Heating a Wire

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Science 09 Nov '15 21:25
  1. Subscribersonhouse
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    13 Nov '15 19:371 edit
    Originally posted by joe shmo
    There is no special atmosphere other than a hot one. Iv'e been told that electromagnetic induction heating is expensive, but its not out of the realm of possibilities yet.
    Is this heating for the purpose of drawing to smaller diameter through die's? I assume there is some kind of production going on here.

    I'm thinking it would be pretty inefficient to just run the wire through a pipe with atmosphere pressure and the air is what is the heat transport mechanism.

    I would think it a lot more efficient to directly heat the wire with electricity or RF induction. RF has the advantage of not touching the wire and current has the advantage of being simple, like a couple of metal wheels with each wheel being one polarity and the other the opposite and current flows between the space between but only in the wire. That goes inside out as far as heating goes, much less heat loss to pipes and air.
  2. R
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    14 Nov '15 18:22
    Originally posted by sonhouse
    Is this heating for the purpose of drawing to smaller diameter through die's? I assume there is some kind of production going on here.

    I'm thinking it would be pretty inefficient to just run the wire through a pipe with atmosphere pressure and the air is what is the heat transport mechanism.

    I would think it a lot more efficient to directly heat the w ...[text shortened]... in the wire. That goes inside out as far as heating goes, much less heat loss to pipes and air.
    Is this heating for the purpose of drawing to smaller diameter through die's? I assume there is some kind of production going on here.


    Its for a hot dip aluminium plating line. A liquid flux is applied to the wire pre-entering the molten aluminum. If the flux is not dried before it enters, it contaminates the aluminum. Contaminated aluminum must eventually be discarded (time depends on carry over rates), increasing operating costs. Also, coating efficiencies are a function of these pre-heat temperatures, so it would be desirable to optimize with regards to this point as well.

    I'm thinking it would be pretty inefficient to just run the wire through a pipe with atmosphere pressure and the air is what is the heat transport mechanism.


    Radiation from the heating element is the primary mode of heat transfer to the wire, not convection. Anyhow, I'm sure it is rather inefficient compared to directly heating the wire, and the wire only with induction heating. The question is 'what is the payback?' I've heard pretty high prices for induction heating in this type of application, the payback for an economical system may render it un-viable from a business/financial standpoint. Besides, everything we need is practically in place already, its mostly a matter of applying more power (natural gas heating is fairly cheap).
  3. Standard memberDeepThought
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    15 Nov '15 00:57
    Originally posted by joe shmo
    Is this heating for the purpose of drawing to smaller diameter through die's? I assume there is some kind of production going on here.


    Its for a hot dip aluminium plating line. A liquid flux is applied to the wire pre-entering the molten aluminum. If the flux is not dried before it enters, it contaminates the aluminum. Contaminated alumi ...[text shortened]... place already, its mostly a matter of applying more power (natural gas heating is fairly cheap).
    To be honest I think that you need a hack's calculation and some experiments. The hack calculation is to get an idea - forget about complexity just clump geometric factors into overall (emprical) factors, and do as simple calculation as you can. The heater is not a perfect black body, the wire won't absorb all the radiation - blah blah blah. You'll find you have to adjust all your constants to fit experiments anyway, so you just need to determine what you can say theoretically and what you need a little empiricism for.
  4. Subscribersonhouse
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    15 Nov '15 22:11
    Originally posted by joe shmo
    Is this heating for the purpose of drawing to smaller diameter through die's? I assume there is some kind of production going on here.


