Ok friends!, to find what SQL statement is using my Temporary TS,we used this query:
SELECT s.username, u."USER", u.tablespace, u.contents,
u.extents, u.blocks, a.sql_text, u.sqladdr, u.sqlhash
FROM v$session s, v$sort_usage u, v$sql a
WHERE s.SADDR = u.SESSION_ADDR
and a.hash_value = u.sqlhash and u.contents = 'TEMPORARY'

Right now,we run it and show us that there are 5 users using this TS with this statement: "SELECT NOMBRE,DIA_PROCESO FROM ARINCD WHERE NO_CIA = :b1 AND CENTRO = :b2",with extents between 110 and 115, also with #blocks between 2775 and 2850.

Our block size= 8K, SORT_AREA_SIZE= 192K and the TS TEMPORARY= 240 M, with initial=next = 192K.

We'd like to know,if the above query we are using to analize the Temporary TS is right or wrong ? If you have another better,can you bring it to me ?