#!/usr/bin/perl
use strict;
use warnings;

my %hash_merge;

while (<DATA>) {
    chomp;
    my ($key, $value) = split /\|/, $_;
    push @{$hash_merge{$key}}, $value;
    print "key for $key merge values: ", $hash_merge{$key}->[0], "\n";
}

use Data::Dumper;
print Dumper \%hash_merge;

__DATA__
9344220001|sei10720013,21/07/2009-00-00-00,23/07/2009-12-34-44
9344220001|sei10720014,23/07/2009-20-00-23


##</code><code>##

key for 9344220001 merge values: sei10720013,21/07/2009-00-00-00,23/07/2009-12-34-44
key for 9344220001 merge values: sei10720013,21/07/2009-00-00-00,23/07/2009-12-34-44
$VAR1 = {
          '9344220001' => [
                            'sei10720013,21/07/2009-00-00-00,23/07/2009-12-34-44',
                            'sei10720014,23/07/2009-20-00-23'
                          ]
        };