Chapter 3 Refractory Installation In The Cement Rotary Kiln 5e6z2r

REFRACTOTRY INSTALLATION TECHNIQUES IN CEMENT INDUSTRY

Chapter 3 Refractory Installation in the Cement Rotary Kiln 3.1 Installation of refractory bricks in the Cement Rotary Kiln The installation of refractory bricks in the Cement Rotary Kiln is classified into 2 types. 3.1.1 -

Refractory installation in the Rotary Kiln with rotation This type of refractory installation is only suitable for Rotary Kiln that has less than 4 meters in diameter. It is only ideal for small quantity of bricks to be installed. It requires longer installation time compared to refractory installation without rotation (see 3.1.2) Low investment cost for and accessories and bricking equipment are its major advantages. The necessary requirements for kiln rotations during the installation may affect other subsequent works. There are several methods of refractory installation with a rotation of Rotary Kiln, they are as follows;

3.1.1.1 Screw Jack Method - The procedures to be followed starting from the beginning are shown in 3.1.2.1 - 3.1.2.5, discussed in the succeeding sections. - Install the refractory bricks on the lower-half portion of the Rotary Kiln, for about 1-3 running meters, then pause for installation break and proceed with the instruction below. - Place the rectangular timber battens against the installed bricks on both sides along the kiln axis, then the timber battens are pressed against the installed bricks using the Screw Jacks, as shown in Fig. 3-1 and Fig. 3-2.

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Screw Jack

Sharp pins for pressing the timber batten

Fig. 3-1: Picture of Screw Jack

Fig. 3-2: Pictures illustrating the use of timber batten and Screw Jack in pressing against the installed bricks

REFRACTOTRY INSTALLATION TECHNIQUES IN CEMENT INDUSTRY

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The distance between the individual jacks should not be more than 80cm. Tighten the jacks as tight as they can be, as shown in Fig. 3-3.

Fig. 3-3: Picture illustrating the Screw Jacks tightening -

Inspect any bricks that are not directly pressed by the Screw Jacks, they should be tightened using wooden wedges, in order to prevent them from falling while rotating the Rotary Kiln, as shown in Fig. 3-4.

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Fig. 3-4: Picture illustrating the use of wooden wedges to tighten the bricks in each ring -

After the inspection, remove all refractory and equipment from the Rotary Kiln, then rotate the Rotary Kiln by 90 degrees, and then continue the same procedures as in the beginning, as shown in Fig. 3-5 and Fig. 3-6.

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Fig. 3-5: Picture of the Rotary Kiln ready for rotation

Fig. 3-6: Picture of the Rotary Kiln after a 90 degrees rotation

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Proceed until all refractory bricks are installed completely in full rings, and repeat the same procedures until all are completed, as shown in Fig. 3-7.

Fig. 3-7: Picture illustrating the proceeding installation of refractory bricks to completion 3.1.1.2 Gluing Method - The procedures to be followed starting from the beginning are shown in 3.1.2.1 - 3.1.2.5, discussed in the succeeding sections. - The adhesive glue consists of resin mixtures with Hardener. - The surface to be glued must be kept clean and dry at all times; the presence of contaminants will affect the adhesive performance. - The procedures are shown in Fig. 3-8. - Begin with section I, install the refractory bricks about 5-6 pieces and leave them until the glue dries up. - Soon after, install about 10-15 pieces of refractory bricks in counter clockwise direction, without gluing.

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Repeat the same procedure with glue as in section II, install about 5-6 pieces of refractory bricks and leave them until the glue dries up. Rotate the Kiln in clockwise direction and place the installation area in a convenient position for installation. Repeat until all refractory bricks are installed in the full rings completely. It should be noted that the glue to be used must be within the range of its shelf life, since the bonding property could degrade if the glue is kept for longer than its shelf life.

Fig. 3-8: Picture illustrating refractory installation in the Rotary Kiln with rotation, gluing method 3.1.1.3 Channel or bolt & nut method. -The method was applied from screw jack method. The Equipment usage in this method similar to screw jack method. Only if it doesn‟t use screw jack the important tools are M-20 bolt, nut, two sides screw bar with 20 mm diameter and 250 mm length, special washer, electric drill, Channel steel or 10x10x400 cm Harden wood and transformer for welding Nut with kiln shell are required for installation as following;

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1. Cleaning and marking the center line are the first things for rotary kiln work. 2. Selecting the straight pattern of brick laid which is easily manage and control the quality of installation. 3. Installing brick by starting at the center line, this method need 12 meter length and less 25 pieces axial lay. 4. The marking of nut for welding on kiln shell is measured in every 5 courses. It has to be cut the side edge of wedge type brick as shown in the below picture: In case of gluing application, corner cutting is not necessary.

Fig. 3-9: Picture illustrating the corner and side cutting brick. 5. Marking every 1 meter length along the kiln and 25 courses of the brick circumference distance then weld M-20 nut. 6. Using the distance of welded location, drill the 2223mm diameter through channel steel or harden wood 7. The special washer can be prepared by cut steel sheet 5 mm thickness, 40*40 mm width and drill 25 mm hole for washer attachment. 8. Installing cutting bricks by connecting both of cutting bricks as shown in the below picture.

