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DesJardins
COOLING TOWER CONSULTING SERVICES

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Over 52 years of service to the evaporative cooling industry

 COUNTER FLOW AND CROSS FLOW COOLING TOWER PROGRAMS

PSYCHROMETRIC PROBLEM SOLVING PROGRAMS 

EVAPORATIVE AIR PRE-COOLERS FOR AIR COOLED HEAT EXCHANGERS

COOLING TOWER CONSULTING SERVICES

Many companies which no longer have the luxury of having an experienced cooling tower engineer on their staff now use our services.  Our client list includes some of the most notable engineer-constructor firms in the world, major power producers, refineries, consulting engineers, developers, tower manufacturers, cooling tower repair firms, and industrial and air conditioning users.

 

 

Custom developed thermal rating programs for both counter flow and cross flow towers are used to provide quick, accurate tower performance predictions.  Computerized standard specifications are adapted to your unique requirements. It is usually much less expensive to make a computer study than field tests, and while field testing may tell you what your tower is doing now, it does not predict what it will do after you make additions or modifications.

Although we are the leading independent expert in cooling tower thermal performance, we also have 52 years experience in every aspect of the cooling tower industry from component design of structures, mechanical equipment, and other tower features to practical solutions for citing and installing your tower complete with all the controls and associated equipment.

SERVICES WE HAVE PROVIDED FOR OUR CLIENTS HAVE INCLUDED:

  • Bid analysis and thermal performance evaluations
  • Specification preparation
  • Inspections
  • Review for thermal upgrade
  • Economic comparisons and evaluations
  • Practical review of project needs
  • Confidential preliminary tower sizing and budget pricing
  • Review material requirements
  • Psychrometric, water conservation, and plume abatement problem analysis and design
  • Evaporative cooling process studies
  • Designs of cooling tower and evaporative cooling sections
  • Dry and wet tower economic analysis
  • Owner's Representative to monitor thermal performance test
  • Thermal performance tests
  • Expert Witness
  • Technical assistance for attorneys and management

SOME EXAMPLES OF THOSE WHO HAVE BENEFITED FROM OUR SERVICES

  • A major power producer now saves over $300,000 per year because tower performance was up-graded at the time of replacement.
  • A repair contractor's fill replacement recommendation was changed to get greater performance for less cost.
  • Bid analysis of many proposals revealed possible performance problems, and material and design deficiencies were discovered.
  • A specification was developed to encapsulate a failing galvanized steel tower in fire retardant fiberglass, saving the client over $250,000.
  • A thermal performance rating program was developed for a major cooling tower repair firm.
  • Many specifications have been prepared for refinery and power plant projects.
  • Tower repair inspections and construction inspection services have been provided for many projects including specification preparation and thermal performance improvement review.
  • Evaporative air pre-coolers have been designed and built for air cooled heat exchangers and turbine air inlet cooling.
  • Several turbine inlet air chilling studies have been made, including formal preparation of turnkey bids.
  • Plume abatement studies and designs have been provided for several environmentally sensitive projects.
  • A complete line of packaged cooling towers was designed for a foreign company including drawings for every part, computerized thermal rating system, inspection of prototype, operation manuals and installation instructions.
  • Thermal tests complete with analysis for energy rebates have been provided for high-rise office buildings.
  • Expert witness data has been provided for attorneys.
  • Complete design and operational analysis of plume abated cooling towers located in noise and vibration sensitive areas.

 

A COMPLICATED COOLING TOWER

 

   

 

The design of the tower shown above included the following:

 

  • Cooling tower thermal performance assessment and design for a 1.3 MW cogeneration central plant retrofit to a 1,000,000 + square foot office building.
  • Design parameters for an architectural enclosure and layout to meet existing building space and structural requirements including visual and environmental concerns.
  • Plume abatement coil design including by-pass dampers and control system designed to use external heat source for plume abatement and also for emergency heat load dump from the plant generator engine to the coils when the absorption chiller is not in operation.  Coils and dampers per API design requirements with conservative fouling factors.
  • Fans provided with VFD and controls to assure proper air velocities in the wet section if coil dampers are open or closed.  Control system requirements were developed for plume control for all expected atmospheric and load conditions.
  • Mechanical equipment selected for noise control to meet city ordinance.
  • Vibration isolation of each 2-cell tower.  One tower is over an auditorium.
  • Piping and valves, and equalization piping designed for hydraulic water balance between the cold water basins of both towers for various combinations of cell operation.

 

      

 

  • Fiberglass tower structure and casing with all welded stainless steel cold water basin.
  • PVC fill and drift eliminators selected for design conditions and water quality.
  • Fire sprinkler system to meet local codes.
  • Redundancy of cells and considerations for reliability for different weather conditions, heat loads, and number and types of turbines, engines and chillers running.

