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Keep a Lid on It!  Global Shelters by WeatherPort

Lake Aeration Diffusers and Aeration/Destratification Systems

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Do you need an outside covering over your spawning area?  Do you long for a portable covering for a workshop area?  Do you dream of a covering over your outside broodstock ponds, fish distribution truck or pumping station?  The MTAN has worked under WeatherPort shelters for several years and have found them to be very useful structures.  If your fish culture operation would benefit from such an improvement, you may want to consider these shelters for your aquaculture needs.

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Outdoor Fish Culture Shelters
by: WeatherPort
Email,  888-970-6411 or 800-569-1804

Global Shelters understands that special situations exist where WeatherPORTs are needed. With decades of experience our capabilities extend far beyond our standard line to provide a custom structure designed and engineered for your specific applications. 
 

 

Technical Specifications

Doors:
Standard options include single zip entries, double zip roll-up doors, solid locking personnel doors (steel or fiberglass/aluminum), fabric or metal fold-up doors, metal roll-up doors, equipment openings, vehicle doors, hangar doors, double personnel doors, and sliding doors - all available to be included for your project.

Sealing/Insulation:
Double layer liner-insulation systems rated from R-6 to R-30 depending on your needs. These structures can be sealed completely for environmental control purposes.

Ventilation:
Zip screened vents, roll-up screened side/strip vents, vertical drop/roll-up curtains, electric fans, blowers, roof turbines, heating/air conditioning are all available to meet your requirements.

Lighting:
Our non-block-out fabrics transmit approximately 40% of the natural light that is diffused and is typically sufficient for most day time operations. We can incorporate skylight fabric into the end panels or cover panels as well as provide clear windows and any conventional lighting system that is available on the market. Our screened vents also afford good light infiltration.

Frame:
Small Structures include a full-perimeter galvanized steel base, pre-drilled for anchors, and an all slip-fit, self-aligning galvanized steel framework - very strong, very durable. Interchangeable frame components.  Curved Arch units use 1 round structural steel, 17 ga.  Standard Soft Curve Gable units use 2 square tubular structural steel,15 ga.  Heavy Duty Soft Curve Gable units use 2 1/2 square tubular structural steel, 12 ga. No bolts or screws.

Large Structures are fully engineered with modular, self-aligning, trussed arch designs. Complete with galvanized or coated structural steel main framework with aluminum fabric tracks - very efficient, very strong, very durable. Interchangeable components. Versions for all snow and wind loads. See Technical Specifications Tables for widths, module sizes and load ratings. Custom sizes available.

Fabric:
Several types of fabrics are available, all are UV resistant and meet various fire codes. All fabric seams are heat or electronic welded. Fabric is attached to frame via aluminum tracks and cable, cable or webbed ratchet tensioning systems. Fabric options include: 

• 18 oz. durable vinyl (PVC) coated polyester with a life span of 9-15 years.
• 24 oz. long life structural vinyl coated/special treated fabrics typically used for permanent installations: 12 to 20 year life span.

Colors:
White, Tan, Grey, Blue, Red, Yellow, Green, Translucent-Clear and other colors available, including camouflage, olive drab, including light block-out. Accent stripes or color combinations are also available.

 

Anchoring:
Small Structures use a full-perimeter base that is pre-drilled and can be staked to the earth or asphalt, or bolted to wood or concrete. The site conditions, load requirements and your portability needs determine the anchoring required.

Large Structures- Every arch sets on a steel base pad which is predrilled and can be staked to the earth or asphalt, or bolted to concrete. Usually concrete footings or pad are not required.
 

Warranty:
Five year warranty on frames and vinyl fabric; three year warranty for vinyl clear translucent and polyethylene fabric; longer pro-rata warranties on special fabrics.

 

Installation:
All joints are self-aligning and convenient to assemble. All units include complete instructions and free 800# support. Full turnkey installation also available.
 

Delivery:
Usually 3 to 6 weeks depending upon stock supply and production schedules at time of order.
 

 

Taxes/Permits/Fees:
These structures are frequently used on a permanent basis; they are usually classified as temporary structures and are not subject to property taxes, however, local restrictions may apply. Commercial/Public uses may require permits and wind/snow load data or fire certification.
 

 

Custom Design and Size:

• Aluminum or steel frame
• Arch spacing to meet your wind and snow loads
• Truss or single arch
• Porticoes, partitions, vestibules, lean-tos, domes
• Variety of entry options
• Zippered entries (Single or double)
• Slam latch entries
• Panic hardware
• Glass, metal or wood
• Sliding glass doors

Windows:

• Zip screened vents

• Sliding glass windows

• Aluminum or vinyl clad

• Jeep clear plastic
   

Cover options:

• Black out vinyl

• Camouflage vinyl

• Arctic canvas or vinyl

• Insulation package

 

Lake Aeration Diffusers and Aeration/Destratification Systems
The following information was obtained from Aquatic Eco-Systems, 1767 Benbow Court, Apopka, FL 32703,
(407) 886-3939, 24 Hour Fax  (407) 886-6787, Email info@aquaticeco.com

The air diffusers used will determine the overall efficiency of a lake aeration/ destratification system. The two most common styles are the synergistic airlift assembly and the rubber membrane diffuser. Each was designed for different tasks. The synergistic airlift assembly (SAM) is made to lift a large volume of bottom water, thus removing stratification. The rubber membrane type (RM) was designed to aerate wastewater.

