The Core Cause of Frequent Wear and Perforation of the Magnetic Pump’s Isolation Sleeve Due to High-Salinity Concentrated Mother Liquor

I. Continuous Abrasion of the Gap Between the Inner and Outer Isolation Sleeves by Hard Salt Crystals

There is only a thin-walled isolation sleeve between the inner and outer magnetic rotors of the magnetic pump, with an extremely small gap.

The saturated salt crystals in the concentrated mother liquor are highly hard, and during circulation and discharge, the crystals are forced into the cooling jacket of the isolation sleeve:

Fine salt crystals become lodged in the narrow gaps and, under the high-speed rotation of the rotor, continuously rub and scrape against the inner wall of the isolation sleeve, causing the wall thickness to thin uniformly over time;

Larger crystal particles cause localized, intense abrasion, rapidly creating pits and cracks until perforation occurs and fluid leaks out.

Ordinary clean water without solid-phase media exhibits virtually no such wear, whereas the wear rate in high-salt slurries increases exponentially.

II. High electrical conductivity of the medium causes eddy current heat to rapidly raise the temperature and soften the isolation sleeve

High-concentration brine has an extremely high ion content and is a highly conductive liquid.

Magnetic drive rotation cuts through magnetic field lines, causing the conductive medium to generate a large amount of eddy current heat within the isolation sleeve:

The temperature of the isolation sleeve continues to soar, significantly reducing the strength and toughness of plastic or metal isolation sleeves and degrading their wear resistance;

When the cooling flow in the interlayer is insufficient, heat accumulates, causing the isolation sleeve to soften at high temperatures; even slight friction from crystals can easily cause damage;

Alternating hot and cold temperatures cause thermal fatigue cracks in the isolation sleeve, which rapidly expand and perforate the sleeve due to abrasion.

III. Liquid shortage in the pump chamber and dry-running conditions exacerbate localized high-temperature damage

The liquid level range during staged concentration discharge is narrow, making it prone to cavitation and brief liquid shortages:

The jacket’s interlayer loses medium cooling, preventing the dissipation of eddy current heat, which instantly scorches the jacket;

Without liquid lubrication, the magnetic steel rubs directly against the jacket, wearing through it in a short time;

A small amount of residual salt crystals sinter and harden under the high temperatures of dry grinding, further enhancing their cutting ability.

IV. Low circulation flow rate causes salt crystals to settle and accumulate in dead corners of the jacket

During intermittent discharge operations and low-flow conditions, salt crystals deposit in the jacket at the bottom of the isolation sleeve:

Long-term static accumulation of crystals, combined with high-speed scouring and compression at the bottom of the isolation sleeve during each startup, leads to localized concentrated wear; perforations mostly occur in the lower half of the isolation sleeve.

V. Synergistic Damage from Electrochemical Corrosion and Wear (Metal Isolation Sleeve)

High-salt solutions contain chloride ions; prolonged immersion of the thin-walled isolation sleeve erodes the surface passivation film:

Confined corrosion forms at wear sites, where electrochemical pitting occurs simultaneously with mechanical erosion, causing wall thickness to decrease at a rate far exceeding that of mechanical wear alone; corrosion pits become stress concentration points, making the sleeve highly prone to cracking and leakage.

VI. Silica Gel and Organic Flocs in the Medium Exacerbate Crystal Adhesion

Trace amounts of silicate colloids and flocculation residues in the feed solution adhere to salt crystals, forming a layer of composite scale on the inner wall of the isolation sleeve. This scale acts as a continuous abrasive medium that cannot be flushed away by the water flow, leading to the gradual erosion of the isolation sleeve’s wall thickness.