The Water Chiller

As Dan mentioned, I had the pleasure of draining the water chiller last week. Few have worked with the water chiller and come away clean. The water pump has as much power as a small lawn mower and can move a gallon of water in 2 seconds up 100 feet, which led to a fantastic disaster scene the first time we tested it in the lab.

For the past couple months we've been refilling the water chiller at about 2 gallons per week. The system is closed, so we were sure there was a leak. We were never able to find it though because you can't open the access panel with the exposed 1.5HP finger eating fan running inside.

Once it was open for draining, I toggled the manual bypass valve to try to get some of the last liquid out of the maze of pipes inside, and found this gem:


The manual bypass valve has a 1" long 1/16"wide crack running down the length of the body, which vomits a vile mixture of antifreeze and fungus water when toggled.

The other user accessible valve I needed, naturally, is also broken:
This valve shuts off the flow to the water pump, so that you can disconnect the device you're cooling water for. It now only closes to the point of the chiller drooling like an old dog.

Almost there

Since we stopped observation on August 22nd we've been reversing our work of the past year, taking pieces off the telescope and putting our gear back into boxes. It turns to be easier to take things apart than to put them together: in under two weeks we've gone from a fully operating instrument to a bare telescope with only mirrors and servos still attached. While Dave and I have been crawling all over the telescope, Ian and Tom have been going through the storage container, packing boxes and making sense of all the junk we've accumulated. Bryan was trying to work on data analysis so we made him drain the water and antifreeze from the chiller into jugs. Today we took apart the gantry, which was the last structure we're going to take apart ourselves.

To remove the various panels we had the telescope in birdbath position for a few days, and an overnight rain left this tree stump pattern on the primary. The Vertex guys are showing up in a little more than a week to handle the dis-assembly of the major pieces with the big crane as well as final preparations for shipping. We're in good shape for their arrival so we're taking a few days off this weekend.