    Its for a hot dip aluminium plating line. A liquid flux is applied to the wire pre-entering the molten aluminum. If the flux is not dried before it enters, it contaminates the aluminum. Contaminated alumi ...[text shortened]... place already, its mostly a matter of applying more power (natural gas heating is fairly cheap).
    What about using an inert gas in the pipe, maybe eliminate the need for flux? What is the original wire made of? What is the purpose for coating the wire with aluminum anyway?
  5. R
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    16 Nov '15 00:37
    Originally posted by sonhouse
    What about using an inert gas in the pipe, maybe eliminate the need for flux? What is the original wire made of? What is the purpose for coating the wire with aluminum anyway?
    There is no "pipe"... The flux is there to wick the molten aluminum around the steel wire. The same process is used when you solder a copper pipe at your home. It has many applications, a main one is chain link fence, but there are many others. Basically, any type of corrosion resistant application for steel wire would either be aluminized or electro-galvanized.
  6. R
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    16 Nov '15 02:022 edits
    Originally posted by DeepThought
    To be honest I think that you need a hack's calculation and some experiments. The hack calculation is to get an idea - forget about complexity just clump geometric factors into overall (emprical) factors, and do as simple calculation as you can. The heater is not a perfect black body, the wire won't absorb all the radiation - blah blah blah. You'll fi ...[text shortened]... just need to determine what you can say theoretically and what you need a little empiricism for.
    Yeah, that's pretty much where I'm at this point as well, simplification.

    (p*Ac*v*C)*dT = α*(σ * T_s^4) * dA - (σ * ε * T^4) * dA

    α = 0.60 ( 60% absorption from the "blackbody" source, hoping to be sand bagging a bit)
    ε = 0.80 ( emissivity of the steel @ 1000K ~ 0.40, again sand bagging)

    I just numerically integrate this equation for a set of parameters, varying Ts until the desired temp is reached in the wire in the prescribed length I have to achieve it.

    Also, ignore the view factor stuff, and assume that the radiation flux over the wire is constant. The next part is somewhat cloudy to me.

    I have the Temp "Ts" of the "black body" from the solution. So I surmise the flux that has to be provided by the heater over the entire length of the chamber is:

    q"_heater = σ * T_s^4 (Power per unit Area)

    The thing is that heaters aren't sized this way, they seem to be sized by a power input, not a heat flux intensity so this part has me a little confused, actually a lot confused.

    To me, the flux is what seems tantamount to solving this problem, and the overall power output is not. That is to say,... the best I can seem to do is specify a heater with a power output per unit length with this result. I'm hoping this next bit properly addresses this issue?

    Now, lets say that the actual power "q_in" needed comes from a steady state energy rate balance of the actual proposed system itself with its interior walls at Ts, and it surroundings at T∞, also include the power carried out by the wires, etc... I would find the following:

    q'_heater (power per unit length)*W = Σq_out

    From which "W" ( a characteristic width) the "width" of the heater can be found from:

    W = Σq_out / q'_heater

    And Hence the total power of the heater from:

    P_in = q'_heater * W

    Since I cant select a flux intensity directly, if I select a heater that is "L" ft long, that has the power input equal to "P_in" with a safety factor ( better to be overpowered in this case since heaters can be turned 'down', but not so much 'up' ), or "N" heaters, each with 1/N*th of the power requirement and uniformly distribute them over the unit, would this theoretically get me in the ball park?
  7. Subscribersonhouse
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    18 Nov '15 13:05
    Originally posted by joe shmo
    Yeah, that's pretty much where I'm at this point as well, simplification.

    (p*Ac*v*C)*dT = α*(σ * T_s^4) * dA - (σ * ε * T^4) * dA

    α = 0.60 ( 60% absorption from the "blackbody" source, hoping to be sand bagging a bit)
    ε = 0.80 ( emissivity of the steel @ 1000K ~ 0.40, again sand bagging)

    I just numerically integrate this equation for a set of para ...[text shortened]... t and uniformly distribute them over the unit, would this theoretically get me in the ball park?
    I keep wondering what is the industrial use of a wire coated with Al? what is the diameter of the original wire and what kind of thickness are you after and does thickness matter, and if so, how do you measure the resulting layers? Calipers?
  8. R
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    19 Nov '15 00:481 edit
    Originally posted by sonhouse
    I keep wondering what is the industrial use of a wire coated with Al? what is the diameter of the original wire and what kind of thickness are you after and does thickness matter, and if so, how do you measure the resulting layers? Calipers?
    I don't really have a detailed list of specific applications for you. I'm not really part of our plating department,but I do know one thing...we sell it. Here is a link to our website ( they don't offer much info on aluminize wire either, but you can read about the mill in general if you'd like).

    http://www.johnstownwire.com/products/aluminized-wire/

    That link goes straight to aluminum coated wire, browse around for some basic history and other wire products etc...

