Finder Pump LEX25/XX Liquid Ring Vacuum Pump

Finder Pompe LEX25/XX Heavy-Duty Liquid Ring Vacuum Pump

The Finder Pompe LEX25/XX is a single-stage, lantern-bracket mounted liquid ring vacuum pump engineered for continuous, severe-duty gas evacuation, vacuum distillation, priming, and vapor extraction in offshore, marine, and process engineering environments. Operating on an isothermal compression cycle, the LEX25/XX handles wet gas streams, condensable vapors, and liquid carry-over without mechanical impingement or risk of thermal degradation.

Unlike close-coupled monobloc designs (MEX series), the LEX configuration utilizes an independent bearing pedestal and rigid lantern bracket. This design isolates pump hydraulic loads from the driver, enables direct coupling to standard IEC B5 or NEMA C-face electric motors, and complies with international marine classification and ATEX explosive atmosphere directives.

Model Details:

• Manufacturer / Brand: Finder Pompe S.p.A. (A Dover Company)
• Model Designation: LEX25
• Ordering MPN: LEX25/XX-M1 (standard bare-shaft with lantern bracket)
• Standard Motor Power Allocation: 0.75 kW (50 Hz / 2-Pole) | 1.1 kW (60 Hz / 2-Pole)

Key Features

1. Isothermal Compression Principle: Compresses air, toxic gases, and condensable vapors at near-constant temperature, preventing thermal breakdown, polymerization, and internal explosive risk.
2. Single Moving Part Design: High-efficiency dynamic balance with only one moving component—the shaft and impeller assembly—eliminating internal rubbing wear, timing gears, and internal oil lubrication.
3. Rigid Lantern Bracket Construction: Accommodates standardized IEC frame 80 B5 / NEMA 56C electric drivers with zero custom machining, allowing field motor replacement without tearing down wet-end piping.
4. Variable Port Discharge Valve Technology: Automatically self-adjusts discharge flow geometry across fluctuating suction ranges (from 1013 mbar down to 33 mbar), preventing over-compression and cutting motor brake horsepower demand.
5. Standard DIN 24960 Mechanical Seal Chamber: Equipped with an uncooled, balanced/unbalanced mechanical seal flushed continuously by the service fluid, isolating the atmosphere from process vapors.

Applications

• Marine Ballast & Bilge Line Priming: Quickly evacuates large dry suction legs on non-self-priming ballast and fire/bilge pumps.
• Sterilization & Autoclaves: Vacuum extraction during pre-vacuum and drying cycles in chemical and hospital applications.
• Vapor Recovery Units (VRU): Pulls light hydrocarbon gases and volatile organic compounds (VOCs) from marine product cargo tanks during transfer.
• Solvent Distillation & Stripping: Handles aggressive solvents and acidic vapors when outfitted in the full AISI 316 /XX metallurgy.
• Plastic & Rubber Extrusion Degassing: Extracts entrapped air, moisture, and monomers directly from twin-screw extruder barrels.

Frequently Asked Questions

Can the Finder LEX25 run dry without service liquid?

No. The LEX25 will suffer catastrophic seal face damage within 30 seconds if operated without a continuous supply of service liquid. The liquid creates the fluid piston seal inside the eccentric casing and dissipates the friction and heat of compression.

What is the functional difference between the Finder LEX and Finder MEX series?

The MEX is a monobloc design where the impeller mounts directly to an extended electric motor shaft. The LEX features an independent bearing frame and bracket, allowing it to couple to any standard IEC or NEMA C-face motor without special shaft extensions. The LEX is significantly more robust for marine operations and simplifies field motor changeouts.

How do I adjust the flow rate of the service fluid?

Install an inline throttling needle valve and rotameter on the service fluid inlet pipe. Regulate the flow to maintain 0.20 m³/h at 1.0–1.5 bar above the suction pressure. Over-supplying fluid leads to hydraulic drag and motor overload; under-supplying collapses the liquid ring.

Can the Finder LEX25 be utilized as a low-pressure compressor?

Yes. Due to the reinforced bearing design of the LEX frame, the pump can discharge at positive pressures up to 1.5 bar gauge (2.5 bar abs) when operated with properly sized electric motors and adequate heat dissipation.

How do I resolve pump cavitation when operating in high ambient temperature environments?

Crack open the built-in anti-cavitation bypass line that links the discharge air separator back into the suction casing port, or configure an external atmospheric air bleed to keep internal casing pressure above the fluid vapor pressure.