Drying out and Heating up of refractory installations in the cement industry Dirk Basten Refratechnik Cement Supervisor Training Course 2012
Refractory installation of a complete plant
Scheme of the refractory installation of a complete plant
static predominantly castable
dynamic predominantly bricks
static predominantly castable
Water sources – physically bonded water Installation of wet bricks
Strictly follow guidelines
Avoid leaking water
Anme rkunge n: 1* 2* 3* *
Ge ne re ll sollt e vor de m Be ginn de r Trocknung und de s Aufhe ize ns e in minde st e ns 24 st ündige s Aushärt e n de r Masse st at t ge funde n habe n! > Ofe ndre hung 180° a lle 45 minut e s - Re fe re nzmante lt e mpe ra tur in de r Bre nnzone ca . 100 - 150°C > Ofe ndre hung 90° alle 30 minut e s - Re fe re nzma nt e lt e mpe rat ur burning zone ca.. 200 - 235°C > Ofe ndre hung kont inuie rlich - Re fe re nzmant e lt e mpe rat ur burning zone ca . 260 - 310°C t he ore t ical calculat e d she ll t e mpe rat ure - de pe nds on e nvironme nt condit ions
T [°C] 1400
Trocknung
1300
Aufheizen
1200 1100
850°C -1000°C Inbetriebnahme
1000 900 800
3* 700
approx 30 K/h
600
2* 500 400
1* approx 10 K/h
300
approx 13 K/h
200
Entfernen der Abdichtungen / Start des Hauptbrenners
approx 10 K/h
100 0 0
12
24
36
48
60
72
84
96
108
120
132
144
156
168 t [h]
Typical dry out curve for complete new plant
Heating diagram of refractory concretes 1500
Aufheizdiagramm feuerfester Massen (LCC, MCC, SC, JC) Heating diagram of refractory concretes (AR, LCC, SC, JC, G, diagramm of refractory concretes (LCC, MCC, SC, JC) MCG, Heating LCG) Stationary areas wall thickness 5050- 300 mm
1400 1300 1200 1100
Temperatur / °C Temperature / °C
1000 900 30 °C/h bis zur Einsatztemperatur up to temp. of application
800 700 600
Heating Up
10 h / 500 °C
500 400
Drying
25 °C/h
300 20 h / 110 - 150 °C
200 min. 24 h Erhärtungsdauer min. 24 hrs setting time
100
15 °C/h
0 0
10
20
30
40
50
60
Time after installation / h
70
80
90
100
Zeit nach Einbau / h Time after installation / hrs
110
Drying
Behaviour of drying rate rate a function of time as as a function of drying time
100
Phase 1
90
Phase 2
80
Low vapour pressurelow drying rate
Drying rate
Drying rate [quantity/h]
70 60 50
continous drying rate
Decreasing drying rate
40 30 20 10 0 1
2
3
4
5
6 tkn
7
8
Dryiing time
Drying time [h]
9
10
11
12
13
Phase 1: Pmeniskus > Ppore opening air
Inlet
outlet
T [°C] 100° 100°C /1 bar
Ppore opening
Pmeniskus
20° 20°C /0.02 bar
Pcapillary
Low temperatur, continous airstream with high ventilation
∆P≈ 1 bar
Phase 2: PMeniskus < Ppore opening Inlet
Air stream
Outlet
T [°C] 350° 350°C /165 bar
Ppore opening
∆P≈ 164 bar
Pmeniscus
100° 100°C /1 bar
High temperature, low ventilation and airstream
Pcapillary
Pressure- and temperatur gradient in a to be dried refractory body (Dissertation: Modell zur Beschreibung der Trocknung von Feuerbetonen, Ingo Großwendt, 2007, p.25) S a tu r a tio n v a p o u r p r e s s u r e (b a r)
250 200 150 100 50 0 0
50
100
150
200
250
300
350
400
Temperature (°C)
1500
Aufheizdiagramm feuerfester Massen (LCC, MCC, SC, JC) Heating diagramm of refractory concretes (LCC, MCC, SC, JC)
1400 1300 1200
Temperatur / °C Temperature / °C
1100 1000 900 30 °C/h bis zur Einsatztemperatur up to temp. of application
800 700 600 10 h / 500 °C
500 400 25 °C/h
300 20 h / 110 - 150 °C
200 min. 24 h Erhärtungsdauer min. 24 hrs setting time
100
15 °C/h
0 0
10
20
30
40
50
60
70
80
90
100
Zeit nach Einbau / h Time after installation / hrs
110
Explosive spalling of castable surface (satellite cooler)
Dry out - surface cracking
Typical view on a badly predried castable , cooler sidewalls
Explosive spalling of Castable
Spalling of wet LCC castable on burner
Optimized drying schedule
Exhaust gas – sealing of kiln and ducts
Protection against humid exhaust gases (filter, basic bricks)
Evaporation holes in the cycloneroof lockable socket for controled evaporation
Heating up of kiln
Limiting mechanical components
Contraction at tyre
Temperaturedistribution in brick and kiln shell during heating up In 8h to 1000°C
Too slowly heating up, too early turning of kiln
Loose lining migration, relativ movement
Too fast heating up
Axial and radial pressure Spalling , cobblestone surface
Done: Drying and heating successfully finished first clinker in cooler Typical timing: 78 h – 120 h