Heat Exchangers Evaporators and Distillers

 


Heat exchange of water undergoes a complex chain of reactions resulting in both alkaline and acid scaling. Flow dynamics, quality of water, pressure variations and complexity of chemical reactions make predictions difficult. This scaling phenomenon is directly related to alkalinity and hardness in which heat exchange provides the trigger point for this chain to begin. Alkaline scale formation begets from the decomposition hydrolysis of bicarbonate ion as process temperature is increased. Starting with R
eaction A (3 HCO3 - + 3 H2O ↔ 3 CO3≤ - + 3 H2OH+).  Once the solution is heated, alkalinity in form of bi carbonates combines with water to form CO3≤ and hydronium ions. This results in immediate variations in pH values and resultant inability to accurately predict scale and sludge formation. In Reaction B (CO3 2- + Ca2+ →CaCO3 ↓) Carbonate ions then combine with Calcium ions to form a compound that forms hard scale on the contact surfaces. At Reaction C (2 CO3≤- + 2 H2O ↔2 HCO3 - + 2 OH-), carbonate ions combine with water to produce bi carbonates and hydroxyl ions. At Reaction D (2 OH- + Mg2+ →Mg (OH) 2 ↓), the short lived hydroxyl ion cycle quickly combines with magnesium ions to form a precipitate of magnesium hydroxide. It is assumed that steps A to D support deposition of calcium carbonates ahead of magnesium. At Reaction E (3 HCO3 - + 3 H2OH+ →6 H2O + 3 CO2 ↑), hydronium ions react with bicarbonates to form water and carbon dioxide lowering the localized pH conducive to acid scaling of silicates and sulphates, a much harder form of scale. This step is probably related to the pressure fluctuations inside the heat exchange tubes. At Reaction F( 4HCO3 - + Ca2+ +Mg2+ →CaCO3↓+ Mg (OH)2 ↓+ 3CO2 ↑+ H2O) a  double reaction of calcium and magnesium precipitate in the given order forming carbon dioxide and water again leading to acid scaling of silicates and sulphates. This is one explanation why scaling occurs as honeycombs.

 

Some of the most glaring effects of EcoBeam XL are: -

 

  • Changes in pH.
  • There are rapid changes in pH of water due to formation of negative ions, bicarbonates and carbon dioxide. However, the common practice is that pH values of solutions are measured from samples drawn out of heat exchanger tubes of recovery section and not conclusive. EcoBeam XL will stabilize the pH through creation of additional hydrogen and hydroxyl ions and obviate the use of complicated and impractical pH monitoring. These ions, combined with flow dynamics will remove all existing scale in the system accessible to this energized water and inhibit future scaling and corrosion. The sludge formed thereof will be carried away by the flow of the water.

  • Scaling and Hydro Dynamics.
  • Though the explanation above caters for the likely chemical reactions, it ignores the aspects of hydro dynamics created due to heat, flow of water and additions of chemicals in water to control scaling and corrosion. Molecular clusters of water carrying their own electrical charge as well as that of the dissolved solids within them intersect each otherís electrical fields while passing through valves, housings and surfaces creating turbulence. The rapid rise and fall in temperatures act as initiators of another chain of chemical reactions that would constantly be different at different nano seconds. Scale precipitation inside tubes is not only from initial scale formation under pressure but also due to nucleate recirculation due to recycling. EcoBeam XL will stabilize all chemical reactions, separate all peripheral dissolved solids that form scale and enhance the performance of the plant under varying flows and temperatures. The electrical energy (zeta potential) of the scale forming compounds will be used to stabilize pH and form soft slimy sludge instead of hard alkaline and acid scale. At the same time it will be the silicates that shall initiate the process of acid sludge while the other sludge will collect around it.
  •  
  • Reduction in Pressures and Role of Carbon Dioxide.   
  • Formation of carbon dioxide raises the pressure inside the vessels, affecting formation of steam. Some combines with it to make the water acidic. In case of EcoBeam XL, Hydrogen Ions being positive will form a pattern along the surfaces of pipes and chambers. Carbon dioxide formed will convert to carbonic acid which in turn will deplete the hard scale. Because most of the CO2 will be utilized to deplete scales as a result, pressures in the vessels will reduce.
  •  
  • Corrosion.            
  • The formation of hydrogen ions and them being attracted to the sidewalls of the pipes that are ground negative besides removing existing hard scales also forms a thin film by reacting with existing corrosion to reverse the damage and inhibit further corrosion not only in the tubes but also throughout the system.         

 

Before and After Conditions of Heat Exchanger and Pipes with EcoBeam XL on installations in Japan

 

Read More Related Topics:
Cooling Towers
I Heat Exchangers Evaporators & Distillers  I Blow Down I Scale Preventions I Corrosion Control I Control of Biological Growth I Fuel I Water Treatment

 

 

  • Our  Vision and Mission
    Eco Tech operates in the wide range of water treatment and fuel combustion systems with the philosophy of being environmentally friendly and efficient.
    We have operations in over 26 countries. Recently we have also expanded to Scandinavia and Middle East.

     

     

     

     

     
    Ecotech process and water solutions offer technologies throughout the world to improve the quality of drinking water and the water that is critical to essential industrial processes like chemical processing, power generation and the manufacturing of food and pharmaceuticals.

     

     

     

     
events Links
President Mr. Justin Sharaf  
Press clips
Other activity coverage reports
Upcoming events
Media Center
Information about Ecotech team
How to get support
Where to find products
Certification
 
   
News
Latest news and review of our products
New introduction Ecotech XLBeam
   
Information Desk
  Request Information
Request Proposal
Where to Buy
   
  Mail Us
  info@ecotechsi.com