For a 30 hL pneumatic membrane press, allow around 1.5 to 2 m³/min during the pressure rises, which a 15 kW 4-in-1 screw compressor such as the K 150 delivers. With two presses, everything depends on one question: can their pressure rises happen at the same moment? If so, the flow doubles.
The other air needs of the winery, from bottling to cleaning, are covered on our page on the compressor for wineries. The same calculation applied to a smaller cider press is set out in our article on the compressor for a cider press.
Does the press have its own compressor?
Read the manual first. Some membrane presses come with a built-in compressor sized by the manufacturer. Your winery compressor then only supplies the rest of the cellar. If the press needs an external supply, its data sheet gives the inlet pressure and, often, the consumption. That figure is the one that counts.
On a closed press, inerting is done with an inert gas, nitrogen or CO2, from its own supply. That gas does not enter the compressor calculation.
The calculation for one press
When the data sheet gives no flow, you can estimate it: the free air sent to inflate the membrane is roughly the inflated volume multiplied by the gauge pressure in bar.
Example of a 30 hL press, that is 3,000 litres of drum. For the example, take a membrane pressure of 2 bar and the fastest rise in the programme in 4 minutes. Replace these assumptions with the values of your press.
- Free air for a full rise: 3,000 × 2 = 6,000 litres.
- Flow during the rise: 6,000 ÷ 4 = 1,500 l/min.
- With a 25% margin: 1,875 l/min.
The drum volume is an upper limit: at the start of a press cycle, the grapes fill a large part of the drum and the membrane inflates less. Between two rises, during rotation and crumbling, consumption falls.
The K 150, 2.2 m³/min at 8 bar, covers this need. For a smaller press, or a slower rise, the K 110 delivers 1.7 m³/min at 8 bar.
Two presses: add up or stagger?
Staggered rises. If the cycles start at different times and the rises do not overlap, the compressor has to supply one rise at a time, plus holding the pressure in the other press. The K 150 in the example may be enough.
Simultaneous rises. If both presses can rise at the same time, you need 2 × 1,500 = 3,000 l/min, or 3,750 l/min with the margin. The S 220 PM delivers 3.6 m³/min at 8 bar: it is tight. Two compressors on the same network, or a tailored study with our industrial team, give more security.
During harvest, the schedule changes from hour to hour. Start from the busiest case you are prepared to live with.
An air receiver near the press
A pressure rise is a short, strong draw on the air supply. An air receiver placed near the press supplies part of that draw and relieves the compressor. The air receiver size calculator gives an order of magnitude.
Pitfalls of the reception area
- The compressor on the reception area. The press often works on an open area, hosed down every day. Install the compressor in a dry, ventilated room and bring the air through a fixed pipe. Our article on the compressor room sets out the rules.
- Water in the membrane. Damp air condenses in the membrane and the press hoses. The refrigerated dryer built into the K series deals with it. A membrane can also crack: our compressors are lubricated, so add fine filters on the press inlet and set the air class with our technicians and the press manufacturer.
- Pressure. Set the compressor to 8 bar and let the press regulator manage the membrane.
- Maintenance. Do it before harvest, not during. First service at 500 hours, then every 1,500 hours.
If your installation is short of air for only a few weeks a year, top it up during harvest with a rental compressor. For a precise choice, send us the data sheets of your presses with a quote request.
For your trade: Compressor for wineries.