It is true that there are no packed contactor or scrubber unit in DWSIM. As of now there are no unit operation available which can replace them. However you can create your own unit operation using the Python Script Unit Operation available in the flowsheet objects.
Open DWSIM. Go to File >> Open Samples. Open "Membrane Custom Unit Operation.dwxml" file. Click on the Unit Operation named "Membrane" and click "Open Python Script Editor"