28th January 2018

Lithium Bromide Analysis

Lithium Bromide solution used in absorption chiller requires close monitoring to ensure the long life of the chiller. If not properly controlled, Lithium Bromide is highly corrosive and can result in premature component failure, increased maintenance costs, unproductive downtime and shortened chiller life. Our Lithium Bromide analysis gives precise recommendations of correction chemicals for maintaining the Absorption Chiller.

Specific Gravity/ % Lithium Bromide Measures the strength of Lithium Bromide charge. Indicates the operational status of an absorption chiller.
Alkalinity/pH Measures possible air leakage into the chiller. Affects metal corrosion.
Dissolved Copper Measures tube corrosion.
Dissolved Iron/ Suspended Solids Measures corrosion of steel interior. Gives an indication of a degree of internal fouling.
Lithium Molybdate Measures Molybdate inhibitor strength.

The specific gravity indicates the concentration of the Lithium Bromide, whether it is concentrated enough, or too dilute to function as an absorption medium.

The pH and alkalinity provide an indication of any air leakage into the chiller. It also gives some insight into which metals are likely to be attacked. For example, at low alkalinity and pH values, the iron or steel components are susceptible to corrosion. Raising the alkalinity protects these metals while promoting an attack on the Copper portions, such as the tubes.

The Copper content and Suspended Solids shows the magnitude of the corrosive attack and also indicates how aggressively the Lithium Bromide charge is dissolving the machine’s components. It likewise indicates the degree of fouling inside the chiller, and whether or not the spray headers and heat exchangers are likely to be clogged with debris.

The inhibitor is added to the Lithium Bromide brine to protect the various metallic surfaces and slow the rate of corrosion to acceptable levels. Corrosion can never be totally stopped; it can only be minimized. This is the function of the inhibitor.

The Alcohol test indicates the presence of Octyl Alcohol in the Lithium Bromide charge. Octyl Alcohol controls the tendency of the Lithium Bromide to foam under vacuum.

The Correction Chemicals are a small amount of material required based upon the chemical analysis to adjust the Lithium Bromide solution back to its nominal specifications. The Hydrobromic Acid and Lithium Hydroxide Monohydrate adjust the solution alkalinity either down or up respectively. The Lithium Molybdate adjusts the inhibitor strength directly.