    I think our thickness aren't much more than a few mils, but I could be wrong on that.

    To measure they mic the wire for size (diameter, pre and post dip), and do various destructive tests to insure adhesion and a strong alloy layer, coating thickness are criteria are met.
  9. Subscribersonhouse
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    22 Nov '15 12:53
    Originally posted by joe shmo
    I don't really have a detailed list of specific applications for you. I'm not really part of our plating department,but I do know one thing...we sell it. Here is a link to our website ( they don't offer much info on aluminize wire either, but you can read about the mill in general if you'd like).

    http://www.johnstownwire.com/products/aluminized-wire/

    ...[text shortened]... ctive tests to insure adhesion and a strong alloy layer, coating thickness are criteria are met.
    Did you just get a job there? I thought you had posted you were unemployed.

    Anyway, the site says they make the wire by taking a center wire, coating it with flux and dipping the wire in molten aluminum. That makes a lot more sense, especially if you want thick wire like they said, 80 mil to 220 mil thick wire with the starter wire in the center.

    You live in Pa? We are on the east side near Allentown and your company is in Johnstown, near Pittsburg, right?

    Are the questions you are relaying here part of a new way to coat wires they are starting?

    Did I tell you about our company? Gulton, we make thermal printheads, the kind that go into the gas station receipts and grocery stores and such. They only last a year or two so it is a recurring business.

    Gulton.com

    I take care of sputtering machines and design various bits of electronics. My latest project, a home brew Capacitance Manometer readout device, they are very expensive and we needed to be able to calibrate our argon gas pressure in the sputtering machines, we have 4. 3 of them by the same company, MRC/KDF and one by MatVac. Anyway, our resident Phd process engineer was wondering if 10 millitorr in machine A was the same as 10 millitorr in machine B and so forth. The gas pressure can effect the surface coatings we put on our substrates.

    So my box worked perfectly, cost about 100 bucks in parts and saved about 5,000 bucks by not having to buy the official product from MKS, who makes all kinds of vacuum related products like Mass Flow Controllers (MFC's) and Capacitance Manometers and the readout devices and much more.

    I also invented a much improved plasma igniter, the old way was to have a 5 mil tungsten wire basically clamped with just friction between two split posts about 20 mil wide, just pinch the tungsten to the posts. It works but is a pain the butt to change the wire when it breaks, which happens all the time due to needing to clean the inside of the tool, open it to atmosphere and so forth, we inevitably break the tungsten wire in that process.

    I talked our buyer into buying a 500 foot roll of tungsten wire which saves us money every time we redo the igniters. KDF charges us about 20 bucks for a two inch length of that wire and we used quite a bit of it over a year. Now we just clip off a bit we need and can use say 4 inches instead of 2, I coil the wire over a small diameter screw driver which seems to make the wire more robust.


    So my improvement was to take thin wall brass tubing, hollow, less than 1/8 inch diameter and cut it to about 1 inch lengths and screw in a tiny screw in the end and then attach that to the old wire supports and now we can just unscrew the end screw and screw down the new wire which makes that process go about ten times faster.

    It is really labor intensive to do it the old way.

    Anyway, that is the kind of thing I do here every day, some new kind of project to figure out and such.
  10. R
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    25 Nov '15 00:40
    Originally posted by sonhouse
    Did you just get a job there? I thought you had posted you were unemployed.

    Anyway, the site says they make the wire by taking a center wire, coating it with flux and dipping the wire in molten aluminum. That makes a lot more sense, especially if you want thick wire like they said, 80 mil to 220 mil thick wire with the starter wire in the center.

