Tension Calculation & Formulae for Accu. & Bridles

Accumulator Torque and tension calculations Motor Torque = (973.3 * kilowatt) / base speed Tension = Torque * GR * eff.* 2 / diameter Accumulator Torque = D[ (T *n) +(n*t*s*w*7.86*.000001)]/4*-GR

…………………..A

where

w*t*s*n*7.86*.000001= weight of strip D= diameter of winch T= required tension n= Number of falls t= thickness of strip s= displacement of moving frame in mm Assumptions: weight of counterweight is equal to weight of the frame weight of strip is negligible as compared to tension For a simple cross check of the calculation the following formula can be used HP =

tension * speed/4500

………………….B

Now, Multiply this torque with 1.44 and the required torque of the machine is available. Match it with required Kw machine which will give the same torque. We take the example of the Exit accumulator of CSD1, here, T = 600 n= 26 (in case of modifcation of line Linear speed = 150 MPM By the formula B HP = HP= Considering Duty factor of 1.5 times

600*150/4500 20 =22 KW

BY the other formula: Winch Dia (D) Displacement (s) No. of falls (n) Tension (T) Strip width (w) Thickness (t) GR Now, D/4*GR weight of strip Total Tension

= 350mm = 9720 mm = 26 = 600 Kgs = 1000 mm = 0.40 mm = 187 = .350/(4*187) = .000468 = 26*1000*.40*97200*7.86*.00001 =795 Kgs = n*T = 26 *600 =15600 Kgs

Torque

=.000468*(15600+795) = 7.68 As per this Motor required KW =11.3 Kw In case of Accumulator due to heavy duty requirement of the machine it is multiplied by 1.8 t0 2.0 time ,therefore required Kw suitable is 22 Kw. II: To find out the Kw requirement for a Bridles: T1 T T2 The above shows that a geometrical progression and therefore the tension progression will be as follows say

T1 = 500 kgs T2 = 1500 Kgs Ration between T2 and T1 The intermittent tension i.e.,

=1500/500 =√3*T1 =866 Kgs

=3

Now for The total bridle power and also for the individual Bridle power we can calculate the HP or Kw The formula is (differential Tension * speed)/(6116* efficiency)