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2.30  Traps

2.31  When To Use A Trap

 

The Self-Cleaning Dry Vacuum System is constructed of PTFE or fluorinated plastics on all wetted surfaces to

 

resists chemical attack from aggressive solvent, base and acid vapors.  A totally oil free diaphragm mechanism 

 

removes the need for lubricating and sealing fluids for pulling a vacuum.  When pumping gases or low vapor 

 

loads, a trap is not necessary unless you want to capture vapors evolved from the process.

 

When a heavy load of water or organic vapor is evolved from the vacuum process, condensation of vapor in the 

 

pump mechanism may occur.  The reason is the pump is compressing the vapor as it passes through the pump.  If

  

the vapor is dense enough, the compression will cause condensation of the vapor in the pump mechanism.  The 

 

valve system in the pump mechanism is designed to pass the small quantity of liquefied vapor formed when 

 

pumping heavy vapor loads.  The liquid formed will be ejected from the outlet port.  The self-cleaning purge 

 

feature of the Self-Cleaning Dry Vacuum System is designed to eject condensed vapors left in the pump upon 

 

shut-done.

 

The advantage of a cold trap when pumping heavy vapor loads is that it will increase the effective pumping speed 

 

of the Self-Cleaning Dry Vacuum System.  The trap acts as an additional pumping mechanism, increasing the 

 

effective pumping speed.  This higher effective pumping speed will shorten the time needed to strip solvent.  The 

 

time savings will depend on such factors as the solvent stripped, solvent temperature and operating temperature of

 

the cold trap.

 

The cold trap is installed between the pump and the vacuum chamber.  The water or organic vapors evolved from

 

the vacuum process entering the cold trap will come in contact with the cold surfaces of the trap and condense.  

 

Commonly used refrigerants are liquid nitrogen or dry ice with alcohol slurry.  Dry ice provides sufficient 

 

cooling to freeze out most heavy water vapor loads.  A variety of cold traps are available from Welch.  Contact 

 

your closest Gardner Denver Welch Vacuum Technology  sales office. See country directory on back cover, 

 

or visit the Welch Web-Site at www.welchvacuum.com.

2.32  The Care of a Liquid Trap

 

A liquid trap needs no refrigerant.  The key maintenance issue when pumping high vapor loads is to regularly 

 

drain the trap of liquid ejected from the dry vacuum pump.

2.33  The Care of a Cold Trap

 

When using a cold trap the refrigerant should be maintained at a high level in the flask to keep the trap at a 

 

uniformly low temperature.  If the trap is rewarmed it may allow re-evaporation of the condensate.  If the trap 

 

becomes saturated it should be disconnected from the system, drained and cleaned.  An increase in pressure in the

 

 vacuum system will normally indicate that the trap has become saturated.  To clean the trap, remove the trap from 

 

the system and allow the trap to warm up and rinse off the condensate with a suitable solvent in a fume hood.  

 

Thoroughly clean and dry the trap before reinstalling the system.

 

If a liquid nitrogen trap is used, the refrigerant add tube on the liquid nitrogen trap should not be obstructed as the

 

refrigerant boil-off can produce dangerously high pressures.

2.34  Application Note for Cold Trap

 

Cold traps employing a dry ice slurry or liquid nitrogen are effective as long as the refrigerant level is maintained.

 

If the trap warms up while the pump is running, all of the traped condensables will be ingested by the vacuum 

 

pump. Cold traps must be cleaned out at the end of each day. If the pump is run overnight, the trapped 

 

condensables will ultimately be ingested by the pump as the trap warms up. Cleaning a Dry Ice Slurry/Liquid 

 

Nitrogen trap is easy. The steps are:

 

 

1. Turn off the pump.

 

 

2. Leak air into the trap.

 

 

3. Remove the center well and plexiglas ring to a hood. The center well can be washed off into a

 

  

    beaker or the condensables can be allowed to evaporate in the hood.

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Summary of Contents for Welch Self-Cleaning Dry Vacuum System DryFast 2025

Page 1: ...ss underutilized and idle equipment along with credit for buybacks and trade ins Custom engineering so your equipment works exactly as you specify Critical and expedited services Leasing Rentals Demos In stock Ready to ship TAR certified secure asset solutions Expert team I Trust guarantee I 100 satisfaction All trademarks brand names and brands appearing herein are the property of their respectiv...

Page 2: ...fy intake and discharge before using pump See Section 2 28 CAUTION Do not pump liquids with the pump Pumping liquids will cause the pump to stop working 2025 2027 2028 9 Torr 12 mbar 2 Torr 2 7 mbar 2 Torr 2 7 mbar 2026 2 Torr 2 7 mbar Improved to better meet your laboratory needs New electronics with an enhanced self cleaning feature to help extend diaphragm life Superior vacuum level regulator f...

