# How Do You Calculate Pressure and Flow for an Air Float Conveyor?

• mohammed11ahmed
mohammed11ahmed
jrmichler said:
You start by defining in detail exactly what you are conveying:

1) What are you conveying?
2) How heavy are they?
3) What are the dimensions of the surface of the objects in contact with the table?
4) How flat is the surface in contact with the table?
5) How rough is that surface?
6) Is the object porous?
7) Does the table need to move the objects, or merely float them?
8) What are the table dimensions of your prototype, and the finished table?

Use that information to calculate:
10) Calculate the average pressure to float the objects.
11) Calculate the minimum flow rate under the objects.
12) Calculate the plenum pressure.
13) Calculate the air flow through the uncovered holes (or use air table check valves).
14) Calculate total air flow.

Answering questions 1 through 8 above will give you the information to answer 10 and 11. I suggest that you give detailed answers to questions 1 through 8, then we can help you from there.

[Mentor Note: Thread created by moving some posts from a previous thread into this new one by the OP.]

if I have
1)10X10 cm box
2) weight 300g
3) The dimensions of the surface sheet that will be in contact is 60x25 cm
4) should be flat with holes for the air
5) that surface either can be an Acrylic or Stainless Steel sheet
6) no porous
7) it needs to move them along the table
8) 60X30 table

also for the sheet which will be the top surface that the air goes through to lift the object and make it move. I want to make the holes made in angle so when the air goes through it will help not just lift the object but also make it move along the bath. like inclined air jet how we choose the angle and how to calculate the forces acting on it.

Last edited by a moderator:

I want to apply this concept but how do I decide the angles to drill these holes and and how to calculate and what formula to use

1) Assume that the table is exactly the same size as the box. What pressure and how much flow is needed to float the box? If both the box and table are perfectly flat and nonporous, the flow would be quite low. In the real world, nothing is perfectly flat, so there will be a minimum flow. You can estimate that flow by assuming a worst case flatness, then calculating the flow through the gaps at sufficient pressure to float the box. It is better to run a test and measure the pressure and flow.

2) There is a pressure drop through the holes. The pressure under the table is higher than the pressure to float the boxes. How much higher is a function of the hole size.

3) When you have a hole size and pressure under the table, then you can calculate the flow through the holes that are open (not covered by the box). You will need to investigate the effect of hole size - smaller holes at higher pressure versus larger holes at lower pressure.

4) The total flow will be the sum of the flow that floats the box plus the flow through the open holes. You can use large holes (several mm diameter) with a blower or small holes (about 1 mm or less) with compressed air. I have seen air conveyors with both methods, you need to find the best solution for your specific situation.

5) NOW you can use angled holes. Angled holes will move the boxes. I once saw literature from a company that was selling air conveyors that would move the product uphill, so it can be done. If you choose the large hole design, you can explore using louvered sheet similar to the image below. The louver shape will be different, and the sheet metal needs to upside down from that shown:

If you choose drilled holes, try drilling at a 45 degree angle, then experiment from there.

6) If you get enough experience with air float conveyors, you should be able to calculate air flow, air pressure, hole size, hole angle, and hole spacing. Those calculations will start with experimental data, then use standard fluid flow calculations to extrapolate that data to your specific requirements.

7) This is a situation where you absolutely, positively need to do experiments. Then compare the experimental results to your calculations. Then do more experiments based on what you learn. Expect to do the calculate >> experiment >> calculate >> experiment cycle several times before you fully understand how to design this type of conveyor.

8) This sounds like a fun project, so enjoy.

## 1. How do you calculate the pressure required for an air float conveyor?

The pressure required for an air float conveyor is calculated based on the weight of the load, the area of the air float pads, and the desired lift height. The formula used is P = W / A, where P is the pressure, W is the weight of the load, and A is the total area of the air float pads. The pressure must be sufficient to lift the load off the surface and create a cushion of air.

## 2. How do you determine the flow rate needed for an air float conveyor?

The flow rate needed for an air float conveyor is determined by the size of the air float pads, the pressure required, and the number of pads. The flow rate (Q) can be calculated using the formula Q = A * v, where A is the area of the pads and v is the velocity of the air. The flow rate must be high enough to maintain the air cushion under the load.

## 3. What factors influence the pressure and flow rate calculations for an air float conveyor?

Several factors influence the pressure and flow rate calculations, including the weight and size of the load, the surface area of the air float pads, the desired lift height, the air supply system's capability, and the operating environment. These factors must be carefully considered to ensure the system operates efficiently and effectively.

## 4. How do you account for air leakage in pressure and flow calculations for an air float conveyor?

Air leakage can significantly affect the performance of an air float conveyor. To account for air leakage, you need to estimate the leakage rate and include it in your flow rate calculations. This can be done by measuring the actual air loss in the system or using empirical data. The total flow rate required will be the sum of the flow rate needed to lift the load and the estimated leakage rate.

## 5. Can you provide an example calculation for pressure and flow rate for an air float conveyor?

Sure! Let's assume we have a load weighing 1000 kg, and we are using four air float pads, each with an area of 0.1 square meters. The desired lift height is 5 mm. First, calculate the pressure: P = W / A = 1000 kg / (4 * 0.1 m²) = 2500 Pa. Next, if the velocity of the air is 10 m/s, the flow rate for each pad is Q = A * v = 0.1 m² * 10 m/s = 1 m³/s. For four pads, the total flow rate needed is 4 * 1 m³/s = 4 m³/s. Adjust for any air leakage as necessary.

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