    You ...[text shortened]... that is the kind of thing I do here every day, some new kind of project to figure out and such.
    Did you just get a job there? I thought you had posted you were unemployed.


    This is my second time around with the company. They downsized then asked me back (with a raise) six weeks later. So for now, I'm employed with them.

    You live in Pa? We are on the east side near Allentown and your company is in Johnstown, near Pittsburg, right?


    I do live in Johnstown Pa. (~70 miles east of Pittsburgh)

    Are the questions you are relaying here part of a new way to coat wires they are starting?


    No, standard way of doing it. The motives are mainly cost reduction associated with flux drag over. It turns out there is a device submerged in the molten aluminum that needs to be changed frequently if liquid flux is drug into the molten aluminum. The aim is to decrease the frequency of the change (extend the working life of the device). Also, there are benefits to the coating weight/consistency if the wire is heated to certain temps prior to entering the molten aluminum bath.

    [qoute]Did I tell you about our company? Gulton, we make thermal printheads, the kind that go into the gas station receipts and grocery stores and such. They only last a year or two so it is a recurring business.

    Gulton.com

    I take care of sputtering machines and design various bits of electronics. My latest project, a home brew Capacitance Manometer readout device, they are very expensive and we needed to be able to calibrate our argon gas pressure in the sputtering machines, we have 4. 3 of them by the same company, MRC/KDF and one by MatVac. Anyway, our resident Phd process engineer was wondering if 10 millitorr in machine A was the same as 10 millitorr in machine B and so forth. The gas pressure can effect the surface coatings we put on our substrates.

    So my box worked perfectly, cost about 100 bucks in parts and saved about 5,000 bucks by not having to buy the official product from MKS, who makes all kinds of vacuum related products like Mass Flow Controllers (MFC's) and Capacitance Manometers and the readout devices and much more.

    I also invented a much improved plasma igniter, the old way was to have a 5 mil tungsten wire basically clamped with just friction between two split posts about 20 mil wide, just pinch the tungsten to the posts. It works but is a pain the butt to change the wire when it breaks, which happens all the time due to needing to clean the inside of the tool, open it to atmosphere and so forth, we inevitably break the tungsten wire in that process.

    I talked our buyer into buying a 500 foot roll of tungsten wire which saves us money every time we redo the igniters. KDF charges us about 20 bucks for a two inch length of that wire and we used quite a bit of it over a year. Now we just clip off a bit we need and can use say 4 inches instead of 2, I coil the wire over a small diameter screw driver which seems to make the wire more robust.


    So my improvement was to take thin wall brass tubing, hollow, less than 1/8 inch diameter and cut it to about 1 inch lengths and screw in a tiny screw in the end and then attach that to the old wire supports and now we can just unscrew the end screw and screw down the new wire which makes that process go about ten times faster.

    It is really labor intensive to do it the old way.

    Anyway, that is the kind of thing I do here every day, some new kind of project to figure out and such.[/quote]

    Yeah, sounds pretty similar to what I do. (with the exception of being high tech) Our manufacturing environment isn't all that high tech ( which has begun to change in the last 5 years), but we are making an honest effort to modernize.
  11. Subscribersonhouse
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    27 Nov '15 15:172 edits
    Originally posted by joe shmo
    Did you just get a job there? I thought you had posted you were unemployed.


    This is my second time around with the company. They downsized then asked me back (with a raise) six weeks later. So for now, I'm employed with them.

