3 - TO and TU Chains Calculations for chain selection vary according to their usage and arrangement. A sample calculation is given for the arrangement shown to the right.
Step 5 - Top Plate width Generally, the top plate must be wider than the material conveyed. When materials are very wide, and none of the top plate widths are satisfactory, top plates of the same width may be used in multi-strand arrangement. Top plates of different widths can be used together, but this is not desirable since the tension on the chains will be uneven.
Step 3 - Select Liner material The appropriate liner material must be selected from the top plate materials listed in Step 2.
Dry
Lubricated
T = (M + w) Lf2 +wlf2 + ML’f3…………………….Formula 3
Top Plate Material (Chain Type)
Liner Material
Abrasive Atmosphere
No
Yes
No
Yes
4 - Calculation of power required. HP= (TS/33,000 ● ∏ ) ……..Formula 4
Stainless Steel Steel
Step 6 - Calculate Chain tension (T) 1 - Linear movement. (TS, TT,TP,TN,TTP and P chains) T = (M+2.1w) Lf2 +ML’F3……………Formula 1
Stainless Steel TS and TT for straight running TRU, TKU, TO and TU, for curved.
O
O O O
Step 7 - Determine Chain Size Multiply maximum chain tension (T) by the speed coefficient (k1) taken from the Table VII and verify that the following equation is satisfied.
Super-High Polymer Polyethylene
O
X
O O
Stainless Steel
Palyacetal (TP, TTP, TN and P for linear movement, TPU and TNU for curved).
2 - Curved Movement (TRU,TKU,TPU,TNU and TTU Chains)
Steel
O
O
T X k1 ≤ Chain maximum allowable load………………….Formula 5
Super-High Polymer Polyethylene
X
The chain tension for curved movement is calculated similarly to that for linear movement. The tension at corners, however, is compensated for by the angle factor (K2) and length factor (K3).
O = Suggested X = Suggested
Good
Limited Use
When the maximum allowable load is insufficient, it can be corrected by using top plates with narrower width and increasing the number of chain strands, or splitting into many short conveyors.
Step 4 - Determine factors of coefficients (f2, f3, k2, k3) Table IV: Coefficient of Friction (f2) between Top Plate and liner.
Table VII - Speed Coefficient (k1) Chain Speed (ft./min)
Speed Factor (k1)
Coefficient of Dynamic Friction of Liner Material
0 - 50
1.0 1.2 1.4 1.6 2.2 2.8 3.2
Top Plate Material
Lubrication
Ultra High Polymer Polyethylene
Stainless Steel
Steel
50 - 100 100 - 160 160 - 230 230 - 300 300 - 360 360 - 400
Dry
0.35 0.20 0.20 0.25 0.15
0.35 0.20 0.20 0.25 0.15
0.25 0.15 0.15 0.25 0.15
Stainless Steel
Lubrication by soapy water
Oil Lubrication Stainless Steel
Polyacetal
Steel
T = Chain tension (lbs.) M = Weight of material conveyed per foot (lbs./ft. w = Chain weight (lbs./ft.) L = Center distance between sprockets (ft.) l = Distance not loaded (ft.) L’ = Distance of material sliding on the chain for storage (L’ = 0 when items and chain are not slipping) f2 = Coefficient of friction between the top plate and liner f3 = Coefficient of friction between goods moved and top plate k1 = Speed coefficient
Table V: Coefficient of Friction (f2) between Material Conveyed and Top Plate
Coefficient of Dynamic Friction of Top Plate Material Stainless Steel Polyacetal
Top Plate Material
Lubrication
Dry
0.30 0.20 0.35 0.20 0.30 0.20 0.35 0.20
0.25 0.10 0.25 0.15 0.40 0.20 0.25 0.15
Plastic and paper containers and film packages
Lubrication by soapy water
Dry
Cans (with metal tops and bottoms)
Lubrication by soapy water
Dry
Bottles and Ceramics
Lubrication by soapy water
Dry
Industrial parts (metal)
Slack Side Chain tension at A: Ta Ta = L1wf2k2, L1 = l1 + R1k3 (k2 and k3 at 180°) Chain tension at B: Tb Tb = (Ta +L2wf2) k2, L2 = l2 + R2k3 (k2 and k3 at 90°) Chain tension at C: Tc Tc = Tb + L3wf2, L3 + l3 Loaded Side Chain tension at d: Td Td = (Tc + (M+w) L5f2+ ML’4f3) K2, L4 = l3 +R2k3 Chain tension at e: Te Te = (Td +(M + w) L4f2 + ML’4f3) K2, L5 = l2 + R1k3 Chain tension atf: Tf Tf = Te + (M+w) L5f2 + ML’6f3
Lubrication by soapy water
k2 = Angle factor k3 = Length factor
Table VI: Angle Factor (k2) and Length Factor (k3)
R = Radius at corner (ft.) S = Chain speed (ft./min) ∏ = Mechanical transmission efficiency for drive unit HP = Power required
Angle Factor (k2)
Turning Angle
Length Factor (k2)
TPU and TNU Chains
TRU and TKU Chains
Dry 1.15 1.30 1.50 1.70 1.90 2.20
Lubricated
Dry 1.20 1.45 1.75 2.10 2.50 3.00
Lubricated
30° 60° 90°
0.50 1.00 1.60 2.10 2.60 3.10
1.10 1.15 1.25 1.35 1.50 1.60
1.10 1.25 1.35 1.50 1.70 1.85
Conveyor Design The layout of a conveyor varies with the type of chain used. A typical layout is shown below. Goods should be conveyed on the tension side of the chain, and the slack (return) side should be supported by guide rails with sloped ends to prevent chain vibration and conveyor pulsation.
120° 150° 180°
k2 and k3 factors are to be used for curved movement except for TO and TU types. k3 = ∏ ● Turning Angle/180°
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