Put the provider to the test. Ask them to answer the following questions to get an idea of the atomization rates they are able to achieve. Atomization refers to the average droplet size per volume of water they mist. Smaller droplets result in increased surface area, which is essential for maximum evaporation efficiency. Effective atomization requires two critical components – pressure and nozzles. The pump provides the pressure, and the nozzles create the droplets.
If the service provider cannot demonstrate they meet the minimally acceptable answers to the following questions, then you should be aware that performance will rarely exceed 100 bbl/day of evaporation even under the best summer conditions. Winter will be a fraction of this total (click here for example graph of performance expectation). Here are the questions:
1. What it the maximum “head rating” on the pump the service is using?
Minimum acceptable answer: 200 feet
Pump head is provided in feet, and it refers to the height the pump can push a given volume of water under perfect conditions. 200 feet of pump head will result in a pressure of about 85 PSI under optimal setup conditions. Most pumps are designed for volume as opposed to lift performance, thus head ratings are typically in the range of 100 to 125 feet (roughly 40 to 50 PSI) under optimal conditions. Assuming they use the right nozzle (see below), these lower rated pumps will struggle to achieve atomization rates less than 2,400 microns per volume. (Note: micron size is important. Smaller droplets per volume result in more surface area for evaporation)
EvapoRite Systems designed their patented technology around pumps that exceed 200 feet of head. Water Remediation is the only service we are aware of that uses these systems. As a result, they are able to achieve atomization rates of about 400 microns per volume – six times greater than their competitors (assuming competitors use the right nozzles and set up correctly).
Ensure service providers prove their answers. Ask to see the manufacturer’s performance curve, or performance documentation for their pumps.
2. What is the “suction lift” of the pump the service is using?
Minimum acceptable answer: 15 feet
Suction lift is a measure of the maximum distance the pump can “lift” a volume of water without losing its prime. Typical pumps are between 8 and 15 feet. Suction lift is critical because pump head will decrease as suction lift increases. In other words, as the level of the pond decreases most pumps become less and less effective because discharge pressure decreases accordingly. Since these pumps are not designed for this type of work anyway, even a small decrease in performance can have a dramatic impact on evaporation.
Water Remediation pump systems have suction lift capacities of 25 feet. There will be a minimal degradation in evaporation efficiency as the water is eliminated and the surface level of the pond drops.3. What type of nozzle do you use?
Minimum acceptable answer: Hollow Cone (Note: hollow cone spirals are best)
If the service provider says they are using impact nozzles, or sprinklers, or no nozzle at all, then be aware that their efficiency will suffer. Hollow cone nozzles provide the most efficient atomization at low pressure (40 to 100 PSI). Remember, the nozzle is only half the equation. The pressure of the water passing through the nozzle is the other half.
Hollow cone nozzles are so important that EvapoRite’s was granted a separate claim on their patent for their use of the nozzle in oil and gas related evaporation systems. Water Remediation uses the nozzles.
4. What does their setup look like
Minimum acceptable answer: Floated over the middle of the pond, away from the bank, equal pressure to every nozzle, and nozzles spread out in a manner that takes the greatest possible advantage of the airspace over the pond.
Competitors rarely take advantage of these factors, and sometimes their pumps simply won’t allow it due to the pressure losses resulting from pushing the nozzles so far away from the pump. Signs of problems in this area are nozzle arrays that are clustered together, or when the nozzle furthest from the pump has less pressure than the closest nozzle.