    [quote]You live in Pa? We are on the east side near Allentown and your company is in Johnstown, near Pittsbur ...[text shortened]... which has begun to change in the last 5 years), but we are making an honest effort to modernize.
    How much energy does it take to make a vat of melted aluminum? I assume it is not pure aluminum, I found out the hard way pure aluminum is worthless as a building material. I tried to make an air valve and saw this block of aluminum and just started cutting and drilling to make my little valve. Turns out pure aluminum is so soft you have to keep the assembly from squishing and bending just from the forces needed to drill and so forth. I finally finished the project and it works fine but now I know never to use pure aluminum for ANYTHING🙂

    What is the diameter of the center wire and what is is composed of?
  12. R
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    29 Nov '15 14:45
    Originally posted by sonhouse
    How much energy does it take to make a vat of melted aluminum? I assume it is not pure aluminum, I found out the hard way pure aluminum is worthless as a building material. I tried to make an air valve and saw this block of aluminum and just started cutting and drilling to make my little valve. Turns out pure aluminum is so soft you have to keep the assembl ...[text shortened]... e aluminum for ANYTHING🙂

    What is the diameter of the center wire and what is is composed of?
    How much energy does it take to make a vat of melted aluminum?


    In practice its a question of Power, not Energy.

    The "Energy" needed to be absorbed by the aluminum to change its phase from solid to liquid (assuming constant specific heat) is basically given by:

    E_m = M*c*( T_m - To )

    Where:
    E_m is the energy absorbed by the aluminum
    M is the mass of the aluminum
    c is the specific heat of aluminum
    To is the initial temp of the aluminum
    T_m is the melting temp of aluminum

    So you plug in the numbers and you get so many Joules or Btu's etc...

    As I said, in "practice" the above calculation doesn't really have much inherent value in solving the "actual" problem of melting the aluminum.

    The whole time the aluminum is getting energy, it is giving off energy to its surroundings via conduction,convection, and radiation. What portion of energy it gets from the source and gives off to its surroundings pretty much all vary with the state of each.

    So the gist of it is the "Energy" to take the aluminium from State A to State B is fixed, and not much help in practice. The "Power" needed to take the aluminum from State A to State B (the crux of the matter) is not fixed, and is dependent on a host of variables that can't be determined until a specific system is specified.

    What is the diameter of the center wire and what is is composed of?


    The wire is Steel, and the diameters range from 0.075 - 0.25 inches.
  13. Subscribersonhouse
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    29 Nov '15 15:015 edits
    Originally posted by joe shmo
    How much energy does it take to make a vat of melted aluminum?


    In practice its a question of Power, not Energy.

    BTW, I noticed you haven't played in over two years. You plan to ever play here?

    The "Energy" needed to be absorbed by the aluminum to change its phase from solid to liquid (assuming constant specific heat) is basically giv ...[text shortened]... is composed of?[/quote]

    The wire is Steel, and the diameters range from 0.075 - 0.25 inches.
    Ok, BTU's and Joules. Wouldn't the power needed depend on how good an insulation the melt is held in? If the heat was retained the power, Joules or BTU, would be minimized.

    Do they use steel because it is easier for the aluminum to wet to the steel or for strength?

    BTW, I notice in your profile you have not played in over 2 years. You ever plan to play here?

    Also, I ordered a small panel meter, hopefully I can make my little Manometer reader stand alone with it's own 4 1/2 digit readout. The thing I have to come up with is a 5 volt DC supply for the meter and figure out a way to offset the reading by 0.42 volts which is the zero point of the Manometer. It should be able to be adjusted to zero volts out but the best I could get was 0.42 volts so in order for the readout to be readable without doing math is to offset the manometer output before it gets to the meter. It looks like I can do that with a couple of resisters, I think, anyway🙂 Otherwise it's OP amp time....

    Right now I am just using our Fluke DVM which ties it up when we want to make readings. I want to make it a completely independent reader.

    It's funny, MKS charges well over a thousand bucks to do that job, my box is doing it for less than 200 bucks and is just as accurate.
  14. R
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    29 Nov '15 17:58
    Originally posted by sonhouse
    Ok, BTU's and Joules. Wouldn't the power needed depend on how good an insulation the melt is held in? If the heat was retained the power, Joules or BTU, would be minimized.

    Do they use steel because it is easier for the aluminum to wet to the steel or for strength?

