Activate simple the Shuffle Mode of the slider via the option shuffle:"on". It reorders at load the slider, but till new load, it will stay in this order.
<script type="text/javascript">
var revapi;
jQuery(document).ready(function() {
revapi = jQuery('.tp-banner').revolution(
{
delay:9000,
startwidth:1170,
startheight:500,
hideThumbs:10,
shuffle:"on"
});
});
</script>