Files is empty after download

I'm trying to download files of different type from Data Base from the Blob field. When i'm opening files and images, all files is empty. Can`t understand what is wrong here. Thank you for advice.

Here is example of my code:

    $file = DB::table('files')->where('id', $fileId)->get()[0];

    header("Content-length: $file->file_size");
    header("Content-type: $file->file_type");
    header("Content-Disposition: attachment; filename=$file->file_name");
    ob_clean();
    flush();
    echo $file->file;`

`

via Chebli Mohamed