Double Mechanical Seal Circulation for Reverse-Rotation Leakage Control

The sealing system is divided into two independent sealing mechanisms (pump-side and atmospheric-side) that operate separately. Each sealing mechanism has its own sealing elements and pressure control, allowing the system to maintain reliability while managing complexity through modular design. The pump mechanism is segmented into distinct components (pump body, impeller, shaft) that can be manufactured and maintained independently.

A fluid barrier medium is introduced as an intermediary substance between the pump-side and atmospheric-side sealing mechanisms. This medium creates a pressure barrier that prevents toxic fluid leakage without requiring direct mechanical contact between opposing sealing elements. The barrier medium acts as a mediator that transmits pressure forces and maintains sealing integrity while simplifying the overall sealing architecture.

The sealing system is designed with preliminary protective measures against reverse rotation effects. The pump-side and atmospheric-side sealing mechanisms are configured with biasing springs and pressure balancing features that maintain sealing contact regardless of rotation direction. The fluid barrier medium pressure is pre-adjusted to compensate for potential pressure reversals, preventing leakage before reverse rotation occurs.

The sealing system incorporates dynamic elements that automatically adapt to changes in rotation direction. The pump mechanism and fluid barrier medium pressure system are designed to dynamically balance pressures across the sealing interfaces during both forward and reverse rotation. Spring-loaded sealing elements provide continuous adaptive contact pressure that maintains sealing effectiveness under varying operational conditions.

The system carefully controls the pressure parameter of the fluid barrier medium to maintain it above atmospheric pressure but below the toxic fluid pressure. This parameter optimization ensures sealing effectiveness while minimizing the energy and quantity of barrier medium that could potentially leak. The pressure differential is precisely managed to create sufficient sealing force without creating hazardous high-pressure conditions.

An inert or harmless fluid barrier medium (such as clean water or inert gas) is used instead of the toxic process fluid. This creates a safe intermediary environment between the toxic fluid and the atmosphere. Even if leakage occurs, the barrier medium poses no toxic or flammable hazard, effectively eliminating the harmful factors associated with barrier medium leakage while maintaining sealing performance.

The system incorporates preliminary cooling measures through the heat exchanger that can operate passively or with minimal power. The heat exchanger is pre-positioned and pre-filled with cooling fluid, allowing it to immediately dissipate heat when the pump operates. During power failures, the system relies on the thermal mass and passive heat dissipation capabilities that were prepared in advance, maintaining cooling functionality without continuous power input.

The cooling system is designed to partially self-regulate through natural convection and thermal radiation from the heat exchanger. The fluid barrier medium circulation and cooling process utilizes the inherent thermal properties of the materials and fluids involved, reducing dependence on active mechanical cooling. The system serves itself by using the heat exchanger's surface area and the barrier medium's flow characteristics to automatically manage thermal loads without requiring continuous external power input.