Helix Water tank coating in dangerous summer heat

A four-million-gallon Helix Water District water storage tank was scheduled to have an old coating of lead-based paint removed from its roof and support structure. The advent of summer also threatened to cause dangerously high temperatures inside the tank, creating worker safety concerns.

Polygon’s hybrid dehumidifiers, which combine desiccant technology with integrated cooling, maintained optimal temperatures for safety regulations while holding the blast. The contractor also realized $4000 weekly in energy savings as compared to using their own non-integrated equipment.

PROBLEM

Under a very tight deadline, the contractor could not afford to proceed without dehumidification protection. Laborious and time-consuming methods required when blasting away lead-contaminated paint can cause severe “slowdowns” in daily operations. With pressure to have the tank in service by summer, a continuous process of uninterrupted blasting followed by a single clean up period and finally a monolithic coat was needed. Any risk of re-blasting mid-job to correct newly formed moisture-related corrosion had to be eliminated. 

SOLUTION

The contracting company had originally planned to use its own dehumidification equipment. However, the plan to use its own dehumidifiers– which were to be regenerated by electrical heat was causing two serious problems. First, excessive set up cost, the one-time charge for the temporary power line was more than $10,000. Secondly, the alternative, to supply the 436-amp electrical requirement using diesel-powered electrical generators would create unacceptable noise levels in the nearby residential area. Looking for a better solution, the contractor reviewed its situation.

By utilizing four Polygon 4500 propane regenerated dehumidifiers, the contractor reduced its operating expenses by $4,000 per week, as compared to the projected cost of using its own equipment.

The savings were realized in four ways:

1. Eliminating the need to rent large generators,
2. Greatly reduced consumption of electrical power
3. Eliminating the cost of a temporary power supply
4. Reduced generator fuel

RESULTS

Faster Coating

With dry air protection, you can blast and coat around-the-clock during any weather and hold the blast as long as necessary. Polygon controls the dewpoint temperature to meet NACE guidelines, eliminating any chance of corrosion.

Improved Coating

Achieve improved coating life through a monolithic application and use high performance coatings, knowing that dry air protection will allow you to begin the second coat within 24-hours.

Agreeable Working Conditions

By combining chillers and desiccant dehumidification to provide cool, dry air to the tank. Polygon dehumidifiers introduce no foreign matter into the coating environment. You get dried air of the same quality as the air found outside the tank. You meet OSHA temperature standards and achieve higher worker productivity.

Quiet Operation

Our propane regenerated dehumidification systems run silently. No large diesel generators are required.

Lower Energy Costs

Our dehumidification system lowers power costs in two ways:

1. Combining refrigeration with desiccants for a more efficient electrical consumption.
2. Providing propane gas regenerated desiccant dehumidifiers, reducing electrical costs by 80% or more.