Combating energy bills.

Like the rest of the U.S. industrial sector, the U.S. metalcasting industry has been feeling the economic pinch of rising energy costs. In 2004, the industry spent $1.4 billion on purchased fuels and electricity. Since 2004, the commercial cost of natural gas has nearly doubled from $8/MBtu to today's projected cost of $14/MBtu. Some metalcasters have tried to pass along surcharges to their customers in an attempt to accommodate for these rising costs, but this is only possible if it has been written into their contracts. Even then, many customers are refusing to pay the surcharges.

In order to remain profitable at home and maintain their competitive position in the global market, metalcasters must find ways to improve energy efficiency and reduce operational costs. Surveying and assessing current energy systems and operations is a simple and effective way for metalcasters to identify no-cost and low-cost opportunities to reduce their energy bills. Evaluation of a plant's energy consumption can be accomplished with the assistance of a variety of tools developed to promote energy efficiency within the industrial sector. The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) Industrial Technologies Program (ITP) BestPractices portfolio offers a suite of free software tools and services that are available to help metalcasters assess their energy-consuming systems and operations. Additionally, outside evaluators can be brought in for energy assessments with free-of-charge DOE BestPractices industrial assessment teams. Increasing the energy efficiency of the metalcasting industry is a long-term challenge, but with the tools and resources of BestPractices, metalcasters can start saving today.

Boost Process Heating Efficiency

Melting operations and heat treatment in the metalcasting industry account for 55% and 6% of total process energy costs, respectively. Thermal efficiencies of melting operations within this industry vary from 7-76%. Table 1 compares the efficiency and melt loss for different types of furnaces employed by the metalcasting industry. The wide range of thermal efficiencies and high energy costs indicate that metalcasters can realize significant energy and cost savings through modest improvements in their furnace operations.

The Process Heating Assessment and Survey Tool (PHAST) (Fig. 1) surveys melting, holding and heat treating furnaces and produces a report that identifies the best ways to increase the energy efficiency of specific equipment and the entire process heating system. Metalcasters can test equipment performance under varying operating conditions and "what-if" scenarios by inputting operational data into the application--without affecting production.

[FIGURE 1 OMITTED]

The PHAST application offers three benefits:

* Improvements Focused on Energy-Intensive Equipment--Using facility-specific heat input and furnace operating data, the application reports the quantity of fuel and electricity each piece of equipment uses annually, as well as estimated annual energy costs;

* Calculation of Potential Energy Sayings--Utilizing your input parameters, the calculation tools assess energy-saving opportunities by comparing the performance of individual pieces of equipment under different operating conditions and with a variety of retrofit technologies;

* Identification o f Energy Waste--Evaluating all areas in which energy is used, lost or wasted, the application constructs a detailed heat balance report for process heating equipment.

A PHAST assessment at the Alcoa North American Extrusions facility in Plant City, Fla., revealed that recovery of waste heat from the flue gases in two melting furnaces offered potential annual savings of more than $300,000, with a payback period of six to 24 months.

Improve Compressed Air System Performance

Typical metalcasting operations commonly use large quantities of compressed air for air-powered tools, blowing resin-coated sand into coreboxes, blowing green sand into the copes and drags, pneumatically transporting sand, and operating pneumatic cylinders and molding machines. Analyzing and maintaining operating conditions in which water condensation cannot occur within the lines is often necessary in order to prevent chemical reactions between the resin and the moisture in the sand/air.

As part of the 2003 study, Energy Use in Selected Metalcasting Facilities, Eppich Technologies conducted assessments at 15 typical metalcasting facilities that were selected by American Foundry Society (AFS), the North American Die Casting Association (NADCA) and the Steel Founders Society of America (SFSA). At the completion of this study, Eppich Technologies made the general observation that most compressed air system installations were the result of unexpected needs due to progressive plant renovations. Therefore, the systems were often mis-engineered and saturated with water, exhibiting numerous leaks and misapplied air in various situations. Air driers typically were selected based on cost and did not operate efficiently.

