Steam Injecting

Overview

Engineering reference data for Steam Injecting in material science and properties.

Key Formulas

Stress

$\sigma = \frac{F}{A}$

Force per unit area.

Strain

$\varepsilon = \frac{\Delta L}{L_0}$

Change in length per original length.

Hooke's Law

$\sigma = E \varepsilon$

Stress proportional to strain in elastic region.

Thermal Expansion

$\Delta L = \alpha L_0 \Delta T$

Length change due to temperature.

Variables

Symbol	Description	Unit
$\sigma$	Stress	Pa
$\varepsilon$	Strain	—
$E$	Young's modulus	Pa
$\alpha$	Thermal expansion coefficient	1/°C
$\Delta T$	Temperature change	°C

Example: Heating Water with Steam Injection

Consider heating 100 kg of water from $20^\circ\text{C}$ to $80^\circ\text{C}$ in 5 minutes (300 seconds). The specific heat of water is $c_p = 4.2 \, \text{kJ/kg}^\circ\text{C}$.

The power required for heating is calculated as:

$P = \frac{m \cdot c_p \cdot \Delta T}{\Delta t} = \frac{100 \, \text{kg} \times 4.2 \, \text{kJ/kg}^\circ\text{C} \times (80^\circ\text{C} - 20^\circ\text{C})}{300 \, \text{s}} = 84 \, \text{kW}$

Given absolute steam pressure of $220 \, \text{kPa}$, the total enthalpy of steam is $h_g = 2711 \, \text{kJ/kg}$.

The required steam flow rate is given by the steam injection formula:

$m_s = \frac{P}{h_g - (t \cdot c_p)} = \frac{84 \, \text{kW}}{2711 \, \text{kJ/kg} - (80^\circ\text{C} \times 4.2 \, \text{kJ/kg}^\circ\text{C})} = 0.035 \, \text{kg/s} = 127 \, \text{kg/h}$

The total steam consumption for the heating process is:

$q = m_s \cdot \Delta t = 0.035 \, \text{kg/s} \times 300 \, \text{s} = 10.5 \, \text{kg}$

This example illustrates the application of steam injection for direct heating, avoiding heat exchangers and fouling issues.

References

• Original Source