Need an air flow generating unit for automatic wind instrument

Yes, car tyre inflators are always very loud, and also tend to be very low flow rate (and the higher pressure ones are even lower).

I suspect you need something in the region of a couple of liters per minute at a few psi, but it would really be a good idea to find out what pressure and flow rate you actually need. There are plenty of ways to do this, even starting with how hard you have to blow and how long a lungful of air lasts. Come on, you've got these things in front of you.