Case Studies 3. Sand Quarry Variable Speed Drive Air Compressor

Date of compressed air installation: Sept 2016

Location: A Silica Sand Quarry in Scotland

Description: EDC was invited to conduct a plant-wide energy appraisal of our customer's electric motor and compressor loads.The plant in Scotland produces quality- assured, high-silica content sand for use in the glass and other industries, including: sports & horticultural sand, paving & drainage sand, and sand for use in equestrian centres. The quarry was keen to find out how they could improve efficiency, save money, and at the same time further enhance their commitment to the environment.

The Process:  The air compressor was critical to the operation of this plant: no air, no process. As the workhorse of the operation it bore the brunt of the workload controlling the wet plant magnets. The energy appraisal revealed there could be potential energy savings of 390,000 kWh  - with a payback period of as little as 1 yr. 6 months.  

Solution: EDC offered a new 22kw SCR30DV variable speed air compressor, which would allow the plant to precisely control the operation of the compressor depending on the load. The old air compressor (which had nearly 60,000 hrs on the clock) would be retained as an emergency stand-by. The installation of this variable speed drive compressor reduced the existing running costs from nearly £10,000 to £6,000 per annum. Even replacing the complete unit the pay-back time was under 2 years.

Additional benefits for the site included –:

• Plant integrity with online standby.
• Reduced maintenance on the new compressor.

The total plant Co2 savings would be the equivalent of driving an average family car to the moon and back.