there were many homes and buildings that housed orphans & children who were taken from their families for whatever reason. The main building burned along with the records in the 1960's. My mother was in Des Moines Home For Friendless Children, it was on 2018 High St. It's a parking lot today.
I recommend searching your grandpa's name in records on ancestry.com's US Directories.
I have attached a copy of an advertisment from Des MOines with a children's home for you that might give you some help.
Nearly every orphanage in the state of Iowa was connected through the city of Des Moines(capitol) and were owned and sponsored by many church denominations. Lutheran's being the biggest operators. There were homes in Eldora, Toledo, Bremwood, Mitchellville all in Iowa.