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Fig. 3-10: Picture illustrating position of fasten installed brick with kiln shell. 9. The connection of 4 bricks was shown in the picture which is it need to be installed at higher 3 or 4 courses more. 10. Screw the steel rod and twist it tightly with the welded Nut inside the cutting‟s bricks hole. And lay down the channel steel or harden wood by placed it over the bolt. 11. Insert special washer and cover it with the cover nut then Firmly and tightly twist it. 12. In case of incurring gaps between steel or wood bar, wood wedge can be applied by shimming between brick and channel steel. 13. The fasten bolt and nut shall do the both sides which already fixing. Next procedure, Kiln rotation needs to rotate one eighth of the circular length. 14. Install brick with the same pattern. If kiln shell distorted, mortar can trowel for adjustment. 15. Turn the rotary kiln until reaching its end position. And brick can be installed only from left or right hand side direction. Cutting or shimming for tightening brick courses is necessary. 16. When bricking completed for whole brick courses, Nut, washer, Channel steel and steel stud will be removed out.

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17. Starting from the first step again until the bricking work is done then follow the same procedures for the next position. The most important thing is to install and rotate no more than 12 Meters long. If installing distance is longer than separate area, it is necessary to make sure by turning going well. 18. Seal all the cut brick holes with reliable material such as C60A castable or Ram it with plastic 80.

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Fig. 3-11: Picture illustrating refractory installation by Bolt and nut method.

Fig. 3-12: Picture illustrating refractory installation in the rotary kiln with rotation, bolt and nut method.

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Advantage of bolt & nut method The advantage of this method is similar to the Screw jack method. However it is more useful in of no obstruction from Screw jack and longer installation as well as faster for one time installation compared to screw jack method. Disadvantage of bolt & nut method The weakness is to cutting brick and fulfill it with castable; which might run not so long, due to the low quality of product or non-standard installation. 3.1.2 -

Refractory Installation in the Rotary Kiln without rotation This type of refractory installation is suitable for Rotary Kiln that has more than 4 meters in diameter. The refractory installation time is shorter than installation with rotating. It has higher investment cost for accessories and bricking equipment. Mult-O-Ring machine is used as bricking equipment.

The refractory installation without rotating the Rotary Kiln has the following procedures: 3.1.2.1 Cleaning of rotary kiln shell surface - The kiln shell surface must be cleaned; the cleaning includes de-scaling and removal of any foreign materials such as mortars, dusts, and etc. The cleaning could be done by sand- blasting, grinding, and etc., and equipment to be used may include de-scaling hammer, brush, and broom. - The foreign materials may cause uneven kiln shell surface and affect the quality of installation in the kiln

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lining which will result in loose installation of bricks against the kiln shell. 3.1.2.2 Positioning of the Rotary Kiln - The positioning of the Rotary Kiln should be rotated wherein the manholes and deformed kiln shell areas are located at the bottom (at 6 o‟clock) which is necessary for easy and quality installation. 3.1.2.3 Locating the center reference line - It is essential to locate and draw the center line reference of the Rotary Kiln. Use the Levelling Bar and plumb to mark the center points in every 1-2 meters and connect the points to serve as center reference line. The more center points from outlet through inlet direction could be utilized to check kiln shell alignment and accuracy of the centre line. The corrected centre line can count on the harmony of most of center points. The marking acceptance per center line is 80% of all center points. - The most important thing is that center line which marked with 2 center points is highly in risk of incorrect line deviation. The incorrect center line marking will cause alignment of bricking ring to be wrong and shorten brick life. The quality of misalignment bricking installation could be obviously notice as snaking brick line.

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Fig. 3-13: Locating the center point of the Rotary Kiln by using the Leveling Bar and Plumb 3.1.2.4 Drawing of circumference lines Center line and Cross section line by Kiln non Rotation -

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After the center reference line is drawn, draw the circumference line after every 1 meter interval from the center reference line using a Steel Com, 1- 2 meter length, to locate and mark the intersection of two curve lines, as shown in Fig. 3-14. Draw the circumference line fully along the circumference of the Rotary Kiln by connecting the intersection marks, as shown in Fig. 3-15. The lines are used for controlling and monitoring the alignment of refractory bricks installation.

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Fig. 3-14: Picture illustrating the use of Steel Com to locate and mark the intersection of two curve lines

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Fig. 3-15: Picture demonstrating the drawing of the circumference lines in every 1 meter along the circumference and throughout the length of the Rotary Kiln where the refractory bricks are to be installed.

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In addition, if the Retaining Rings are to be used as reference to draw the circumference lines, it must be ensured that the Retaining Rings have been aligned and welded correctly to prevent an erroneous reference point and, consequently, an incorrect alignment of the circumference line drawn.

Center line and Cross section line by Kiln Rotation. - This method is easier than the non kiln rotation method by just checking and drawing center line then rotating kiln every 20 degree. The center line can be drawn by several center points and alternatively draw along with kiln rotation. - Certer line must be exactly separated for every meter with steel com. - Turning approximately 16 times and drawing 1 meter marking point from the center lines, called cross section lines, until completed. - Actually it quit very necessary to check center line on the last line according to Man-hole at 6 O‟clock. - During turning kiln, cleaning, repairing, kiln deformation checking & marking brick location can be done at the same time.

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Fig. 3-16: Picture illustrating kiln center line and radial controlled lines marking. 3.1.2.5 Starting procedures for refractory brick installation -

Place the Angle-Bar Steel (or any alternative) on the center reference line, press one side by putting weighs (use of bricks) to fix the Angle-Bar in place and prevent it from moving. Then start installing refractory bricks on the other side for about 3-5 pieces along the reference center line for 2-3 running meters in a row, as shown in Fig. 3-17.

