The build-up related to another “Cooler Wars” panel discussion for this week’s IEEE Conference Participants turned out to be very anticlimactic. Following the panel discussion, nearly all of the participants polled concluded that there is very little in the way of technology that currently differentiate the major OEMs (KHD, Polysius, FLSmidth, Claudius Peters) when it comes to clinker coolers:
• All current OEM designs (except IKN) are offering a 3rd Generation Cooler based on FLSmidth’s revolutionary Cross-Bar Cooler which was developed more than 12 years ago (having separated the conveying function from the cooling function).
• In the case of IKN, this seems more like a lack of commitment to new R&D than any perceived advantages for a 2nd Generation cooler compared to the other OEM’s 3rd Generation designs.
For cement producers, they really can’t go wrong with any of the new 3rd Generation Coolers:
• Cooler run-time has improved dramatically since the mid-1990s.
• Heat recuperation has increased substantially.
• Low maintenance costs are now verifiable.
KHD and FLSmidth may hold a slight advantage because of their patented airflow control valves for each “grate plate” in the cooler.
Here’s our report of what each OEM had to say:
1. KHD Pyro Floor Cooler, presented by Thomas Binninger:
a. Only 10 coolers in operation. Excellent presentation. Nothing new except published process results which show air consumption as low as 1.6 Nm3/kg to achieve 70 C above ambient temperature clinker.
2. Polysius Track Cooler, presented by Dr. Uwe Maas:
a. About 65 coolers in operation.
b. New static inlet section (zero step discharge) for improved cooling and maintenance.
c. Verifiable low maintenance costs.
d. Probably the most authentic of all speakers (keeping promises regarding wear life of components and working to make it even better):
i. Informed the audience not to confuse expected wear results (anticipated) with guaranteed wear results (warranty).
e. Unfortunately, Polysius again failed to present any verifiable cooling performance data (probably owing to zone aeration compared to airflow control valves).
f. Static grate does not prevent snowman, but removal of snowman becomes easier due to the continuous incline without steps.
g. 200 to 225 mm stroke length.
3. FLSmidth Cross-Bar Cooler with ABC Inlet, presented by Steven Miller
a. Nearly 200 coolers in operation.
b. Snowman prevention systems with variable blast area, frequency, and intensity.
c. FLS is willing to guarantee “no down-time” due to snowman formations.
d. Most credible presentation based on 12+ years of experience and over 200 coolers sold. However, missed an opportunity to really drive this point home (e.g. imitation is the highest form of flattery).
e. Case Study: Standard Cooler Loss decrease from 104 to 96 kcal/kg clinker.o
f. Guarantee 2-3 years for wear components and 5 years for grate “plates”.
g. 180 to 200 mm stroke length.
4. CPAG Eta Cooler, presented by Andre Vos:
a. 16 coolers in operation.
b. Self-protected aeration lanes (93% of grate is protected).
c. Unfortunately, the grate requires pre-charging with sieved gravel because clinker has been shown to breakdown in this cooler over time adding pressure drop across the grate.
i. Reportedly, this was ‘discovered’ by Holcim.
d. Zone aeration (like Polysius) which at least in theory is less effective than airflow valves (KHD and FLS).
e. If a hydraulic cylinder fails, it is possible for the cooler to continue operating with “one lane down”.
f. Run factor of up to 99.95% for cooler alone.
g. Longest and variable stroke length to allow for increased retention time.
h. 200 to 300 mm stroke length.
5. IKN Cooler, presented by Christoph Lange:
a. 96 coolers in operation.
b. Lowest drive power (simple physics – no friction between ‘lanes’).
c. 120 to 125 mm stroke length.