To maintain 350 F on your machine surfaces, steam is supplied to the machine at 175 psig and a temperature of 377 F. As heat transfer occurs to the board passing through the machine, the steam is cooled back to condensate at about 330 F. If this condensate is allowed to vent to atmosphere, it flashes off into very low pressure steam then escapes through your roof vents. This flashing process is a loss of 17% of your total steam flow to the machine.

Over the past 50 years systems have been designed by Armstrong, Donahue, Stickle, and other companies to capture this waste heat. Systems are still offered by these companies but can be expensive to purchase and install. Many of the older systems can be quite complicated to understand, trouble shoot and maintain. Virtually all corrugating plants built since the 1950s include some sort of waste heat recovery system which in many plants is either not operating properly if in fact at all.

We can take your current ailing condensate recovery system and provide options to repair the system instead of your spending the money for a new system. The savings can be significant and the reduction in your fuel bill will pay for equipment very quickly.

You can determine the health of your current steam system with a few simple observations. Is a cold machine costing your production speed and quality? Are you venting large clouds of steam? Do you have large amounts of water around the vent locations? If you have answered yes-continue reading.

As you are aware, natural gas prices have risen dramatically. A combination of supply and demand, environmental issues, and world events can virtually promise that the long term outlook for natural gas prices is current or higher costs. Each extra fuel dollar spent is one less dollar on your bottom line.

Three issues can dramatically reduce fuel consumption, increase machine speeds and improve product quality. Taken from least to most expensive in terms of capital costs:

1. Steam Traps-If your steam traps are old or not the best design choice for a corrugating machine, you are wasting 10% in fuel and 10% in machine speed. Upgrading steam traps is fruit on the ground.
When steam enters your corrugating machine at 175 psig and 377 F it contains 849 BTUs of energy bond the board. Once this energy is used, condensate (water) remains at a temperature close to 377 F. A steam trap is used to discharge the condensate and prevent the loss of live steam.

Steam systems can either be cascade or direct. A cascade system has vertical flash tanks located at each section of the machines and a large single bucket trap to drain the machine. This type of design can be much improved by going to a direct system which has a steam trap on each machine heat transfer area.

Older steam systems use bucket traps which at the time of design were the best choice for corrugating machines. Bucket traps are reliable, provide good service, handle dirt and are inexpensive to repair.

A compete replacement of steam traps on a machine will typically cost $ 6000 - $ 10,000 depending on machine age and system design. Reductions in your fuel bill will pay for the traps in 3-5 months.

2. Waste Heat Recovery-If you are venting steam and water, a current water heat recovery system will pay for itself in 6-8 months.

Of all the number of systems designed to recover vent steam, we have had excellent results with two types; high pressure receiver systems and brazed stainless steel heat exchangers.

Heat Exchanger Systems
Condensate from the machine is returned at a temperature of 340 F using a back pressure control valve. The condensate return is passed through three high efficiency heat exchangers before going to the deaerator. Feed water from the deaerator is pumped through the opposite side of the heat exchangers and remove the heat from the condensate and directs it into the boiler feedwater. With a boiler being fed 340 F water, fuel consumption is dramatically reduced. Pneumatic feedwater controls on the boiler provide for precise level control in the boiler. A complete heat exchanger package with all controls can be fitted to your deaerator or feedwater heater with hardware costs of about $ 60,000. Installation can be done in a weekend. The system is easy to install, understand and maintain. Reductions in your fuel bill will pay for this system in 6 months or less.

High Pressure Receiver Systems
Condensate from the machine is retuned to a 400 gallon receiver tank rated at 200 psig. A capacitance level control on the boiler is connected to a variable frequency drive pump which feeds the boiler the exact amount of feedwater required by varying the pump speed. The system can also be supplied with constant speed pumps and pneumatic boiler water level controls. A back pressure control valve is used to maintain temperatures on the condensate return into the low 300 F range which insures significant reductions on boiler firing rates due to the high feedwater temperatures. Provision through a control valve is made to use excess vent steam to heat deaerator feedwater. Hardware cost for this type of system is about $ 100,000 and installation can be done in a weekend. Reductions in your fuel bill will pay for this system in 6-8 months.

3. Boilers-If you are operating 25+ year old boilers; improvements in boiler design have allowed for fuel reductions in the area of 15% or more. New PLC based combustion control systems using servo motors for fuel and air controls can improve boiler efficiency by 4-6%. Give us a call to look at the most cost effective options to reduce your energy costs, reduce scrap and improve machine speeds.