Page 3: ...struction could result in damage to the equipment associated equipment and process These units confirm to the SI International system of units of measurement The following symbols with recommendation of IEC1010 of warning will be found on the pump Caution refer to accompanying documents Caution risk of electrical shock Caution hot surface WARNING Motor includes a self resetting thermal cutout and t...

Page 4: ...eral Maintenance Section 05 Calibration 5 10 Calibration for Model 2027 only Section 06 Troubleshooting 6 10 Vacuum Problems Section 07 Specification 7 10 Pump Specification Table Section 08 Drawings Parts List and Exploded View 8 10 Dimensional Drawing 8 11 Schematic Wiring Diagram for Models 2025 and 2026 8 12 Schematic Wiring Diagram for Model 2027 8 13 Parts List and Exploded View for Dry Vacuum...

Page 5: ...id serious burns never touch unit during or immediately after operation 1 18 Be sure to properly identify intake and discharge before using pump See Section 2 14 WARNING Remove plug s from Exhaust Port s The Self cleaning Dry Vacuum System has one outlet port and one inlet port The ports are labeled 1 20 CAUTION To reduce risk of electrical shock 1 21 Do not disassemble Disassembly or attempted re...

Page 6: ...ounding temperature remains between 10 C and 40 C 50 F and 104 F Always check to insure the location chosen is protected from direct or indirect moisture contact The pump should be located as closely to its system in order to utilize it most efficiently WARNING Don t operate this pump in an atmosphere containing flammable or explosive gases or vapors WARNING The motor is thermally protected and will...

Page 7: ... must be plugged into an outlet that is properly installed and grounded in accordance with all local codes and ordinances DANGER Improper installation of the grounding plug can result in a risk of electrical shock If repair or replacement of the cord or plug is necessary do not connect the grounding wire to either flat blade terminal The wire with insulation having an outer surface that is green wi...

Page 8: ...is located in the top front section of the system The dial vacuum gauge is commonly used to indicate vacuum level when operating in the rough vacuum range 2 torr 2 7mbar 29 8 in Hg Dial vacuum gauges give negative pressure that is pressure below atmospheric The reference point for the gauges is atmospheric pressure Please keep in mind that atmospheric pressure tends to vary from day to day As a re...

Page 9: ...ballast or vent switch acts to minimize vapor condensation when pumping heavy vapor loads In a pump functioning on an apparatus with a high vapor load compression within the pump takes place in the normal manner until the saturation pressure of gas and vapor is reached causing the vapor to condense in the pump mechanism When air at atmospheric pressure is supplied to the compression stoke by means...

Page 10: ...ill shut off allowing the unit to vent to atmospheric pressure The outlet separator catches any liquid or particulates during the purge cycle To adjust the purge cycle time on Models 2025 2026 2027 from 2 minutes to 2 5 3 0 or 3 5 minutes unplug the pump remove the base panel at the bottom of the pump and adjust the delay in minutes switch SW2 to the desired setting as indicated in table below Dia...

Page 11: ...to freeze out most heavy water vapor loads A variety of cold traps are available from Welch Contact your closest Gardner Denver Welch Vacuum Technology sales office See country directory on back cover or visit the Welch Web Site at www welchvacuum com 2 32 The Care of a Liquid Trap A liquid trap needs no refrigerant The key maintenance issue when pumping high vapor loads is to regularly drain the t...

Page 12: ...p can be made out of readily available material for protecting the pump The trap would consist of a filtering flask placed between the pump and the vacuum chamber The simple liquid trap will act as a buffer for the inlet separator connected to the Self Cleaning Dry Vacuum System 3 13 Leak Detection The importance of eliminating all leaks in a vacuum system is obvious The pump must remove this added ...

Page 13: ...e the valve will be in the closed max vac position AUTO MODE Press AUTO button or Vacuum Control knob in MANUAL mode to enter AUTO mode AUTO mode gives you precise control of the vacuum setting via Up Down arrows Numeric Keypad and the Vacuum Control knob The bottom right of the display shows the set vacuum setting The initial vacuum setting must be set via the numeric key pad and enter button Onc...

Page 14: ...ol knob to scroll to the Program option and press to enter the Program menu screen The Program screen displays all existing stored programs in desired vacuum units and time minutes Use the Vacuum Control knob to scroll up and down and press the Vacuum Control knob to enter your selection If the memory location is empty the following screen will appear Enter the values requested first vacuum setting...

Page 15: ... and display the current units setting with an asterisk Use the Vacuum Control knob to select the desired units and push the Vacuum Control knob to change The screen will now display the new vacuum units Use the Vacuum Control knob to select Exit or Back to make additional changes from the Setup screen 2 SET CLEANING TIME Use the Vacuum Control knob to select the Set Cleaning Time option to change...

