Air-Assisted Reductant Pump Assembly for Exhaust Treatment

The pump assembly merges the motor, pump chamber, mixing device, and nozzle into a single integrated unit. The motor drives the pump mechanism directly within the same housing, eliminating the need for separate mounting brackets and connection pipes, thereby improving delivery efficiency while controlling structural complexity.

The pump assembly serves multiple functions within a single device: it pumps reductant, mixes reductant with air, atomizes the mixture, and directs it into the exhaust stream. The motor provides both mechanical drive and, through heat transfer from exhaust gases, thermal management for the reductant.

Compressed air is introduced into the pump chamber through a dedicated air inlet and mixed with the reductant during pumping. The pneumatic action enhances atomization and promotes thorough mixing, ensuring reliable NOx reduction while keeping the mixing mechanism simple through fluid dynamics rather than mechanical complexity.

The system changes the physical parameters of the reductant by introducing air flow that increases turbulence, decreases droplet size through atomization, and adjusts the temperature through heat transfer from exhaust gases. These parameter changes improve mixing effectiveness without adding complex mechanical mixing components.

The pump assembly uses the hot exhaust gases it is designed to treat as a heat source to warm the reductant and prevent condensation. The motor housing and pump chamber walls act as heat transfer surfaces, automatically thermal-managing the reductant without requiring external heating systems or complex temperature control mechanisms.

The system exploits thermal energy from exhaust gases to maintain reductant temperature above condensation points. The heat transfer through the pump assembly walls and motor housing prevents reductant condensation, ensuring consistent performance across varying exhaust temperatures without active thermal control systems.

The compressed air flow is continuous and integrated into the pumping action itself, rather than being a separate post-pumping atomization step. The air-reductant mixing occurs during the pumping cycle, ensuring continuous atomization without additional energy-intensive separate stages.

Compressed air acts as an intermediary that transfers kinetic energy to atomize the reductant. Rather than using high-energy mechanical atomization mechanisms, the system uses pneumatic energy from compressed air to achieve fine atomization, reducing the direct mechanical energy requirements of the pump motor.