Reducing Noise from Forges and Foundries
The Handbook of the Black Country Forging and Foundry Project (Part 2)

Written by Bob Davis
Original version © 2002, ISVR University of Southampton. All rights reserved.

2 Noise from forges and foundries

2.1 What makes noise?

Noise (or sound) is generated in two ways:

By the vibration of solid surfaces which then act as noise 'radiators'. The vibration may be caused by an impact (such as the strike of a forging hammer or a casting being dropped on to a hard surface) or because of the action of rotating machinery.
By unsteady flows of air or gas. Examples are the flow of air over the blades of a fan, the turbulence within furnaces burning gas or oil, and the discharge of high-pressure compressed air.

2.2 What are the main causes of noise from forges and foundries?

Most industrial processes involve the use of machinery, the movement of materials, and the movement of air for ventilation, heating and cooling. All of these generate noise which can affect neighbours. The following lists show the sources most likely to cause people living near forges and foundries to complain about noise and vibration:

Forges

Impact noise from hammers and presses
Air exhaust noise from air-driven hammers
Combustion roar from gas and oil furnaces
Bar cropping
Compressor houses, particularly if reciprocating compressors are used.
Ground vibration from hammers

Foundries

Fans on ventilation and dust collection systems.
Fettling and grinding to remove flash and sprue from castings.
Loading furnaces (particularly cupolas) - impact of material on feed hopper
Deliveries of sand and clay (usually using blowers mounted on delivery vehicle)
Shakeouts

Sources common to both industries

Outside operations, particularly truck movements in stockyards.
Movement and tipping of materials and scrap - impacts of castings and forgings in stillages, bins and hoppers
Alarms, Tannoy systems, vehicle reversing buzzers
General activity noise - from yards, car parks and open doorways. Shouting, door slamming and music noise can be a particular problem at night, from any industrial premises.

These noises can be grouped under three headings:

Breakout of process and machinery noise from buildings, through the building fabric or through openings, including doorways and holes providing ventilation.
Noise from ancillary equipment installed externally or in perimeter plant rooms - air compressors, cooling towers and heat exchangers, dust extraction and sand reclaim plants etc.
Noise from external activities, particularly movement of materials by forklift truck and the associated impact noise.

Reducing Noise from Forges and Foundries The Handbook of the Black Country Forging and Foundry Project (Part 2)