Post on 09-Feb-2017
ATI GROUP Soluciones de IngenieríaPlantas y Equipos de Proceso
Portafolio Bombas SALVATORE ROBUSCHI para Tratamiento de Efluentes
SALVATORE ROBUSCHIwaste water pumps
DIRTY LIQUIDS: SELECTION OF IMPELLERS
DIRTY LIQUIDS: SELECTION OF MECHANICAL SEALS
WEAR PROOF MATERIALS AND COATINGS
SOME APPLICATIONS
OUR REFERENCES
DIRTY LIQUIDS: SELECTION OF IMPELLERS
In according to the pumped medium we can select different impeller types:
• semi-open• closed
• vortex• channel
DIRTY LIQUIDS: SELECTION OF IMPELLERS
CLOSED IMPELLER
Closed impeller or totally enclosed impeller are designed with blades between two support or shrouds.
Solid’s contamination will destroy the tolerances between impeller and wear ring: these tolerances govern the efficiency of the pump
These impellers are for totally clean liquids because there is no room for suspended solids, crystals, sediments or air.
DIRTY LIQUIDS: SELECTION OF IMPELLERS
SEMI-OPEN IMPELLER
Semi-open impeller has exposed blades with a wearing plate
These types of impeller are generally used for liquid with a small percentage of solid particles like sediment (not abrasive), short fibers, crystals mixed with water and air.
The efficiency is the same of closed impeller
These types of impeller are not suitable for medium with abrasive solids, hard particles and long fibers
DIRTY LIQUIDS: SELECTION OF IMPELLERS
MULTI-CHANNEL IMPELLER
The big suction inlet and the few blades reduces the inlet speed and grants very good suction characteristics, also with gas, air or solids.
Same efficiency than closed impeller with bigger free passage
DIRTY LIQUIDS: SELECTION OF IMPELLERS
MULTI-CHANNEL IMPELLER
Multi-channel impeller allows suspended solids (not filamentous) to be transferred without pump clogging
As for closed impeller, solid’s contamination will destroy the tolerances between impeller and wear ring: these tolerances govern the efficiency of the pump
DIRTY LIQUIDS: SELECTION OF IMPELLERS
VORTEX IMPELLERTHE SOLUTION FORWASTE WATER
85% of the pumped fluid is transported directly from the primary vortex to the pressure connection. Only 15% of the fluid being pumped comes in contact with the impeller (secondary vortex)
The impeller spins in an area of the volute that is completely out of the liquid flow path. The spinning creates a vortex similar to that you can find in a tornado.
DIRTY LIQUIDS: SELECTION OF IMPELLERS
VORTEX IMPELLER
These types of impeller are generally used for dirty medium, containing sediments (even abrasive), long fibers, crystals mixed with water and air.
DIRTY LIQUIDS: SELECTION OF IMPELLERS
VORTEX IMPELLER
Vortex impeller is completely recessed, out of the flow path.
The effiency of this pump is lower than semi-open impeller.
DIRTY LIQUIDS: SELECTION OF MECH. SEALSThe most common mech. seal executions for dirty liquids are:
Gland packing (with or without external flushing)
Single mechanical seal (with or without external flushing)
Double seal (tandem or back-to-back)
DIRTY LIQUIDS: SELECTION OF MECH. SEALSGLAND PACKING
Through the stuffing box and the gland follower, the packing is compressed to accommodate the interior bore of the stuffing box and the shaft surface, sealing the pumped liquid. It is a good practice to tighten the gland just enough to allow for a minimal leak through the packing
A lantern ring substitues one the packing ring to supply ‘back pressure’, which aids in impeding the entrance of abrasive and corrosive material into the stuffing box
DIRTY LIQUIDS: SELECTION OF MECH. SEALSSINGLE SEAL
This type of seal mounts onto the shaft or sleeve inside the seal chamber and pump. The pumped liquid comes into contact with all parts of the seal and approaches the outside diameter of the internally mounted faces keeping them lubricated
This is the most popular type of mechanical seal in clean (no solid particles or crystals) liquid service
In case of dirty liquids we suggest PLAN 32 (clean water injection in the seal chamber) to keep clean and lubricated the mech. seal