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Fig. 3-17: Picture illustrating the refractory bricks installation after the center reference line is drawn - Remove the Angle-Bar Steel, and start to install the refractory bricks on the other side, the installation shall be balanced on both sides (left-right) throughout the Rotary Kiln.

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Fig. 3-18: Picture illustrating a balanced installation of the two sides- left and right 3.1.2.5.1 -

Non- Parallel t (Stagger t) installation method For brick installation at the non-parallel (stagger) t of refractory, a piece of wood (the same length and half thickness of the refractory bricks) is required to place

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alternately in every ring at the beginning point of refractory brick installation on that ring (from the reference center line alignment), thus obtaining stagger ts between each ring, as shown in Fig. 3-19.

Fig. 3-19: Picture illustrating the stagger t of refractory bricks installation between each ring 3.1.2.5.2 Parallel t installation method - For bricks installation in the parallel t of refractory bricks, make sure that the ts between the adjacent bricks of each ring are parallel, then begin to install the refractory bricks on each ring at the same reference, thus it does not require placement of wood like the previous method and obtain the parallel brick ts. - It should be observed that during the installation of refractory bricks, regardless of any method, every brick must be tightened (tight against the kiln shell and each other) by using Plastic Head Hammer to prevent loose installation of refractory bricks on each ring. - A hammer to be used for the refractory bricks installation shall not be a rubber head hammer or metal head hammer, but a plastic head hammer, which can

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better absorb the reflected force and is effective for refractory bricks installation. A plastic head hammer is an essential tool to tighten the bricks which will prevent lining spiral problems after kiln operation.

Fig. 3-20: Picture illustrating the parallel t of refractory bricks installation between each ring

Fig. 3-21: Picture of Plastic Head Hammer [left] that is recommended for refractory bricks installation

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3.1.2.5.3 -

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Advantage and disadvantage of brick straight and stagger t pattern. The selection of bricking pattern is one of the popular question being asked for lining work. It has to emphasis on the skill of brick layer, brick size tolerance, smooth kiln shell condition, corrective centerline marking and counter measure for brick lining. The simplest thing to do is checking brick dimension and size tolerance of both combined brick. In case that the size tolerance is different from 0.5 -1.0 mm on brick length. Clearance will caused the adjacent brick could not put in the shorter length with the ordinary one or longer length brick. Once If size tolerance became more serious parameter. The stagger t brick lining method is recommended to avoid corner chipping. For equivalent and zero size tolerance brick combination is suitable for stagger and parallel t pattern. Another unpleasant shell condition, the stagger pattern brick lining is the key point incurring uncontrolled alignment of bricking ring causing easily damage from thermal mechanic. Skill of brick layers is the major part for pattern of bricking method decision. The skillful brick layer always pays attention to quality installation with uniform mortar pasted, hammering, brick‟s surface seated on shell and cleaning dirt. The stagger pattern surely more difficult to clean while bricking compared to straight pattern. Once the dirt is more difficult to clean causing poor quality of bricking. Straight t pattern on brick lining should have more advantages in this case. Closing the ring with straight pattern will be closed quicker due to it can read easily from the previous ring. Practically installer trusts in stagger pattern however the stagger pattern will cause bricking rate lower than straight pattern approximately by 15-20%.

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3.1.2.6 Refractory Installation in the Upper-Half portion of the Rotary Kiln - After the refractory bricks are laid completely at the lower-half portion for at least 8-10 meters, mobilize the Mult-O-Ring into the Rotary Kiln, a machine needed for installing the refractory bricks at the upper-half portion of the kiln. The procedures to be observed are as follows 3.1.2.6.1 Set up the Mult-O-Ring - First begin to install the Mult-O-Ring and fix the platform, assemble and install the Arch and check the various conditions listed below before starting the refractory installation. o Check the level of the Mult-O-Ring as indicated by the levelling bar that is located next to the Mult-O-Ring Beam. o Check the Pneumatic System that operates the Pneumatic Jig whether there is any leakage of air pressure and the air pressure should not be lower than 5 Bar. o Check the space (distance) between the Arch and the hot face of the refractory bricks, the distance should be around 100 mm. o In case the distance of the Arch is not proper, it can be adjusted by using the folk lift to move the platform either upward or downward then lock the desired height/level using the adjustable lock-bar. 3.1.2.6.2

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Installation of refractory bricks at the Upper-Half portion by using the Mult-O-Ring

Installation in the upper-half portion requires ample luminosity of lighting equipment, ventilation fan, and piling of bricks into groups according to sizes and computed quantity ratio, as these will promote better

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work efficiency. In addition, the Mult-O-Ring shall have the frame for safety purposes, see Fig. 3-17. In carrying the bricks onto the platform the weight of the refractory bricks and other equipment should be considered in order not to overload the weight capacity of the Mult-O-Ring. The installation procedure in the upper-half portion has the same principles as the lower-half portion. Each brick installed at the upper-half portion shall be temporally pressed and ed by the Pneumatic Jig, and each must be tightened against the kiln shell and to each other as much as possible by using the plastic hammer. In case any of the individual rubbers attached to the Pneumatic Jig is found to be worn-out and shorten, which consequently become unable to reach the surface of the bricks when pressed, the use of cardboard, plywood, or shimming plate could compensate the shorten length by placing it above the worn-out portion enabling it to reach and press the bricks against the kiln shell as tight as it can be, see Fig. 3-23.

