Your "problem" is haze inducing proteins. The easiest way to remove them is time. Let the beer sit and the proteins will settle. If you are impatient
You can add your choice of coagulants to cause these proteins to drop out of solution quicker.
Gelatin is an inexpensive choice that works very well. You can do a search of this site that will tell you all you need to know. Roughly, add 1/2 teaspoon of gelatin (Knox brand unflavored is fine) to 1 cup of water. Bring the temp up to 160 F or so. Add to the keg and then transfer your beer on top.
You could also do a "secondary" or conditioning step where you transfer your beer from it's primary vessel to a second vessel with the gelatin added. Keep it there for 3-5 days and your brew will be very clear.
Then you can transfer it to your keg and carbonate as usual.
You may want to experiment with the dosing of gelatin. BierMuchner suggests 1 tablespoon. I have found that amount removes hop flavor and aroma. The 1/2 teaspoon works well for me.
Another fining agent is Polyclar. This is derived from inorganic sources rather than the organic that gelatin is harvested from.