DIRTY LIQUIDS: SELECTION OF MECH. SEALSDOUBLE SEAL: TANDEM
This type of seal is installed instead of single seal when you have to protect the primary seal from run dry reduce the temperature of primary seal create a buffer in case of dangerous liquid
The flushing liquid in the area between the two seals MUST be pressurized at 0,3bar
DIRTY LIQUIDS: SELECTION OF MECH. SEALSDOUBLE SEAL: BACK-TO-BACK
The flushing liquid in the area between the two seals MUST be pressurized at 0,5bar more than discharge pressure
This type of seal is installed instead of single seal when you have to work in vacuum pump dirty medium (high solids %) create a buffer in case of dangerous liquidpump sticky liquid (e.g. paint, resin)pump polymers or resinpump aggressive medium
DIRTY LIQUIDS: SELECTION OF MECH. SEALSFor most applications, single mechanical seal will adequately handle every pump, liquid, and condition.There are, however, some pumping applications that will present problems to even the best of mechanical seals
Slurries and Suspended Solids Should be purged or flushed with:•Water•Filtered or cleaned product a compatible liquid•A posterior additive in the system
Liquids that solidify To deal with liquids that try to solidify (think of ice, cement, glue and paints) it is necessary to identify the cause and solution for the solidification:Air (paint, glue)➔ Quench and Drain or the Double SealChange in Temperature (ice) ➔ Control the temperature, either up or down
DIRTY LIQUIDS: SELECTION OF MECH. SEALS
Dry Running Pump Again, no lubrication or dissipation of heat. Remove the heat with a double seal and barrier tank with forced convective flow.
Film or Skin Formation Some liquids form a skin (like hot milk) with heat. Others form a film (like paints) on contact with air.Temperature control ➔ See Crystallization.Contact with air ➔ Double seal with pressurized barrier fluid
Crystallization Some liquids form crystals with heat (think of sugar and rock candy), and others with cold (think of ice). To control and prevent crystallization in the seal chamber it is necessary to control the temperature using:
•External Flush•Thermal Jacketed seal chamber•Quench and Drain•Dual Seal
WEAR PROOF MATERIALS AND COATINGSTo increase the life of impeller and casing, we can select special materials or special coatings:
CAST IRON HG 15.3 hardness 600 BrinellExcellent protection against wear No protection against chemical aggression
CA6NM ALLOY hardness 400 BrinellGood protection against wearGood protection against chemical aggression
WEAR PROOF MATERIALS AND COATINGS
CAST IRON HG 15.3 hardness 600 BrinellExcellent against wear No protection against chemical aggression
BELZONA 1313 ceramic paintGood protection against wearGood protection against chemical aggression
WEAR PROOF MATERIALS AND COATINGSWhen the pumped medium contains abrasive particles:
Use vortex impeller
Decrease, if possible, the pump speed
Don’t use impeller with max diameter
Verify the pH of pumped medium
Flush the mechanical seal (using plan 32 or double seal)
SOME APPLICATIONS
VORTEX IMPELLER Liquid: waste water with tomatoes skin, grass and soil
VORTEX IMPELLERLiquid: sludge recirculation
SOME APPLICATIONS
VORTEX IMPELLER Liquid: sludge (biomass) recirculation
VORTEX IMPELLER Liquid: sludge (biomass) concentration (with high vacuum)
SOME APPLICATIONS
VORTEX IMPELLER Liquid: DAF system
SOME APPLICATIONS
VORTEX IMPELLER Liquid: fish waste
REFERENCESPESQUERA POLAR ECUADOREEKELSKEMIRATOMSA DESTILSIEMENS WASTE WATERENEL POWERAREVASANOFIVEOLIATMCI PADOVANCFTNAVATTA GROUPFENCOHRS SPIRATUBEALFALAVALSOFINTER – SWSARKEMAWATERLEAUSTORK MAREL
PROCTER & GAMBLECHEVRONCAVIROWATER ENGINEERINGECOTECNOECOINTERNATIONALCONDOROILVILOKANWIENTJENSSHELLMINGAZZINIPROTECNOLUCCHINIENELAGIPALMA PETROLILA PETROLIFERA ITALO-RUMENAYARATEKNODEPURAZIONI
ATI GROUP
Contacto
Telmo Becerra +51 990 722 336 telmo@ati.com.pe
Calle Pedro Yrigoyen 285 Of. 101Miraflores- Lima 18 PERUTlf. 637 7900