Anon-mechanical, rigid, and fully insulated mixing tank is used to combine two inflows to produce wet steam. one inflow consists of superheated steam flowing at 3 kg/s, 300+c and 8 bar, while the other inflow is saturated liquid water at 25+c. the combined stream exiting the tank consists of wet steam at 2 bar and 90% quality. what is the mass rate of wet steam that can be produced and what is its temperature? how much mass inflow of saturated liquid water is needed?

Explanation:

As it is given that stream A is super heated. From stream tables, we get that specific enthalpy, () is 3054.29 kJ/kg.

For stream B, it is saturated water at 25 degree celsius. It's is 2546.54 kJ/kg.

Stream C, data will be as follows.

                P = 200 kPa,         = 0.9

So, =  

        = 504.47 + 0.9 \times 2201.7

        = 2486 kJ/kg

Now, energy balance formula will be as follows.

            =

              =

              = 28.16 kg/s

Hence, inflow of saturated liquid is 28.16 kg/s. According to steam table, temperature of wet steam is

Mass flow rate of out flow is 31.16 kg/s.

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol