# Calculating Maximum Flow Rate for Vacuum Chamber

• bigdream
In summary, a vacuum chamber is being made with a gauge pressure of 250 mmHg and a gap on the operating surface of 2 mm width and a thickness between 1 - 10 mm. The maximum flow rate per meter is being sought after and a sketch has been provided for reference. The commenter also suggests using a negative gauge pressure in Pa or Psi units and referencing mmHg using Torr.
bigdream
I'm now making a vacuum chamber.
The gauge pressure inside the vacuum chamber is about 250 mmHg.
There will be some gap on the operating surface, about 2 mm width.
The thickness of the gap is between 1 - 10 mm.
What is the maximum flow rate per meter for the vacuum chamber?

ummm, shouldn't a vacuum chamber have a negative gauge pressure (and could you put it into Pa or Psi)? also, a sketch would help greatly.

redargon said:
ummm, shouldn't a vacuum chamber have a negative gauge pressure (and could you put it into Pa or Psi)? also, a sketch would help greatly.

Thanks for the comment. The vacuum chamber have a negative gauge pressure. The attachment is the rough sketch of the chamber.

#### Attachments

• chamber.JPG
10.5 KB · Views: 365
75 Mpa does not seem like vacuum to me, also it is more common to refer to mmHg by Torr.

Are you trying to find the flow rate based on 250 Torr pressure difference acros a slot of 2 mm width?

## 1. What is the purpose of calculating maximum flow rate for a vacuum chamber?

The maximum flow rate for a vacuum chamber is important because it determines the rate at which gas can be removed from the chamber, which affects the pressure inside. This is important for processes that require a specific pressure range, such as thin film deposition or semiconductor manufacturing.

## 2. How is maximum flow rate calculated for a vacuum chamber?

The maximum flow rate for a vacuum chamber is calculated based on the chamber volume, pump capacity, and desired pressure. It can be determined using the ideal gas law, which relates the pressure, volume, and temperature of a gas, along with the pumping speed of the vacuum pump.

## 3. What factors can affect the maximum flow rate for a vacuum chamber?

Several factors can affect the maximum flow rate for a vacuum chamber, including the type and size of the vacuum pump, the gas being pumped, the temperature of the gas, and the size and geometry of the chamber itself. Additionally, any leaks or obstructions in the chamber can impact the flow rate.

## 4. Why is it important to consider the maximum flow rate when designing a vacuum chamber?

The maximum flow rate is an important consideration when designing a vacuum chamber because it affects the efficiency and effectiveness of the vacuum system. If the flow rate is too low, it may take longer to reach the desired pressure, and if it is too high, it may cause turbulence or other issues within the chamber. It is also important to ensure that the vacuum pump is capable of handling the maximum flow rate for optimal performance.

## 5. Can the maximum flow rate for a vacuum chamber be increased?

Yes, the maximum flow rate for a vacuum chamber can be increased by using a larger or more efficient vacuum pump, optimizing the chamber design to minimize obstructions and leaks, and controlling the temperature and composition of the gas being pumped. However, it is important to ensure that the increased flow rate does not exceed the pumping speed of the vacuum pump.

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