Bal-Tec 010 HPM (High Pressure Freezer) Operating Instructions
CAUTION: Operation of the high-pressure freezer releases a significant volume of nitrogen gas which can displace enough oxygen from the room to create danger of asphyxiation. Do not ever close the door to the room while HPF is in operation.
START UP Procedure
- Check to ensure there is a full tank of liquid nitrogen (LN2) connected to the HPF.
- Check alcohol overflow bottle inside left end panel. Empty if more than 1/4” full.
- Fill alcohol tank to within 1/2” of the top of the window using isopropanol alcohol.
- To do this, open top of alcohol tank with Allen wrench (Hex Key) that lives on top of the HPF
- Be careful to keep hold of the nut as you lift out of the top of the machine (do not let it drop in the guts of the machine)
- Insert funnel into alcohol port and fill slowly with isopropanol until the bubble in the window is approximately 1/2” from the top
- Careful seat the nut back onto the top of the alcohol tank and tighten until just finger tight. If too tight, then it becomes extremely difficult to loosen after the tank is pressurized
- To refill alcohol during a run: Close the dry nitrogen tank completely. Then bleed off the nitrogen pressure in the alcohol tank by barely loosening the nut on top of the tank. Once the hissing stops, open the tank and repeat step 3c-d.
- Check that the hydraulic oil pressure relief value is closed by firmly turning it clockwise.
- The valve is a black knob located inside and toward the middle of the machine
- Check the water circulator and fill with tap water to 1” of the top. The circulator is located on the floor just to the left and behind of the machine.
- Turn on the main switch. First put key in “On” position, then turn red switch to the right 90°.
- Open dry nitrogen tank all the way. Nitrogen tank’s regulator should read 80 psi (red scale).
- Once open the Alcohol Pressure Gauge should read between 4-5 bar.
- Turn on air heater by pressing the small square Air Heater Let warm air blow for at least 1 minute.
- Open liquid nitrogen tank all the way. (No sounds are expected at this step, if you hear something coming from the line, check that the connections are tight)
- Press START button and wait until PISTON IN POSITION light is on. (Light should automatically come on with START).
- Press NITROGEN button, to activate the flow of liquid nitrogen into machine. NITROGEN LEVEL light will come on to indicate the dewar is low on LN2.
- Back flush the system with dry nitrogen:
- Wearing a cryo-protective glove, hold the rubber stopper to the bottom of the LN2 exhaust. The exhaust is a thin copper pipe that points down on back of machine.
- Hold rubber stopper to exhaust pipe opening to create a seal for 1 minute, then release.
- To exchange LN2 tank during run: Press NITROGEN to stop the flow of LN2. As quickly as possible, close the LN2 tank completely and disconnect it from the line; move in a full LN2 tank and connect it to the line and open the tank completely. Press NITROGEN. If more than 10 mins has passed, press STOP and enter shut down procedure.
- Wait for NITROGEN LEVEL light to go off. Once it is off, press DRIVE IN. The piston will move up and down three times and the oil pressure will reach ~100 bar
- Watch for DRIVE IN light to go off, then press AUTO. After approx. 15 minutes, proceed with test runs.
- Wait for and check throughout the run for the following:
- Oil Pressure should reach 300 bar
- Exhaust Temperature should read 170-180°C (really temp is negative °C)
- Object Head Temperature should read 30-37° If it dips below 30°C, then adjust the temperature on the water circulator.
- Do an initial check and monitor the O-ring stability of the sample holder throughout run, if it looks frayed, change it!
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