Energy Management in Rubber Processing - Part 2 - The Rewards
The second in a series of energy efficiency worksheets by Dr. Robin Kent for
the Carbon Trust help the
rubber industry reduce costs through efficient
use of energy.
UK Government Environment and Energy Helpline 0800 585 794
Energy efficiency measures can improve your profits significantly for minimum effort and costs. For a rubber company with an annual turnover of £10 million per year and a net profit of 10% (i.e. a profit of £1 million. The average electricity bill will be approximately £200,000 (between 1% and 3% of turnover). Simple no-cost or low-cost energy reduction practices can reduce this by a minimum of 10% (and possibly up to 20%) and increase profits by at least 2%. This is the equivalent of adding sales of £200,000 to turnover and is a worthwhile investment by any standards.
Low cost energy efficiency measures can improve profits significantly
The cost savings possible from energy efficiency will only be achieved if there is management commitment to actually carry out the work necessary and save money. This is best ensured by having an energy policy that is as much a part of the overall company operations as the quality policy. The energy policy should ideally be part of a broader company environmental policy and, at the very least, should be formally adopted with top-level management commitment. The policy should be the responsibility of a designated Energy Manager who has clear responsibility for energy matters. There needs to be regular communication with major users who are held accountable for their energy usage, which should be monitored and targeted. The quantified savings from the implemented energy policy should be promoted within the company and used to create a favourable climate for investment treatment of other energy saving programmes.
Energy efficiency is a competitive advantage in any market and an initial site survey is the start of gaining the advantage for your company.
This Worksheet shows how to carry out an initial site energy survey - the starting point for all improvement plans.
The objective of the initial energy survey is to gain an overview of the general site energy use. It is a walk around the site with Ďan energy managerís hat oní. This will identify some rapid no-cost or low-cost improvements that can be made to save money.
The survey should be carried out as soon as possible - if energy is being wasted now, it is costing money now. The diagram shows the main areas of energy use in rubber processing. Use this as a guide during your walk-around to look for areas of high or unnecessary energy usage.
An initial site survey is a key starting point for energy saving
Energy uses in rubber processing
How do you carry out a site survey?
Take an unannounced walk around the site at around mid-shift. If there is no night shift it can also be worthwhile to take a walk around the factory when there is no production.
The questions to ask (and answer):
- Which areas have the largest electrical load? Look for the largest machines, they are most likely to have the largest motors and create the largest load, when they are used.
Is the thermal insulation, if present, on all the machines in good condition? If there is no insulation then why not?
- Are there any good reasons why machines need to be kept idling to be ready for the next production run, or when not in production? These include conveyors, water pumps, vacuum pumps, motors, granulators, fans, and machine heaters etc.
- Why are the motors the size they are and would a smaller motor be more efficient?
- Is the airflow from fans being throttled back with dampers and could variable speed drives be used instead?
- Are there leaks for water, air or steam?
- Where can you hear steam and compressed air leaks? The hissing noise you hear from leaks is costing real money. If there is no production being carried out then why is the compressed air system still running?
Is compressed air being used for expensive applications where other cheaper methods can be used e.g. cleaning or drying?
- Does the compressed air pressure need to be so high, or the vacuum so low?
- Is the lighting dirty or broken?
- What are the good, simple maintenance measures that can be adopted to reduce energy use?
- Are Ďacceptedí practices wasting energy?
- Can they be modified at no cost at all?
- Are there clear setting instructions for all machines and are they implemented when a machine is set up?
A site energy survey is only worthwhile if action is taken as a result of the findings. Use the survey to estimate the excess energy usage of the site and arrange for an electrician to measure the factory electrical load and calculate the costs involved. Use the survey to identify operating practices that cost money and need to be changed. The results of the survey should be distributed with full recommendations and costs for carrying them out.
The "Energy Management" series is designed to give plastics processors an insight into how to manage a valuable resource.
Part 1 - Reducing energy costs - the first steps
Part 2 - The rewards (This Section)
Part 3 - Compounding
Part 4 - Moulding
Part 5 - Extrusion
Part 6 - Motors and drives
Part 7 - Compressed air
Part 8 - Buildings