Indirect Cryogenic Cold Trap System Instructions

Transcription

1 Indirect Cryogenic Cold Trap System Instructions Part Number:

2 1.0 INTRODUCTION Congratulations on your purchase of the SGE Indirect Cryogenic Cold Trap System. Please take time to carefully read the instructions in this manual to ensure trouble-free operation of your cold trap. The SGE Indirect Cryogenic Cold Trap is a device whereby a gas is cooled externally to the Gas Chromatograph by passing it through a heat exchanger immersed in a cooling medium. The cold gas is conveyed through insulated tubing to a "Tee" fitting inside the chromatographic oven. The capillary column is passed through this "Tee" before connecting it into the chromatographic system. There are several advantages to this procedure. A "cold spot" can be created on the column to hold components while the rest of the oven can remain heated. This saves time in terms of not having to heat and cool the whole oven and is far more economical in the use of coolant e.g liquid nitrogen. Secondly, the coolant can be a liquified inert gas or can be a mixture of alcohol/dry ice or even ice/salt water, depending on the temperature required. Finally, the cooling gas can be any gas convenient to the lab, even air directly from a diaphragm pump. WARNING: Do not use air as the cooling gas if you are using liquid Nitrogen or Argon as the coolant. There is the danger of freezing out oxygen which could lead to explosion. For further information and ordering of spare parts, please visit our web site at:

3 2.0 DESCRIPTION The SGE indirect cryogenic cold trap consists of a control module, a copper coil (heat exchanger) which is immersed in a Dewar flask (not supplied) containing the coolant, an insulated transfer line, a mounting bracket and "Tee" fitting which is located inside the oven. 2.1 CONTROL MODULE See figure Front Panel The front panel comprises two sections. (a) Cooling Gas The regulator and gauge enables pressure control of the cooling gas as it passes through the heat exchanger, transfer line and "Tee" piece. (b) Vent When the analysis is completed and/or cooling gas is no longer required, the gas flow is turned off and the heat exchanger is removed from the coolant. This leaves the system closed but containing gas at sub ambient temperatures. As the system warms up to laboratory temperature the gas expands and will generate quite high pressure unless vented. This is the purpose of the "Vent" REAR PANEL COOLING GAS IN This 1/8" compression fitting allows the cooling gas to be connected to the control module. COOLING GAS OUT This 1/8" compression fitting allows the pressure controlled cooling gas to be connected to the heat exchanger.

4 3.0 INSTALLATION 3.1 Locate a suitable position on the roof or side of the gas chromatograph and mount the "Tee" support bracket base plate using the two self tapping screws provided. (fig 2) 3.2 Drill a 3mm hole through the oven wall to allow the "Tee" to be inserted from the oven. 3.3 Connect the "Tee" into the 1/16 union and slip it into the spring clip supported by the bracket. Adjust the height using the set screws and Allen key provided. (fig 3) 3.4 Position the empty Dewar flask for the coolant convenient to the gas chromatograph and insert the heat exchanger. 3.5 Cut a piece of 1/16" SS tubing sufficient to allow connection between the "Tee" and the exit union of the heat exchanger. (fig 4) 3.6 Cut a similar length of foam insulation material and thread it onto the stainless steel. 3.7 Connect the insulated stainless steel line to the exit union of the heat exchanger and to the union on the "Tee" support bracket. 3.8 Position the Control Module alongside the Gas Chromatograph. 3.9 Connect the cooling gas - preferably Nitrogen or Argon, into the rear of the Module at the 1/8" connection labelled "COOLING GAS IN". NB: Compressed air may be used if alcohol/dry ice or salt water/ice coolants are used. DO NOT USE AIR IF LIQUIFIED GASES ARE USED AS COOLANTS DUE TO THE DANGER OF CONDENSING OUT OXYGEN Using a suitable length of 1/8" OD metal tubing, connect the "COOLING GAS OUT" port to inlet side of the head exchanger.

