Typical applications for emergency gas scrubbers in the chemical industry include the absorption of emissions, such as chlorine gas, bromine, phosgene, NOx, ammonia, HF, and SO2. To neutralize these gases, caustic solutions like sodium hydroxide or potassium hydroxide are predominantly used in wet chemical gas scrubbing. The gas stream is passed through the scrubbing liquid, and in the event of an accident or leakage, the release of hazardous emissions can be prevented.
Speed of sound measurement with LiquiSonic® 40
Application
In the emergency gas scrubber, the scrubbing liquid circulates and is brought into contact with the gas stream to be cleaned. If toxic components are present after an accident, they are chemically bound. Even during normal operation without an emergency, certain components, such as CO2 are absorbed, causing the concentration (NaOH) to decrease. To ensure maximum absorption and a consistently sufficient amount of absorbent, usually NaOH, the concentration of sodium hydroxide and salts (NaCl and Na2CO3) must be monitored.
The measuring system LiquiSonic®enables concentration measurement in a 3-component mixture by detecting two physical quantities, such as speed of sound and conductivity. If the sodium hydroxide content is too low, it must be replenished. If the salt content is too high, it is removed to prevent crystallization in the system, which could clog nozzles, etc.
Installation
The LiquiSonic® Immersion sensors can be easily installed directly into the pipeline. A common installation site is in the pipelines (DN80) from the gas scrubber to the regeneration tank. The robust sensor design and the choice of special materials, such as HC2000, ensure long process uptime of the system.
The LiquiSonic® Controller 40 is connected with the LiquiSonic® ultrasonic sensor and the measuring unit for the second physical quantity. The controller displays the concentration of sodium hydroxide and salts in the main menu.
Typical measurement range:
- Concentration range NaOH: 5 to 20 wt%,
- Concentration range Na2CO3/NaCl: 5 to 30 wt%
- Temperature range: 30 to 60 °C
Customer benefits
LiquiSonic®ensures precise inline concentration measurement with permanent data recording. By automatically controlling the NaOH concentration in the area of maximum absorption of the gas scrubber, a sufficient amount of caustic soda is always available in case of an emergency.
LiquiSonic®reduces time-consuming laboratory measurements:
- Time required: 1 h per day
By avoiding over- and under-dosing, material costs are saved.
In addition, the LiquiSonic® system ensures consistent plant safety - even in emergencies.
In the chemical industry, emergency vent scrubbers are increasingly used for the absorption of toxic or environmentally hazardous emissions. In addition to classic process gas scrubbers, the focus here is on continuously ensuring plant safety, so that even in emergencies, above-average and highly concentrated quantities of gas streams can be reliably chemically bound.
