applications, thesubmersible pump will be totally submerged and operate in the presence ofmethanegas.

InSouthAfrica,theareasthathavebeenminedoutarereferredtoas“madalasites” and submersible pumps aremainly used to pump away the sludge andwaterfromtheseareasandhereoftenthereisalsomethanegaspresent.

CoalMinewater isusuallycontaminatedwithacidandthepumpsrequiredfortheseapplicationsneedtobemanufacturedfromspecialisedmaterialssuchasDuplexStainlessSteelswhichareabletohandletheerosionandcorrosionasaresultoftheacidicliquids,containingsolids,beingpumped.

To minimize the damage when an electrical flash occurs inside an electricalenclosure it is essential that these enclosures comply with IEC 60079-1, thisapplies to all submersible pumps as well. It should be ensured that there issufficientprotectiontoensurethatfailureofthemechanicalsealsofthepumpis

detectedbeforetheliquidcomesintocontactwiththeelectricalwindingofthepump.

Thesurfacetemperatureoftheelectricalwindingisnormallyaround120oCandshouldasealfailureoccurthecolderliquidbeingpumpedwillcomeintocontactwiththewindingandthiswouldsubjectthewindingtoathermalshock-causinganelectricalshortcircuitdowntoearth, inanoccurrencelikethis it ispossiblethat therewillbeanelectrical flash. In instanceswherethesubmersiblepumpdoesisnotflameprooftheelectricalflashwillignitethemethanegaswithfatalresults.

Mostsubmersiblepumpsrelyontheliquidbeingpumpedforthecoolingoftheelectrical winding and should there be no liquid available to be pumped theelectricalwindingwilloverheatandburnout.Shouldthesubmersiblepumpnotbeflameproofandmethanegasbepresentthiswouldresultinanexplosion.

The electrical windings should be fitted with thermistors measuring thetemperature of the electrical windings and should the windings overheat theelectricalsupplytothepumpwillbecutofftopreventanelectricalshortcircuitaswellasanypossiblesubsequentexplosions.

Toprotectflameproofsubmersiblepumps,itisalsoessentialtohaveaflameproofelectrical control panel installed as close as possible to thepump. The controlpanel needs to firstly have overload protection, secondly a sensing device tomeasurewhenthemechanicalsealshavefailedandthirdlyarelaysuitedtothethermistorstopreventtheelectricalwindingoverheating.

HIPPOFlameproofSubmersiblePumprangecontrolpanel

TheHIPPOFlameproofSubmersibleElectricalControlPanelshowingthecontrolrelays

HAZLETON PUMPS manufactured its first flameproof pumps in 1993 and thecompanycontinuallyresearcheswaystoimprovethesafetyfeaturesoftheHIPPOFlameproofSubmersibleSlurryPumprange.In order to move the HIPPO Flameproof Submersible Slurry pump effectivelyaround underground a Flameproof Submersible Pump Systemwas developed.ThissystemconsistsofaHIPPOFlameproofSubmersibleSlurrypumpmountedonaskipthatcanbemovedaroundwithatractortoreachthevariousplaceswherenuisanceliquidispresentthatneedsberemoved.

TheskidmountedHIPPOFlameproofSubmersibleSlurryPumpSystem

In areaswhere a tractor cannot be utilised tomove the skidmounted HIPPOFlameproof Submersible Slurry pump system a trolley mounted FlameproofSubmersibleSlurrypumpsystemcouldbeprovidedwhichcanbemovedaroundbyhand.

ThetrolleymountedHIPPOFlameproofSubmersibleSlurryPumpSystem

TheskidmountedHIPPOFlameproofSubmersibleSlurryPumpSysteminundergroundoperationinatypicalcoalmine

Due to themajor increase in volume of liquids that have to be pumped fromundergroundincoalminesdirectlytosurfaceHAZLETONPUMPShassuccessfullydesigned and manufactured the world’s first High-Volume; High-Head;Medium/High Voltage Flameproof Submersible Slurry Pump. This pump hasspecialized protective features to ensure that the statorwinding would neverburnoutduetooverheatingorthefailureofthemechanicalseals.

