Recirculating Ice Water Bath From Battery Operated Desktop Fountain

Lets say that you have a Microchemistry condenser column and you need a recirculating ice water bath to cool the condenser. These can cost up to $1000. We show you how to how to make one from a cheap battery operated desktop fountain for under ten dollars. It can run continuously for two days on one set of AA batteries and provides a steady stream of ice-water or room temperature water to the condenser column.

Find a fountain that you can take apart. We went to the local "$5 and below" store to pick up a few battery operated desktop fountains. This one was small and cost $4. It runs continuously on two AA batteries for about two days. It measures about 6 inches in height and the bowl diameter is 5 inches.
It runs very quietly. Other places that have small fountains are the grocery store gift sections, sometimes the dollar stores or even swap shops and garage sales.

Take a screw driver and crack the glue that holds the upper fountain onto the base reservoir. This fountain had three places that were easy to see from the top. Placing the end of the screw driver in between the edge and the fountain and tipping the screw driver back (away from the base) will crack the glue. In this image you can see down into the reservoir where the pump pump is. One of the three glue points is seen at the front of this fountain, next to the screw driver tip. When we opened the fountain we saw that the pump had been wrapped in bubble wrap with a twisty tie around the outside of the pump, presumably to keep it running quietly without vibration.

In this step we tipped the fountain head back from the reservoir to expose the hose that leads from the pump, up into the fountain. The power wire for the pump is black and leads into the battery block in the bottom of the reservoir. The water goes into the from of the pump through the little hole in the end, just in front of the tube attachment point.

The second image below shwos how to cut the tube that goes up into the fountain head. Once you cut this tube you can throw the fountain part away. You are left with the reservoir and the pump.

Once we take the little stub of tubing off of the pump outflow nozzle (I used and exacto blade) you can then attach a pice of latex rubber tubing to the pump outflow. We used the latex tubing because its flexible and would not put any additional stress on the microchemistry glassware.

After attaching the latex rubber tubing to the pump then fill the reservoir with water and turn on the pump. These fountains usually have a switch on the outer surface that turns them on.

To determin the flow rate, fill the researvoir and get a measuring cup that has metric measurements. Hold the latex rubber tubing over the cup and turn on the pump. If you look at a clock and see how many seconds it takes to transfer 500 mililiters of the water to the cup then you can figure out the flow rate in liters per minute. For example if it takes 1 minute to fill 500 ml then you would have a flow rate of 0.5 liters/minute.

Now glue a return tube to the bottom of the reservoir. It should be pointed away from the intake of the water pump so that it does not return the water warmed by the condenser column directly to the intake for the pump. we used a little crazy glue to hold the tube down. We added to bayonet type connectors and some ties to hold the tubes together. Plastic 1/4 inch double bayonet connectors are lighter than these and they cost about 0.88 cents each.

Now its time to hook up the latex rubber tubing to the condenser column. The outflow from the pump goes into the lower port on the column and the retrun to the water bath is connected to the upper port on the condenser column.

This is a slightly larger fountain that had a fake candle with LED lights that made it look like the candle was flickering. We pushed the LED lights down inside the fountain before we cut the top off. Now the water proof LED's are lighting the ice bath. Totally unnecessary but very cool!

Here are a few good hints!

Good luck and be safe!