Answer :
By calculating the heat energy required to raise the water temperature and dividing it by the specific enthalpy of steam, we can find the steam required in pounds per hour for the contact-type heater.
To find the steam required in this contact-type heater, we first need to calculate the heat energy required to raise the water temperature from its entering temperature of 276°F to the desired temperature using the formula:
Q = mass flow rate * specific heat * temperature difference
where Q is the heat energy in BTU, mass flow rate is 450,000 lbs per hour, specific heat is the heat capacity of water (approximately 1 BTU/lb°F), and temperature difference is the desired temperature (in °F) minus the entering temperature (in °F).
Next, we need to determine the heat energy in the steam at the entering condition using its specific enthalpy of 1254.0 Btu/lb at 139 psia. The mass flow rate of steam can be calculated by dividing the heat energy required in BTU by the specific enthalpy of steam.
Therefore, by performing these calculations, we can find the steam required in pounds per hour to operate the contact-type heater and raise the water to the desired temperature.
Know more about Enthalpy here :
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