A meat processing plant is studying the feasibility of utilizing skin and bone waste to obtain gelatin through treatment with HCl, hot water extractions, and subsequent vacuum concentration. The available quantity of bones and skin is 500 kg/h. Laboratory studies indicate that this raw material yields 18% gelatin, which is obtained in the form of a 10% aqueous solution. This diluted solution needs to be concentrated to 35%. To achieve this, the construction of a double-effect evaporator equipped with an injector capable of creating a vacuum of 610.766 mmHg absolute pressure and heating the evaporator with steam at 1.7207 kgf/cm2 gauge pressure is proposed.

The cost department needs to establish the following approximate data:

a) Steam consumption for heating per hour.

b) Evaporator efficiency.

c) Number of tubes, each 1 meter long with an internal diameter of 2.5 cm, required for each heating unit.

d) Amount of 15C cooling water needed per hour in the surface condenser that is planned to be connected to the evaporator to condense the vapors coming out of the second effect, ensuring that the water temperature at the outlet does not exceed 70C.

Note: Literature data allows assuming overall internal heat transfer coefficients of 1800 and 1700 kcal/h m2 C for the first and second effects, respectively.

1 atm = 760 mmHg = 1.0333 kgf/cm2