Remove broken test results

biosteam/units/stirred_tank_reactor.py

@@ -171,8 +171,6 @@ class StirredTankReactor(PressureVessel, Unit, isabstract=True):
  Total purchase cost USD 2.05e+06
  Utility cost USD/hr 152
  
- >>> R1.results()
- 4
  '''
  auxiliary_unit_names = (
  'heat_exchanger', 
@@ -277,8 +275,6 @@ def _design(self):
  P_pascal = (self.P if self.P else self.outs[0].P)
  P_psi = P_pascal * 0.000145038 # Pa to psi
  length_to_diameter = self.length_to_diameter
-
- N = 0
  if self.batch:
  v_0 = ins_F_vol
  tau = self.tau
@@ -302,7 +298,6 @@ def _design(self):
  V_reactor = V_total / N
  Design['Reactor volume'] = V_reactor
  self.N_reactors = N
-
  D = cylinder_diameter_from_volume(V_reactor, self.length_to_diameter)
  D *= 3.28084 # Convert from m to ft
  L = D * length_to_diameter