Question

A fruit juice is being heated in an indirect heat exchanger using steam as a heating medium. The product flows through the heat exchanger at a rate of 1000 kg/h and the inlet temperature is 30 oC. Determine the quantity of steam required to heat the product to 100 oC when only latent heat of vaporization (2230.2 kJ/kg) from steam at 110oC is used for heating. The specific heat of the product is 4 kJ/(kg oC).

Answer 1

The appropriate response will be "125.55 kg/hr".

Step-by-step explanation:

The given values are:

Rate of heat exchanger,

m = 1000 kg/h

Inlet temperature,

T = 30°C

Specific heat,

`c_p` = 4 kJ/(kg°C)

Now,

The heat taken by juice from steam will be:

⇒
`Q=mc_p(\Delta T)`

On substituting the values, we get

⇒
`=1000* 4(100-30)`

⇒
`=280000 \ kJ/hr`

The heat given by the steam to juice will be:

⇒
`Q=m* L`

On substituting the values, we get

⇒
`=m* 125.55`

On equating both the heat values, we get

⇒
`280000=m* 2230.2`

⇒
`m=(280000)/(2230.2)`

⇒
`m=125.55 kg/hr`