Current sensing relay
You can probably use them, but DON"T DO IT! You clearly know nothing about wiring practices, and your project has plenty of room for you to kill yourself or burn down your house.

If you must, this is the general approach







simulate this circuit &ndash; Schematic created using CircuitLab

The motor current closes the switch output, which applies 24 VAC to the relay coil. The coil contacts switch 220 to the blower.

A few caveats. First, although you have a 24 volt relay, you do not specify that the coil is AC. If it's a DC input, you're out ouf luck (unless you rectify the transformer output). Second, you do not specify the coil current requirement. If you need 2 amps on the coil, the power needed from the transformer is 2 x 24, or 48 VA, and your transformer is too small. Third, I recommend you get a spark arrestor for your relay contacts. If you don't, sooner or later your relay will fail from the transients involved with switching the blower.