how to save blob data into hard disk using PL/SQL?

I have following tables structure, where I have blob data column and extension of files..

SQL> desc ec_blob;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 TEST_INSTANCE_ID                     NOT NULL NUMBER(10)
 TIME_STAMP                                NOT NULL NUMBER(20)
 VERIFIER_ID                                 NOT NULL NUMBER(10)
 SEQ_NUMBER                              NOT NULL NUMBER(10)
 BLOB_NUMBER                            NUMBER(20)
 TYPE                                             NUMBER(10)   => extension type in number format
 BLOB                                            BLOB        => BLOB data column

SQL> desc BLOB_TYPES;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 TYPE_ID                                   NOT NULL NUMBER(10) => extension type in number format
 TYPE_NAME                              NOT NULL VARCHAR2(20) => extension name like .csv, .txt, .xml, .pdf etc....
 CHARSET                                  VARCHAR2(128)


 I am looking pl sql code which can migrate these information and save into hdd location... there are 1000 of rows can not do manually...