Retrofitting a clinker cooler within 25 days

27 October 2015

In order to meet increasing market demands, cement producers may choose to install a new production line or upgrade their existing components. When deciding to upgrade the existing equipment, it is not only important to purchase the highest technical standard but also to accomplish the refurbishment in the shortest possible time frame to minimize down times.

Therefore, Pioneer Cement Industries was careful in designating their partner for the cooler upgrade project at Ras-Al-Khaimah (Fig. 1) where production was to be increased from 4000 to 4400 tpd. IKN was not only selected as the preferred supplier for the cooler upgrade but also took over the responsibility for the turnkey installation of the new cooler into the existing housing. The installation only took 25 days from flame off to flame on.

Existing situation at Pioneer Cement
Pioneer Cement operates a kiln line with a 6-stage, single string preheater. The kiln has a diameter of 3.95 m and a length of 65 m. The existing cooler should be replaced with the latest technology Pendulum Cooler® by IKN.

The reason for the cooler replacement was the high clinker outlet temperature of the existing cooler, above 160°C, which prevented the planned increase in capacity. Even though the existing cooler was in good condition, frequent stoppages on the existing hammer crusher occurred and hindered the efficiency of the pyro line.

The decision for a complete retrofit of the cooler was made after a thorough evaluation of different options.

Proposed solution
The project partners agreed to retrofit the existing cooler with a modern Pendulum Cooler® with a targeted capacity of 4400 t/d.

Cooling of the clinker is realized with a total grate area of 97.9 m2. For this purpose, the existing housing including the upper cooler housing refractory was reused. In addition, the housing was extended to give space for the increased grate area. The installed crusher is a robust and highly efficient roll crusher with 4 rolls.

The KIDS® for the new cooler at Pioneer Cement consists of 6 rows and has an inclination of 15 degrees. The Pendulum section consists of 83 rows. Cooler aeration occurs with high efficiency cooling fans. During the detailed planning stage it was determined that 8 fans could be re-used and 2 new fans have to be added. For the existing fans, new silencers were supplied by IKN.

The calculated clinker load is 45 t/m2/d at an installed cooling air of 2.05 Nm3/kgclinker. Tertiary air is taken from the kiln hood. The entire design of the cooler focused on fast erection in order to keep the shutdown time to a minimum.

This involved pre-assembled grate surface packages as well as special tools to prepare preassembled units which could be easily handled. The kiln hood remained as is. Only the bull nose was newly lined with refractory. A detailed analysis of the existing general arrangement was carried out in order to identify and mark equipment that had to be removed prior to and during shutdown.

Detailed time and material management
In order to meet the tight schedule, a detailed plan was made at the very beginning. The project partners agreed that all of the works which could be done prior to shut-down needed to be completely finished before the shut-down.

The most crucial points were the positions and foundations of the new equipment. Therefore, as much foundation work as possible was done during operation of the kiln line. A precise plan for the working area and storage logistics was prepared when the dismantling of the old cooler and the installation of the new cooler began.

The clock started to run when the kiln stopped on 23.06.2014. Directly after stopping the kiln, the dismantling of the old cooler started. At the beginning, the dismounting of the support of the old inlet section was very challenging since the old cooler components were heavily welded especially in the area of the cooler. In addition, the refractory of the upper cooler housing was in worse shape than expected.

Since it was targeted to be maintained, additional efforts had to be taken into account to fix or repair it. New refractory was only targeted for the KIDS® (horseshoe) area, the side curbs, the extended cooler housing and the bull nose. In order to save time, the refractory for the new extended cooler housing was installed in workshops near Ras-Al-Khaimah and then delivered to the plant. Electrical and mechanical works were done simultaneously in order to speed-up the entire project.

Optimized pre-assembly and installation
Special measurements were taken in advance to facilitate a quick modular pre-assembly as well as the fast installation of the new cooler parts. Prior to the shipment of the components, the main parts of the mobile and fixed frame including the LPS® were pre-assembled in Germany. Special provisions for alignment and measuring tools have been installed to allow for a fast, modular and easy installation and alignment on site.

The grate surface was shipped pre-assembled in large blocks, while the movable frame was pre-mounted at the plant. The roll crusher was installed as a single unit at its designated maintenance position.

Once the old cooler was dismantled, the pre-assembled components were installed following a compulsory sequence according to the prior determined pre-assembly and erection plan. Components of the fixed and mobile frame were installed once the basement together with the dust hoppers were finished.

The KIDS was pre-assembled on site and lifted as a unit into its designated position along with the grate supports and the pre-assembled grate modules. After only 25 days the mechanical work on the cooler was successfully finished (Fig. 2).
This excellent outcome was a result of the close and efficient cooperation between the plant representatives from Pioneer Cement, the technology supplier IKN and Mertec, who was responsible for the construction.

After flame-on, hot commissioning was successfully completed and the executed performance test showed that the guaranteed values had been achieved. Recuperation efficiency and electrical consumption exceeded their guaranteed figures.

Thanks to the intensive cooperation between all project partners, the project could be successfully finished in the targeted time frame. The project partners, above all the project leader Pioneer Cement Industries LLC, agreed that it was a challenging but very successful project.

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