| tm1 |
|
(initial medium temperature, deg F) |
| tm2 |
|
(final medium temperature, deg F) |
| tb1 |
|
(initial batch temperature, deg F) |
| tb2 |
|
(final batch temperature, deg F) |
| U |
|
(Overall heat-transfer coefficient, BTU per hr per ft2 per deg F) |
| A |
|
(heat-transfer surface, ft2) |
| M |
|
(weight of batch, lb) |
| c |
|
(batch specific heat, BTU per lb per deg F) |
| θ |
|
(time, hr) |
| wm |
|
(medium flow rate, lb per hr) |
| cm |
|
(medium specific heat, BTU per lb per deg F) |
| wb |
|
(batch flow rate, lb per hr) |