How to increase the concentration of HCl
Add Calcium Chloride to destroy the azeotrope.  Then distill and capture the vapor phase.  

See the second method "Extractive Distillation" here:

http://www.jacobs.com/uploadedFiles/wwwjacobscom/20_Learn_About_Us/25_Products/252_Chemetics/Hydrochloric%20Acid%20Concentration.pdf

(Obviously, proper equipment and safety precautions are essential.)