Destratification is the most economical form of lake aeration. This is only accomplished by moving large volumes of water. The synergistic airlift assemblies were developed through extensive underwater flow testing to lift the maximum amount of water from above the diffuser to the surface of the lake with a minimum amount of air (8,000 gpm/hp). This technique requires a specific spacing of the individual diffuser fingers to provide non-turbulent entrainment of the bottom water into the column of rising bubbles. For that reason, each diffuser is optimized for a specific depth range.

The smaller ALA4 manifold is designed for shallow lakes from 4 to 8 feet in depth. These shallow depths cause short circuiting of the lifted water back to the diffuser, which limits their effectiveness. Therefore, more diffuser manifolds per surface acre of water are required than for a deeper lake of the same size.

The ALA6 diffuser manifolds are best used in water 8 to 40 feet deep. The deeper the water, however, the greater volume of air that needs to be used by each diffuser. This is true for all diffusers. The ALA8 diffuser manifold is typically used in water deeper than 30 feet.  The system is simple, safe and virtually maintenance-free. It is the most effective lake aerator made! As little as 3/4 horsepower can be used to properly aerate a eutrophic 10 acre lake!

Rubber membrane diffusers are not designed to lift water for destratification, so they are not recommended for lake aeration. If used for lake aeration, many more of them must be used to achieve the same result as a single synergistic airlift assembly.

When the rubber membrane diffusers are used in saltwater or wastewater, they may operate for a year or more in clean, soft water without clogging. After that, remote cleaning can be accomplished by doubling or tripling the amount of air delivered to a diffuser. This will blow up the rubber, as in a balloon, dislodging the fouling matter. Wastewater treatment plants are designed for this, but it may be impractical for lake applications, where there is only one compressor.  Sometimes, rubber membrane diffusers will tear, greatly reducing their oxygen transfer ability. If detected, retrieve the diffuser and replace the rubber membrane.

The ceramic diffusers used on SAMs should be inspected every three years. Clogging can be detected by recording the air pressure when new, then annually checking the pressure to see if it has increased. Diffusers can be cleaned by pouring muriatic acid into the airlines and turning on the compressor. The original pressure will be quickly restored and the small amount of acid will be diluted and have no effect on the lake.

Technically Speaking ...

• When oxygen levels are low, you can expect transfer performance of more than 10 pounds of dissolved oxygen per horsepower! (Pumps, fountains and "air bubblers" are typically less than 2 pounds per horsepower.)
• Bubbles expand and spread out as they rise. The column of water entrained within the bubbles from a synergistic diffuser rises at about a foot per second, moving 2,000 gpm from the area above the diffuser. (A drilled pipe diffuser with the same air volume would move only about 200 gpm.)
• The surface boil created by the kinetic energy of the rising water rises approximately two inches above the surrounding water level. From there, the water rushes outward until its energy has dissipated, sometimes traveling more than 100 feet, depending upon temperature, surface tension and wind.
• The lake surface tension is ruptured in the boil area. Supersaturated gases, including carbon dioxide and hydrogen sulfide, escape from the bottom water and oxygen is absorbed.
• There's no danger to swimmers, boaters or aquatic life even a marking buoy is unnecessary. And, like hundreds of others, you'll enjoy watching the surface "spring" boils. There is no electricity in the water.
• It's best to install the system prior to stratification. If the volume of anaerobic bottom water is greater than 1/6 of the lake's total volume, contact AES for start-up instructions.
• Every lake is different. An AES aeration specialist will be happy to assist with equipment selection and system design. We'll need to know the lake's shape, size, depths, history, bottom type, water source, flow, etc.

 

Related Links:  Great LakesPond Aeration Systems, Great Lakes aeration/destratification system

 

How to Clean Sweetwater Diffusers

The Sweetwater air diffusers, made of glass bonded silica, are virtually indestructible and will give many years of service.

The only maintenance normally required is periodic cleaning. The frequency of cleaning will be determined by the mineral and organic content of the water in which the air diffusers are used. In clean, cold, soft water, cleaning may only be necessary every 2 or 3 years. In very hard water or water high in organics, it could be necessary as often as every 2 months.

1. Remove from service and blow out excess water. If fouled with  foreign material, scrape or hose off.
    
2. Immerse completely in undiluted muriatic acid for a sufficient time to dissolve the clogging material. If you have a 1/2" NPT white fitting on the end of your diffuser, we recommend immersing the diffuser only, not the fitting. This may take from one minute to eight hours in the most extreme cases. Be very careful when using acid! Wear eye, face and hand protection and have clean water available for rinsing and acid diluting in the case of an acid splash or spill.
    
3. After the clogging material has been dissolved, rinse thoroughly before reuse.
    
4. Discard the used acid by first reducing its strength to a neutral pH, by diluting with at least ten times as much water as acid.

  

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Product and company names mentioned in this publication are for informational purposes only. It does not imply endorsement by the MTAN or the U.S. Government.

 

 

 

Last updated: August 28, 2009

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