B737-300 ACR FLC DISCOVERS ON POST FLT INSPECTION THAT BOTH ENG'S FAN SECTIONS HAD BLADE TIP DAMAGE; APPARENTLY FROM ICING. THE FORWARD COWLING OF THE CFM-56-3C ENGS IS DEICED; BUT THE NOSE DOME IS NOT. BOTH ENGS WERE REPLACED. ICING WAS NOT FORECAST.

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WE ARRIVED AT THE ACFT AND WERE INFORMED BY THE PREVIOUS CREW THAT ALL ALTS ABOVE FL240 WERE EXTREMELY TURBULENT. PREFLT AND DEP WERE NORMAL. WHEN HANDED OFF TO ZDV WE ASKED AND WERE GIVEN FL240 FOR A FINAL ALT. AS WE CROSSED THE MOUNTAIN RANGE S OF PUEBLO WE BEGAN TO EXPERIENCE LIGHT AND OCCASIONALLY MODERATE TURB. ZDV CONFIRMED RPTS THAT ALL ALTS ABOVE FL240 WERE EXTREMELY TURBULENT; BUT FL220 HAD BEEN RPTED AS GOOD. WE REQUESTED AND RECEIVED CLRNC TO FL220. AS WE DSNDED WE TURNED ON BOTH ENG AND WING ANTI-ICE SYS. OVERWING ILLUMINATION LIGHTS WERE TURNED ON AND WE MADE SEVERAL VISUAL SCANS TO MAKE SURE NO ICE ACCUMULATION HAD DEVELOPED. INITIALLY AT FL220 WE EXPERIENCED LIGHT TURB; BUT THE CTLR SAID IT WAS REGIONAL AND AS WE CONTINUED S OF ALAMOSA IT WOULD GET BETTER. WE THEN HEARD A 'THUMP' ON THE ACFT AND IMMEDIATELY REQUESTED A CLB. WE ENDED AT FL260 AND LATER FL280; BOTH OF WHICH WERE COMFORTABLE RIDES. APCH AND LNDG IN PHOENIX WERE NORMAL; BUT POSTFLT REVEALED DAMAGE TO COMPRESSOR BLADES AND BOTH ENGS. THERE HAD BEEN NO RPTS OF ICING AT ANY ALT EITHER FROM WX SVCS OR ATC. IN THE FUTURE WE WILL USE CAUTION WHEN RECEIVING ADVISORIES FROM OTHER CREWS AND ATC. WX PATTERNS CAN MOVE QUICKLY AND CHANGE RAPIDLY.