What did I hit?

[Lena]

I was thinking tonight about an old friend and myself at his farm's dump ground there was an old fridge standing there, we checked inside both doors to be sure and backed off 30 yds or so and fired 6 each from S&W 29's, freezer was on bottom about half way through this thing just blew up in a red ball of fire with a muffled explosion we were very surprised, always wondered what we had hit as there was nothing inside of it. Any ideas?

[FCH]

It is possible someone recharged that refrigerator with an illegal refrigerant like isobutane (which has been used legally in Europe). Here is an article about dangers from illegal AC refrigerant (R22a) but that is not the refrigerant used in small appliances.
EPA Issues Warning on Flammable A/C Refrigerant

[puma guy]

Older compressors used mineral oil for lubrication. Perhaps the oil was being atomized by a leak and a subsequent round sparked the ignition.

[TexasJohnBoy]

I was thinking tonight about an old friend and myself at his farm's dump ground there was an old fridge standing there, we checked inside both doors to be sure and backed off 30 yds or so and fired 6 each from S&W 29's, freezer was on bottom about half way through this thing just blew up in a red ball of fire with a muffled explosion we were very surprised, always wondered what we had hit as there was nothing inside of it. Any ideas?

yeah flammable refrigerant.

But, was it cool? Is everyone OK?

[goose]

But, was it cool?

TJB asked the correct question. :-)

[puma guy]

The heating/burning of freon creates phosgene gas BTW.

[Gunner4640]

The heating/burning of freon creates phosgene gas BTW.

which hurts the ozone like everything else now a days

[puma guy]

The heating/burning of freon creates phosgene gas BTW.

which hurts the ozone like everything else now a days

Not too healthy for humans either!

[Lena]

Just very surprised and all ok, we got so shoot a pickup with a MG34 and a car years later but the fridge really got to us. Almost every round went all the way through the fridge.

[puma guy]

Just very surprised and all ok, we got so shoot a pickup with a MG34 and a car years later but the fridge really got to us. Almost every round went all the way through the fridge.

maybe it was a gas refrigerator.

[TreyHouston]

Just very surprised and all ok, we got so shoot a pickup with a MG34 and a car years later but the fridge really got to us. Almost every round went all the way through the fridge.

maybe it was a gas refrigerator.

[Pawpaw]

Just very surprised and all ok, we got so shoot a pickup with a MG34 and a car years later but the fridge really got to us. Almost every round went all the way through the fridge.

maybe it was a gas refrigerator.

I take it you never heard of a gas refrigerator?

[Jusme]

Just very surprised and all ok, we got so shoot a pickup with a MG34 and a car years later but the fridge really got to us. Almost every round went all the way through the fridge.

maybe it was a gas refrigerator.

I take it you never heard of a gas refrigerator?

They have sure gone up in price. I haven't seen one in several years, but I know that most RV fridges in the 70's ran off of propane. One of the summer camps my son attended, had a huge gas walk in cooler, in the dining hall.

But with the one the OP spoke of, the gas should have been all gone since, unless I'm mistaken, there is no storage of gas. Once they are disconnected, the gas should dissipate. There may be a little bit in the regulator valve, but not much.

[treadlightly]

Absorption cycle refrigeration, very interesting. I don't have all the details down, but it's sort of like a closed loop distillation process. A volatile refrigerant is in mixture with another substance. Heat is applied to the solution to boil the volatile out of solution. The added heat energy is captured by the state change of the volatile from liquid to gas. Next, the volatile refrigerant, in gas state, is cooled by direct radiation to the environment. This is where energy is shed, turning it liquid at a lower heat content than before it was boiled. Then the liquid refrigerant it is evaporated, transferring heat out of the refrigerator into the state change from liquid to gas and cooling the brewskis.

The evaporated refrigerant is then recaptured into solution to get boiled out again.

At least that's how I understand the cycle.

Physicists Einstein and Szilard thought the concept had merit and worked out improvements, which they patented and sold to Electrolux. It's an interesting world any time nuclear scientists get mixed up with vacuum cleaners.

More info here - https://en.wikipedia.org/wiki/Einstein_refrigerator.