My Epson scanner 1640SU won

My Epson 1640SU scanner was working fine in Sept 1919, but today when I opened the application it gave me this error: You can’t open the application “EPSON Scan” because PowerPC applications are no longer supported.

I looked on the Epson website but the driver I downloaded 5.8.8_41 did not work for me to open the application. Any ideas from this community?

I have an iMac running OS X v10.11 ...... this is an older iMac and was upgraded to El Capitan early last year.