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Fig 3-22: Picture illustrating the refractory installation at the upper-half portion by Mult-O-Ring with the safety frame and platform

Shimming plates

Pneumatic Jig

Arch

Fig. 3-23: Picture illustrating the use of shimming plates to offset the shorten length of the worn-out portion of the Pneumatic Jig attached rubber enabling to press or the bricks tightly against the kiln shell -

In installing refractory bricks on each ring, there should be a balanced installation rate between the two-sides,

REFRACTOTRY INSTALLATION TECHNIQUES IN CEMENT INDUSTRY

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while following the circumference curve of the kiln shell. Once the remaining space to be installed between the two sides has reached 0.8-1.0 m., apply the Hydraulic Jack to tightly push the two-sides of the refractory bricks against each other, as shown in Fig. 324. Then turn off the air pressure valve of the Mult-ORing to release down the Pneumatic Jigs and then move the Mult-O-Ring through slide rails to the next installation ring position. The closure procedure of each ring and the use of shimming plates are to be discussed in the succeeding topics. After the refractory bricks have completely reached 1.52.0 running meters, remove the wheels‟ lock-bars of the Mult-O-Ring , then push the Mult-O-Ring manually or by Forklift.

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Fig. 3-24: Picture illustrating the use of Hydraulic Jack 3.1.2.7 Ring closure installation The last refractory brick to be installed for ring closure is one of the most important steps that determine the quality of installation work and shall adhere to the principles below; - In each ring, once the remaining space to be installed between the two sides has reached 0.8-1.0 m., as shown in Fig. 3-25, measure the exact distance between the two-sides of the opposite bricks, and calculate the quantity combination of full and key bricks to be used in advance to improve the installation time rather than doing trial and error approach which consumes more installation time. - The last brick to be used as ring closure should be the full bricks and not the key bricks, which are better at adsorbing the stress from hitting during the ring closure than the key bricks. - The installed key bricks shall not be adjacent to each other rather they should be installed alternately with full bricks, and the key bricks to be installed in each ring must not exceed 4 pieces, as shown in Fig. 3-26.

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Fig. 3-25: Measuring distance of the remaining space to calculate the bricks combination for ring closure

Key Brick

Steel Shimmed Plate

Fig. 3-26: Picture illustrating the allocation of key bricks and shimming plates -

When the last brick has been inserted as a ring closure, the bricks within the ring are often remained loose (untight), therefore the shimming plates with a thickness of 2-3 mm. are to be inserted between the bricks until the ring is sufficiently tightened. Take note that the ring is tightened when there is difficulty and friction force observed when inserting the shimming plate. In

REFRACTOTRY INSTALLATION TECHNIQUES IN CEMENT INDUSTRY

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inserting the shimming plates, use proper equipment such as Pneumatic Hammer, or hammer to push or hit the shimming plate until it fully penetrates into the small gap between the bricks, as shown in Fig. 3-27. The shimming plates shall be sharpened at its insertion edges and lubricants such as grease shall be thoroughly applied for ease of insertion. Also, it is strongly prohibited to insert the shimming plate more than 1 piece per t, and shall not be more than 4 pieces per ring. The shimming plates shall only be inserted in between the full bricks, as they have higher strength to overcome the collision force from shimming.

Fig. 3-27: The use of hammer to hit the shimming plate

3.1.2.8 Installation of refractory bricks on the deformed/ distorted kiln shell area. The deformed or distorted areas are, for example, swollen and bended portion, where they might have experienced abnormal temperature or conditions that caused bricks falling down or

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thin lining. Such areas need special installation procedures in fixing the deformities following the principles below. -

In case the deformation or distortion in the kiln shell area is small and does not exceed 2-3 mm. from the original curve, use the Refractory Mortar to compensate the deformed area, as shown in Fig. 3-28. In doing so, it would keep the bricks combination installed in the area and not deviate from other non-deformed areas.

Fig. 3-28: Picture illustrating the use of Refractory Mortar to compensate the deformity -

In case the deformation or distortion in the kiln shell area is larger and exceeds 3 mm. but less than 8 mm., use the Refractory Plastics or Castable which can withstand the weight better than the Mortar. If need to use the Refractory Castable, remove the coarse grains and use only the fine grains, mix with water and apply to patch-up the deformities, then leave it set before installing the bricks and follow the original designed bricks combination ratio.

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In case the deformation or distortion in the kiln shell area is extreme and exceeds 8 mm., repair of kiln shell is strongly recommended. This could be done by welding the steel plates and smoothing the surface by grinding, as shown in Fig. 3-29.

Fig. 3.29: Welding applied in the kiln shell area with extreme deformation 3.1.2.9 Installation of refractory bricks at the Retaining Ring Area inside the Rotary Kiln The installation of refractory bricks at the Retaining Ring area could be done in several ways, for example, Chipping or Cutting Method, Installation above the double Retaining Rings and Fixing Anchors as shown in Fig. 3-30, Refractory Castable Method, as shown on Fig. 3-31.

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Fig. 3-30: Picture illustrating the refractory installation at the Retaining Ring area

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Fig. 3-31: Picture illustrating the installation of C 60 A at the Retaining Ring located in the middle of the Rotary Kiln

Fig. 3-32: Picture illustrating the installation of ing castable at brick retainer. 3.1.2.10 Installation of refractory bricks at the Tyre Areas. It is known that the refractory linings under the tyre areas are often more damaged at the hot face of the bricks and form more brick spalling, as compared to other areas (shown in Fig. 3-33). This is a result of either excessive mechanical stress generated under the tyre area or high kiln ovality value exceeding 0.1% of the Kiln Diameter length.

