Energy Saving Ideas?

[Big Country 3]

I have been assigned to find some cost saving ideas, I currently work for a welding company that makes various types of seat tracks and frames. We have alot of resistance welding and mig welding so our electric bill is a bit on the high side. We also paint these parts through an automated paintline which uses alot of natural gas. I guess what I was wondering is there any things that you all have ran into that would stand out and make a difference quickly.

[burnerman 4]

Paint drying ovens: Reduce heat losses a. through the walls - can you improve the insulation? If you can't put your hand on the outer skin of the oven you're losing too much heat. b. through openings - have you got adequate door seals / air curtains? If you can feel a blast of hot air out of the door then you're losing heat. If you blow smoke near the door and it's sucked straight in then the burner's heating up all that air that the oven's sucking in and then just throwing it up the chimney. Are your burners set up correctly, do you have them maintained regularly? Do you turn the burner(s) off when there's no product going through the oven?

[jstolaruk 9]

We put "energy saving shut down" timers in our machinery that turns off all motors, blowers, exhaust, heaters, etc. if the line is blocked, starved, or just hasn't run a cycle in any period that is longer than a employees break/lunch.

[waynes 8]

Except for the operational savings, have you tried power factor correction on your feeders/ incomers? Do you currently monitor and log the usage of the plant's power.You will have to start with this so that you can study the peak power usage during shifts. At least this way you can see if you are really saving. I have seen this implemented at big body shop that also do a lot of welding (spot welding) and it saves the company quite a bit. They also have their own on site transformers. This allows them to use 11kV incoming and reduce it to whatever they need (typically 380VAC). Another way to save, is to automatically control (switch on/ off) all (major) lights and fans in the factory during tea/ lunch time. A few lights will still be on during the tea/ lunch break, but only those required to see where you are walking. Natural light can also assist in lighting up the 'darker' areas by replacing metal sheeting with fibre/ glass.

[BobLfoot 301]

How much Hot Water are you using? This may not sound like much but it was for us. We added a methane generator to our WWTP and used the methane to pre-heat all our Hot water. System ahs paid for itself and then some.

[Big Country 3]

All of this is great information I have checked on doing some of the suggested items and have already done some of them such as the lighting control panel. The insulation is something that really stood out to me I don't think we have looked at that yet. Thank all of you for your replies, Please keep them coming and maybe all of us can use them. I will post some of the things that we have done around here later I don't have much time right now.

[TERdON 9]

Pumping systems and ventilation systems may be oversized. Using a frequency inverter to lower the rpm of the pump/fan may save quite a lot money. Especielly if you have to run it even at night-time, but on a lower rpm.

[jstolaruk 9]

Good point! I'd forgotten that. Recently we did a study for a customer that showed that an investment in VFD's for the 250hp motors we supplied on previous machines would save enough energy to pay for themselves in two years. Run them at a lower speed and it would still satisfy their process requirements.

[TimWilborne 108]

With that your power is definately going to be lagging. Get with your power company and see if they will check out your capacitor banks. Chances are they will do it for free and this can have a tremendous savings on your electric bill.

[TERdON 9]

My company once even calculated the payback time for frequency-controlling a big ventilation fan to just half a year. They still didn't buy the stuff...

[BobLfoot 301]

1. You have to Spend Money to Save Money. 2. You have to have money to spend it. Many companies don't feel they have the extra money to spend, even if in the long haul they save money. After all we have become a society of instant gratification.

[Big Country 3]

I have tried to get approval for a power factor but the RECC here doesn't charge us for demand. But I thought that some capacitors would help us also. I agree that they want to see instant savings from an investment or change that you do. We have installed timers on all of our equipment to shut the smoke collectors after a set amount of inactivity. I also have built a lighting control panel and installed many of those motion detector to replace light switches that are left on often such as bath rooms and confrence rooms.

[GerryM 2]

So will the lights go out when you're takin' a dump??? At my plant they added a VFD to our air compressor. It paid for itself within a year. The manufacturer or dealer, I'm not sure which, supplied it as an option. Edited 27 Sep 2006 by GerryM

[Big Country 3]

I researched the VFD for our compressor but the ones that we have won't except a VFD.

[robh 12]

Why is that?

[fluidpower1 0]

Mount the Directional Control Valves on all air powered actuators directly to the actuator. Any length of line between the valve and the actuator port is being filled and exhausted each cycle without doing any work. The bigger the line the greater the energy waste. The best approach is a port mounted valve on each actuator port so a minimum amount of air is wasted each cycle. Any hydraulic circuit with a HEAT EXCHANGER is an energy waster. You are not only paying for extra energy to heat the oil but paying for some method to cool it. You can see an article I wrote many years back on my web site. It explains all the ways to design a circuit to reduce energy and heat. www.fluidpower1.us

[Snerkel 0]

One of the reasons these sort of things don't always get taken up is the different way they are assesed for tax purposes, though I think this may be changing. Fuel costs are taken in full from the annual profit. Assets are usually depreciated over a number of years, so only a percentage of the cost is set against profit each year, thus it takes a number of years for the bean counters to actually see the saving.

[Big Country 3]

I'm not for sure I asked Atlas Copco and they said that the motor would not except a VFD, my experience with VFD is very limited. What do you think are they just telling me that so I will buy or upgrade my compressor.

[robh 12]

I wonder if they meant that the compressor would not work with changing RPMs? I have been told that some older compressors will not work so well with changing RPMs. We did a plant air demand study, found out how much air we needed and put in a new compressor that has a freq drive on it. I believe that the reason we went this way was because the power company and the government gave us a sizable rebate the helped cover the cost. Plus our old Joy compressor had 250,000+ hours on it. Might be something to look into. Edited 3 Oct 2006 by robh

[GerryM 2]

Same with my company, we bought a new compressor and the VFD was added immediately after, within a month or two. The old compressor is now a backup. I don't know the details beyond that, it was someone else's project. Edited 3 Oct 2006 by GerryM