Venturi vacuum generators
vs. mechanical vacuum pumps
Expert recommendations for choosing your vacuum pumps in automated handling:
There is no benefit of a vacuum that isn’t right for your business. Therefore, it is important to compare your options carefully before committing to an investment.
Electromechanical vacuum pumps and Venturi vacuum ejectors serve different purposes and have distinct advantages and disadvantages in pick-and-place applications. Sourcing a vacuum system should never be done on a whim. The investment not only has an initial purchase cost, but also an ongoing financial impact on operations and maintenance.
But how do they compare in the long run? We are here to help.
When choosing your source of vacuum, you’ll find manufacturers of both Venturi vacuum systems and motor-driven (mechanical) vacuum pumps.
Venturi generator manufacturers include companies such as Air-Vac Engineering, Gast, SMC Pneumatics, Thomas, and PIAB to familiarise you with your options. While Becker, Busch, Travianni, G-D, Dekker, and Gast are examples of mechanical vacuum pump manufacturers.
What is a 'Venturi vacuum ejector'?
The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of a pipe. In the case of a vacuum ejector, compressed air is passed through a nozzle, creating a high-velocity jet.
Becker manufactures positive displacement and turbo dynamic pumps. Covering a wide range of operating principles, our portfolio includes rotary vane, screw, claw, and radial vacuum pumps, and regenerative blowers configured for vacuum applications.
With a little help from Becker expert, Dario, we hope that you can weigh up the most suitable solution to your unique concerns and application.
Factors to Consider Before Choosing a Venturi Generator or Mechanical Pump
Here are eight factors to compare before purchasing a vacuum system.
1. Energy Costs
OEMs often supply Venturi vacuum systems. Saving a small amount on the initial investment, Venturi pumps may seem like a deal at first with a lower upfront cost when compared to mechanical vacuum pumps.
However, there are additional costs, such as the maintenance involved with a large air compressor. Additionally - and more importantly, depending on the size and type of venturi vacuum, the energy needed to run the supporting compressor is between eight and 17 times the required horsepower of a standalone mechanical pump.
For example, a Becker Model KVT 3.100 uses a 3 KW motor, whereas the comparable Venturi generator uses between 30 and 40 KW worth of compressed air. That’s eight times more electrical costs to run the Venturi than a mechanical vacuum pump; a high operating cost to bear the burden of.
With energy prices continuing to rise year-on-year, using a system that chugs electricity will, inevitably, get more costly as time goes on.
If you are seeking to lower both energy consumption and your operating costs, an electromechanical vacuum pump will be the most sustainable solution for you.
2. Moving Parts
While the actual Venturi suction system has no moving parts, the compressor that runs it has plenty (significantly more than a mechanical pump). Chances are, the Venturi requires oil - a major obstacle for many industrial uses. For instance, in the packaging industry, there’s often no room for the oily sludges and smells, making Becker’s line of oil-less vacuum pumps an ideal solution.
3. Air Compressor Capacity
If your in-house air compressor is close to using its full capacity, an additional compressor (and air dryer, filter, and regulator) will need to be purchased to satisfy the requirements of a Venturi. That is not an economical option.
4. Heat Output
While a mechanical vacuum pump generates heat, a Venturi’s compressor will generate about 8-10 times more, because its motor is 8-10 times larger.
5. Precision in every placement
Achieving precise control over vacuum levels with vacuum ejectors can be a challenge. Therefore, in applications where this precision is crucial, Venturi ejectors may not be the ideal choice.
Electromechanical pumps allow engineers to adjust and maintain precise vacuum levels according to the specific needs of their processes, which is a challenge faced when ejectors are engaged. Electromechanical vacuum pumps will save money when a high vacuum level is needed. E.g. when handling heavy parts, high accelerations, or small grippers.
6. Noise Levels
A Venturi generator needs to vent air, creating noise levels almost 16 times louder than a mechanical vacuum pump. Yes, a vacuum pump makes noise, too, but it can be remotely located in a separate pump room if desired. These are particularly favoured in industries such as food packaging and woodworking.
7. Piping Requirements
A Venturi vacuum system must have compressed air piped to it, which is extremely costly to install unless the machine is pneumatically operated and piping is already in place. A mechanical pump goes under or next to the equipment it supports, thus eliminating any piping needs.
Another note-worthy factor - in the operating point, the consumption of compressed air is approximately three times higher than the vacuum flow rate of the ejector – in continuous operation, this translates to three times the operating costs; another considerable expense to take the burden of.
8. Compressor Failure
If your shop air compressor fails for any reason, the primary source of your Venturi vacuum is out of commission. The resulting downtime will cost you in production loss and work hours. With a mechanical vacuum pump, you only need one backup pump for all machines to ensure uptime.
Examples of Becker Electromechanical Vacuum Pumps
in the Pick and Place industry:
- Rotary Vane, oil-free vacuum pumps (VT, VX and KVT series)
- Side channel vacuum pumps (SV series)
- Claw vacuum pumps (BCV series)
Other named benefits that these pumps enjoy are:
- Adjustable vacuum levels
- Continuous operation - suitable for long cycle times
- Compact design
- Lower-noise levels
The right solution for you:
When choosing the right vacuum pump to replace an ejector always consider the operating point. Comparing the open flow will result in over-dimensioning of the vacuum pump and reduce possible savings.
It is important to note that the choice between an electromechanical vacuum pump and a vacuum ejector depends on the requirements of the application, including desired vacuum levels, flow rates, energy efficiency, and operational considerations.
Your local Becker Vacuum Solutions expert can support you with sizing and calculation of the right pump. Don't forget, you can book a free consultation to learn more, with our technical sales experts.
For additional information in an instance, our data sheets are available for direct download from our website.
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