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Fig. 3-33: The condition of refractory lining under tyre area with the spalling effect. -

When installing bricks on this area, it is strongly recommended to apply Refractory Mortar with thickness of not more than 2 mm. between each side of every bricks installed below the tyre area, along (+/-) 1.5 - 2.5 running meters from the center of tyre area, as shown in Fig. 3-34.

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3 Meter (15 rings)

Fig. 3-34: Picture illustrating tyre area -

It is noted that the application of Refractory Mortar would increase the installation time as compared to normal clench lining installation method, as show in Fig. 3-35.

Fig. 3-35: Graph of brick installation rate

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The application of Refractory Mortar method usually takes more time than other methods. Especially at the upper- half portion, if the masons are inexperienced and apply Refractory Mortar too quickly, the ring may be loose.

Fig. 3-36: Picture illustrating tire area and covering mortar applied.

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Fig 3-37: Installing refractory bricks at the tire area with refractory mortar -

For the convenience and efficiency of the refractory installation, SRIC had set a team to study and innovate a “Pre-Mortared Brick System” to solve those disadvantages of mortared lining. By this system, the advantages of clench lining and mortared lining are combined. The refractory mortar is applied on the bricks‟ surface from SRIC plant and those bricks are ready to be installed as clench lining. The applications of this system were applied in many Cement Rotary Kilns and the outcomes were very satisfactory. All previous difficulties were solved, especially the speeds of installation were approximately 2.5 times faster than regular mortared lining, as shown in Fig. 3-35.

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Fig. 3-38: Picture illustrating the Pre-mortared Bricks installation under the tyre area In case the problem of mechanical stress in the lining under the tyre area is not severe, it can be mitigated by inserting 1-2 mm thickness Ceramic Paper, 1260C, between the sides of the bricks at an interval of 7-10 pieces of refractory bricks (radial direction) of each ring along (+/-) 1.5-2.5 running meters from the center of tyre area.

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Good performance after 8 months of service

M.2-4 without Mortar some surface spalling

M.4-7 with Pre-Mortared Brick good performance

Fig. 3-39: The pictures illustrate good performance of PreMortared Brick after 8 months of service 3.1.2.11 Cutting of refractory bricks for the installation on the last ring. To complete the installation of the last portion or last ring, the installation of the last ring often requires brick cutting, as shown in Fig. 3-40. The important principles for the installation of the last ring are given below; - The cut brick shall remain at least 2/3 of their original length. - The bricks in the last ring that is adjacent to the old lining or Retaining Ring must be the original un-cut/full bricks. - If cutting is required in more than 1 ring, the cut brick rings must not be adjacent to each other. - In all cases, the cutting of bricks must not be for more than 3 rings. To remedy the cutting work, or to reduce cutting of rings, SRIC produces special length bricks for the last ring installation, they are 150, 200, 230, 250,

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and 300 mm. in length which help to reduce the possible cutting to 1 ring only. Before the installation of the last ring that is adjacent to the remaining old lining, the bearing that were previously temporarily fasten to the old lining as protection to its movement must be removed and the kiln shell surface of the area must be smoothed by grinding. Retaining Ring or Line of the Old Lining

2/3 L<X

: Cutting of bricks for 1 Ring

X = remaining space to cut the bricks L = original length of full bricks

1/3 L<X<2/3L : Cutting of bricks for 2 Rings 0 <X<1/3L

: Cutting of bricks for 3 rings.

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Full Brick

Cut Brick

Fig. 3-40: The picture illustrates the cutting of bricks for 2 rings 3.2 Installation of Refractory Castables in the Rotary Kiln -

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Other than the refractory bricks lining in the Rotary Kiln, Refractory Castable are also to be installed in the Kiln Outlet and Kiln Inlet areas. Normally, the kiln inlet and outlet areas are approximately 1-2 meter long and install with low cement castable.

REFRACTOTRY INSTALLATION TECHNIQUES IN CEMENT INDUSTRY

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The Refractory Castable are to be installed in the Kiln Outlet/areas either before or after the installation bricks in the Rotary Kiln, as shown in Fig. 3-41 and Fig. 3-42. However in normal practice, the sequential order is to install the Refractory Castable in the lower-half portion first, and then rotate the Rotary Kiln 180 degrees after the castable is set and remove the forms/ moulds. Afterwards, the installation of the refractory bricks as well as the remaining parts to be installed with Refractory Castable follows. This method will allow more time for the installed Refractory Castable to cure, which will reduce the possibility of Refractory Castable explosion during the heating up period.

Fig. 3-41: Installation of Refractory Castable before the installation of refractory brick in the Rotary Kiln

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Fig. 3-42: Installation of refractory castable after the installation of refractory bricks in the Rotary Kiln -

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The installation of Refractory Castable could be done in 3-4 s at the bottom portion of the kiln simultaneously at a time. After they have been set, approximately 2-3 hours, the Rotary Kiln could be rotated to install the castable on the succeeding s, and so on until all s have been fully installed. This method does not require covering or closing of moulds, and thus can be ensured that the Refractory Castable will be consistently filled up by means of gravitational force as visibly observed. The Refractory Castable installation of this method often done before installation of refractory bricks. For Refractory Castable installation method for the whole lower-half portion without kiln rotation, rotate the Rotary Kiln 180 degrees after the installed castable is set to install again the castable in the remaining portion. The moulds are needed to be covered or closed at the casting s so that the Refractory Castable will not spill out especially at the side s of the kiln.

