Too much humidity can produce a host of problems in many business applications. In production processing particularly, high seasonal humidity periods can overtax a cooling system, causing slowdowns or shutdowns. The resulting loss of productivity can cost thousands of dollars or even compromise a company's reputation.
In addition, during humid months, hygroscopic inventories can suffer moisture gain while in storage. Mold can form. Freshness or product appeal can suffer and packaging can deteriorate. In new product development applications, laboratory tests that demand rigorous humidity control may be required.
In addition, when power generation equipment goes out of use or electronics become inactive, or any number of other industrial equipment becomes idle for too long, it becomes vulnerable to microscopic corrosion. Dehumidification can end moisture-related slowdowns, safety concerns, sanitation issues, conveyor clogging and maintenance hazards. It can be utilized to preserve inventories and prevent corrosion. Small systems compatible with laboratory environments can be used to create and hold the conditions needed.
When implemented into a facility's HVAC system, temporary dehumidification can provide a business with all the benefits of climate control without the cost and commitment. Using dehumidification on a temporary basis not only limits risks but gives facility managers the practical knowledge to build an efficient, permanent solution.
The following application examples illustrate how temporary dehumidification works.
1. Poultry ProcessingPoultry processing facilities constantly strive to maintain
an extremely clean processing environment. To accomplish this, thousands of gallons of water are sprayed on a daily basis throughout areas of the plant. Although much of the water drains away, a considerable amount becomes water vapor and condenses on ceilings, piping, walls and equipment within the processing area.
Claxton Poultry, based in Claxton, Ga., sought a solution to its condensation issue. The plant processes about 1.6 million chickens per week and employs 1,500 workers.
For many years, Claxton, like many other poultry processors, combated condensation by using plastic sheeting hung from the ceiling and dedicating personnel to wiping away the moisture as it formed. However, this method was time-consuming and expensive, and even with these efforts, plants could be overwhelmed by uncontrolled humidity.
Claxton's plant manager contacted Munters Moisture Control Services, Amesbury, Mass., for a better solution. After analyzing the operation, Munters recommended a test use of one of its condensation control systems to remedy the condensation-related problems.
After installation of the temporary system in the eviscerating area of the facility, it didn't take long for Claxton Poultry to realize the benefits. The condensation in the plant began to disappear within hours. The equipment now allows the facility to operate without condensation-related problems. Workers who were dedicated to wiping away moisture and installing plastic sheeting now perform other functions within the facility, reducing labor costs. In addition, sanitation has improved within the plant.
2. Food ProcessingThe Bagel Bites Division of Ore-Ida Foods, following its own strict internal sanitation standards as well as those of the U.S. Department of Agriculture guidelines, performs a daily washdown process at the company's Fort Myers, Fla., facility. However, the washdown took up to four hours a day due to excessive fog and condensation. In addition, the reduced visibility created a significant safety hazard for the 17 employees who conducted the washdown.
Operations teams set out to find a process that would reduce the fog and condensation while increasing operating efficiencies. It was through this search that they first considered desiccant dehumidification.
Ore-Ida officials were enthusiastic about the desiccant dehumidification concept for addressing their fogging and condensation issues, but they were reluctant to make the capital investment in a technology they had not previously used. Company officials decided to try a temporary dehumidification system to gauge its effectiveness.
On the first day of operation with the rental unit, the washdown began and fog was allowed to fill the area. Then the dehumidifier was started. Within 15 minutes, all the fog was cleared from the room. The fog that had previously obscured the cleaning process and presented a hazard to workers was eliminated, and washdown could continue at a safe, efficient pace.
In addition to clearing the fog, the unit continued to run after the washdown to allow drying of the equipment, walls, floors and ceilings. Drying time was reduced significantly. With the dehumidifier in operation, the washdown took little more than two hours.
3. Power PlantsTemporary dehumidification also has a place in power plant preservation. A power plant's components are subject to corrosion when they are not in operation, commonly referred to as standby corrosion. A plant may be shut down due to planned or unplanned maintenance, or due to low seasonal power demand. And, because the risk of irreparable corrosion damage is great during a long-term shutdown, preventive measures such as the use of temporary dehumidification must be taken.
During shutdown, corrosion can take place on all turbine parts where ambient air -- which always contains a certain amount of water vapor -- comes into contact with metal surfaces. The ambient air's ability to absorb water vapor depends on its temperature and pressure. If the temperature drops below the dewpoint temperature, or if an object whose temperature is below the dewpoint comes into contact with air, water droplets form on its surface, creating a moisture film.
Corrosion, though, is not necessarily associated with the presence of condensable moisture. Metal surfaces also can corrode when they are exposed only to an atmosphere with a high humidity. Of the various metals and alloys used in the construction of turbines, not only carbon steels but also alloy steels exhibit an inclination to corrode under certain conditions.
Tests and practical experiences prove that corrosion on turbosets can be reliably avoided if the ambient air can be maintained at less than 35 percent relative humidity. This condition is easy to fulfill if dehumidified air is used for the preservation. Temporary dehumidification equipment can be used to perform this function and requires almost no maintenance.
4. PharmaceuticalPharmaceutical manufacturers also can benefit from the use of temporary desiccant dehumidification. Utilizing the equipment can give a pharmaceutical plant an opportunity to increase production and profits -- especially during humid summer months, when ambient conditions sometimes exceed what in-house cooling systems can handle. Too much humidity can cause pills to stick together or come apart during the production process. Too much moisture also can cause the drying process to take longer.
As an adjunct to an in-house system, desiccant technology will allow a plant to obtain the desired air temperature and dewpoint levels, resulting in increased productivity and more consistent pill-drying times.
5. Tank-CoatingAnother useful application for temporary dehumidification is in tank-coating work. With a controlled climate, condensation problems are eliminated. This prevents tank-surface corrosion and premature coating failures, and maximizes coating life while shortening work time.
Because desiccant dehumidification maintains low humidity at the metal surface, moisture cannot condense. Proper conditions also permit the coating to be applied and cured the way the manufacturer intended. Tank end-users benefit from much longer coating life, which can reduce lifecycle coating costs by as much as 20 percent.
Sidebar: Temporary Dehumidification OpportunitiesWhen implemented into a facility's cooling system, temporary dehumidification offers the benefits of climate control and gives facility managers the practical knowledge to build a permanent solution. Whether it's for preventing corrosion or improving production processes, a climate control company should be able to design a temporary system that:
- Integrates to meet specific needs.
- Holds strictly defined conditions and controls humidity separately from temperature.
- Is cost-effective and does not interrupt business.
- Handles any increased demand caused by sudden changes in weather.
Abundant opportunities remain for temporary dehumidification technology in manufacturing and processing. It is appropriate when weather variations affect production rate or product quality, when corrosion or condensation cause problems, and when product must be dried at low temperatures.