Air Quality Control System

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Karin Hodge
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1 Hercules Thermal-Wet Scrubber Air Quality Control System Suite 30, San Jose, CA Phone (408) Fax (408)

2 1.0 System Summary 1.1 Process Summary The TecHarmonic High Temperature Vortex Water Scrubber (HTVS) with a single heater is called the Hercules. It is designed to abate pyrophoric, explosive and acidic gases. The electrically heated thermal oxidizer with a ceramic heater is used to oxidize pyrophoric and explosive gases. The Vortex water scrubber below the heater absorbs acid gases, cools the gas stream, and entraps particulates in a spray of fresh water. The horizontal scrubber/sump below the Vortex directs the solids to drain and the gas to the wet column. The discharged water is recirculated to the wet column and Vortex or discharged to the facility s AWN system to control the sump water level. An optional filtration system can be installed on the discharge line to more quickly remove particles and minimize sump maintenance. The counter-current packed-bed column water scrubber absorbs the remaining acid from the gas stream. The system is designed for continuous operation during the process. Safety features ensure a secure and controlled operation. Audio and visual alarms trigger when alarm conditions arise. Soft alarms and hard alarms help signify the severity of the alarm. Suite 30, San Jose, CA Phone (408) Fax (408)

3 1.2 System Features Oxidizer and Heater 1 Super Alloy Thermal Oxidation Assembly 1 Ceramic Heater Assembly (20,000W Peak Power) Water Scrubbers 1 Super Alloy Vortex Scrubber Patented heat removal device that also scrubs particles and acid gases Horizontal Metal Sump - Particle Removal/Water Scrubber Polypropylene Counter-Current Packed-Bed Water Scrubber Programmable Controllers Siemens PLC Color Touchscreen Display User Interface Relays Safety EMO Emergency OFF button FM Limit Alarms Vortex Flow Limit Switches Main Water Flow Limit Switch Sump High Level Acoustic Sensor Secondary Containment Liquid Sensor Clean Dry Air Supply Sensors 2 System Photohelics Exhaust Photohelic 2 PLC Based Temperature Alarms Bypass Valves (per customer application) The Hercules System was built to comply with the following codes Uniform Plumbing Code Uniform Mechanical and Electrical Code S2 93 Compliance CE Mark Certification Suite 30, San Jose, CA Phone (408) Fax (408)

4 Front View of Hercules Cabinet 1. Main Cabinet Frame 2. Main Breaker 3. Light Tower 4. LCD Display 5. Photohelics 6. Watlow Controller 7. EMO 8. Status Light (Green) 9. Status Light (Red 10. Status Light (White) 11. Enable Button 12. Cabinet Cooling Fan Suite 30, San Jose, CA Phone (408) Fax (408)

5 Hercules process flow diagram - series Suite 30, San Jose, CA Phone (408) Fax (408)

6 Process Gas Flow: a. Process exhaust gas enters the Heater (Thermal Oxidizer) through a NW160 Process Gas Inlet Port. The bypass valve is closed during normal conditions. b. The Heater oxidizes flammable process exhaust gases (with injected CDA) at process dependent temperatures (from 1300 o F to 1700 o F) and SiO2 particles are formed. Other gases, like NF3, are decomposed by pyrolysis. c. The exhaust gases, now very hot and containing particles, and occasionally acid gases, flow into the patented Vortex section immediately below the Heater. Recirculation water from the sump swirls around the Vortex s gas path and constantly flows down the walls of the tube leading from the Heater to the below sump. This wall of water prevents the formation of clogging in this tube. d. Fresh water from eight nozzles is sprayed into this tube to rapidly cool the gas and wet the particles. Wetted particles fall out of the gas flow and into the sump. When water-soluble acid gases are present, they are partially removed by being adsorbed into the spray of fresh water. e. High temperature oxidized exhaust gases leaving the Heat are quenched to an average temperature of 35 o C in the Vortex system before entering the below sump. f. Gases then leave the sump and flow up into a tall, pack-bed wet scrubber column. Remaining water-soluble gases are essentially all removed by this wet scrubber. g. Cleaned gas is then exhausted through a 6-inch ANSI butterfly valve into the facility s duct system where it flows up to the house scrubber on the roof. Fresh water flow Fresh water enters the Fresh Water Inlet port and then flows through the following components: a. Particle filter Traps solid particulates larger than 70 microns to protect the Vortex water-spray nozzles b. Ball Valve, Normally Closed when Hercules is not energized c. Flow Switch (main) checks for incoming water flow Suite 30, San Jose, CA Phone (408) Fax (408)

7 Water is then distributed to the following sub-components: a. Vortex i. Water is sprayed into the oxidized gas stream via eight nozzles to wet the particulates formed in the Heater and cause them to separate from the gas stream and fall into the sump water. ii. Water-soluble acid gases are partially scrubbed (removed) in the Vortex. iii. High temperature oxidized gas is quenched to an average temperature of 35 o C. iv. There is one flow switch to check fresh water flow to the Vortex spray inlets. The Vortex sprays are the only source of Makeup water to the Hercules.Packed-bed Wet Column v. Remaining water-soluble gas is removed in this wet scrubber. b. Top of Heater tube i. A small amount of water is continuously injected into the process exhaust gas flow to create steam used to disassociate certain gases. Recirculated water flow A pump is used to re-circulate water through the following components: a. Vortex i. Tip-Over channel surrounding the pipe to the sump below b. Packed-Bed Water Column scrubber i. Spray jets at the mid-point or top of the water column ii. Packed-bed wet column The pump is also used to purge water from the system. Liquid level sensors detect the water level in the sump. The water level sensors control the normally closed valve on the discharge side of the pump. When the valve is closed, the water level continually rises until it reaches the high level sensor. When the sensor is tripped, the water discharge valve opens and the water s discharged flow rate becomes greater than the make-up water s incoming flow rate. As the water level inside the sump drops, it triggers the lowlevel water sensor which then closes the water discharge valve causing the sump s water level to again rise. The water level in the sump continually rises and falls as the water is continually discharged in batch-mode. Suite 30, San Jose, CA Phone (408) Fax (408)

8 1.3 Facilities Requirements Site Location Requirements The Hercules system must be placed in an area that is: Well illuminated Well ventilated Easily accessible to maintenance personnel Clearance Proper clearance surrounding the Hercules must be provided to allow adequate access during maintenance. Place the Hercules system on a level surface with 3 feet of clearance at the front of the system and a least one additional side (left, right or rear) Facilities Requirements Suite 30, San Jose, CA Phone (408) Fax (408)

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T F E Dust Collector Principles of Operation The Spin Filter contains a series of tubes with stationary air spinners. Through centrifugal force contaminants are removed from the air stream as it is drawn through