 

PAGE DOWN FOR DATA ON COOLING TOWER AND PSYCHROMETRIC PROGRAMS

 

ADIABATIC EVAPORATIVE AIR PRE-COOLERS

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INDUSTRIAL QUALITY FOR

AIR COOLED HEAT EXCHANGERS

GAS TURBINES

INDUSTRIAL BUILDINGS

Evaporative air pre-cooling can significantly decrease your initial capital costs, operating costs, and in some cases allow you to do what otherwise would be impossible. Standard air cooled heat exchangers operate on the dry bulb temperature as the lowest temperature sink for disposal of heat. By using evaporative sections in advance of the air cooled exchanger it is possible to reduce the dry bulb to near the wet bulb temperature by evaporating moisture into the air stream, thus either reducing the amount of surface required, reducing the operating temperature, or increasing the number of hours you can operate at the design dry bulb temperature.  Often the use of an air cooled heat exchanger with evaporative air pre-cooling sections can be used where a cooling tower that requires much more year-around water supply would preclude the building of a plant.

We have over 52 years of experience with evaporative cooling equipment.  Our computerized sizing system allows accurate design at any elevation and inlet design condition.  Our attention to details meets the requirements of the media manufacturer for elimination of leaks, drips, scaling splash-out and proper distribution. Additionally, the distribution of each system design is operated in the factory test unit prior to fabrication of the final product to assure you of a properly functioning field installation.

DESIGN CONSIDERATIONS

As a standard cooling media we use Munters Corporation Glasdek material.  Performance and pressure drop are typically defined as shown in the attached "Efficiency" and "Pressure Drop" graphs with further adjustments made for high altitude applications.  For preliminary design investigations please consider that most applications will be economically viable with 6" and 8" thick media operating at about 1.5 gpm per square foot of media plan area and a face velocity of 650 fpm maximum. The maximum net height of each media section generally cannot be more than 10 feet. Applications requiring greater height will require split distribution systems.  Standard structures are all welded #304 stainless steel.  If you are investigating the use of evaporative air pre-cooling sections, please contact us for assistance. We would be pleased to provide you with information on reducing fan power requirements, make-up and blow-down requirements, and where to obtain proper information on water treating and general layout requirements.

"EVAPORATIVE EFFICIENCY" IS DEFINED AS THE REDUCTION IN DRY BULB TEMPERATURE AS A PERCENTAGE OF THE DIFFERENCE BETWEEN THE DRY BULB TEMPERATURE AND THE WET BULB TEMPERATURE.

EVAPORATIVE EFFICIENCY AND PRESSURE DROP

CUSTOM OPTIMIZED FOR YOUR SPECIFIC SITE CONDITIONS AND EQUIPMENT

NO WATER CARRY OVER

Air cooled heat exchanger applications are designed for air velocities which do not require drift eliminators.  Gas turbine inlet applications are designed with securely fastened drift eliminators

NON CORROSIVE CONSTRUCTION

All welded stainless steel frame

PVC pipe manifolds and fittings

Stainless steel air inlet screens

Munters Glasdek or Celdek media

LOW PRESSURE DROP

0.1  to 0.5 inches w.g.

CUSTOM FIT TO YOUR EQUIPMENT

We will custom design structural attachment beams and channels, flashings, doors, piping, fans, pumps, valves, flow meters, water treatment equipment package with controls and filter, winter by-pass louvers and freeze protection, etc. to meet the specific needs of your project.  Special attention is given to making each part accessible for maintenance.

 

STANDARD FEATURES                       OPTIONAL EQUIPMENT

WELDED STAINLESS STEEL FRAME                WATER TREATMENT EQUIPMENT

BLOW-DOWN FITTINGS                                       BALANCE VALVES

GLASDEK OR CELDEK MEDIA                          COLLECTION BASIN

PVC PIPE MANIFOLDS                                          PUMPS

STAINLESS STEEL AIR INLET SCREENS         DRIFT ELIMINATORS

DOUBLE DISTRIBUTION PADS                          FLOW METERS      

WEST COAST ENGINEER:

"We investigated several installations and this is the best we have seen."

CONSTRUCTION MANAGER:

"WE INSTALLED 40 SECTIONS IN ONE DAY"

OVER 49 YEARS OF EXPERIENCE WITH EVAPORATIVE COOLING EQUIPMENT

 

EVAPORATIVE COOLING WITH FOGGING NOZZLES

We provide design, consulting and supply (though one of our associate companies) of evaporative cooling fogging nozzle systems for large air cooled heat exchangers.  These installations require about the same design parameters as listed above for wet surface sections, but the cooling efficiency is limited to about 50% to assure all the water is evaporated.  Two distinct advantages are no additional pressure drop and no start-up time required.  The designs usually include high pressure pumps, required RO water supply, and controls.  Nozzles are high technology to provide very fine fog droplets that are staged to evaporate in only 2 to 4 feet from the nozzle, thus minimizing or eliminating wetting of the surrounding structure, fans and coils.  The first cost of this type of system is generally less than wet surface sections, but wind effects can affect the operation, and the parasitic pump power is higher.

