How to calculate force for problem attached. 4

[ISBind]

Hiii

I need to calculate force required(F1) to pull the plate out with block leaving behind on Floor(to eventually calculate motor HP).

If
W1 is Weight of block
W2 is weight of plate
Cf1 is Coefficient of friction between block and plate
Cf2 is coefficient of friction between plate and floor

Anyone contribute anything on this will be really helpful.


Regards

 

[ISBind]

thanks for showing interest

weight of plate 21 tonne
weight of block 34 tonne
plate M.S.
floor brick
block coal

how to calculate U1 and u2???

i know it seems stupid but is there any software that can verify this?? like can it be checked in any analysis software???

and we dont have any friction factor available

Regards

 

[Kinemenematics]

have you tried coming up with a friction factors via interpolation/extrapolation of existing material data? Chances are you'll have to fill in the friction factors yourself if you use software.

also, can you draw us the FBD of the block itself? The block will go with the plate when you pull it out slowly (as there is no inertial tipping moment) so your design does incorporate some form of resistive force opposing F1? Unless your plate moves at speed of light i can't imagine the block staying in the oven

 

[rb1957]

"The block will go with the plate" ... isn't there some structure resisting the body?

Quando Omni Flunkus Moritati

 

[dhengr]

ISBind:
Reread my first post for some of the deeper meaning btwn. the lines. You are not going to find these friction factors in some nice clean mech. engrg. handbook list or some computer program. In that industry, these are brute force calcs., not finesse calcs. If you really want to know what those avg./approx./max. friction factors or forces are, you’ll have to measure the force it takes to push that plate in and out empty; and then do the same test with the block of coal in place. Do this at each plant (for different oven design details, etc.), at different oven positions (for plate guidance system fit-up, clogging, etc.); do this as many times as you want and look at the averages and the max. force required, for some design criteria. Then, back calc. for some Coef. of Friction if you wish. With your OP and your latest post, you seem to expect this to be some nice M.E. text book problem. It is not, in the slightest. I wonder if the smarter thing to do wouldn’t be look at what’s working and not working very well, or needs continuous repair, and ask what can I do in the way of design to improve that performance. RE: motor HP, what are they using now, and how long is it lasting? Long life means maybe you can reduce the motor size a bit, for a few dollars saved; maybe downsize gearbox, chain, etc. But, you’ll more than use that savings the first time one of these parts fails. Calculating the motor HP the way you are trying to do is a really tough assignment. Refining what’s working may be the easier route, or at least knowing what works is a good starting point for a design improvement or new design.

 

[rb1957]

"Long life means" it's working well .. don't touch the damn thing!

Quando Omni Flunkus Moritati

 

[mikekilroy]

i know it seems stupid but is there any software that can verify this?? like can it be checked in any analysis software???

and we dont have any friction factor available

What order of magnitude hp u talking about? there are application sales engineers all over the world who would love to come look at ur application and 'SIZE" it for you in exchange for chance to SELL u there stuff. CALL THE EXPERTS who sell ur size motor and invite them to come SIZE this for you?

Meanwhile if YOU want try YOUR hand at figuring this out yourself, try this free sizing software that can model this applicatioin:

http://www.kollmorgen.com/en-us/service-and-support/technical/motioneering/

http://www.KilroyWasHere<dot>com

 

[Kinemenematics]

rb1957: "The block will go with the plate" ... isn't there some structure resisting the body?",

Yeah there is, ISBind mentioned some kind of resistive component with wheels. But that resistive force was not indicated on his first FBD.