Inclined Belt Conveyor for Veolia North America in City of Lynn, MA

General Description

The Lynn Wastewater Treatment Plant (WWTP) in Lynn, MA receives flows from four communities: the City of Lynn, and the Towns of Saugus, Nahant, and Swampscott. The plant operates as a primary and secondary treatment facility. Primary treatment focuses on eliminating settleable and floatable materials, including sludge and grease. Secondary treatment targets the reduction of biodegradable organic matter and suspended solids. The plant’s design capacity supports an average flow of 25.8 million gallons per day under dry weather conditions, with the capability to handle flows exceeding 110.8 million gallons per day during wet weather events.

Lynn’s wastewater first undergoes preliminary treatment via bar screens before joining the flows from the other communities at the aerated grit chambers. Settleable pollutants are subsequently removed in primary clarifiers, while non-settleable pollutants advance to secondary treatment, where biological processes utilizing microorganisms facilitate their removal. Following treatment, chlorine disinfection is applied before the effluent is discharged into the outer harbor. Biosolids generated during primary and secondary treatment undergo dewatering and are managed through on-site incineration or off-site disposal methods, including composting, land application, incineration, or landfill placement.

The Lynn wastewater treatment facility upgrade involves replacing the original mechanical bar screens and screening handling equipment, which have reached the end of their operational lifespan. This project aims to enhance screening efficiency, reliability, and safety during the plant’s preliminary treatment phase. KWS was selected to supply an inclined belt conveyor system designed to capture screenings from the new mechanical bar screens and transport the material to a screening washer compactor for processing.

Design Parameters

1. Product Type: Screenings
2. Material Density: 70 Lbs. per Cubic Foot
3. Capacity: 47 Cubic Feet per Hour
4. Duty: Intermittent

KWS Advantages

KWS engineering staff worked closely with JWC Environmental to ensure the KWS equipment would effectively capture material from the three bar screens and deliver it to the screenings washer compactor. Using advanced 3D CAD modeling, KWS developed a detailed three-dimensional model of the inclined belt conveyor, including both upstream and downstream components. This design methodology streamlined the installation process. Following installation, a KWS field service representative performed thorough equipment commissioning and conducted operator training, ensuring successful system integration and smooth operational startup.

KWS Special Features

KWS utilized a 24-inch-wide cleated belt featuring 3-inch SBR sidewalls that were hot vulcanized to the base belt along both edges, forming a unified belt assembly capable of handling heavy-duty and inclined conveying applications without delamination. The system incorporated multiple inlet points to collect screenings from three separate mechanical bar screens and convey the material up a 22-degree incline.

To enhance safety and protect equipment, the belt conveyor features a cable-actuated emergency stop system and a speed monitoring sensor. The emergency stop cable allows operators to immediately halt conveyor operation from any location along the equipment through an externally mounted cable that runs the conveyor’s perimeter and connects to a central control unit. The zero-speed switch detects when the conveyor stops moving and sends a signal to upstream control panels, triggering an automatic shutdown of connected machinery in the event of a sudden jam or mechanical failure. Together, these safety features provide comprehensive protection for both personnel and equipment.

KWS utilized shaft guards to eliminate exposed rotating shafts and the chance for an accident. Shaft guards were installed on both drive and take-up end of the conveyor. With over 45 years’ experience in the bulk material handling industry, KWS has developed shaft guards for any application that meet the requirements of both OSHA and MSHA (Mine Safety & Health Administration).