Either by transposition for 'ariy'el or, more probably, an orthographical variation for har'el; the altar of the temple -- altar.
see HEBREW 'ariy'el
see HEBREW har'el
H741. ariel
אֲרִאֵיל noun [masculine] hearth, altar-hearth (ᵐ5 Ἀριηλ; from ארה with ל aff. according to Ew§ 163 g Ol§ 220 Sm Ezekiel 43:15 Di Isaiah 29:1 and elsewhere; but this formation very rare & here dubious; ᵑ7 Hi De Brd Or 29:1 derive from אל + ארי = hearth of El, see also RSSemitic i. 469, who thinks of pillar-altars; compare אראלדודה MI12 see Sm & So, and DrSm xci) — אראיל Kt Ezekiel 43:15-16, (Qr אֲרִיאֵל); = הַרְאֵל 43:15 (Vrss Co אריאל), all with article, — of altar-hearth in Ezekiel's temple.