Sand Silo
A Sand Silo is a storage and discharge unit designed to temporarily hold and discharge
dewatered sand and grit separated during the grit removal process in wastewater treatment
plants. Sand silos are installed downstream of grit classifiers or grit washers and serve as an
intermediate holding unit before final disposal. They are engineered to allow for efficient
filling, controlled discharge, and easy removal of accumulated grit by manual or automated
means.
Sand silos can be operated intermittently and are typically equipped with a conical hopper
base to ensure smooth material flow.
Main Components of Sand Silo
Silo Body
The silo body is a vertically oriented cylindrical or square container fabricated from stainless
steel or hot-dip galvanized carbon steel. It is designed to handle heavy grit loads and is
typically mounted on structural support legs. The upper body includes an inlet chute or pipe
connected to the grit washer or classifier outlet.
Conical Hopper
Located at the bottom of the silo, the conical hopper facilitates gravity-driven discharge of
collected sand and grit. The cone angle is optimized to prevent material bridging and ensure
complete emptying. It is typically welded to the silo body and fabricated from abrasion-resistant
material.
Conical Hopper
Located at the bottom of the silo, the conical hopper facilitates gravity-driven discharge of
collected sand and grit. The cone angle is optimized to prevent material bridging and ensure
complete emptying. It is typically welded to the silo body and fabricated from abrasion-resistant
material.
Discharge System
The discharge outlet at the base of the hopper is designed to accommodate containers, screw
conveyors, or manual removal setups. It can be equipped with a manual or pneumatically
actuated slide gate valve or a rotary discharge feeder, depending on the desired level of
automation.
Support Structure
The silo is supported on galvanized or stainless steel legs that provide clearance underneath
the discharge outlet for bins, bags, or conveyors. Each leg is bolted to a concrete foundation
using anchor bolts for structural stability.
Access Hatch and Ventilation
The silo includes a top hatch or access cover for inspection, cleaning, and maintenance. A
ventilation pipe or filter may be installed to equalize pressure and minimize dust emissions
during filling.
Level Indicator (Optional)
A mechanical or ultrasonic level sensor can be installed to monitor the fill level and send a
signal when the silo is full or needs emptying.
Design Data
• Silo capacity: 0.5 – 5 m³ (customizable)
• Inlet diameter: DN 100 – DN 250
• Discharge outlet diameter: DN 150 – DN 300
• Material: Stainless steel AISI 304 / 316 or hot-dip galvanized steel
• Cone angle: 45° – 60° (depending on material flow characteristics)
• Mounting height: Custom, based on discharge method
• Discharge method: Manual or automatic (via screw conveyor or valve)
