For full quench blades here's what I use.
It's a modified electric hot water heater. It maintains a constant temperature and circulates the quenchant. The tank is mounted on a dolly so that I can roll it right over beside the heat treat oven when needed. The lid is big pizza pan. The temperature is controlled with the rheostat mounted at the bottom of the tank.
Here's a shot from the top.
No need to email me about how it was made. I didn't make it and I don't have a clue. I can make knives, but I can't nail two boards together with calling someone for help.

I traded a hunter for it.
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For edge quenching I use a big, deep stainless steel steam tray. That's those things they use in a cafeteria to keep food hot. You can see it in the first shot on the work bench behind the full quench tank.
I also have a third container that I use for little knives like the Platypus ultra-light. It's a stainless steel mud bucket that is used in drywall work. I ran a bead of J.B. Weld on all the seams to make it water tight. I've used that little thing since about 1993 and it's still working fine (I love J.B. Weld).
To control the temperature on the two edge quench containers I use a hotplate.