CONTROLLED HYDRODYNAMIC
CAVITATION
Chemical-Free Cooling Tower Water Treatment System
A Marmon Water/Berkshire Hathaway Company
February 10, 2015
! Cavitation
Metal Destruction from Uncontrolled Cavitation CAVITATION BUBBLE COLLAPSE
cav.i.ta.tion \ kav' i ta' shun \ n [1. the rapid formation and collapse of vapor pockets in a flowing liquid in regions of very low pressure.
Shear stress = 150,000 psi Temperature rise = 10,000 F
Inside the CHC Cavitation Chamber
! The opposing water streams collide in the cavitation zone, causing millions of high energy, micro-sized cavitation bubbles to rapidly form and collapse. This stresses any bacteria and forces calcium carbonate to form in the bulk water.
" Water from the sump is pumped under pressure into the cavitation chamber, where it is forced to rotate at high velocity through precision nozzles.
# The treated water exiting the cavitation chamber is returned to sump where the precipitated calcium carbonate is removed by the integral filtration system.
$
$ $
%
&
Controlled Hydrodynamic Cavitation
! Mechanical Non-chemical Device (NCD) ' Controls Scale by precipitating
and removing CaCO3 ' Controls Bio-Fouling by
shredding the cell walls of bacteria
' Controls Corrosion by increasing pH by 0.5 to 1.0 unit
! Side stream system that
includes integrated filtration
Scale Control Using CHC
CO2 Stripping: High-vacuum exceeds partial-pressure of CO2; CO2 is vented - pH increases 0.5 to 1.0 units - Water is in a non-corrosive pH range
Hardness Removed: As CO2 vents, reaction shifts right. A powdery CaCO3 colloid is created. Aragonite forms, precipitates and is filtered
Ca(HCO3)2 (CaCO3 + H2O + CO2 Dissolved Precipitate Gas (vented)
How Do We Measure CoC?
A Marmon Water/Berkshire Hathaway Company
! Traditionally we measure CoC:
' Ratio of metered make up water to metered blowdown water
' Ratio of ions such as Conductivity or Total Dissolved Solids
! What happens when CaCO3 is physically removed from the water?
Measuring Cycles of Concentration (CoC) based on Chloride Ions
CoC can be calculated using any ion in the water or by using Conductivity/Total Dissolved Solids (TDS) that measures all conductive ions in solution. However, chloride is considered the most accurate ion to use for this purpose because: 1. Chloride (Cl-) is present in all raw waters. 2. Chloride is the most soluble of the dissolved solids in water, the last to precipitate and therefore, no other solid will concentrate more. This assures the accuracy of the measurement and calculation. The calculation for CoC is given below:
Cl-S (sump water chloride) CoC Cl-MU (makeup water chloride)
Cooling Tower
1000 gallons Conductivity = 300 μS#
100 ppm CaCO3 10 ppm Chloride
EVAPORATION 750 gallons
250 gallons Conductivity = 1200 μS#
400 ppm CaCO3 40 ppm Chloride
Traditional
Ratio = 4 = 4
Cycles of Concentration Mass Balance
CoC = 4
CoC = Cycles of Concentration = Make Up/Blowdown
Cooling Tower
1000 gallons Conductivity = 300 μS#
100 ppm CaCO3 10 ppm Chloride
EVAPORATION 750 gallons
250 gallons Conductivity = 900 μS#
200 ppm CaCO3 40 ppm Chloride
Controlled Hydrodynamic Cavitation
Ratio = 2 = 4
Cycles of Concentration Mass Balance
50% CaCO3 removal No Chloride removal
CoC = 4
Cooling Tower
875 gallons Conductivity = 300 μS#
100 ppm CaCO3 10 ppm Chloride
EVAPORATION 750 gallons
125 gallons Conductivity = 1500 μS#
400 ppm CaCO3 70 ppm Chloride
Increase CoC with CHC
Ratio = 4 = 7
Cycles of Concentration Mass Balance
50% CaCO3 removal No Chloride removal
CoC = 7
Cycles of Concentration SUMMARY
50%$CaCO3$REMOVAL
Traditional With,CHC Water,Savings,with,CHCMake,Up,(Gal) 1000 1000 875Blowdown,(Gal) 250 250 125Evaporation,(Gal) 750 750 750Make$Up/Blowdown 4 4 7
Conductivity,IN,(μS) 300 300 300Conductivity,OUT,(μS) 1200 900 1500OUT/IN 4 3 5
CaCO3%IN%(ppm) 100 100 100CaCO3%OUT%(ppm) 400 200 400
OUT/IN 4 2 4
Chloride,IN,(ppm) 10 10 10Chloride,OUT,(ppm) 40 40 70OUT/IN 4 4 7
Water Savings
Examples of Water Savings Through Increased Cycles of Concentration
State Tons System Gallons
Chemical CoC
CHC CoC
Water/Sewer Savings
% Savings-Makeup
% Savings-
Blowdown
VA 730 2,610 4.5 7.0 991,408 Gallons 18% 40%
FL 850 4,000 2.0 4.0 5,400,000 Gallons 40% 73%
ND 4,500 80,000 3.5 5.8 10,830,000 Gallons 15% 50%
CoC = Cycles of Concentration
A Marmon Water/Berkshire Hathaway Company
Legionella
! 1976: American Legion Convention, Philadelphia ' 221 cases; 34 deaths
! 1985: Stafford District Hospital, United Kingdom ' 175 cases; 28 deaths
! UK Health and Safety Executive ' Publishes First L8 ACOP in 1991
How Concerned Should We Be About LEGIONELLA?
