Specific Procedure For Lining Kiln Outlet_rk2

PROCEDURE FOR INSTALLING REFRACTORY LINING AT RK2 KILN OUTLET

Objective: To describe the process of installing refractory at kiln outlet section

Domain of application: Production Department – Rotary Kilns Document date: August 2016

Emergency numbers: Shift Coordinator +254 720 627 023 CCR ext. 3233

Revisions and approvals: Review

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PROCEDURE FOR INSTALLING REFRACTORY LINING AT RK2 KILN OUTLET

Contents: OBJECTIVE: ................................................................................................................................................................. 1 CONTENTS: .................................................................................................................................................................... 2 OBJECTIVE: ................................................................................................................................................................. 2 1.

INTRODUCTION ................................................................................................................................................. 3 1.1. 1.2. 1.3.

2.

SAFETY ................................................................................................................................................................. 4 2.1. 2.2. 2.3.

3.

SAFETY DOCUMENTS ........................................................................................................................................ 4 PPE REQUIREMENTS......................................................................................................................................... 4 SAFETY ASPECTS .............................................................................................................................................. 4

INSTALLATION OF ANCHORS ....................................................................................................................... 5 3.1. 3.2. 3.3. 3.4.

4.

EQUIPMENT & TOOLS REQUIRED ...................................................................................................................... 3 PERSONNEL REQUIRED ..................................................................................................................................... 3 MATERIALS REQUIRED ..................................................................................................................................... 3

MATERIAL SELECTION ...................................................................................................................................... 5 WELDING PREPARATION................................................................................................................................... 5 WELDING OF ANCHORS .................................................................................................................................... 5 ANCHOR DENSITY ............................................................................................................................................ 5

CASTING ............................................................................................................................................................... 6 4.1. 4.2. 4.3. 4.4. 4.5.

SHUTTERING ..................................................................................................................................................... 6 EXPANSION ....................................................................................................................................................... 6 MIXING ............................................................................................................................................................. 6 BALL-HAND TEST ............................................................................................................................................ 6 POURING ........................................................................................................................................................... 7

Specific Definitions: Distribution list: Production Manager Production Superintendent Production Coach Refractory Champion Process/Production Engineer - CIP

Objective: To describe process of installing refractory lining at kiln outlet section

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PROCEDURE FOR INSTALLING REFRACTORY LINING AT RK2 KILN OUTLET

1.

Introduction

The kiln outlet section is subjected to significant thermal and mechanical stresses. In MOM RK2, the kiln outlet is lined using monolithic castable from the nose ring segments up to the retainer. The castable length is 1.1m.

1.1.       

1.2.     

1.3.        

Equipment & Tools Required Cement mixing machine Buckets Shovels Pneumatic vibrator Hammers Fork lift Welding Machine

Personnel Required Refractory Supervisor (1 No.) Refractory Masons (2 No.) Carpenters (2 No.) Helpers (5 No.) Welder (1 No.)

Materials Required Prescribed low cement castable Prescribed Steel/Ceramic Anchors Clean portable water for mixing Expansion joint material (Ceramic blanket) Shuttering timber Nails Binding wire Prescribed Welding rods

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PROCEDURE FOR INSTALLING REFRACTORY LINING AT RK2 KILN OUTLET

2.

Safety

2.1.

Safety Documents

1. 2. 3. 4. 5. 6.

Job Safety Analysis form Permit to Work Confined Space Entry Permit LOTOTO Checklist Hot Work Permit Emergency Response Plan

2.2.

PPE Requirements

2.3.

Safety Aspects

1. 2. 3. 4.

Safe access platform into kiln Adequate lighting (24V) Disposal of used castable cement bags Availability of emergency eye wash

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PROCEDURE FOR INSTALLING REFRACTORY LINING AT RK2 KILN OUTLET

3.

Installation of Anchors

3.1.

Material Selection

   

3.2.  

3.3.  

3.4.   

Anchors used are floating “Omega” type of anchors – AISI 310, 10mm diameter. The omega support diameter should be 2mm larger than the anchor diameter. The anchors must have the same mechanical properties as the castable intended for use The welding rods used must be compatible with the kiln shell (mild steel) and anchors (heat resistant stainless steel).

Welding Preparation The surface for welding anchors must be cleaned to prevent contamination of the welded joints. Pre-heating of the surface and welding rods to about >80 degC is recommended. Supplier instructions should be considered.

Welding of Anchors The anchors are tack welded onto the Omega support base. The support base is continuously welded onto the kiln shell.

Anchor Density The correct anchor density is important for adequately supporting the castable onto the kiln shell. Desired anchor density is a spacing of 200mm by 200mm placed at right angle to each other. The number of anchor is thus a minimum of 12 anchors per segment.

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PROCEDURE FOR INSTALLING REFRACTORY LINING AT RK2 KILN OUTLET

4.

Casting

The casting is done by working clockwise as the kiln moves in an anti-clockwise sense.

4.1.   

4.2. 

4.3.      

4.4.  



Shuttering Shuttering is made by use of plywood to secure the poured castable mix in a box The box dimension should follow the width of the nose ring segments. Thus each box is 300mm wide by 600mm long.

Expansion 6mm expansion fiber (ceramic fiber or mansonite board rated 1600 degC) is placed on the edges of each box.

Mixing The castable is mixed in a motorized rotary cement mixer. WARNING! Water content of the mixture is important since too much water adversely affects the castable porosity and cold crushing strength. Follow the manufacturer’s instruction. Place 5 to 6 bags in the mixer and rotate for about 1 minute. Add about 80% of the required water content and mix for about 2 minutes. Stop the mixer and let it rest for about a minute and test for consistency using ball-hand test. If necessary, add the remaining 20% of the water, mix then repeat the ball-hand test

Ball-Hand Test Collect a handful of the mixed castable and roll to form a ball. Correct consistency is attained when the ball is formed and remains in firm shape and does not disintegrated when tossed up and down. If correct water content, no water should seep out when squeezed.

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PROCEDURE FOR INSTALLING REFRACTORY LINING AT RK2 KILN OUTLET

4.5.   

  

4.6.  

4.7.  

Pouring (Rotocasting Method) Pouring of castable is started from 8 o’ clock position so as to settle well in the shutter box and prevent concentric segregation The castable mix is poured into the box and compacted by pneumatic vibration. Compaction is done over the whole volume to remove all air inclusions.

Vibration should not exceed 5 minutes on each area to avoid segregation of particles. When complete, the surface of the refractory should appear shiny. Carefully withdraw the vibrating needle to prevent formation of an air bubble Pierce a steam escape hole using a steel needle and leave to set for 30 – 45 minutes

Curing Every casted segment must be left to cure for 30 to 45 minutes Rotation of the tube can be done only when the surface is firm

Drying At the kiln outlet, drying is done by the main burner during warming Rapid increase of surface temperature from flame radiation can be controlled by covering the nose ring area with 3 mm mineral fiber blankets.

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