The main performance indicators of a dual-speed aerator are oxygenation capacity and power efficiency. Oxygenation capacity refers to the amount of oxygen that the dual-speed aerator adds to water per hour, measured in kg/h; power efficiency refers to the amount of oxygen added to water per kilowatt-hour consumed by the dual-speed aerator.

The primary performance indicators of a dual-speed aerator are oxygen-boosting capacity and power efficiency. Oxygen-boosting capacity refers to the amount of oxygen that the dual-speed aerator adds to the water per hour, measured in kg/h. Power efficiency refers to the amount of oxygen added to the water per kilowatt-hour of electricity consumed by the dual-speed aerator, measured in kg/kWh. Taking the 1.5 kW aquatic vehicle dual-speed aerator as an example, its energy efficiency is 1.7 kg/kWh—meaning that for every 1 kWh of electricity consumed, it can add 1.7 kg of oxygen to the water body.

The function of a dual-speed aerator is to increase the dissolved oxygen content in water, and this process involves both the solubility and the dissolution rate of oxygen. Oxygen solubility is influenced by three factors: water temperature, salinity, and oxygen partial pressure. The dissolution rate, on the other hand, depends on three key factors: the degree of oxygen saturation in the water, the surface area and method of contact between water and gas, and the movement of the water itself. Among these factors, water temperature and salinity represent stable conditions of the water that generally cannot be altered. The degree of oxygen saturation, however, is a variable we can and must adjust—it reflects the current state of the water. Therefore, to increase the oxygen content in the water, we must directly or indirectly modify the following three factors: oxygen partial pressure, the surface area and method of water-gas contact, and the movement of the water. In response to this situation, the following measures are adopted when designing a dual-speed aerator:

1) Use mechanical components to stir the water body, promoting convective exchange and interface renewal;

2) Disperse water into fine droplets and spray them into the gas phase, thereby increasing the contact area between water and gas.

3) Through negative pressure suction, the gas is dispersed into microbubbles and forced into the water.

Based on these principles, different types of dual-speed aerators have been designed and manufactured. These aerators either employ a single measure to promote oxygen dissolution or utilize two or more measures.

Types of aerators:

1. Impeller aerator

It is currently the most widely used aeration device, with an annual output of approximately 150,000 units. Its aeration capacity and power efficiency both outperform those of other models, but it generates relatively high operating noise. It is typically used in large-scale pond aquaculture where the water depth exceeds 1 meter.

2. Waterwheel aerator

Suitable for ponds with relatively deep silt and an area ranging from 1,000 to 2,540 square meters.

3. Jet Oxygenator

This aerator boasts a higher power efficiency than impeller aerators, paddle-wheel aerators, and spray-aeration devices. With its simple structure, it can generate water flow and thoroughly mix the water. The jet aerator gently oxygenates the water without harming fish, making it ideal for use in fry ponds.

4. Waterjet Oxygenator

It has excellent oxygenation capabilities and can rapidly increase dissolved oxygen levels in surface water within a short period of time. At the same time, it offers aesthetically pleasing visual appeal and is ideal for fish ponds in gardens or tourist areas.

5. Inflator

The deeper the water, the better the effect. It’s suitable for deep water.

6. Inhale oxygen concentrator

Through negative-pressure suction, air is drawn into the water and mixed with it, creating a vortex that propels the water forward with strong mixing power. The aerator’s aeration capacity for the lower layer of water is greater than that of impeller aerators, while its aeration capacity for the upper layer of water is slightly lower than that of impeller aerators.

7. Vortex Oxygenator

Primarily used for oxygenating subglacial water bodies in northern regions.