Page 16: ...e the Vacuum Control knob to select Exit or Back to make additional changes from the Setup screen 4 ABOUT Use the Vacuum Control knob to select the About option The About option lists the product model version and contact information Section 4 MAINTENACE 4 10 General Maintenance Welch dry vacuum units are 100 oil free The pump employs a diaphragm with uninterrupted Teflon coating No maintenance is ...

Page 17: ...d place over both pins See figure calibration mode below Step 4 Attach gauge to inlet of pump Step 5 Re apply power to the unit CAUTION Unit will start up as soon as power is applied Display will flash SEt CAL WARNING Unit is power be careful when removing calibration jumper Step 6 Step 6 When external gauge shows 2 Torr or less remove the jumper The unit will either go into purge cycle or normal op...

Page 18: ...uum Note Pump Cannot Start Under Vacuum Turn off and UNPLUG PUMP remove top housing and turn fan a few times Replace cover and turn on if problem still persists contact Welch Technical Support Turn pump off disconnect from application restart pump Check vacuum pressure of 2027xx with external vac gauge attached to pump inlet fitting If external vac gauge pressure is different than unit s display b...

Page 19: ...vel around 30 40 Torr indicates bad exh stage valve or diaphragm Bad valve or diaphragm Change Valve Diaphragm Loose eccentric or counterweight Tighten Loose Parts Use Loctite Broken diaphragm threaded insert Change Diaphragm Bad Con Rod bearing or motor bearing Change Con Rod Broken motor shaft Change Shaft Loose housing cover Tighten housing screws on back of unit Slide rail loose remove housing...

Page 20: ...p off and UNPLUG PUMP wait 30 seconds re connect to power and turn pump back on Digital gauge Displays CAL Err Unit has detected a calibration error Mechanical Failures Poor Vacuum Leaks Check inlet jar for leaks Check inner gasket and fittings tighten if loose Disconnect pump from system block off inlet port check vacuum level on the gauge If vacuum level reading is good work back through your ap...

Page 21: ...Bump Anti Foam Button N A N A N A YES Tubing needed I D in mm 1 4 7 1 4 7 1 4 7 1 4 7 Intake Exhaust Thread NPT 3 8 3 8 3 8 3 8 Weight lbs Kg 30 13 6 30 13 6 30 13 6 30 13 6 Programmable Repeat Function N A N A N A YES Store Programs N A N A N A up to 5 Timer N A N A N A 1 999 min Overall Dimensions L in cm 13 6 42 2 13 6 42 2 13 6 42 2 13 6 42 2 W in cm 12 30 5 12 30 5 12 30 5 12 30 5 H in cm 11 ...

Page 22: ...Section 8 DRAWINGS PARTS LISTS AND EXPLODED VIEWS 8 10 Dimensional Drawing 21 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com ...

Page 23: ...8 11 Schematic Wiring Diagram for Models 2025 2026 22 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com ...

Page 24: ...8 12 Schematic Wiring Diagram for Model 2027 23 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com ...

Page 25: ...bing PTFE Duality 1 30 Ft 6 1 See Note 1 Gasket 1 7 1 See Note 1 U Clamp 1 8 1 726123 Vacuum Gauge 2 Dial mbar kPa 8 1 726125 Vacuum Gauge 2 Dial in Hg cm hg 9 2 1423B Glass Jarr Assembly 10 2 1415B Replacement Glass Jarr Note 1 These parts are not available seperately but they are supplied in the 2025K 06 Service Kit 67 0994 Sheet 2 of 2 Rev 10 06 03 for Models 2025 2026 2027 2028 with S N ECO913...

Page 26: ...rts List Exploded View for Repair Kits Repair Kit 2025K 01 for Model 2025 Repair Kit 2027K 01 for Models 2026 2027 25 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com ...

Page 27: ..._______________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ ____...

Page 28: ...t will be repaired under this warranty rather than replaced The warranty is effective for one year from the date of original purchase when 1 The warranty card has been completed and returned 2 The product is returned to the factory or other designated service centers freight prepaid 3 The product in our judgment is defective through no action or fault of the user If the product has become defectiv...

Page 29: ...okie IL 60077 Phone 847 676 8800 Fax 847 677 8606 Technical Support Fax 920 451 4397 Ordering Copyright 1997 2004 Gardner Denver Welch Vacuum Technology Inc Welch is registered trademarks of Gardner Denver Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com ...

Page 30: ...quipment Have surplus equipment taking up shelf space We ll give it a new home Learn more Visit us at artisantg com for more info on price quotes drivers technical specifications manuals and documentation Artisan Scientific Corporation dba Artisan Technology Group is not an affiliate representative or authorized distributor for any manufacturer listed herein We re here to make your life easier How...

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