Airjec®-System

for the aeration at water treatment plants
Ideal aeration for biological activity with low energy consumption.

Introduction

The supply of oxygen to aerobic bacterial in a biological treatment plant consume a large quantity of energy whether by turbines, conventional diffusers or by conventional venturi.

The design of the Airjec® maximizes the use of the kinetic energy of a side-stream of water, producing bubbles that are small enough, with very high surface energy to get extremely high oxygen transfer.

Application

A small flow of water (typically < 1200 L/min at 4 – 5 bar) is used in each Airjec® to draw the air into the aerated water flow, which is delivered into the tank of the unit or into the recycled settled sludge.

If the MLSS is lower than 10 000 mg/L this can be used as the motive water.

The water passing through a venturi draws in air from the surroundings, or if necessary from some distance away.

The size and quantity of the micro-bubbles are independent of the properties of the water. Where compressed air is being replaced the use of surrounding air at ambient temperature can reduce the need for cooling during summer months.

Airjec® advantages

  • Large reductions in energy consumption are possible by utilizing the Airjec in place of compressors or surface aerators

  • Additional air can be introduced to reaction tanks at low capital and running costs

  • Better control of DOC

  • Better system stability

  • Aerated water injection points can be moved around to better mix dead-spots

  • Where compressed air is being replaced the use of surrounding air at ambient temperature can reduce the need for cooling during summer months