 

PSYCHROMETRIC PROBLEM SOLVING PROGRAM 

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Much more than just a data point look-up tool.

Use it to quickly and accurately step through your process, changing the pressure as you go, as actually happens in the real world, combine air streams, add or remove heat, and quickly solve evaporation or condensation problems. Solve psychrometric and heat transfer problems for air pollution control scrubber systems, HVAC, chemical processes, evaporative cooling with just a few key strokes.  No more having to read a single pressure chart until your eyes pop out.

  • Combine two air streams using three different types of input.
  • Given two known streams - find the combined stream properties.
  • If the first and final streams are known - find the missing stream.
  • Second stream flow is a percentage of the first stream - find results.
  • Add or remove heat from an air stream.
  • Find the sensible and latent heat added or removed when given two known points.
  • Given a starting point, add or remove latent and sensible heat from an air stream.
  • Given a starting point and "Cooling Efficiency", solve evaporative cooling problems.

Condensation and evaporative heating or cooling calculations are made easy.  The amount of water added or condensed is calculated. Flow entry can be in CFM or pounds of dry air or pounds of mix.  The psychrometric program calculates the properties of moist air at any elevation to 20,000 feet and for pressures to 35 psia.  Temperature range is from -80oF to 2,000oF.

The Mol Weight and Specific Heat can be revised to allow calculations of properties of other moist gases (such as flue gases).  Hot gas scrubbing calculations are made easy.

  • The program uses four different pressure input modes: altitude, psia, inches mercury or inches water gage absolute.
  • Nine different property input modes are possible: dry bulb - wet bulb; dry bulb - relative humidity; wet bulb - humidity ratio; enthalpy - humidity ratio; dry bulb - humidity ratio; dry bulb - enthalpy; wet bulb - relative humidity; enthalpy - relative humidity; and humidity ratio - relative humidity.
  • Given any two of the above properties and a pressure, the other properties are calculated along with three different specific volume options, the dew point temperature, three vapor pressure options, and the density of the mix.

Easy use:  The program saves your last results or inputs to save you time in going to the next portion of your problem.  Extensive error warnings help keep you from obtaining false results. You can add notes to your print-out to explain your process or project. Results can be saved to a file for import to a spread sheet or other program for further calculations.

COUNTER FLOW AND CROSS FLOW COOLING TOWER

THERMAL PERFORMANCE PREDICTION PROGRAMS

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An example of Output from Counter Flow Cooling Tower Thermal Performance Prediction Program. The program includes a built in estimator and help function guidelines for practical tower design parameters.  It is all you need to know to check the size of a cooling tower design or make an economic evaluation.

     COUNTER FLOW COOLING TOWER CHECK RATING PROGRAM

 

CALCULATE MECHANICAL DRAFT TOWER PERFORMANCE: Included are data for the most commonly used new tower fans, fills and eliminators.  Also included are data for many old fills and other components so you can thermally analyze existing towers.  What used to take hours now takes seconds.

OBTAIN ACCURATE PREDICTIONS:  Use either standard Cooling Tower Institute performance theory (Merkel Theory) or an advanced theory which has built in hot water correction and adjusts for other traditional inaccuracies that might lead to an undersized tower.

ANALYZE YOUR BIDS:  Be a knowledgeable buyer.  Although the Cooling Technology Institute recommends you test your tower after it is installed to be sure it was designed and built as expected, towers often do not get tested.  You can add a degree of protection by checking the predicted performance before you buy.

EASILY INVESTIGATE ALTERNATE OPPORTUNITIES:  Study alternate tower configurations, estimate the power evaluated cost, or find the best way to up-grade. Use the cost estimator to investigate the optimum use of fan and pump power as compared to installed capital cost.  Use the help screens to be sure the design is within normal design parameters for good air and water distribution, minimum drift and windage losses.  Predict performance at high altitude.

ASK US.  If you have a cooling tower question, send us e-mail.  We will answer it.
 

MEMBER COOLING TECHNOLOGY INSTITUTE

DesJardins
COOLING TOWER CONSULTING SERVICES

RICHARD J. DESJARDINS
38373 CHERRYWOOD DRIVE
MURRIETA, CA 92562
Telephone & FAX: 951-600-1564      Cell phone: 760-641-4264

 e-mail us: richard@rjdesjardins.com   or coolingtower@verizon.net

 
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