TheHIPPOHighVolume;HighHead;Medium/HighVoltageFlameproofSubmersibleSlurryPump

Toensuretheeliminationofanelectricalflashinsidethepumpenclosurewhenusing Medium/High Voltage equipment such as submersible pumps in areaswhere flammable gasses might be present, HAZLETON PUMPS developed theessentialadditionalprotectionrequired.

Thepumpenclosurewillbeundervacuumpressureandthispressurecouldalsobemonitoredbymeansofapressuretransmitter.Intheeventoftheenclosureleaking,thevacuumcreatedwillbelostandthepressuretransmitterwillcausean indicator light tobeactivatedtoconfirmthe lossofvacuum.Theenclosurecould thenbe isolated, resealed, re-vacuumedand returned tooperation.Thisinventionhasbeenpatentedaswellastrademarked.

Thisdevicecanbefittedtoallenclosuresandequipmentsuchastransformersandsimilarequipment.Whensuchequipmentshouldfailitcouldhaveanimpactonthesafety-inparticularwhereitisinstalledinanexplosiveenvironmentsuchasundergroundincoalmineswheremethanegasispresent.

Bypreventingtheelectricflashfromignitingtheatmosphereintheenclosurethedamagethatcouldbecausedwillbecontainedandnomajorexplosionwilloccur.Anexampleofthedangerwhenatransformerexplodeswasillustratedwhentwoemployeesat theTENKEcoppermine inDemocraticRepublicofCongo sufferedinjuries inanelectrical fireat theweekendof15–16 July2017when themineexperiencedanelectricalshortinasingletransformerthatsuppliestheSAGMillattheKwatebalaplant,resultinginalocalisedfire.

HAZLETONPUMPShaswonseveralawardsfortheHIPPOFlameproofSubmersibleSlurryPumprange:

2006 Winnerof an award fromDesign Instituteof SouthAfrica (DISA) for theHIPPOFlameproofSubmersibleSlurryPumpRange.

2011 WinnerTT100Award forExcellence inManagementofResearch for theHIPPOFlameproofSubmersibleSlurryPumpRange.

2015 EngineeringFederationofSouthAfrica(SEIFSA)AwardedtheCompanyoftheYearandwinnerintheCustomerServiceCompanyoftheYearawardfordevelopmentoftheHIPPOHigh-Volume,High-Head,Medium/HighVoltageFlameproof Submersible Slurry Pump range as well as the repair andrefurbishmentoftheHIPPOSubmersibleSlurryPumprange

2015 HAZLETONPUMPSwon the prestigious SouthAfrican Premier BusinessAwards’ (SAPBA) Manufacturer of the Year award for the design,development and manufacture of a Medium/High Voltage SlurrySubmersiblePumpwhilealsowinningoftheSMMECompanyoftheYear.

2016 The Southern African Development Corporation (SADC) Quality Awards

bestowed the honour of the winner of the Southern African SMMECompanyoftheYearontheCompany,andProductoftheYearfortheHigh-Volume,High-Head,Medium/HighVoltageFlameproofSubmersibleSlurryPumprange.

2016 South African Flameproof Association (SAFA) for the HIPPO FlameproofHigh Voltage Submersible Slurry Pumpwhichwas awarded as theMostInnovative Product or Engineering Solution of the Year and is the onlyproductofitstypeintheworld

2017 EngineeringFederationofSouthAfrica(SEIFSA)AwardedtheCompanyoftheYearandwinnerintheCustomerServiceCompanyoftheYearawardfordesign, development andmanufacture of the HIPPO Submersible SlurryPump rangeaswell as the repair and refurbishmentof this SubmersibleSlurryPumprange.

Forfurtherinformationpleasefollowthelinktoour“pressoffice”intheMiningWeeklymagazine:

http://www.miningweekly.com/page/press-office-home/company:hazleton-pumps-2017-01-31