Strength calculation of grid support plates

Thread Content

Grids for preventing packing accumulation are commonly used in tower equipment, and the calculations for the grid support plates can refer to the following data. Uniform load on the grid bars (including the weight of the liquid held): q = Hp*t*γ*10^-8 + 0.35*Hp*t*γ1*10^-8
Maximum bending moment of the grid bars: Mmax = q*L^2/6
Section modulus of the grid bars: W = 1/6*(δ-C)*(h-C)^2
Bending stress in the grid bars: σ = Mmax/W
Allowable bending stress for the grid bars: w = 1.2σb/2.2
Condition for satisfactory strength: σ ≤ w
The minimum required height of the grid bars can be calculated as follows: h’ = sqrt[(Hp*t*L^2*γ + 0.35*Hp*t*L^2*γ1)/w] + C
Requirement for compliance: The actual height of the grid bars, h, must be greater than or equal to this minimum height, h’.
Where:
Hp: Height of the packing layer
γ: Density of the tower packing
t: Spacing between grid bars
L: Length of the grid bars
δ: Thickness of the grid bars
h: Height of the grid bars
C: Corrosion allowance for the grid bars
σb: Tensile strength of the grid bars
γ1: Specific weight of the liquid