Efficient kiln seals – a strategic component for kiln optimization:Yoann Picard, Iteca Socadei SAS (France)
Filmed at Cemtech MEA 2015, 8-11 February, Grand Hyatt Dubai, UAE
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The kiln seals of course are now a big component of your plant so that's the biggest one. But I will try to show you, if you increase the efficiency of your kiln seals, how you can save energy. I will give you figures, I will give you some case study to know how you can optimize your energy consumption only by increasing of kiln seal efficiency.
So the problem of kiln seals, the problems, is in the inlet and the outlet, is you have cold air, you have false air entering into your kiln. So this cold air, you have to use, you're losing some kilo-calories, you're using your burner only to compensate the problem of this false air. So you are losing a lot of energy. Some plants they know approximately how much we are losing,
some plants we have no idea how much we are losing. If we list all the problem, it's not only energy savings, the main problem of inefficient kiln seals is the fuel consumption of course because of the false air. You have also production capacity decrease because if you burn your fuel to compensate the false air, you don't burn your fuel to produce kiln air. I will show you some figures.
You have also to think about the ID fan electricity consumption. If you have false air, your sucking false air with ID fan, with no force air your ID fan can be used only for the process, not sucking false air. If you have dust ceiling, you will also have a escape of dust maybe if you have positive pressure into the kiln, you can have also hot material escaping from the ceiling, so you will have damage on every mechanical component in the area, fans, belt, motors, something like that.
So you have also maintenance cost, difficult to estimate which you have to take account about it. Also important, it is unstable pressure into the kin. If you have false air, you cannot control as best as possible the pressure into your kiln, so with a perfect sealing you have stable pressure into the kiln, your operator will manage your kiln better.
And also just environmental concern because in some plants, even in UAE, we have one of two plants in UAE where if you're near cities, if you're in the middle of cities, you can have if you have escape of the dust from the sealing, it can be a problem. So you have also environmental concern with the sealing not only the tower, not only the filter you have also dust escaping from this side.
Some examples, the most common seals we can see is piston, spring, lamellas, we have all kinds of systems but mainly lamellas and piston. So you can see here are some typical example is the piston seal, you have the gap, here you have the red light inside, so it's very little gap, 1 cm may be 2 cm but I will show you with estimation, calculation with even 1 cm, it's a big loss of energy, okay.
Lamellas also, you know that lamellas, it's not so bad sealing at the beginning when it's new but you have to do a lot of maintenance. If you shut down, you have to replace some lamellas, you have to put cables to keep in pressure into the kin, it's not really good solution. Another example, here you have kiln with positive pressure, you have dust escaping, it's a problem for the surrounding area, you have no system to [xx] the dust and here even hot materials escaping, may be you have a ring which is the kiln.
So even for safety, it's not a good solution for you people walking around, it's hot material maybe 700 degrees, very dangerous, okay. I will not explain you all the mathematical formulas, we are not here for that. It's just to show you you can easily in your plants, estimate, you can estimate the air flow entering into the kiln, you just observe how much leakage you have 1cm, 2cm, 3cm, average leakage. You can estimate air flow and with some values of temperature and pressure, outside and inside, you can estimate the kilo calories you are using to compensate the problem of false air.
And if you know the cost of your energy, you can estimate how much money you're losing everyday, every week, every month, every year, only because of the false flow problem. I did the calculation for you in average case,
So the problem of kiln seals, the problems, is in the inlet and the outlet, is you have cold air, you have false air entering into your kiln. So this cold air, you have to use, you're losing some kilo-calories, you're using your burner only to compensate the problem of this false air. So you are losing a lot of energy. Some plants they know approximately how much we are losing,
some plants we have no idea how much we are losing. If we list all the problem, it's not only energy savings, the main problem of inefficient kiln seals is the fuel consumption of course because of the false air. You have also production capacity decrease because if you burn your fuel to compensate the false air, you don't burn your fuel to produce kiln air. I will show you some figures.
You have also to think about the ID fan electricity consumption. If you have false air, your sucking false air with ID fan, with no force air your ID fan can be used only for the process, not sucking false air. If you have dust ceiling, you will also have a escape of dust maybe if you have positive pressure into the kiln, you can have also hot material escaping from the ceiling, so you will have damage on every mechanical component in the area, fans, belt, motors, something like that.
So you have also maintenance cost, difficult to estimate which you have to take account about it. Also important, it is unstable pressure into the kin. If you have false air, you cannot control as best as possible the pressure into your kiln, so with a perfect sealing you have stable pressure into the kiln, your operator will manage your kiln better.
And also just environmental concern because in some plants, even in UAE, we have one of two plants in UAE where if you're near cities, if you're in the middle of cities, you can have if you have escape of the dust from the sealing, it can be a problem. So you have also environmental concern with the sealing not only the tower, not only the filter you have also dust escaping from this side.
Some examples, the most common seals we can see is piston, spring, lamellas, we have all kinds of systems but mainly lamellas and piston. So you can see here are some typical example is the piston seal, you have the gap, here you have the red light inside, so it's very little gap, 1 cm may be 2 cm but I will show you with estimation, calculation with even 1 cm, it's a big loss of energy, okay.
Lamellas also, you know that lamellas, it's not so bad sealing at the beginning when it's new but you have to do a lot of maintenance. If you shut down, you have to replace some lamellas, you have to put cables to keep in pressure into the kin, it's not really good solution. Another example, here you have kiln with positive pressure, you have dust escaping, it's a problem for the surrounding area, you have no system to [xx] the dust and here even hot materials escaping, may be you have a ring which is the kiln.
So even for safety, it's not a good solution for you people walking around, it's hot material maybe 700 degrees, very dangerous, okay. I will not explain you all the mathematical formulas, we are not here for that. It's just to show you you can easily in your plants, estimate, you can estimate the air flow entering into the kiln, you just observe how much leakage you have 1cm, 2cm, 3cm, average leakage. You can estimate air flow and with some values of temperature and pressure, outside and inside, you can estimate the kilo calories you are using to compensate the problem of false air.
And if you know the cost of your energy, you can estimate how much money you're losing everyday, every week, every month, every year, only because of the false flow problem. I did the calculation for you in average case,