    BTW, I notice in your profile you have not played in over 2 years. You ever plan to pla ...[text shortened]... ousand bucks to do that job, my box is doing it for less than 200 bucks and is just as accurate.
    Ok, BTU's and Joules. Wouldn't the power needed depend on how good an insulation the melt is held in?


    Yes

    If the heat was retained the power, Joules or BTU, would be minimized.


    Btu and Joule are a units of Energy, they are not units of Power (Energy/Time).

    The Btu's or Joules [Energy] would be the same, the Btu/hr or Joules/s [Power] could be minimized. There is an important distinction to be made between the two quantities, and they cannot be used to mean the same thing. Power =/= Energy

    Power is the rate at which Energy is added to the system. So if the aluminum were contained in a system that has no thermal communication with its surroundings you could heat the a 5 ton chunk of aluminum to its melting point with a 100 W power source (it would just take a really long time). In reality there is no perfect insulator, and most normal applications are nowhere near it, so it requires much more power to do it, but the needed absorbed Energy to do it remains the same.

    Do they use steel because it is easier for the aluminum to wet to the steel or for strength?


    The steel is core is for strength ( plated steel wire is used a lot in guy wires for power distribution systems)

    BTW, I notice in your profile you have not played in over 2 years. You ever plan to play here?


    Chess wasn't a life long interest of mine. I picked it up in my 20's, read some books, and played it for a few years on this site. I was more interested in conversing with intellectual people at the time (what better place to talk with smart people from around the world than an chess website), than I was in playing the game. I guess its appeal must have somewhat faded for me when I didn't really excel at it (it wasn't a conscious decision to stop playing). So I may play again, or may not.

    Also, I ordered a small panel meter, hopefully I can make my little Manometer reader stand alone with it's own 4 1/2 digit readout. The thing I have to come up with is a 5 volt DC supply for the meter and figure out a way to offset the reading by 0.42 volts which is the zero point of the Manometer. It should be able to be adjusted to zero volts out but the best I could get was 0.42 volts so in order for the readout to be readable without doing math is to offset the manometer output before it gets to the meter. It looks like I can do that with a couple of resisters, I think, anyway🙂 Otherwise it's OP amp time....

    Right now I am just using our Fluke DVM which ties it up when we want to make readings. I want to make it a completely independent reader.

    It's funny, MKS charges well over a thousand bucks to do that job, my box is doing it for less than 200 bucks and is just as accurate.


    Yeah, sounds like a job for some resistors. Congrats, on your invention, I hope it does well at market for you!
  15. Subscribersonhouse
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    30 Nov '15 11:386 edits
    Originally posted by joe shmo
    Ok, BTU's and Joules. Wouldn't the power needed depend on how good an insulation the melt is held in?


    Yes

    If the heat was retained the power, Joules or BTU, would be minimized.


    Btu and Joule are a units of Energy, they are not units of Power (Energy/Time).

    The Btu's or Joules [Energy] would be the same, the Btu/hr ...[text shortened]... e a job for some resistors. Congrats, on your invention, I hope it does well at market for you!
    I knew the dif between energy and power, for instance, your 100 watt example would still require the same amount of power whether you put in 100 watts or 100,000 watts per second, so if it took say 1000 seconds to melt a ton of aluminum with 100,000 watts in or 100 megawatt seconds or 27 kilowatt hours, and assuming perfect insulation in both cases, 100 watts would take 100,000 seconds to melt the tub of aluminum, or over a day, compared to 20 minutes at the 100 Kw level and would still tip the power meter for the same 27 Kw hours.
    That was just a bit of intellectual laziness on my part. 😲

    As for my manometer reader,
    I never even imagined this as a viable device for market.

    The thing is, if I was to pursue that, I did it on company time with company money and company purchased parts and so I could never get a patent for it with my name on it separate from Gulton, right?

    I don't think I personally would benefit much except to keep my job and get a few more attaboys.

    They already call me the god of electronics🙂

    That based on some of the out of the box thinking I do in bad situations.
    I could give examples but it would start to sound egotistical🙂
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