"How They Made it Work" is a column that features some of the latest technological advancements in the chemical process industry. Here, Chemical Processing asks experts from various technology providers to provide insight into their innovations and how they're helping chemical manufacturers operate their plants more efficiently and effectively.
Company
Vesconite
Technology
Vesconite Hilube is a self-lubricating bushing material for immersed applications including pumps. It is a propriety material developed to use as a plain bearing acting as a low-friction, hard-wearing surface between a steel shaft and its steel housing. This bearing material exhibits long wear life in immersed applications, is resistant to water absorption, has low friction and resists certain chemicals.
Explanation of development, design and purpose
Bearing design is typically dictated by the geometrical properties of the housing and shaft environment that it will be working in. Here, running clearance, interference fits and bore closure is calculated. However, before the geometrical design can be approved, it's necessary to assess the load-bearing capacity and heat-dissipation rate to prevent failures. This is done by calculating the static stress and the dynamic PV value which is the product of the dynamic stress and the surface speed. The bearings were designed using Vesconite’s suggested running clearance, which is typically smaller than the specified Bronze API standard for bushing running clearance.
Description of its significance in chemical plants
The bearing provides a wear-resistant solution to pump-shaft supports and wear rings in vertical turbine pumps. Other applications, such as agitators and rotating drums, are suitable for the product as the material provides a simple solution and is able to withstand the abrasion and a range of chemicals present in these types of plants.
Unique features
Extended wear life, low friction, no swell and self-lubricating bushing materials
Success Story
Sodium hypochlorite, commonly known as bleach, is a staple in water-treatment and cooling systems and is hailed for its potent disinfectant, anti-microbial and marine-growth-inhibiting properties. These properties led to hypochlorite being adopted at a Gulf Coast seawater cooling pump station.
However, when its concentration was inadequately monitored at the pump station, the consequences were severe.
Pumps fitted with conventional A106 seamless carbon steel and bronze wear components incurred considerable damage due to exposure to concentrations of hypochlorite exceeding the typical 2-3 ppm concentrations.
In contrast, pumps fitted with Vesconite Hilube parts emerged unscathed, demonstrating resilience to the corrosive effects of hypochlorite. After eight years of operation in these conditions, Vesconite Hilube bearings show no deterioration.
The success of Vesconite Hilube bearings in this demanding application has prompted the facility to replace pumps fitted with bronze components with Vesconite Hilube parts.
