(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

This is for one of my engineering classes. I missed class due to sickness, and can't figure out how to even begin this problem. No numbers are present, so I'm confused. Here is the problem:

Problem 1 (7 points). A conservative (non-reactive) pesticide is injected into the input flow of a CFSTR on continuous basis, beginning at time t = 0 and resulting in a constant input concentration of pesticide = Cin.

(a) Determine C, the reactor output concentration of this pesticide, as a function of time, and

(b) plot the pesticide output response curve (i.e., reactor output (C/Cin) versus the hydraulic residence time. Use C/Cin scale from 0 to 1 and HRT scale from 0 to 10.

(C) What is the ratio of C/Cin for 1 HRT?

(d) How many HRTs are required to reach 95% of input concentration at the reactor output?

(e) How many HRTs are required to reach 99% of input concentration at the reactor output?

---I think it is actually CSTR(continuous Flow/Stiring). The problem is also about mass balance, if that helps.

I understand that these reactors have inflow and outflow(equal I think). They are considered instantaneous and perfect in mixing.

2. Relevant equations

I understand that these reactors have inflow and outflow(equal I think). They are considered instantaneous and perfect in mixing.

3. The attempt at a solution

I'm not sure if this is even relevant, but in an example problem we showed that C = constant = dC/dt = 0.

Thank you for the help.

Brad

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# CSTR Problem

**Physics Forums | Science Articles, Homework Help, Discussion**