By optimizing the configuration of a com pressed air system, metalcasters can reduce their energy costs. AIRMaster+, another free software tool offered by the DOE, can help metalcasters identify energy saving opportunities in the compressed air systems throughout their facilities (Fig. 2). Using plant-specific data, the tool assesses the compressed air systems and evaluates operational costs for various equipment configurations and system profiles. It estimates savings based on potential energy efficiency improvements and calculates the associated payback periods.

[FIGURE 2 OMITTED]

The tool evaluates the energy savings potential of any or all of the following actions:

* reduction of air leaks;

* end-use efficiency improvements;

* reduction of system air pressure;

* use of unloading controls;

* adjustment of cascading set points;

* use of automatic sequencer;

* reduction of run time;

* addition of primary receiver volume.

In 2002, Techni-Cast, a metalcasting facility based in Southgate, Calif., specializing in centrifugal casting, implemented the AIRMaster+ tool on its compressed air systems. The facility was served by two rotary screw compressors--one 100-horsepower (hp) unit and one 50-hp unit. Based on the results from the analysis, the facility replaced the 100-hp compressor with a new 50-hp compressor, upgraded the compressor controls to increase the system's efficiency, and utilized the old 50-hp unit as a backup. Implementing the recommendations allowed the facility to reduce its compressor capacity by 50%, resulting in annual compressed air energy savings of 242,000 kWh and annual maintenance cost savings of $24,200. The implementation required an investment of $38,000; however, the plant received a $10,000 incentive payment from the California Public Utilities Commission, and the total cost was reduced to $28,000, yielding a 14-month payback period.

Improve Motor System Efficiency

Motor-driven equipment plays an essential role in the metalcasting industry. Electric motors in the U.S. industrial sector account for 64% of the total industrial electricity use. Making sound decisions about repairing or replacing motors requires a thorough knowledge of efficiencies, maintenance histories and costs.

DOE's free MotorMaster+ software tool analyzes motor and motor system efficiency to simplify the repair/replace decision-making process (Fig. 3). The tool can help a metalcasting facility identify inefficient or oversized facility motors and compute the energy savings associated with their replacement by more energy-efficient models to assist in the decision-making process. In addition to facilitating repair and purchase decisions, the tool offers inventory management, maintenance logging, lifecycle costing, conservation analysis, savings evaluation, energy accounting and

[FIGURE 3 OMITTED]

Finding Help Online

The first step to taking advantage of the no-cost opportunities to reduce your plant's energy bills starts with a click. Visit the following websites for more information or to download the software tools: environmental reporting capabilities. These features can help metalcasters comprehensively manage their electric motor systems.

A large industrial motor repair shop reports using the tool to assist customers in making sound motor purchases and replacement decisions. One of these applications at a large facility in Indiana led to the replacement of 125 motors with premium efficiency motors, resulting in a cost savings of $80,000 per year. The tool also specified premium efficiency motors on new OEM equipment at the facility, yielding another $128,000 in annual savings.

The Ellensburg Wastewater Treatment Plant in Washington State had to decide whether to replace or rewind two 50-hp aerator motors. The application not only determined that it would be more cost-effective to purchase new motors than to rewind the existing motors, but it also compared the cost-effectiveness and simple payback periods of various new 50-hp motors to help justify the purchase of new standard efficiency units.

Industrial Assessment Centers

Industrial Assessment Centers, or IACs, are a resource provided by the DOE that offer free technical assistance to metalcasters. To date, the IACs have performed more than 300 assessments at metalcasting and diecasting facilities across the country. The assessments are performed by a team of engineering faculty and students from one of more than 26 participating universities. These university-based teams conduct a one-day site visit to perform an assessment at the participating plant. Students are equipped with data loggers in order to analyze the entire plant's operation, including the compressed air systems, furnaces, molten metal handling, lighting, etc.

Once the assessment is completed, the IAC will provide a detailed report of the analysis, findings and recommendations to the plant within 60 days. On average, recommended actions by the IAC result in an annual savings pf $55,000 per plant. Table 2 provides a list of the most common recommendations by the IACs, their average implementation costs, and their resultant annual savings for metalcasting operations.

