Resources
November 5, 2018

Steam Overview and Why We Use Steam in Industrial Process Applications

STEAM OVERVIEW AND WHY WE USE STEAM IN INDUSTRIAL PLANT OPERATIONS

STEAM SYSTEM OPTIMIZATION AND STEAM SYSTEM ENGINEERING

My name is Kelly Paffel, I’m with Inveno Engineering. I’m the Technical Manager. We are a domestic and international engineering firm, specifically working in steam systems. Today, I kind of want to talk about steam system optimization. One is just a steam overview and the second question, why use steam? Our company has been very fortunate. We’ve traveled the world. We’ve been throughout North America and South America and Asia and Australia and parts of Africa and the thing about is steam is used throughout the world. We’ve seen things that are done very well in the steam system, things that are not done so well in the steam system and I’ll kind of talk about that today.

Why use steam in today’s plant operation? Benefits. High usable heat content. Steam contains a tremendous amount of energy. Constant temperature, which is really, really good because 100 PSI is 303 degree Fahrenheit. 150 PSI is 366 degrees Fahrenheit. So, the thing is when it comes to heat transfer, the constant temperature throughout the heat transfer is a big plus. Produced from water, I don’t need a chemical plant to produce a chemical to be used to make steam. And the other thing is I can use it over and over again. It’s clean, odorless and tasteless. It generates power or be used as a prime mover. So, the thing about steam is I can do it as a prime mover, get the mechanical energy from the steam and then send the steam out and have the thermal energy consumed. Easy distributed control, it’s easy to control steam.

The negatives about steam. Everything has pluses and everything has negatives and the negatives of steam, the biggest negative, is water hammer, premature failure and safety issue. And we’ve done several videos of which are at our website regarding water hammer. Freezes. People say, “Steam coils freeze.” Incorrect. People freeze steam coils. Erodes. We buy valves that are already leaking through and then they just wire draw even more and there’s more significant leakage. Phalanges leaking. The thing with phalanges today you need to know are the torque spec and the torque pattern. Cavitation, pump failure, loss of condensate. The thing with condensate is you have to have 18 inches of NPSH, net positive suction head, even at 212 degrees or 100 degrees [inaudible 00:02:50] condensate. So, remember, NPSH when you’re selecting a condensate pump system.

Safety code violations. Today’s industrial top five items. Safety’s always number one. Reliability’s number two. Optimization’s number three. Energy’s number four. Emissions is number five. Those are our focuses today in the steam system. Steam system safety. Understand the codes, B31.1, B31.3, the pressure vessel codes and the boiler codes. Example, heat exchanger, ASME plate reads, 150 PSI at 338 degrees Fahrenheit. Is this unit able to operate in the 100 PSI steam system? No. 150 PSI is 366 degrees Fahrenheit, not 338. So, the vessel has to be rated for the pressure and its correct temperature for the operation. A valve is rated for 700 PSIG. Can I use the valve in a 125 PSI steam system? No. 700 PSIG is normally CWP, cold working pressure. Any valve that I put in a steam system I must know the pressure and the temperature. Pressure and the temperature.

Reliability. Today, it’s very important. When purchasing a product, boiler valve, a heat exchanger, how long do you want the component to last? One year? Three years? Five, 15 or 30? So, when we make a selection, we’re always looking at the reliability. One year is going to be more cost effective than 15 years. So, the thing is, is that when we go to purchase a product, we want longevity and we’re willing to pay for it because 15 years we know it’s going to cost more than a product that’s only going to last one year. But evaluating products today, you must know the longevity of that product. 250 PSI steam pressures or less, all products and components need to operate and perform for 15 years without failure. We do not accept failure today. Today’s steam operations, we cannot afford to have premature failures. We don’t have the manpower or the money to take care of premature failures, so we want the reliability.

Optimization. What’s more efficient, a fire tube or water tube boiler? And I get this question all the time. I have said, “Geez, I have somewhat of a sports car. When I drive that sports car I get about 26 miles to the gallon. I have two sons. When they drive that sports car, they get about 10 miles to the gallon. Same sports car.” The thing about it is, is how you drive your steam system is how efficient it’s going to be. So, how you manage your steam system is how efficient your steam system’s going to be. The efficiency today, boiler efficiency, steam venting, steam leakage, insulation, condensate recovery. How efficient is your boiler? Efficiency is PTC 4.1. Efficiency’s not some ticker tape off of a combustion analyzer. Venting steam. We did that, stopped that about 10 years ago. We don’t vent steam in the atmosphere any more. Steam leakage. Maximum number of leaks per year in your facility, maybe three, max and your benchmark for condensate recovery, 90% today.

To achieve optimization in the steam system, change must occur. Results does not equal no results plus a good story. Without change, no improvements can be achieved or are achieved. Today, this is as it says here, venting steam to atmosphere. We don’t vent steam to atmosphere any more. All that does is heat up the ducts [inaudible 00:07:20]. As you can see here, the duct is [inaudible 00:07:27]. Things change just like in our first [inaudible 00:07:31]. We have cell phones that are more powerful today. In the steam system, we have products that last very long periods of time. Steam is used in all types of industries, as you can see here by the pictures here. Steam distribution systems. There are steam distribution systems throughout the world. The largest steam grid in the world is New York City. There’s 1800 some buildings on that grid. Electric generation. Steam is still the motivator for the steam turbines.

Rubber products to make tires, you have to have steam. Pulp and paper production. Over 70% of the utility cost is for steam to make paper. Food processing, we use that to deodorize cocoa butter, to puff your cereal up, to sanitize your yogurt cups. We use steam for everything. In pharmaceutical, we use clean steam, a very specific steam. And, of course, fuel production and chemical products. Steam system efficiency. In order to improve efficiency, reliability, reduce down time, increase production and, of course, reduce energy, it’s necessary to evaluate and understand each component of the steam system. What we do not want to do is componentize and what we mean by componentize is looking at one specific component in the steam system. So, out here, we’d go make the heat exchanger [inaudible 00:09:09] the frame more efficient.

But maybe our biggest losses are right here off the boiler. Remember, when we start the boiler up, that the average is going to be 20% percent loss of energy. So, the thing is, is we want to make sure the boiler’s as efficient as possible, but the other big loss is condensate recovery and we’ve got to bring the condensate back to the system. So, don’t componentize, look at it as a system. Thank you for your time today and as you can see here, this is our information. We are your partner. So, if there’s any question or whatever please contact us. Have a great day.