How Ammonia Scrubbers Lower Your CEMS Operating and Maintenance Costs
NOTE: For Use With Cold Extractive, Condensing Cooler Based Sample Conditioning Systems. Perma Pure Ammonia Scrubbers are designed to remove ammonia from a gas stream to protect the analyzer from clogging due to the formation of ammonium salts. Ammonia is a highly reactive gas. It is sometimes added to stack gases to reduce the nitrogen oxide content of the gases by conversion to nitrogen and water (the DeNOx process). When present in gas samples, ammonia will readily react with other components such as sulfur dioxide in the sample to form ammonium salts. This salt is relatively low-boiling, so it is present as a gas at the higher temperatures in the stack and in the heated line. When the sample cools down while passing through our dryer, it precipitates out as a solid, clogging the dryer or analyzer. For this reason, we recommend installing an ammonia scrubber before the condensing cooler to prevent damage to the analyzers downstream.
For Nafion-based sample conditioning systems, Ammonia Scrubbers are required when any Ammonia might be present in the sample gas to protect the Nafion dryers in the system, as Ammonia reacts with the membrane material and will lower the water transfer rate over time.
Principle of Operation
The Perma Pure ammonia scrubber consists of a polysulfone or stainless steel shell housing filled with a housing filled with a phosphoric based scrubbing media and inert ceramic burl saddles. The water vapor in the sample activates the scrubbing media to produce phosphoric acid. The phosphoric acid then reacts with the ammonia in an acid-base neutralization reaction producing a phosphate of ammonia. This compound is a solid even at elevated temperatures, and deposits immediately within the ammonia scrubber as a visible salt residue. For proper operation, the ammonia scrubber should be kept at a temperature above the sample dew point to avoid the loss of water-soluble analytes. For this reason, Perma Pure now offers a heated ammonia scrubber which can be placed in the sample path.
AS-Series Ammonia Scrubbers Specifications
|Description||Polysulfone shell with stainless steel housing||Polysulfone shell with heater blanket||All 316 stainless steel construction||Stainless steel shell with heater blanket|
|Maximum Pressure||30 psig||30 psig||100 psig||100 psig|
|Maximum Temperature||125°C||* See Note||130°C (200°C with hex bolt replacing thumbscrew)||* See Note|
|Ports||1/4″ FNPT||1/4″ FNPT||1/4″ FNPT||1/4″ FNPT|
*NOTE: The heated ammonia scrubber is supplied with 5 leads. It can be wired for 110VAC or 220VAC. You may use the provided thermocouple which will regulate the temperature to 90°C or you may wire the unit to your own temperature controller and readout. If using your own controller, use the max. temperatures for the unheated unit as a reference.
AS-Series Media Replacement Part Numbers
|AS-200-3||Replacement O-rings, 3 per set|
|AS-200-08-E||Replacement absorbent, burl saddles and reagent, 3 fillings|
|AS-200-08-EB||Replacement absorbent, burl saddles and reagent, 15 fillings|
|AS-200-08-EB OPT1||Bulk supply of reagent only (no saddles), 15 fillings|
AS-Series Media Replacement Procedure
Replacing the Scrubbing Media:
- If you have a heated version, unplug the device and remove the heater blanket>
- Unscrew the thumbscrew on the bottom of the housing>
- Rotate the yoke which holds the housing together>
- Remove the old media and dispose of properly.>
- Rinse the housing with soapy water to clean
- Fill the housing with 50cc of part A material (Ceramic burl saddles)
- Fill the housing with 150cc of part B material (White pellets)
- Replace housing on top manifold
- Turn housing gently to allow o-ring on center tube and shell tube to seat properly
- Replace the yoke and tighten thumbscrew finger tight. Do not over-tighten! Over tightening will cause splintering of the plastic shell.