/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 14-11-15
 * Time: 上午10:48
 */
function K_Split($min, $max, $str){
    $a = array();

    while ($str != ''){
        $p = rand($min, $max);
        $p = ($p > strlen($str)) ? strlen($str) : $p;

        $buffer = substr($str, 0, $p);
        $str = substr($str, $p, strlen($str)-$p);

        $a[] = $buffer;
    }
    return $a;
}
$test_string  = '136919X5206135XX225117136X68077XX1376020341213X980985821353XX9246561861708X03313XX62256731392XX9';
print_r(K_Split(11, 11, $test_string));
/**
 * restult
 * Array
(
[0] => 136919X5206
[1] => 135XX225117
[2] => 136X68077XX
[3] => 13760203412
[4] => 13X98098582
[5] => 1353XX92465
[6] => 61861708X03
[7] => 313XX622567
[8] => 31392XX9
)


 * 
 * 
 */