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-

-

-

The installation procedures for the Kiln Inlet are the same with the Kiln Outlet. Depending on the work quantity, that is if Kiln Outlet requires total demolishing/ removal and installation, they can be done simultaneously. The detailed guidelines for mixing and installing Refractory Castable, including preparation of anchors and mould setting shall strictly follow the Refractory Castable Installation Guidelines explained in Chapter 7 to ensure the best quality outcome of the installation. The most appropriate type of Refractory Castable for the Kiln Inlet and Kiln Outlet areas is Low Cement Castable, because of its o High mechanical strength at both ambient and working temperature. o High resistance to clinker abrasion. o High resistance to thermal shock. o High resistance to alkali and chemical attack. The appropriate Refractory Castable to be used in these areas are TufDura S 300 and TufDura S 600 which are the special series of Low Cement Castable containing Silicon Carbide, produced by special technology. Such castable have excellent abrasion and thermal shock resistance properties. Alternatively, C60A and C70A could also be used.

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Positions marked for fixing anchors

Fig. 3-43: Picture illustrating the marking of anchor positions, alternating pattern

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Fig. 3-44: The anchors are fixed at the Kiln Outlet area

Fig. 3-45: Picture illustrating the preparation of wooden moulds for installation of Refractory Castable at the Kiln Outlet Area

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Fig. 3-46: Pictures illustrating the installation of Refractory Castable during casting

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Fig. 3-47: Picture of Kiln Outlet area lined with Refractory Castable after completion of installation - The entire refractory repairing for cement rotary kiln was not only brick, but also castable repairing too. The areas with do need repairing such as outlet area, inlet area. - By general, kiln outlet and inlet length approximately 1-2 meter long will be installed with low cement castable. - Kiln outlet repaired refractory can be installed before and after brick installing as show in Figure 9-42 and 9-43. In generally practice, castable shall be installed firstly at lower half portion then kiln will be rotated 180 degree. The sequential on installation with was illustrating step by step as below pictures. Installing will be completed on former no 1-11 and rotated 180 degree for the less installing on former no. 12-20.After castable became hard, formers had been released and brick started in next step. With this method, the installed castable have sufficient and more time for curing which can prevent castable explosion cause from initially heat up.

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Fig 3-48 : picture illustrating castable installation prior brick will be installed. SRIC

(KILN OUTLET)

Fig. 3-49: Installation of refractory castable after the installation of refractory bricks in the Rotary Kiln

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15

20

12 13

16

14

17 18

19

10

9

8 4 7

3 6

2 5

11

1

Fig 3-50: picture illustrating casting position.

- Castable installation can be described in 2 methods as following. 1) For this method, boundary of former have to be located after anchor completely welded for castable installing as illustrated in picture before. Former will be shuttered at side views of kiln outlet and reinforced with steel rod or anchors by wire rod. Then the first portion of castable will be installed within 120 degree. After castable became solid or 2-3 hours later, Kiln will be rotated 120 degree for adjacent casting on the second time. Castable will be installed as previously done in next step.

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Fig. 3-51: Installation of refractory castable at nose ring step by step. 2) In some occasion as above installing method, castable might face with it will not completely fulfil at the corner from unskilled installer. We can solve this problem with other installing method by placing the wood expansion t on radial direction firstly. (Please see figure 3-52) Castable will be filled close to axial expansion t level; Wood expansion which prepares will be installed as illustrated in Figure 3-54. For this method, it‟s ensuring that improperly casting problem will not happen.

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Fig. 3-52: Installation wooden former at bottom dead position.

Fig. 3-53: Picture illustrating the side former for prevention castable spill out.

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Fig. 3-54: Picture illustrating charging of castable at side from top part. - Installation castable with surface covered former. - For this method, castable will be installed a half lower part . Kiln will be rotated for the less of castable installation. This method needs former to cover on castable surface which prevent castable spillage. The most specific formers placed at left and right side especially 3-4 formers from center.

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ภาพแสดงการติดตั้ง steel rod สาหรับใช้ยึดแบบไม้ ภาพแสดงการติดตั้ง radial expansion t กับ steel rod

Steel rod apply for plywood.

Fig 3-55 : picture illustrating tie rod for ing.

Plywood 3 mm. installed as radial expansion t.

Fig 3-56: picture illustrating radial expansion t.

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Pour castable here

Fig 3-57: picture illustrating castable feed in prepared former.

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Fig 3-58: picture illustrating insertion of axial expansion while casting. - For the last formers at both left and right sides, it had to adapt castable former with extra castable opening hole to charge castable and include vibrator insertion as Fig 3-57. Anyhow, it shall apply vibration at external of formers surface while casting which can assist castable flowing. - For kiln inlet‟s casting position, it has the same guide line as casting at kiln outlet with base on amount of repairing areas. If castable at kiln outlet and inlet were be replaced. These both sides were be managed and executed in the same time. - Mixing castable detail and its installation, anchor, former preparation are followed casting instructions refer in chapter 7 strictly. In order to achievement the best installation quality.

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Fig 3-59: picture illustrating the remaining of casting position.

Fig 3-60 : picture illustrating castable extra hole at the last former.

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- Installation castable without surface covered former For this method, boundary of former have to be located after anchor already welded for castable installing as illustrated in picture before. Former will be shuttered at side view of kiln outlet and reinforced with steel rod or anchors by wire rod. Then the first portion of castable will be installed within 120 degree. After castable became solid or 2-3 hours later, Kiln will be rotated 120 degree for adjacent casting on the second time. Castable will be installed as previously done in next step.

