ALPHA-ROWEN LTD

Alpha-Rowen Limited provide specialist heat treatment services to a range of industrial sectors. The company has an annual energy consumption of 8.1 MWh with a cost of £880,000 per annum. Alpha-Rowen operate continuous processes, 24 hours per day, 6 days per week.

Alpha-Rowen have recently built a new factory to house several energy intensive heat treatment process lines to serve increasing and changing customer demands in an efficient way.  The nature of the process remains one of controlled heating of component batches, in a specialised endothermic atmosphere where carbon potential is strictly controlled, and oxygen is eliminated.  

At the new location, much of the work involves quenching of the hot components in hot molten salt contained in large baths before washing in clean, cold water and drying. The nature of the process involves heating of components to high temperatures and then cooling to room temperature within a matter of hours. This is highly energy intensive and energy consumption must be carefully monitored and controlled.

Any avoidable energy consumption: maybe an item of plant left on longer than is required or a burner running out of specification, must be quickly identified and rectified.  Similarly, any energy improvement projects, or processes must be accurately monitored over extended periods.  Success or failure in the heat treatment sector in the UK is highly dependent on an operator’s ability to control energy costs.  This is not generally a labour-intensive sector and there is no component manufacture involved.

The Old System

Pro Enviro already had experience of installing and operating aM&T systems at two other Alpha-Rowen heat treatment locations where the energy saving benefits have been proven.  Heat Treatment equipment, where automated monitoring is essential was quickly identified, and a robust and cost-effective system was designed and installed.

Before the aM&T system (SEE Change) was installed the client had no method of determining the energy consumption of each of their furnaces and their ancillary equipment. These high energy consuming plant were not monitored and managed efficiently, resulting in inefficient start up and shut down processes.

New System and Rational

The new SEE Change, aM&T system makes use of 3-phase pulse output electricity meters and a variety of suitably rated pulse output natural gas meters all collecting consumption data from the heat treatment furnaces and their ancillary equipment and transmitting data online to secure, dedicated SEE Change servers. This information is then processed and made into tailored reports, graphs and alarms.

Authorised managers and manufacturing personnel within the company were provided with personal login accounts to access and analyse the data and review system generated charts and reports. A personalised dashboards were created for each member of the management and engineering team, displaying the relevant information to help optimise the use of the plant within pre-set limits.

Project Cost and Savings

Overall, the project cost was £23,284 followed by an annual £2,620 Licensing and Support fee. From this Pro Enviro were able to assist Alpha-Rowen in monitoring and managing their production process costs closely with a view to securing significant energy and cost reduction on ongoing basis at the new site.

Energy costs are carefully controlled by calculating the kWh usage and energy cost per kg of metal heat treated in each process line each day. This ensures that estimates of the cost of processing work are realistic and accurate and that every opportunity to reduce energy cost can be evaluated and accurately monitored.  This could include simple issues such as improved insulation on furnaces or better process burner control or more complex technologies such as improved methods of generating and controlling special furnace atmospheres.

Savings generated were calculated as 375,000 kWh of gas and 37,500 kWh of electricity, representing a cost of £46,800 per year at the current unit rates for energy and reduction of 75 tonnes of CO2_e per annum.