Isothiazolin

Isothiazolin is an organic heterocyclic compound from the azole class, which contains a five-membered aromatic ring composing of three carbon atoms, one nitrogen atom, and one sulfur atom. Its official IUPAC name is 1,2-thiazol-3-one, and is also called isothiazolinone, isothiazolin-3-one, and 3(2H)-
isothiazolone. Isothiazolin has a molecular mass of 101.13 g/mol. Its derivatives are used as biocides including methylisothiazolinone, chloromethylisothiazolinone, benzisothiazolinone, octylisothiazolinone,
and dichlorooctylisothiazolinone.

Isothiazolins are used for water systems, fuel tanks, oil extraction systems, wood preservation, and antifouling processes as antimicrobial agents. It is non-oxidizing and commonly used in 1.5 percent formulation – an excellent broad-spectrum microbiocide over a wide range of pH level in cooling water
and closed-loop systems. It is non-foaming and is compatible with halogen biocides.

Isothiazolin is usually shot-fed directly from the shipping container at a minimum of 150 ppm. Specific treatment control levels are dependent on a system’s conditions. Tanks, pumps, pipings, and valves to be treated should be made of stainless steel, polyethylene, or PVC to avoid galvanic corrosion, as isothiazolin contains a small amount of copper. To ensure efficiency, oxidizers like sodium hypochlorite should also be applied to the water system alternately with isothiazolin.

Bacterial development in water systems should be monitored as well. The maximum limit of bacterial count should only reach 10,000 or less. To determine microorganism count objectively and quantitatively, dipslide technique should be done. Dip the slides in water for five seconds and wait for
24 hours to observe. Appearance of red dotes on the slides is indicative of bacterial colony presence. After treatment of the system, a chlorine test will now validate if treatment is successful or not.

Isothiazolin products are available at QualiChem Technologies. Acticide WP is developed to protect water systems against microorganisms, and contains unique non-metal salts stabilizing system. Product is free from organic solvents and formaldehyde. Acticide GA-W contains 5% bronopol, specifically
designed for SRB control and protection against bacterial and fungal spoilage. Product is free from organic solvents as well. Both are available in 55 gallons and are ready to be delivered.

References:

Ezine - http://ezinearticles.com/?Isothiazolin-Uses-For-Controlling-Bacteria-and-Legionella-in-Cooling-
Water-Systems&id=3793167

Wikipedia - http://en.wikipedia.org/wiki/Isothiazolinone

Brine Chiller Corrosion Inhibitor

Brine chillers provide heat transfer for food products, particularly milk, brew, and processed meat. The system provides faster heat conduction, uniform temperature reduction, and precise cooling control. High volume of brine also provides temperature uniformity which lowers production costs and lengthens product shelf-life.

Like other metal systems, brine chillers are prone to corrosion. Corrosion is the degradation of metal in its natural state due to various chemical reactions in its environment (i.e. metal disintegrating to its original ore). Various condition can contribute and aggravate corrosion, especially with closed loop systems like brine chillers.

There are six main types of corrosion, five of which are present in closed loop systems namely:

1. Galvanic corrosion (also called bimetallic corrosion) – an electrochemical process in which one metal corrodes with another when both are in contact and immersed in an electrolyte.
2. Oxidation corrosion – due to high oxygen saturation in the system.
3. Erosion corrosion – occurs in systems that has high flow rate and are contaminated with unwanted material on surfaces, especially in aquatic environment.
4. Uniform corrosion – due to high acidity, normally seen in glycol and brine systems.
5. Stress cracking corrosion – occurs due to high chlorine content.
6. Microbiologically-induced corrosion – due to biofouling in the system. Microorganisms, algae, and other living materials accumulate especially on soaked structures.

Chiller circuit corrosion affects business operation which can result to capital loss. Rust conducts heat and electricity poorly and can decrease cooling capacity in turn. It also tends to contaminate fluids/antifreeze coolants and plugs tube. Rust flakes are also abrasive and cause further erosion of metal system, thereby reducing flow rate.

In the long run, excessive corrosion or metal cavitation can cause leaks and burst of heat exchangers. In cases of beverage, brewery, or milk food refrigeration, these leaks can also cause product contamination.

Brine Chillers use corrosion inhibitors to minimize metal system degradation. Cooling Water Chemical 1609 of Chemicals Direct is an organic closed water system treatment program. Product contains a combination of phosphonate, polymer, and azole formulated to minimize corrosion and deposition. Cooling Water Chemical 1609 is designed for calcium chloride brine closed systems and suitable for ice rinks as well. 5 gallons of product can treat 350 gallons of fresh brine solution.

Features:

• Effective corrosion control
• Extends equipment life
• Improves overall equipment efficiency
• Non-nitrite, non-molybdate based
• Protects multiple metallurgies 
• Effective in both hot and cold brine systems

*A maintenance solution of 240 to 360 ppm. of phosphonate is recommended. Every 100 ppm. of product fed yields 2.25 ppm. of active phosphonate as HPA.

Boiler Corrosion Inhibitors

A corrosion inhibitor is any chemical compound that lessens the corrosion rate of metals or alloys when added to a liquid or gas solution. The National Association of Corrosion Engineers (NACE) further defines it as a “substance which retards corrosion when added to an environment in small concentrations”. The efficiency of corrosion inhibitor is caused by various factors including but not limited to: fluid composition, water quantity, and flow regime. A high efficiency (90%-99%) is guaranteed if the correct inhibitor and quantity are chosen.

Corrosion inhibitor works in several ways. One chemical mechanism is passivation, or the formation of a thin film on the surface of a material that inhibits contact of the corrosive substance -- preventing either oxidation or reduction. In cases of corroding materials, mechanism is done either through adsorption -- as a thin film on the surface of a metal, or scavenging -- inactivation of the dissolved oxygen. A lot of corrosion inhibitors are available in the market which includes hexamine, benzotriazole, phenylenediamine, diamethylethanolamine, polyaniline, nitrites, nitrates, cinnamaldehyde, chromates, phosphates, hydrazine, ascorbic acids, condensation products of aldehydes and amines, and a lot more. The suitability of a chemical to inhibit is dependent on the material of the system that they have to act in, the nature of the substances that they are added into, and their operating temperature. Failure to use a boiler corrosion inhibitor may lead to premature failure and excessive corrosion to the water system.