Industrial Coolant Antifreeze Chemical

4/2/2012

0 Comments

 
Picture
Propylene glycol is used as antifreeze agent and industrial coolant in different industries where contamination with food is possible, de-icing solutions etc. Propylene glycol is generally regarded as safe for use in food. It is used in the industries like food, beverage etc for heat transfer, also used in vehicles. Antifreeze Coolant should be efficient in transferring the heat as well as preventing scale and corrosion.

Propylene glycol [HO-CH2-CH(OH)-CH3] is pronounced as pro'puh-leen-gly'col. It is a clear, colorless, slightly syrupy liquid at room temperature. The compound may exist in air in the vapor form though it must be heated or briskly shaken to produce a vapor. It is actually a multi-variant chemical compound. Propylene glycol - in an industrial cooling and heating process terminology is referred as industrial coolant or heat transfer fluid (HTF) or the common fluid that is used in large installations for transporting heat from one place to another.

Features :
  • serves as a solvent
  • offers outstanding stability with high flash and boiling points
  • reduces the freezing point
  • increases the boiling point
  • helps to bind and transport other substances (excipient)
  • holds and dissolves active ingredients equally in a medium
  • connects and stabilizes insoluble fluids (emulsifier)
  • attracts/holds water/moisture (hygroscopic)

Usage :
  • As an emulsification agent in Angostura and orange bitters
  • As a moisturizer in medicines, cosmetics, food, toothpaste, shampoo, mouth wash, hair care and tobacco products
  • As a carrier in fragrance oil
  • To produce polyester compounds
  • As a base in deicing solution
  • In smoke machines to make artificial smoke for use in firefighters' training and theatrical productions
  • As a solvent for food colors and flavorings
  • As an ingredient, along with wax and gelatin, in the production of paintballs
  • As a wetting agent, used to determine drying time in paints and coatings

A non-toxic substitute of Ethylene Glycol :

Propylene Glycol is the replacement of Ethylene Glycol in newer automotive antifreezes and de-icers in aircrafts. Like Ethylene Glycol, Propylene Glycol also has the special physical characteristics of depression of freezing point when mixed with water. It happens due to disruption of hydrogen bonding. Pure water freezes at 0OC. But aqueous solution of Propylene Glycol (10% by weight) has a freezing point of -3OC. 30% by weight aqueous solution of Propylene Glycol freezes at -12OC and a 60% by weight Propylene Glycol and water mixture can further lower down this freezing point to -51OC.

Why Glycol turned into red color ?

Because of the extensive corrosion & rust in the system metal makes the glycol turn reddish in color. At this point the glycol is fouled with iron contaminants that increase the glycol degradation rate. It is important to add corrosion inhibitor to the glycol system to avoid such degradation of glycol.

Application Areas :

Beverages & Juices, Breweries & Distilleries, Packaged Food Freezing, Canneries & Preservers, Fish Processing Units, Pharmaceutical & Bulk Drugs, Poultry Processing Industry, Thermal Storage System, Heating and Cooling Systems, Snow Melting and Refrigeration, Ice Skating Rinks, Vegetable Oil Industry, Ice Manufacturer, Cold Storage Systems etc.

Product Physio-Chemical Data :
  • Form and Appearance - Clear, colorless liquid
  • Assay as Propylene Glycol - 99.8%
  • Specific Gravity - 1.04 (approx.)
  • Molecular Wt. -  76.0548 gm/mol
  • Solubility in Water - 100%

Handling Measures, Precaution & Storage :

Propylene Glycol is slightly hygroscopic & the storage temperature is not critical, it must be stored under conditions so that contamination with water and adsorption of moisture are prevented. It should be noted however for product quality reasons the storage temperature should not go above 40°C. At below freezing temperatures the product viscosity might become too high for transfer from the storage containers with the pumps available. PG is a stable chemical and is not expected to deteriorate significantly with time provided if it is stored as indicated. The drums should be stored in dry condition, better to use the original drums rather than the other drums and if the drums are opened then it must be closed tightly at unused situation. The chemical can be stored up to 6 months. 

0 Comments

Nitrite based Corrosion Inhibitors for chilled water

1/24/2012

1 Comment

 
_
Nitrite based Corrosion Inhibitors for chilled water systems is a multi-metal corrosion inhibitor based on nitrite and other organic compounds with special yellow metal corrosion inhibitor and anti-scaling agent that helps to prevent scale deposition or also removes adhering loose scale deposits from the heat transfer fluid system.

                There are several disadvantages for not treating the closed circuit water and in long run it can create troubles for the system operator. The corrosions caused by chiller water, Mono Ethylene Glycol or Brine can cause system leakage in PHE (Plate Heat Exchanger) and AHU (Air Handling Unit). Corrosion can also cause plugging and clogging of tubes and thus reduce flow rate. This will affect the heat transfer rate and will force the system to reduce heat transfer efficiency. This way the system needs regular descaling that incurs shutdowns, leads to additional costing for labor and wastage of time.

                “Scale” is a hard deposit of inorganic material on heat transfer surfaces. This is caused by gradual precipitation of mineral particles in water on the surface. During the evaporation of water in a evaporative condenser, pure water vaporizes out and the dissolved solid materials concentrate in the remaining water on the surface. The solids will then settle in pipelines or on heat exchange surfaces, where it frequently solidifies into a relatively soft, amorphous scale.

                Next to scale, the next most important concern is the prevention of “corrosion”.

                Corrosion is defined as the destruction or loss of metal through chemical or electrochemical reaction with its surrounding environment or material. Mild steel is a most commonly used metal in the cooling water system. But this metal is most susceptible to corrosion. However in some waters and in presence of dissolved gases, such as H2S or NH3, the corrosion to these metals is more severe.

                Common problems arising from corrosion are reduction in heat transfer and water flow resulting from a partial or complete blockage of pipes, valves, strainers, etc. Also, excessive wear of moving parts, such as pump, shaft, impeller and mechanical seal, etc. may resist the movement of the equipment. Hence, thermal and energy performance of heat exchange may degrade.

                The water treatment in closed system is thus not very critical. Once the initial volume is chemically treated, the quality of the circulating fluid needs to be monitored on a regular basis and additional chemicals added as required to maintain recommended residual concentrations of treatment chemicals.

                Most closed-loop water systems use a sodium nitrite based inhibitor for corrosion control and a biocide to prevent biological contamination. These inhibitors will protect both the ferrous and non-ferrous materials in your piping system.

The major advantages of using nitrite based corrosion inhibitor are as follows:-

  • Removes dissolved oxygen by converting the nitrite to nitrate.
  • Negligible loss of metal or corrosion.
  • Excellent heat transferability and flow rate.
  • No need of descaling closed circuit equipments.
  • Long and extended life of Water without fouling.
                Application: Engine Jacket Cooling or heating system, Chiller Water Circuit, Glycol Brine System, Hot Water or steam Circuit, Engine Coolant, Process chilling and heating system etc.

                Dosage: Nitrite based Corrosion Inhibitor for Water and Glycol Brine is normally fed continuously to the re-circulating closed system by injection dosing pump or dosed to the expansion tank. The amount of Nitrite based Corrosion Inhibitor for Water and Glycol Brine to inhibit corrosion depends on the type of system and plant operating conditions. The specific dosage rates will be specified by the Chemtex's technical representative.

Picture
1 Comment
UA-25903097-1