Скачать или смотреть Paper Mill Lime Kiln Cleaning - Heavy Build-Up Removed Using CARDOX Blasting

PAPERMILL KILN “CARDOX" BLASTING

BENEFITS
• Can be completed online, no production loss
• No shock waves or damaging vibration • No damage to refractory bricks
• No weakening of the kiln
• No lost time due to cool down and reheat times


A papermill in the eastern United States was experiencing heavy buildup in their rotary lime kiln. Industrial Access solved the problem by implementing Cardox blasting as a solution. Cardox is the most efficient, reliable and cost-effective method of clearing dry material buildup and blockages. This approach requires minimum amount of maintenance and can be performed without completely interrupting the production process, making it the best new alternative in the pulp and paper industry.


TIME
Only requires periodic pauses in rotation, so no shutdown or loss of production

COST
Small (4) man crew with Cardox and safety equipment

SAFETY
Takes place outside the structure which eliminates any risks to workers


CLIENT NEED
In rotary kilns, ring formation or snowman buildup usually occurs in one particular section, around 12’ to 16’ along the length of the kiln. The material buildup in the client’s lime kiln was so severe that the papermill was forced into unplanned outages during the year, interrupting plant production, to perform emergency cleanouts. Industrial Access (IA) was contracted to provide the best solution to handle the recurring buildup issue as effi- ciently as possible, to prevent unplanned outages and keep the plant in production.

SOLUTION
IA first mobilized to the site to perform a visual inspection of the structure to determine the size and location of the buildup in the kiln. Due to the fact that the kiln was still in operation, the team employed infrared technol- ogy to visually assess the structure and quantify the location and type of blockage issue. This visual assess- ment was completed by utilizing a FLIR camera to detect thermal radiation and heat variances in the kiln. This allowed the IA team to pin point exactly where the buildup was located and to develop a specific approach to remove material buildup.

Industrial Access put forth the solution of Cardox blasting. Cardox tubes are filled with liquid carbon dioxide, like a fire extinguisher. When energized by the application of a small electrical charge, the chemical heater in- stantly converts the liquid CO2 into a gas. The conversion expands the CO2 volume and builds up pressure in- side the tube until it causes a disc, located at the end of the tube to burst, which releases CO2—now 660 times the original volume—through directional discharge nozzles. This creates a powerful force of air pressure, up to 40,000 psi, strong enough to safely blast buildup off the walls in closed structures. This process can dislodge more than 3 tons of buildup in milliseconds.

In order to perform the blockage removal, IA team developed a plan to halt the rotation of the kiln for 30 min- utes at a time, which would prevent the structure from warping. To remove the ring formation buildup, skilled technicians drilled into the kiln in the area notated in the FLIR photos and installed Cardox ports. After the
ports were welded into place on the exterior surface, the contractor then inserted the active Cardox tubes into the ports. Since Cardox CO2 systems can be used in high heat applications, there was no need for extended shutdown waiting for the equipment to cool. The fast and efficient process of deploying the tubes and initiating the gas expansion enabled the field crew to clear the buildup at controlled pressures that caused no damage to the refractory lining or weakening of the kiln walls.

RESULTS
The lime blockage was successfully cleared, which allowed the plant to continue operation until the next scheduled outage. A program of on-going maintenance was submitted in which the blasting procedure would take place quarterly or once the buildup exceeded a specific level on any of the kiln walls. This plan will enable the facility to run from one scheduled shutdown to another without experiencing any forced production stop- pages or expensive emergency clean-outs.

Serving the United States & South America
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