Fig 3-61: picture illustrating Sequent of uncovered former casting

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In some occasion as above installing method, castable might face with incompletely fulfil at the corner from unskilled installer. We can solve this problem with other installing method by placing the wood expansion t on radial direction firstly. (Please see figure 3-56) Castable will be filled close to axial expansion t level; Wood expansion which prepares will be installed as illustrated in Fig 3-58. For this method, it‟s ensuring that improperly casting problem will not happen. - The suitable refractory concrete for kiln outlet and kiln inlet should be low cement castable according to its properties following. 1) High strength at low and high temperature. 2) Ability to anti abrasion from clinker and raw meal. 3) Ability to withstand for suddenly temperature changing. 4) Good for anti chemical reaction cause from Alkali. - The suitable refractory castable shall be installed in this area are TUFDURA 300, TUFDURA600 with contain low cement and silicon carbide ingredient. The compound properties gain higher properties on abrasion and sudden temperature or might consider to use C-60-A castable for installation.

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SRIC

Fig 3-62: Installed refractory castable completely. 3.3 Final inspection of installation works -

After the completion of refractory installation in the Rotary Kiln, before moving out the Mult-O-Ring, the quality of installation of refractory bricks must be individually inspected for their tightness in every ring. This could be done with the use of plastic-head hammer or timber batten to knock the upper-half portion of the bricks installed in every ring. In case any of the refractory brick is found loosen, insert again the shimming plates until they are sufficiently tight. Then the Mult-O-Ring can now be removed out of the Rotary Kiln.

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Fig 3-63 Picture illustrating ring tightening checked. -

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In order to make sure that the whole rings are already perfectly installed, kiln might be rotated 180 degree and physical checking on brick surface and mark ring by ring again. In case that brick surface still have some clearance mortar or shim plate have to be applied. For the small clearance 1 mm or less mortar is preferred and the wider clearance than 1 mm shim plate is necessary to insert and impact with plate driver until it tight enough.

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Fig 3-64 Picture illustrating the 180 degree kiln rotated prior ring tighten all clearances. -

The damaged brick or corner chip can be applied with mortar. However serious damaged brick which is chipped or broken into surface depth nearly 30 % of brick thickness must be fixed by partial replacement. For upward installing has to be detected and replaced at the right position if found during final inspection.

Fig 3-65 Picture illustrating the upturn brick installed.

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Fig. 3-66: Picture of completed refractory installation work 3.4 Installation of Refractory Castables for Main Burner (or Burner Pipe) 3.4.1 Horizontal casting This simple method is widely use in cement factory with acceptance on easily arrangement. The burner body must be cleaned from dirt and mark for suitable anchor welding prior to horizontally former closing. - The Main Burner is the major burner of the production process in burning kiln feed to be the quality expected cement clinkers. - Normally, it is located at the front gate of the Rotary Kiln above the Cooler. - The Refractory Castable recommended are Low Cement Castable, for example TufDura S300, TufDura S600, and C60A, because they have properties of high mechanical strength at ambient and working temperature, thermal shock resistance, high abrasion resistance and anti-oxidation. - At the tip of the burner approximately 1 meter in length, the refractory lining should be thicker of about 10 cm.

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than the normal burner body thickness in order to yield better resistance to clinker abrasion. The refractory installation procedures for Main Burner are listed below;

3.4.1.1 Place the Main Burner on the „bedding frame‟, as shown in Fig. 3-67. 3.4.1.2 It might be possible to repair the refractory without removing it but the use of scaffolding is needed, as shown in Fig. 3-68. 3.4.1.3 Demolish the damaged portion of refractory and clean the metal surface with metal-brush. In case the body of the burner is severely damaged, fix it by welding and grinding.

Fig. 3-67: Picture illustrating the damaged part of Main Burner that requires repairing

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Fig. 3-68: Picture illustrating the refractory maintenance of the burner at its original position (without removing) 3.4.1.4 Fix the stainless steel anchors, which have the grade above SUS 310S, and apply compatible Welding Electrodes to the selected anchors. Remove the welding deposits along the welding seam t to check its consistency. 3.4.1.5 There are 2 types of mould for installing the Refractory Castable, one is a wooden mould affixed with galvanized iron sheet, and another is made of metal sheets, with half circular shape and approximately 1 meter in length. 3.4.1.6 Before installing the Refractory Castable, wrap the Main Burner with Ceramic Fiber Blanket, 13 mm. thick, with glue or wire. This will protect the Main Burner from heat transfer from outside to the metal surface during its operation, as shown in Fig. 3-69.

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Fig. 3-69: Picture illustrating how the Main Burner is wrapped with Ceramic Fiber Blanket 3.4.1.7 Assemble the moulds prepared, one by one, starting from the lower-half portion. The casting can be started right after the completion of assembling the mould. The continuous use of vibrator will ensure a consistent smooth flow of the Refractory Castable in filling up the mould fully.

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Fig. 3-70: Picture illustrating the installation of Refractory Castable at the lower-half portion of the Main Burner 3.4.1.8 Remove the moulds from the casting s, only after the Refractory Castable are already set. Then insert the Ceramic Fiber Blanket- 6 mm. thickness, or Cardboard or Plywood 4 mm. thickness in between the connecting sides to other adjacent s (both radial and axial sides directions) in order to create the expansion ts that allow possible expansion of the Refractory Castable, as shown in Fig. 3-71.

