Sitefinity CMS Deployment in WebFarm environment

We have deployed the Sitefinity CMS in WebFarm environment, however once we publish any changes then Text changes are getting updated however images are not. We need to manually recycle the app pool of IIS  else this is taking more than 4-5 hrs to update.  We are using Enterprise Edition version 7.0.

Please share your experience and details to address this issue.