Calculating The Penetration Rate
This example illustrates the calculation process for determining the maximum penetration rate for a long radius elbow. The calculation includes the following steps:
- Determine the elbow radius factor (ERFr/d).
- Calculate the particle impact velocity;
- Equivalent stagnation length L
- Dimensionless parameters, NRe and F;
- Compute the penetration rate in a standard elbow.
- Determine the penetration rate in long radius elbow.
In this example, a 2-in. pipe with a Schedule 40, ASTM 234 Grade WPB seamless elbow with an ID of 2.067 in. was used. The r/d ratio of the elbow was 3.0, and the liquid used was clay/mud at a velocity of 25 ft/s; the sand rate is 1800 ft3/D.
Elbow Radius Factor
In this calculation, the unit of density is lb/ft3 and the viscosity of mf is cp. The calculated ERFr/d is 0.304.
Particle Impact Velocity
The particle impact velocity is calculated based on the methods illustrated.
1: Equivalent Stagnation Length L.Calculation of the equivalent stagnation length L
2: Compute NRe and F:
The dimensionless numbers NRe and F are calculated using parameters with consistent units. These parameters are used for:
3: Determine the vp/v of a Valve.
Penetration Rate in Standard ElbowIn this example, semirounded corner sand is assumed.
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