Inclined Screw Conveyors for Rensselaer County Sewer District in City of Troy, NY

General Description

The Rensselaer County Sewer District serves two main purposes. Its principal role is safeguarding the Hudson River through secondary wastewater treatment prior to discharge. This treatment process eliminates 85-percent of both Carbonaceous Biochemical Oxygen 5-Day Demand and Total Suspended Solids from incoming wastewater.

The district’s secondary objective is revenue generation through direct billing of all service users, including residential, commercial, and industrial customers. These revenues fund annual operations, maintenance expenses, and outstanding debt service obligations. The district’s treatment facilities were built during the mid-1970s and commenced operations in 1976.

During the plant’s upgrade and improvement project, KWS was contacted to supply two inclined screw conveyors designed to collect thermally dried biosolids from a vibratory screen separator. Dried biosolids meeting specifications were transferred to an existing truck loading conveyor that transported it outside the building, while non-conforming material was returned to the dryer inlet for reprocessing.

Two KWS Inclined Screw Conveyors Receive Dried Biosolids from Screener

Design Parameters

Product Type: Dried Biosolids
Material Density: 50 to 65 Lbs. per Cubic Foot
Capacity: 20 Cubic Feet per Hour
Duty: Intermittent

KWS Advantages

KWS engineering personnel engaged in extensive technical collaboration with Collett Mechanical’s design team to engineer a comprehensive material handling system. Leveraging advanced 3D CAD modeling technology, KWS provided two inclined conveyors to fit underneath a vibratory screen separator. This design approach facilitated seamless installation execution. Upon completion, a KWS field service representative conducted comprehensive equipment commissioning and operator training protocols, resulting in successful system integration and operational deployment.

KWS Special Features

KWS applied hard surfacing to both the carry side and flight periphery of the conveyor screws to extend operational lifespan. Hard surfacing involves applying an abrasion-resistant coating over the base material, which increases screw durability, minimizes maintenance requirements and downtime, and reduces total operating expenses.

For enhanced safety and equipment protection, each screw conveyor incorporated a cable-actuated emergency stop system. A safety mechanism enables immediate conveyor shutdown during emergency situations through an externally mounted cable that runs along the conveyor perimeter and interfaces with a centralized control unit, providing operators with accessible emergency response capability from any position along the length of the equipment.

KWS employed a split tubular housing configuration for the 37-degree inclined screw conveyor, incorporating a reduced pitch screw to enhance conveying performance. The inclined screw conveyor design reduces material backflow over the screw flights on steep angles. Additionally, the split tubular housing provides superior access to internal components, simplifying maintenance procedures compared to conventional solid tubular designs.

KWS provided a 4-inch drain with 150# ANSI flanged connection to facilitate complete material evacuation during equipment cleaning and maintenance operations. The drain assembly is strategically positioned at the conveyor’s lowest elevation point on the non-carrying side to minimize potential material accumulation and prevent system blockages.