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Fig. 3-71: Picture illustrating the insertion of expansion t. After the completion of installation at the lower-half portion, begin to install in the upper-half portion following the preceding procedures. 3.4.1.9 After the completion, inspect all the installation quality for any non-filled pores. This can be done by using metal hammer to knock on the casted Refractory Castable and observe the reflection sound. A fully filled castable gives strong solid sound. 3.4.1.10 The heating up time of the Refractory Castable installed in the Main Burner is the same as that of the Rotary Kiln, which is around 24 hours. 3.4.1.11 The alignment of the Main Burner must be set right in the center of the Rotary Kiln which will give the frame fire right into the center and will not affect any sides of the refractory lining from direct fire , which deteriorates the service life of the lining.

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Fig. 3-72: Picture illustrating Refractory Castable installation at the upper-half portion of the main burner

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Fig.3-73: Picture of Main Burner completely lined with Refractory Castable

3.4.2 Vertical casting. The vertical casting is better in vibrating quality than horizontal casting, since we could put vibrator through formwork in straight way not in curvature. However this method needs special equipment to lift and lock the burner body. For vertical casting, the preparation steps have to be done same as horizontal casting such demolishing old refractory, cleaning burner shell, fixing the anchor and these jobs could be done on floor before stand the burner up. 3.4.2.1 Prepare Scaffolding for casting along burner length; the casting step could be done from both top to bottom or bottom to top.

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Fig 3-74: Picture illustrating on site preparation for vertical casting. 3.4.2.2 Wrap the Main Burner with Ceramic Fiber Blanket 13 mm. thick, with glue or wire. The Ceramic Fiber Blanket will protect the Main burner from heat transfer from outside to the metal surface during its operation. And cover the Ceramic Fiber by plastic sheet as shown in Fig 3-75.

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Fig 3-75: Picture illustrating of Ceramic fibre wrap around burner body.

Fig 3-76: Picture illustrating plastic sheet was used to cover on ceramic fibre blanket.

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3.4.2.3 Assemble the moulds prepared, half circular shape with 700-1000 mm. length, from one side. Starting casting there and move to above section after castable already set and insert Ceramic Fiber Blanket 6 mm. thick for radius expansion t.

Fig 3-77: Picture illustrating casting in vertical direction at one side.

Fig 3-78 : Picture illustrating radial expansion t with ceramic fiber blanket.

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3.4.2.4 Continue casting work, repeat, until completion one side casting. Remove moulds from all casting and insert Ceramic Fiber Blanket 6 mm. thick for axial expansion t.

Fig 3-79: picture illustrating an axial expansion t with ceramic fibre blanket. Begin casting work on another side by aassembly the moulds prepared, cast by preceding procedures.

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Fig 3-80: picture illustrating completed casting. 3.5 Application of gunning castable instead of casting. - In emergency cases, Refractory materials can be utilized for preheater cyclone, cooler wall, hot gas duct and riser pipe with castable rather than brick. The more advantage and convenient of material preparation are attracting while compared to brick. - However, refractory repairing with castable required a lot of man power and former preparation. Moreover timing was being utilized longer as necessary for castable setting before former release to next casting. In the urgent case with customers have limit on time and man power. Repairing with gunning castable is most alternative appropriation, due to it‟s not necessary to employ 50-60 man power. In additional reason, former will not be required and shortly times spend while waiting for castable curing and setting. This method shall minimum operating time spending.

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Fig 3-81: Picture illustrating various kinds of refractory materials being chosen for preheater cyclone.

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Fig3-82: Picture illustrating refractory materials chose for Clinker Cooler.

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- Repairing by gunning castable can be applied on existing material‟s surface without dismantling. However this principle was recommended to dismantle the whole damaged area and install new anchor then gunning will be operated. - Regarding to amount of anchor per area and expansion t for installation with following to casting standard.

Fig 3-83: The perfected anchor welding which have been installed with gunning castable.

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Fig 3-84: Picture illustrating on gunning castable has Being applied on bull nose‟s existing surface.

Fig 3-85: Picture illustrating bull nose after gunning Successfully did.

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Fig 3-86: Picture illustrating cooler‟s roof had been gun in over head direction.

Fig 3-87: Picture illustrating cooler‟s roof with Complete installed by gunning castable.

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Fig 3-88: Picture illustrating the 8 months gunning castable performance with well physical figure. - Gunning castable installation shall be prepared some facility such as 1) Air compressor with minimum capacity 650 CFM at 700 Kpa. 2) Constant water pressure 250 Psi. - Avoiding for low impaction and too high rebound. It shall be considered by operating with competent person. - The essential of gunning castable will primarily nozzle concern and summarized in 3 points as following;

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Fig 3-89: Picture illustrating the effective of nozzle angle. 1. Nozzle angle  For installation in the general area, the nozzle shall be installed in a perpendicular angle to the work piece being installed with gunning castable, otherwise the amount of rebound will be high and cause to reduction of the compact. There is an exception for the corner that gunned by directing the nozzle in the plane bisecting the angle of intersection of the two surface 2. Nozzle distance  Distance between the nozzle and surface is about 0.5-1.0 meter  Distance > 1.0 meter  rebound increase , compaction and strength reduce  Distance < 0.5 meter  rebound also increase if no reduction in pressure 3. Nozzle motion

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Fig 3-90: Picture illustrating nozzle motion. 

A steady circular or elliptical movement of the nozzle across the surface



The nozzle should not be directed toward one spot for extended periods increase rebound , difficult control the thickness of the layer



consistency moved  consistency compacted area.

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