ARMEX® - Baking Soda Abrasives: Case Studies - Pulp and Paper: Lime Removal
Lime Removal in Paper Mill Enhances Worker Safety
- Application Overview
- In the recaust area of a Weyerhaeuser paper mill in Canada, limestone is burned in a kiln to produce lime – a caustic chemical used in the paper manufacturing process. This fine white powder becomes airborne and builds up on every surface in the recaust area – from walls, floors and equipment to pipes, walkways and hand rails. The lime build-up must be removed periodically to protect employees from the risk of chemical burns. Removal must be done while the recaust area equipment is operating.
- Substrate
- Substrates found in the recaust area include steel, cement and glass. Equipment includes tanks, pumps, pump bases, motor bases, etc.
- Previous Methods
- The lime was loosened manually with hammers and chisels, ice picks and scrapers. High pressure water removed the remainder. All equipment was covered in plastic to protect it from water damage.
- Project Schedule:
- The recaust area is thoroughly cleaned once a year, with spot cleaning done on a continuing basis. With ARMEX the contractor is able to clean the entire recaust area – including all equipment – in just two weeks with five workers working eight hours a day, five days a week. Previously, it took contractors six weeks to manually clean the recaust area.
- Special Concerns
- The cleaning method must not cause damage to vital bearings and seals on the process equipment and must be nonsparking.
- Equipment Specifications
- The recaust area is cleaned using two Accustrip System Model 12SX units, fitted with #8 ARMEX Performance Nozzles and each powered by a 750 cfm compressor. ARMEX Maintenance Formula XL with SupraKleen Rinse Accelerator is blasted wet at an air pressure of 90 psi. The contractor uses the in-house water source at approximately 10 psi.
- Containment
- The media is blasted with a minimal amount of water to reduce dust, yet dry enough to eliminate the need for plastic protective covers on the equipment.
- Results/Benefits Summary
- ARMEX provides a highly effective solution by thoroughly cleaning every surface to a level of cleanliness not achievable with the previous manual method. This reduces the risk of chemical burns to employees, thereby enhancing worker safety.
- Cleaning time is cut from six weeks to two and associated cost also are reduced by approximately $10,400-$13,400. ($14,000-$18,000 Canadian) per year. There is no downtime required for cleaning, and, unlike with the previous method, the equipment does not even need to be covered. Sensitive bearings and seals are not damaged, and there is no sparking or substrate pitting. Waste disposal is simple. The effluent is washed down the drain and is disposed through the onsite waste treatment facility.
