So where do you start an investigation to determine if your existing or proposed new system is energy efficient? The investigation on existing equipment will require a technical person skilled in measuring or obtaining the pertinent data related to the equipment evaluation. With new equipment, it should be provided in the proposal or obtained during technical reviews of the planned project. If you plan to perform an internal evaluation of the energy efficiency of your existing process, be sure to consider the following process characteristics:
Define the process lines heat load distribution. Determining where the energy is going will help identify where efficiency can be improved. How much heat is going to:
- Substrate and coating?
- Solvent evaporation?
- Makeup air and exhaust?
Equally important, how much heat is available in exhaust solvents via recovery or combustion?
Define the solvent rate and range. How much variation exists in the solvent input rate for the product range produced? Factor in the amount of production run time on each product, e.g., a low solvent input rate may be a high percentage of your production. The line sizing and your process exhaust are likely based on the higher input rate product(s) produced.
Generate an accurate flow diagram for the process line being evaluated. Record the entire product input and output conditions that define your process. Obtain all the associated flow, temperature, pressure, installed and operating horsepower, etc., data vs. the product input data. This data gathering process can expend a great deal of time and energy, but it is essential to getting results.
Identify payback opportunities. If you have the necessary skills and manpower within your organization to evaluate and implement energy savings programs, congratulations, there are benefits available to your bottom line. Another option is concluding your process has opportunities to save energy, but you need help! Consulting engineering firms or capital equipment manufacturing companies that offer additional engineering services may be the best way to gather the data and analyze the savings opportunities.