Upgrading for growth

Staying ahead of market demand is key to a cement producer’s long-term competitiveness. Because of increasing demand for cement in the Indonesian region, the PT Semen Indonesia Group (PT SMI) decided to grow its production capacity. This would be achieved with a multifaceted strategy, including construction of new plants, acquisition and plant upgrades.


PT Semen Gresik is a subsidiary of PT SMI. For its Tuban plant, the strategy to increase capacity involved upgrading the plant’s cement lines 1, 2 and 3 from 7,500 to 9,000 tpd.


Bambang Tridoso is General Manager of PT Semen Gresik. He explains the reason for prioritising an upgrade of the Tuban plant: “Upgrades are particularly important as capacity can be quickly and easily expanded at a reasonable cost. First, the technology selected for upgrading must be readily compatible within the existing plant operations. Second the equipment should be successfully benchmarked against similar plants, and third, the equipment must be easy to maintain.”


The overall scope of the upgrade included a coal mill, preheater feed split, new ID fans, new burners, a new kiln drive and a cooler retrofit. The plant’s line 1 was the first to be upgraded. Shortly after it was commissioned in 2010, the upgrades of lines 2 and 3 commenced. A significant part of this involved upgrading and retrofitting the two lines’ coolers.  

Tuban_Indonesia Cross bar cooler
Installation of FLSmidth Cross-Bar® cooler units

Choosing the right supplier

Bambang Tridoso and his colleagues evaluated several potential cooler technology suppliers. Reputation and experience were key, he explains.

We wanted the cooler supplier to have an established international presence and demonstrate outstanding experience in cement technology with equipment installed in various countries.

Bambang Tridoso General Manager of PT Semen Gresik

Competitive pricing was essential, as were performance guarantees for power consumption and clinker temperature. As this was the final part of Tuban’s upgrade project, with all other components already in operation, the supplier needed to commit to a very tight time schedule. Furthermore, PT SMI required that some of the major equipment components were fabricated locally.


Having supplied equipment and services to PT SMI for more than 100 years, FLSmidth was among those evaluated for the project. After an extensive evaluation process, PT Semen Gresik chose FLSmidth as supplier. According to Bambang Tridoso, FLSmidth met the evaluation criteria for the project and was chosen for its extensive experience in cement technology as well as its competitive pricing. He points to the global supplier’s experience dating back more than 130 years and to its tried-and-tested product technology.


Omar Rabia, Sales Manager at FLSmidth, says that the two companies have enjoyed a special relationship and talks about his own experiences of working with the Tuban team and why this cooler retrofit was so important:


“I have always enjoyed good relations with the people at Tuban. The relationship features frequent communications and constructive dialogue. We understood that this cooler project was of the highest priority, because it was an essential element of increasing the plant’s capacity.”

Tuban_Indonesia Cross bar cooler
The PT Semen Indonesia and FLSmidth team sign off on performance testing of the FLSmidth Cross-Bar® cooler on Tuban’s line 3

FLSmidth provides a fast solution

Supported by FLSmidth’s technical specialists, Omar Rabia discussed different solutions with Tuban’s engineering department, who was responsible for the technical evaluation of FLSmidth’s proposal. Together, they arrived at a solution that involved reusing as much of the existing equipment as possible. This included cooler fans, cooler casing and an ABC™ inlet, which had already been supplied. The primary project would then involve replacing most of the internals of the old grate coolers with FLSmidth’s Cross-Bar® coolers.


Omar Rabia says, “We demonstrated the ability to reuse existing equipment, specifically the cooler fans, which would contribute significantly to reducing investment costs and payback time.”


The agreement between FLSmidth and PT SMI involved the Tuban staff performing most of the upgrade themselves. As part of the brief to support with specialist supervision and commissioning assistance, FLSmidth was asked to help with competency transfer.


Three FLSmidth supervisors were onsite to assist and answer questions associated with their specific areas of expertise. The mechanical supervisor helped to ensure equipment was installed correctly and that all tests were carried out according to instructions. The electrical supervisor assisted with wiring and electrical installations, while the commissioning supervisor oversaw start-up and subsequent optimisation of the coolers, including meeting performance guarantees. The plant was restarted vertically without stoppage until performance guarantee testing was complete. 

The FLSmidth Cross-Bar® cooler units being moved from the pre-assembly area
Installation of FLSmidth Cross-Bar® cooler units
The newly installed FLSmidth Cross-Bar® cooler


Søren Skov Hansen, Project Manager at FLSmidth, explains how FLSmidth’s supervisors helped to ensure a safe and smooth start-up: “They possess very important core knowledge, with intimate details of how to install and operate equipment. Having this available onsite is highly valuable. Not only does it save time during commissioning, because they are there to answer questions immediately, but it also reduces the risk of problems during the start-up phase.”


The first cooler was erected and commissioned in just 30 days. The only unexpected challenge the team had to overcome was a hydraulic pipe leakage, which was easy to overcome. The second installation was performed even faster and with no interruptions.


In a further move to optimise the coolers’ performance, the plant was monitored in real time remotely via the internet for several weeks following commissioning. Søren Skov Hansen explains that this was an additional service to ensure long-term smooth running of the plant, saying, “It is a very efficient way for us to provide any necessary advice on how Tuban can optimise operations.”

Successful performance

Bambang Tridoso and his colleagues are highly satisfied with the successful retrofit of the two coolers, which has increased overall plant capacity. The accompanying table shows how the performance guarantees for both coolers were matched and beaten.


Performance guarantees
  Design Achieved, line 2 Achieved, line 3
Cooler size CB 16x73

Effective cooling area 200.8 m3

Capacity 9,000 tpd 9,164 tpd 9,073 tpd
Grate loading 44.8 tpd/m2 45.6 tpd/m2 45.2 tpd/m2
Clinker temperature 65° C + Amb.  61° C + Amb.  44° C + Amb. 
Cooler efficiency
75.1% 76.2%

Power consumption
(reused fixed speed fans & drives)

6.75 kWh/t 6.71 kWh/t
6.36 kWh/t
The success of the cooler retrofits and capacity upgrade have taken PT SMI a step further on its road towards its long-term goals.

We would be happy to work with FLSmidth again, because we are familiar with the performance of the equipment, which has demonstrated stable, optimal conditions during operation.

Bambang Tridoso General Manager of PT Semen Gresik

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