# Chemics¶

The Chemics package is a collection of Python functions for conducting calculations in the field of chemical and fluidization engineering. Source code for the package is available on GitHub and contributions from the community are encouraged.

## Installation¶

The Anaconda or Miniconda distribution of Python is recommended for scientific computing. After installing Anaconda, the Chemics package can be downloaded and installed with the pip package manager:

```
pip install chemics
```

## Usage¶

The example below imports the Chemics package then uses the `rhog()`

function to calculate the density of a gas based on its molecular weight,
pressure, and temperature.

```
import chemics as cm
cm.rhog(28, 170100, 773)
```

The `ut()`

function calculates the terminal velocity of a particle
according to the Haider and Levenspiel 1989 paper as shown below.

```
import chemics as cm
# Parameters
dp = 0.00016 # particle diameter [m]
mu = 1.8e-5 # gas viscosity [kg/(m s)]
phi = 0.67 # particle sphericity [-]
rhog = 1.2 # gas density [kg/m^3]
rhos = 2600 # particle density [kg/m^3]
# Haider and Levenspiel terminal velocity [m/s]
ut_haider = cm.ut_haider(dp, mu, phi, rhog, rhos)
```

Use the `ChemicalEquation`

class to get properties of the reactants and
products from a given chemical equation.

```
import chemics as cm
ce = cm.ChemicalEquation('2 HCl + 2 Na -> 2 NaCl + H2')
ce.balance
# returns True for balanced equation
ce.rct_properties
# returns a dataframe of the reactant properties
# HCl Na
# moles 2 2
# species HCl Na
# molwt 36.458 22.99
# mass 72.916 45.98
# molfrac 0.5 0.5
# massfrac 0.613275 0.386725
```

More examples are available in the chemics-examples repository.

## Documentation¶

Details about the functions available in the Chemics package are provided below. Equations and associated references used to develop the functions are also given.

- Atomic elements
- Bed expansion factor
- Bubble velocity
- Chemical equation
- Choking velocity
- Conversions
- Devolatilization time
- Gas density
- Gas thermal conductivity
- Gas viscosity
- Geldart particle classification
- Minimum fluidization velocity
- Molecular weight
- Terminal velocity
- Transport disengaging height
- Transport velocity
- Wood heat capacity
- Wood thermal conductivity

## Contributing¶

See the CONTRIBUTING document on GitHub for guidelines on contributing to the Chemics package.