Controlling Milking Equipment with Compressed Air
instead of Electronics or Vacuum
Copyright 2007 Technology For Agriculture LLC * All Rights Reserved
Technology For Agriculture LLC
1855-A West Davenport St., Rhinelander, WI 54501 | Rolf's Mobil 715-360-3660 * Fax 715-362-7595 |
The benefits of using compressed air to control milking equipment
All three methods are being used around the world, different manufacturers - different preferences.
The majority of engineers prefer electronics, because they are the most versatile and flexible. You can do more with electronics than with either air or vacuum. But, while electronics have made tremendous progress over the 40 years they have been used in milking parlors -moisture, lightening strikes, transient voltages and stray voltage are still part of the bargain. Not as much as they used to be, but factors never-the-less.
Electronics are also the most expensive parts to replace. If a printed circuit board fails you'll rarely replace it for less than $500 and $1,000+ is not uncommon.
In some instances you can self-service electronically controlled equipment but you have to know what you are doing.
Vacuum is the lowest cost way to control milking equipment, but it is also a weak operating force - only 7 psi vs 70 psi for compressed air.
'Automation' by definition means timing things and timing with vacuum is not possible for all practical purposes.
Maybe you remember the old Surge pulsators used on their Surcingle buckets. That was timing with vacuum, like 60 cycles a minute. And if you personally milked with them, you'll remember that you had to keep track of the 'timing' or the pulsator would gradually run slower and slower.
Very important - Vacuum operated detachers are usually electronically controlled. 'Operating' means doing work. 'Controlling' is the thinking part.
Compressed air is a positive operating force and therefore can be used for timing circuits, i.e. automating things, the logistics or thinking part..
Moreover, with vacuum operated equipment you are drawing the dirty barn air into the equipment first, then thru the pipes and out thru the vacuum pump.
The air compressor draws the dirty barn air in thru an intake filter. The air then goes thru a refrigerant drier and two more filters - a pre-filter and a coalescing filter - before we use it to control equipment. At that point the air is considerably cleaner than what you are breathing all day long.
- Timing stays consistent over many years. There's no dirt to gum up the works
- Exhaust noises are controlled with exhaust mufflers
- Cylinder speeds can be controlled with variable speed controllers.
- Most important - compressed air is safe in contrast with electronics.
- And you'll buy replacement parts at amazingly reasonable prices. Most valves and other control components cost less than $50.
- Once you have a compressor on the farm you'll use it for tires, basket balls and bicycles.
(Question asked by Darius Simler, early May 2010: "What are the advantages of compressed Air over Vacuum?")