! Centers for Disease Control and Prevention (CDC)
' Between 2000 and 2009 reported cases increased 3X
' Between 2000 and 2009 there were 22,418 reported cases
' In the US, 8% of the cases result in death = 2,018 deaths
World-class Bacteria Control Effect of CHC on Numbers of Legionella Pneumophilia Initial dose = 10,000,000 cfu/litre
Data from Merican Sciences, J Usher and G. Hatchhroft and Principle Consultant Alan Edwards C.Chem MRSC from Alan Edwards and Partners, UK 2008
World-class Bacteria Control
! CHC is an approved non-chemical technology for Legionella control under world’s most strict standard, L-8 in the UK.
! Bacteria may adapt to traditional chemical treatment. However, they cannot adapt to CHC.
Legionella Testing Conclusion
! The CHC cavitation zone is extremely efficient in controlling or even eliminating all microorganisms. This is achieved by impacting high velocity rotating streams of water together. The tremendous localized temperatures and extreme fluctuations in fluid pressure within the CHC chamber causes cell walls of microorganisms to rupture. – Alan Edwards
CHC Value Proposition ! Remove scale causing
ions ' Increase Cycles of
Concentration " Reduces make up water
consumption " Reduce blowdown volume
' Cleaner heat transfer surfaces " Saves energy " Saves maintenance " Extends life of the assets
! Kill bacteria including Legionella
' Improved employee and guest safety
' Reduce liability risk as safety legislation similar to the UK’s L8 rules spread to the rest of the world
' Eliminate the need for toxic biocides that flow into our waste treatment and water supply
Water & Sewer Savings
! Average customer reduces make-up water 20%
! Average customer eliminates 50% of blow-down
! Because CHC is chemical-free, blow-down may be repurposed for other applications, (i.e. irrigation) saving significantly more water!
Eliminate Chemicals
! Save money ' Eliminating direct costs ' Reducing reporting &
management
! Reduce Risk ' System failure from chemical
overtreatment " System damage is more
common than you think! ' Environmental, Health &
Safety
Meet Environmental Sustainability Goals
No Hazardous Chemicals
Water Savings Water Reuse* Energy Savings
*Additional Permitting may be required for Blowdown Reuse
CHC Qualifies for USGBC LEED-NC Innovation and Design (ID) Credit 1.1.
An additional point may be earned (Water Efficiency 1.2) by using cooling tower blowdown for landscape irrigation purposes.
Improves Efficiency
Lowers Costs
Minimizes Factors that Reduce Efficiency 1. Controls scale 2. Prevent biological fouling 3. Inhibits corrosion
Reduces Total Cost of Ownership 1. Eliminates chemical costs 2. Cuts water & sewer usage 3. Improves energy efficiency 4. Minimizes maintenance
Economically Achieves ‘Green’ Initiatives 1. Eliminates hazardous chemicals 2. Improves water conservation and reuse 3. Provides energy savings 4. World-class bacteria control
Proven Technology
Over 15-years of successful, chemical-free cooling water treatment world-wide
Meets Environmental
Sustainability Goals
Top Related