Refrigerated Air Dryers for Bottling & Canning

Size it to the rinser alone, which on most lines is 20 to 60 SCFM, not to the compressor. Feed it from the refrigerated dryer outlet so the desiccant bed starts with air already near a 38°F dew point; most of the water is gone before the bed sees it, and the purge shrinks with it. End the branch in a sterile filter at the rinser manifold, with a sample port just ahead of it so the -40°F class can be checked on a schedule.

Often it is wet machine air sticking the capper's torque heads. When the dryer runs short of capacity on a hot, humid afternoon, condensate reaches the head cylinders, strips their lubricant and makes them hesitate, and a head that grips late starts the cap off-axis. Seamer lifters suffer the same way and score can seams. Check the dryer outlet dew point when the rejects peak before changing torque settings, because a mechanical fix on a wet-air fault only moves the symptom.

Not to the class the food-grade codes set for air entering an open container. A sterile filter removes organisms and particles but not water vapor, and a 38°F pressure dew point leaves enough moisture for droplets and growth in a branch that cools overnight. The contact class calls for a -40°F dew point, which only a desiccant stage reaches. Keep the sterile filter as the final element at the rinser and put the desiccant unit ahead of it.

No. A three-shift filling hall keeps the compressor loaded, and at full load a non-cycling dryer draws about what a cycling one does while carrying fewer parts to service. The cycling premium pays back only from hours spent at partial load: seasonal plants that slow down in winter, or halls that lose long stretches to product changeovers. Look at a week of compressor load data before deciding, and if it rarely falls far below capacity, buy the simpler dryer.

At two places: after the coalescer on the machine-air header, and after the desiccant stage on the rinser branch. A reading from inside the dryer describes the refrigeration circuit, not the air the filler receives. One portable monitor with a quick-connect can serve both points. Take the readings on the hottest afternoons, when the compressor room is close to 110°F, because that is when a marginal dryer gives itself away and when an auditor's question is hardest to answer.

Partly, and it is worth trying before buying a larger dryer. Duct the compressors' and the dryer condenser's discharge air outdoors, bring makeup air from the cool side of the building, and keep the dryer off the wall the pasteurizer shares. Where tower water reaches the room, a water-cooled dryer settles the matter, because its rating no longer depends on room air at all. Sizing up by the ambient correction is the fallback when neither step is practical.