| PHYSIOLOGICAL
INSTITUTE Medical Faculty Ludwig-Maximilian University Munich |
|||
Prof. Dr. E. Gerlach, Prof. Dr. Dr. h. c. K. Thurau | |||
 | |||
|---|---|---|---|
| Dipl.-Phys. Franz Rucker | |||
| Physiological Institute, Pettenkoferstrasse 12, 80336 Munich | Pettenkoferstrasse
12 80336 Munich Telefon + 49-89-59 96-247 Telefax + 49-89-59 96-216 |
||
| MAXX TECH Mozartstraße 9 A-4063 Hörsching |
December 18, 1996 | ||
| Test of the Vulcan 5000 electronic water treatment device for the cooling system of the Coherent GmbH Innova 90-K laser (user report) | |||
| Dear
Mr. Kleefisch, With reference to our telephone conversation on 18.12.96, I hereby send you a description of our test use of your Vulcan 5000 electronic water treatment device. The Vulcan 5000 system was installed here in the cooling water inline fed by normal mains water for a Coherent GmbH Innova 90-K crypton gas ion laser at the end of March 1996, in order to reduce or even eliminate chalk deposits on the ceramic casing of the laser tubes (see enclosed diagram). In recent years, we have had continuous difficulties with laser pipes that were no longer operational and hence required replacement as a result of heavy deposits of chalk around the tube ceramics, along which the cooling water flows at a through-flow quantity of approx. 9 l/min and at a pressure of approx. 2.5 bar, heated up to 608C to 708C depending on gas discharge current (tube current) between 30 A and 40 A. The Vulcan 5000 system is an inexpensive alternative to expensive heat exchangers, i.e. enclosed cooling water circuits with treated water. The price of such heat exchangers is around DEM 10,000.-. The Vulcan 5000 device has been used since the end of March 96 for experimental cooling water treatment for our gas laser. On 12.12.96, Coherent GmbH inspected the laser tubes for chalk deposits on the ceramic surface. No traces of chalk deposit were found, i.e. overall a positive inspection result (see service report by Coherent GmbH, enclosed). During the test period, the laser was in operation for approx. 200 hours at between medium and maximum laser tube current, operational periods being between 4 and 8 hours. These operating hours and performance requirements correspond with the normal use of the laser in our fluorescence microscopy experiments. With similar operating data, considerable chalk deposits developed on the previous laser tubes which were operated without cooling water treatment. | |||