Maybe try:
=ArrayFormula(if(len(B2:B), B2:B&C2:C&D2:D&E2:E&F2:F&G2:G&H2:H&I2:I,))
or
=ArrayFormula(substitute(transpose(query(transpose(B2:I),,rows(B2:B)))," ",""))
or, in case you want a space between the concatenated values:
=ArrayFormula(trim(transpose(query(transpose(B2:I),,rows(B2:B)))))
For using split() in arrayformula a workaround can be found here