This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The historical development of 焭 is uncertain. It visually contains 火, 冖, and 几, but the original component relationships are unclear.
The kanji looks like a fire 火 under a cover 冖 resting on a table 几, but its meaning is unclear. Imagine a lone person sitting by a small fire under a shelter.
For ケイ, imagine a lone person (ひとりもの) named Kay sitting by the fire: Kay -> ケイ.