11510 Goldcoast Drive • Cincinnati, OH 45249-1621 • Phone (513) 671-3322 FAX (513) 671-3363 • E-mail: [email protected] • www.exair.com 151 Vacuum Generators The Model 840008M Adjustable E-Vac can be substituted for picking up the wood or the glass since the vacuum level and vacuum flow is easily adjusted to suit the porous or non-porous application. The Adjustable E-Vac is especially useful for loads that vary. How to Build An E-Vac System: 1. Select the E-Vac type. A. Determine if the part to be lifted is porous or non-porous (page 152 and 153). B. Select a style - In-Line Low Vacuum, In-Line High Vacuum, or Adjustable (pages 152, 153 and 155). The E-Vac type determines max. vacuum available for lifting the part and vacuum cup selection. Porous low vacuum generators max. vacuum = 21" Hg (71 kPa) Non-porous high vacuum generators max. vacuum = 27" Hg (91 kPa) Adjustable E-Vac vacuum generators max. vacuum = 25" Hg (85 kPa) 2. Determine the weight of the part. 3. Multiply the weight by the vacuum cup safety factor (see page 157) for the total vacuum cup capacity needed. 4. Determine the number of vacuum cups needed by considering the following: A. How many cups are needed to distribute the weight for stable lifting and placement? B. What is the weight that each vacuum cup can lift based on maximum vacuum available (E-Vac type)? C. Select vacuum cups from chart on page 157 based on max. vacuum available (E-Vac type) and holding weight/cup. 5. To choose an E-Vac model number, consider the entire vacuum system from the E-Vac to the part. A. Number of vacuum cups per E-Vac. B. Length and size of vacuum tubing. C. Vacuum cup size and type. • The volume of air to evacuate from your vacuum system and the vacuum flow of the E-Vac you've selected (pages 152, 153 and 156) will determine the time it takes from E-Vac activation to vacuum cup holding the part. As the vacuum level in the system increases, the volume of evacuating air decreases. • A lower volume of air in the vacuum system and/or a higher capacity (SCFM/SLPM) E-Vac will give faster pick-up times. • An exact pick-up time cannot be calculated. • If the E-Vac vacuum generator doesn’t meet your needs, return it for a different model, with no restocking charge (U.S. and Canada only). Need Help Selecting the Correct E-Vac? Our Application Engineers can assist you in determining the correct model E-Vac and vacuum cups (if required). Call 1-800-903-9247 or visit www.exair.com/appassist.htm Here is an example using the steps outlined above: A sheet of material measures 3' x 3' (.91m x .91m) and weighs 25 lbs (11.3kg). Each sheet is in a stack and will be placed on a conveyor. E-Vac® Vacuum Generators If it is porous, like wood, and positioned vertically: 1. Choose a porous, low vacuum In-Line E-Vac. The maximum vacuum is 21" Hg (71 kPa). 2. The weight is 25 lbs (11.3kg). 3. If the part is picked-up and hung on an overhead conveyor vertically, the safety factor is 4. The vacuum cup capacity needed is 4 x 25 = 100 lbs (45.4kg). 4. Four vacuum cups will be used for stability when lifting the sheet. Each cup will need at least a 25 lb (11.3kg) capacity. In the table on page 157, at 21"Hg (71 kPa), the Model 900755 Vacuum Cup will hold up to 25.3 lbs (11.5kg). 5. Use 4 small round vacuum cups that are positioned close to one another. The vacuum system has a small to medium volume and pick-up and release time is not critical. To reduce the sound level, use the straight through muffler. Order: (1) Model 800008M In-Line E-Vac (4) Model 900755 Vacuum Cups See Page 160 for other accessories. If it is non-porous, like glass, and positioned horizontally: 1. Choose a non-porous, high vacuum In-Line E-Vac. The maximum vacuum is 27" Hg (91 kPa). 2. The weight is 25 lbs (11.3kg). 3. If the part is picked-up and placed on a belt conveyor horizontally, the safety factor is 2. The vacuum cup capacity needed is 2 x 25 = 50 lbs (22.7kg). 4. Four vacuum cups will be used for stability when lifting the sheet. Each cup will need at least a 12.5 lb (5.7kg) capacity. In the table on page 157, at 27" Hg (91 kPa), the Model 900754 Vacuum Cup will hold up to 20.8 lbs (9.4kg). 5. Use 4 small round vacuum cups that are positioned close to one another. The vacuum system has a small to medium volume and pick-up and release time is not critical. To reduce the sound level, use the straight through muffler. Order: (1) Model 810006M In-Line E-Vac (4) Model 900754 Vacuum Cups See Page 160 for other accessories.
