Emissions Control | Intermittent High‑Pressure Duty

Flush on Schedule. Start on a Spinning Motor. Never Trip.

VFDs built for the unique demands of wet ESP flushing—where pumps sit idle, then must deliver full pressure instantly.

Wet electrostatic precipitators (WESP) capture fine particulate and acid mists from industrial exhaust streams. Keeping collection electrodes clean requires periodic high‑pressure flushing with water or wash solution. These flushing pumps operate on an intermittent duty cycle: idle for extended periods, then called upon to deliver full pressure and flow within seconds. Standard VFDs struggle with…

When Your Flush Pump Fails, Your Permit Is at Risk

- We shold know the pain point! -

Overcurrent trips on spinning motor restart

Flush pumps often coast for minutes after power is removed. Standard VFDs cannot synchronize with residual back‑EMF, tripping on overcurrent when commanded to start into a spinning load.

Timed sequences fail intermittently

Flush cycles require precise on/off timing. Drives lacking internal real‑time clock or timer logic rely on external PLC commands—adding failure points and commissioning complexity.

Corrosive atmospheres destroy unprotected electronics

WESP installations expose drives to sulfuric acid mist, high humidity, and condensing atmospheres. Unprotected PCBs corrode within months, causing premature failure.

High static head demands full pressure at startup

Flush nozzles require minimum pressure to achieve proper spray pattern. Soft‑start ramps that slowly build pressure result in poor cleaning and electrode fouling.

Flush When Scheduled. Start Every Time. No Exceptions.

- How We Solve It? -

We solve the spinning‑motor restart challenge through integrated flying start capability that samples residual motor back‑EMF frequency and phase before energizing—synchronizing VFD output to the spinning rotor without overcurrent or DC bus overvoltage events, regardless of motor coast‑down state. Our built‑in real‑time clock and programmable timer logic enable fully autonomous flush cycle execution: the drive wakes from sleep, executes a pre‑programmed run duration at set speed, and returns to idle without external PLC commands. Heavy‑duty hardware includes conformal coating on all PCBs to resist sulfuric acid mist and condensing humidity, while our fast‑acting current limit delivers full pressure within one second of start command to achieve immediate spray pattern development. For systems with multiple flushing zones, the VFD supports sequential valve interlock logic that prevents pump operation against closed discharge valves. Integrated pump dry‑run protection via power factor monitoring safeguards mechanical seals during loss of suction events.