HE Venturi Scrubbers
Venturi scrubbers are used to remove very small particles; mist and can also remove gases. The open design eliminates opportunities for the solids buildup and minimizes maintenance.
Particles down to and including submicron sizes can be captured.
Venturi scrubbers can also absorb gases such as Sulfur Dioxide or others that react with neutralizing chemicals. The scrubber can handle high temperature gases and variable gas rates by use of an adjustable throat design.
The amount of energy used by the scrubber is dependent on the size of the particle to be captured. Pressure drops are in the range of as low a 6” WG / 1.5 kPa up to 60” WG / 15 kPa. The relative amount of liquid per volume varies as well depending on the specific design of the scrubber. For larger particles, a low pressure drop design is available. As the size of the particle decreases your energy use will increase. Branch will provide the design value and guarantee the performance.
Since the gas and liquid is co-current in the Venturi scrubber, a separation vessel is required. To keep the design as open as possible, the gas out of the Venturi is usually directed into a Cyclone separator where the gas and liquid are allowed to spin together forcing the liquid to the wall where it is collected and drained to the bottom for recirculation.
Our Venturi scrubbers have been used on applications requiring capture of solids from many different industries.
- All performance levels are guaranteed.
- Virtually any material of construction is available including Fiberglass, Stainless Steel, special alloys, Teflon lining and others.
- Complete packages with all components including controls, control panel, fans and pumps for a complete single source responsibility.
- Shop fabricated units up to 80,000 cfm (135,000 m3/h). Larger size units are available using field fabricated designs.
Principle of Operation
The Venturi uses a converging section where the gas velocity increases. Just prior to the smallest diameter section, the liquid is introduced at 90° to the gas direction. This results in the liquid becoming shattered into small droplets. The extremely small droplets and gas are then sent through s Venturi throat area where the velocity is increased to very high velocities. This extreme mixing results in the capture of small micron and submicron particles. A diverging section is used to gently slow down the gas and recover as much as the energy as possible.
The gas and liquid is then discharged into a Cyclone chamber where they are separated.
The most common design is a fixed throat. For a turndown range of 2:1, the fixed throat is the simplest and lowest cost choice. For the absolute highest efficiency or for higher turndown, a variable throat is installed which adjusts the cross-sectional area to keep the same pressure drop. Remember, the pressure drop is equivalent to high velocity and the resulting mixing that captures the small dust. So as the velocity drops, you need to compensate by closing the Venturi throat. An automatically adjustable design is included when necessary. Branch will make recommendations on the best design for your specific case.