Case Studies
Case Study: Zoo Water Treatment
Ozonation System Installation
Caldwell Zoo - Tyler, Texas
Founded in 1937, Caldwell Zoo is now one of the finest small zoos in the country, attracting more than 600,000 visitors each year. The zoo is home to 2,000 animals of 250 different species. The zoo promotes education and research in conservation issues and participates in breeding programs, including those for endangered species.
Challenge
As part of a major renovation project, the zoo planned to recycle the water from flamingo and spoonbill pools. Safety for humans, animals, and aquatic life was a major requirement for the new recycling treatment system.
Solution
A Model N-60 Ozonation System installed at the zoo produces ozone from ambient air — instead of from pure oxygen, which can be hazardous. The Ozonation System mixes the ozone with recycled pool water in a contact tank, purifying the water. The purified water is then returned to the pools.
An ozone off-gas destruct unit converts any undissolved ozone to oxygen and discharges
it harmlessly to the outside air.
Results
The Ozone Technology Model N-60 Ozonation System is safely, efficiently, and dependably treating the recycled water from the flamingo and spoonbill pools.
Benefits
- Improves zoo visitor experience by dramatically reducing odor and producing clear, beautiful water.
- Creates a healthy environment for the birds.
- Eliminates water-borne bacteria and viruses.
- Saves water by reducing the need to draw down exhibit water to remove solids.
- Produces a safer environment for birds by eliminating the need for chlorine and other hazardous biocides.
Manager of Operations,
Caldwell Zoo
Technical Information
Model N-60 Ozonation System
Theory of operation
Ambient air is cooled and dried. The air then enters an ozone generator, where ozone is produced. Suction form a venturi ozone injector pulls the ozone from the generator and mixes it with recycled exhibit pool water in a contact tank.
An ozone off-gas destruct unit converts any undissolved ozone to oxygen and discharges it to the outside air. Filter backwash is discharged into a city sewer pipe.
The Model N-60 Ozonation System is completely pressureless, enhancing safety and greatly reducing maintenance.
The suction (vacuum) created by the venturi injector is the only force that moves air through the system.
Technical Specifications
General system specifications
| Ozone produced |
60 grams per hour (3.2 pounds per day) of 2% ozone from ambient air |
| Total flow rate | 800 gpm |
|
Ozone treatment side-stream flow rate |
150 gpm |
|
Ozonation contact tank size |
600 gallons |
| Ozonation and off-gas destruct time | 4 minutes |
Ozone Generation subsystem specifications
| Number of ozone generators | 1 |
| Ozone output | 60 gr/hr |
| Ozone concentration | 24 gr/m3 (2% wt) |
| Gas flow to ozone generator (at 60 gr/hr) |
2.5 m3/hr (1.47 cfm) |
| Cooling water required (at 60 gr/hr) | 120 lph (0.6 gpm) at 45 psi (maximum) |
| Cooling water temperature at inlet to ozone generator | 70°F (21.1°C) nominal |
| Supply voltage | 460 (480) VAC, 3-phase, 60 Hz |
| Control voltages | 24 VDC and 120 VAC |
| High voltage | 10,200 VAC (maximum) |
| Number of high voltage electrodes in ozone generator | 42 |
Air Preparation subsystem specifications
| Number of air dryers | 2 |
| Dryer type | Non-pressurized desiccant (negative pressure) |
| Air drying capability | -40°F dew point or better |
| Desiccant type | Granular silica gel |
| Dryer operation cycle time (between changes) | Equivalent of 36 hours operation at full output |
| Dryer regeneration time | 8 hours (maximum) heating plus 28 hours (minimum) cooling |
| Dryer heater power | 2,000 watts, 120/240 VAC, 3-phase, 60Hz |
| Regeneration air inlet temperature | Room ambient |
| Regeneration air outlet temperature | Approximately 240°F (116°C) |
Ozone Injection subsystem specifications
| Number of ozone injectors | 1 (1½-inch KYNAR) |
| Number of ozone injector pumps | 1 |
| Ozone injector pump power (from ozone generator control cabinet) | 5 hp (460 VAC, 3-phase, 60 Hz) |
