How to Calculate and Solve for Relative Freezing Time | Foundry Technology

The image above represents relative freezing time.

To compute for relative freezing time, four essential parameters are needed and these parameters are Constant (L), Constant (C), Volume of Riser/Volume of Casting (y) and Relative Contraction of Freezing (B).

The formula for calculating relative freezing time:

x = L / y – B + C

Where:

x = Relative Freezing Time
y = Volume of Riser / Volume of Casting
B = Relative Contraction on Freezing
C = Constant
L = Constant

Let’s solve an example;
Find the relative freezing time when the volume of riser/volume of casting is 26, the relative contraction on freezing is 21, the constant is 8 and the constant is 11.

This implies that;

y = Volume of Riser / Volume of Casting = 26
B = Relative Contraction on Freezing = 21
C = Constant = 11
L = Constant = 8

x = L / y – B + C
x = 8 / 26 – 21 + 11
x = 8 / 5 + 11
x = 1.6 + 11
x = 12.6

Therefore, the relative freezing time is 12.6 s.

Calculating the Constant (L) when the Relative Freezing Time, Constant (C), the Volume of riser/Volume of Casting and the Relative Contraction on Freezing is Given.

L = x (y – B) – C

Where;

L = Constant
x = Relative Freezing Time
y = Volume of riser / Volume of Casting
B = Relative Contraction on Freezing
C = Constant

Let’s solve an example;
Find the Constant when the relative freezing time is 24, the volume of riser / volume of casting is 14, the relative contraction on freezing is 8 and the constant is 10.

This implies that;

x = Relative Freezing Time = 24
y = Volume of riser / Volume of Casting = 14
B = Relative Contraction on Freezing = 8
C = Constant = 10

L = x (y -B) – C
L = 24 (14 – 8) – 10
L = 24 (6) – 10
L = 144 – 10
L = 134

Therefore, the constant is 134.

Continue reading How to Calculate and Solve for Relative Freezing Time | Foundry Technology

How to Calculate and Solve for Pouring Speed | Design of Gating System

The image above represents pouring speed.

To compute for poring speed, three essential parameters are needed and these parameters are Co-efficient for friction (μ), Acceleration due to Gravity (g) and Rated head static (Hs).

The formula for calculating pouring speed:

v = μ√(2gHs)

Where:

v = Pouring Speed
μ = Co-efficient for Friction
g = Acceleration due to Gravity
Hs = Rated Static Head

Let’s solve an example;
Find the pouring speed when the co-efficient for friction is 14, acceleration due to gravity is 9 and rated static head is 16.

This implies that;

μ = Co-efficient for Friction = 14
g = Acceleration due to Gravity = 9
Hs = Rated Static Head = 16

v = μ√(2gHs)
v = 14 x √(2 x 9 x 16)
v = 14 x √(288)
v = 14 x 16.97
v = 237.58

Therefore, the pouring speed is 237.58 m/s.

Calculating the Co-efficient for Friction when the Pouring Speed, the Acceleration due to Gravity and the Rated Static Head is Given.

μ = v / √(2gHs)

Where;

μ = Co-efficient for Friction
v = Pouring Speed
g = Acceleration due to Gravity
Hs = Rated Static Head

Let’s solve an example;
Find the co-efficient for friction when the pouring speed is 24, the acceleration due to gravity is 9 and the rated static head is 11.

This implies that;

v = Pouring Speed = 24
g = Acceleration due to Gravity = 9
Hs = Rated Static Head = 11

μ = v / √(2gHs)
μ = 24 / √(2 x 9 x 11)
μ = 24 / √198
μ = 24 / 14.07
μ = 1.70

Therefore, the co-efficient for friction is 1.70.

Continue reading How to Calculate and Solve for Pouring Speed | Design of Gating System