Plants that may be eligible for an IAC assessment include small- to

medium-sized manufacturing plants in Standard Industrial Classification (SIC) Codes 20-39. The plant should be located within 150 miles of an IAC participating university and meet the following criteria:

* gross annual sales below $100 million;

* fewer than 500 employees at the site;

* annual utility bill of more than $100,000 and less than $2 million;

* no in-house professional staff to perform such an assessment.

Save Energy Now

Save Energy Now is an initiative that is part of a national campaign, "Easy Ways to Save Energy," announced by the U.S. Secretary of Energy in 2005. The campaign aims to assist U.S. industrial and government entities in reducing energy use, support national goals for energy security, and educate the public about simple but effective energy choices. Save Energy Now is helping industrial plants find effective ways to reduce energy use in steam and process heating systems so they can operate more efficiently and profitably. This initiative also is addressing energy saving opportunities for compressed air, fan, motor and pumping systems.

Save Energy Now efforts are available to companies, states, utilities and other industry groups. One service available to U.S. metalcasters provides energy savings assessments performed by teams of professional energy efficiency experts for the nation's large, energy-intensive plants. These large energy users will be determined through a competitive solicitation process.

The initiative also will make available phone consultations and technical assistance provided by experts at the Energy Efficiency and Renewable Energy Information Center. Training, webcast events and workshops regarding the use of BestPractices software analysis tools and ways to improve energy efficiency and productivity throughout the plant also will be provided.

Finally, the initiative provides manufacturers free access to its extensive portfolio of helpful information including tip sheets, case studies, and handbooks.

Process Heating Assessment and Survey Tool (PHAST)

http://eereweb.ee.doe.gov/industry/bestpractices/software.html#phast

AIR Master+

http://eereweb.ee.doe.gov/industry/bestpractices/software.html#air

MotorMaster+

http://eereweb.ee.doe.gov/industry/bestpractices/software.html#mm

Industrial Assessment Centers (IAC)

http://www.eere.energy.gov/industry/bestpractice/acs.html

Save Energy Now

http://www.eere.energy.gov/industry/saveenergynow/assessments.html

Ehr Ping Huangfu is a technology manager for the U.S. Dept. of Energy. Robert Naranjo is a senior researhc analyst for BCS Inc., and Krista Bentz is a senior communications analyst for BCS Inc.

For More Information

"Surviving the Energy Crisis in Your Induction Melt Shop," M.T. Eckert, MODERN CASTING, Nov. 2001, p. 37-40.

Table 1. Efficiency and Melt Loss for Different Casting Furnaces

                                                   Thermal
Melting furnace     Common use     Melt loss      efficiency

Cupola                 Iron          3-12%          40-50%
Direct arc            Steel           5-8%          35-45%
Immersion              Zinc           N/A           63-67%
Electric             Aluminum         1-2%          59-76%
reverberatory          Zinc           2-3%          59-76%
Gas crucible         Aluminum         4-6%           7-19%
                    Magnesium         4-6%           7-19%
Gas                  Aluminum         3-5%          30-45%
reverberatory          Zinc           4-7%          32-40%
Gas stack melter     Aluminum         1-2%          40-45%
                     Aluminum      0.75-1.25%       59-76%
                   Copper-base        2-3%          50-70%
Induction           Magnesium         2-3%          59-76%
                       Iron           1-2%          50-70%
                      Steel           2-3%          50-70%

Table 2. List of Top Ten Recommendations for Metalcasters

                                                  Average       Average
                                               implementation   annual
Recommendation                                      cost        savings

Utilize energy-efficient belts and other
  improved mechanisms                              1,263         2,169
Utilize higher efficiency lamps and/or
  ballasts                                         4,080         1,758
Install compressor air intakes in coolest
  locations                                        1,653         5,538
Insulate bare equipment                             574          2,259
Reduce the pressure of compressed air to
  the minimum requirement                          1,148         5,423
Use of waste heat from hot flue gases to
  preheat combustion air                          213,731       145,876
Use most efficient type of electric motors         12,725        5,727
Replace electric motor with fossil fuel
  engine                                            436          8,765
Use multiple speed motors or AFD for
  variable pump, blower and compressor loads      103,018       57,061
Analyze flue gas for proper air/fuel ratio          720         54,517