5 4.0 OPERATION 4.1 Thread the capillary column through the "Tee" and connect it appropriately for the chromatography required. 4.2 Establish the carrier gas flow. 4.3 Move the VENT valve on the control module to the "CLOSE" position. 4.4 Insert the heat exchanger into the Dewar containing the coolant. 4.5 Turn on the cooling gas and adjust the flow required by means of the pressure regulator on the control module. 10 to 20 psi should be adequate for most applications. 4.6 Observe the "Tee" in the oven as the temperature drops, "snow" will form indicating that the device has cooled to operating temperatures. Allow a few minutes to stabilize. 4.7 Introduce the sample, trap and hold it for as long as is required. 4.8 Turn off the cooling gas flow. The low thermal mass of the "Tee" allows it to come to oven temperature very quickly. 4.9 When required, re-establish cooling by turning on the cooling gas flow When there is no longer any need for cryofocussing, follow the SHUT DOWN PROCEDURE (5.0) 5.0 SHUT DOWN PROCEDURE To shut down the SGE Indirect Cooling System; 5.1 Turn off the cooling gas. 5.2 Move the VENT valve from the CLOSE to the OPEN position. 5.3 Then, and only then, remove the heat exchanger from the Dewar containing the coolant.

6 6.0 PACKING LIST Part No. Description Qty Cooling Tee 1 - Control Module 1 - Heat Exchanger 1 - Dewar Cap - Wooden 1 - Support bracket 1 - Swagelock 1/8-1/8 Union 1 - Swagelock 1/8-1/16 Union /16 Stainless Steel Tubing 2M 1 - Foam Insulation 2M VSR 16 Sealing Rings x 5 1 Pkt VSR 8 Sealing x 5 1 Pkt - Self tapping Screws 2 - Spanner 1/'' x 5/16'' 1 - Allen key 1/16'' 1 - SSU Union 1 - SSN 16 Nuts 2

7 FIGURE 1 Side View of Control Module Vent Vent Valve Gauge 0-60 Cooling Gas Out Pressure Regulator Cooling Gas In FIGURE 2 Support Bracket Fastened to the top or side of GC

8 FIGURE 3 Support Bracket with Cold Trap Tee FIGURE 4 Heat Exchanger

9 7.0 WARRANTY STATEMENT This Indirect Cryogenic Cold Trap and Control Module are guaranteed against faults in materials or workmanship for a period of twelve months from the date of invoice. This warranty implies free repair and or replacement of defective goods only, upon proper written proof and, where authorised, return of the defective product. It does not cover 'disposables'. This unit has been designed to fulfill the purpose of cryogenic focussing and this warranty is void if the instrument is used for any unrelated purpose. SGE reserves the right to refuse free service under warranty on any unit which has been abused or tampered with in any way. No other warranty or representation is expressed or implied by SGE for its products with respect to merchantability and fitness for any particular use or purpose or any other matter. SGE shall not under any circumstances, be liable for any incidental, consequential, or compensatory damages arising from use of or in conjunction with its products. The maximum liability for breach of warranty shall be the invoice price of said products. SGE acknowledges that there are many service engineers in the field who have the expertise to service the Cold Trap or Control Module and to assist them we have enclosed the necessary data in this manual. To protect your interest, however, we respectfully suggest that any failures during the warranty period be attended to by SGE service personnel or by SGE authorised service people.

10 SGE International Pty. Ltd. SGE Australia SGE, Incorporated Tel: +61 (0) Toll Free: Tel: (800) Fax: +61 (0) Fax: (03) Fax: (512) support@sge.com sales@sge.com usa@sge.com Web: SGE Europe Ltd. SGE France Sarl SGE Italia Srl. Tel: +44 (0) Tel: +33 (0) Tel: Fax: +44 (0) Fax: +33 (0) Fax: uk@sge.com france@sge.com sge.italia@tin.it SGE Laboratory Accessories Pvt Ltd SGE China Service Centre SGE Japan Inc. Tel: +91 (022) Tel: 86 (10) Tel: Fax: +91 (022) Fax: 86 (10) Fax: sgeindia@bom4.vsnl.net.in sge@bj.col.com.cn japan@sge.com SGE Deutschland GmbH Tel: +49 (0) Fax: +49 (0) germany@sge.com Publication No. MN-0195-A Rev:02 03/01