Vulcan Drying Systems - Indirect-Fired Rotary Calciner/Kiln System, 2 Tons/Hr

Description

Vulcan Drying Systems indirect-fired rotary calciner/kiln system, designed for approximately 2 tons per hour. Drum dimensions are 4' dia. x 23.5' heated zone. Material of drum is Inconel 600 with 1,800°F operating temperature.

Operating Information:
- Nominal capacity: 2 TPH
- Heating arrangement: indirect fired, six independently controlled zones
- Fuel: natural gas
- Kiln-zone control temperatures shown around 1,900°F
- Kiln-zone high-temperature shutdowns shown at approximately 1,900°F to 2,075°F, depending on the measurement point
- Kiln exhaust temperature alarms:
1,000°F warning
1,350°F warning
1,500°F burner/feed shutdown
- Product-discharge temperature alarms:
1,400°F warning
1,700°F warning
1,800°F burner shutdown
- Exhaust entering the gas-treatment section is identified as approximately 1,200°F and containing steam, particulate matter, and carbon dioxide
- Gas leaving the cooling section is shown at approximately 160°F
- Quench-water supply is shown as approximately 120°F at 65 PSIG
- Condensed-water return is shown as approximately 140°F at 65 PSIG

Major Components of System:
- Vulcan RK-1033 indirect-fired rotary kiln/calciner
- Six natural-gas burners, tags B-1022 through B-1027
- Six dedicated combustion-air blowers, E-1133 through E-1138
- Live-bottom feed bin feeder, LBF-1108
- Inclined feed screw, IFS-1096
- Solids feed hopper, FH-1042
- Variable-speed kiln feed screw, KFS-1042
- Variable-frequency-controlled kiln drive
- Product discharge hopper
- Inclined discharge screw, IDS-1035
- Water-quench scrubber, VS-1053
- Quench-water circulation pump, QP-1056
- Air-cooled heat exchanger, ACHX-1059
- Induced-draft fan, identified in the component legend as IDF-1076
- PLC-based temperature, pressure, burner-safety, level, and drive controls

System Description:
The system features a refractory-lined rotary kiln with six independently heated zones. Heat is supplied by six natural-gas-fired burners, each equipped with a dedicated combustion-air blower, gas-flow control valve, automatic shutoff and safety valves, pressure monitoring, spark ignition, burner controller, and burner-status indication.

Feed material is introduced through a live-bottom feeder and transferred by an inclined feed screw to a solids feed hopper. A variable-speed kiln feed screw meters material from the hopper into the rotary kiln. The kiln is driven by a variable-frequency-controlled drive, allowing adjustment of drum speed and material retention time.

The kiln incorporates multiple temperature-monitoring points along its length, with individual zone temperature-control loops and high- and low-temperature alarms. The controls include burner permissives, flame supervision, gas-pressure alarms, draft-pressure control, drive overload protection, feed-hopper level monitoring, and automatic burner shutdown interlocks.

Calcined product exits the kiln through a discharge hopper and is removed by an inclined discharge screw conveyor. The discharge section includes temperature monitoring and high-temperature alarms designed to shut down the kiln burners at elevated product temperatures.

Kiln exhaust gases are maintained under negative pressure by an induced-draft system. System includes exhaust-gas temperature and draft-pressure monitoring, a water-quench scrubber, recirculating quench-water pump, air-cooled heat exchanger, and induced-draft fan. The gas-handling system is designed to cool and condition a process stream containing steam, particulate matter, and carbon dioxide before routing the exhaust toward sequestration and/or atmospheric discharge. Condensed water is cooled and returned to the client’s water-storage system.