Influence of Sorbent Characteristics on Fouling and Deposition in Circulating Fluid Bed Boilers Firing High Sulfur Indian Lignite

Table 4

Deposit sampling using probes.

(a) Foul probe test conditions—position windward

Test serial number	Gas temp. °C	Probe temp. °C	Exposure hours	Limestone tonnes/hr	SO2 ppm	Rate of buildup g/m^2 hr	Lignite fired during test Giral sample numbers (Table 1)
1	685	500	0.5	0	>5000	62	Sample number 2
2	635	500	0.5	0	>5000	34	Sample number 3
3	720	600	0.5	0	>5000	73	Sample number 2
4	680	500	2	5	1800	39	Sample number 3
5	690	500	0.5	8	1800	27	Sample number 4
6	700	500	2	12	1200	61	Sample number 2

(b) Chemical composition of foul probe deposit samples

Serial number	Na2O	MgO	Al2O3	SiO2	SO3	K2O	CaO	TiO2	MnO	Fe2O3
1	3.3	3.5	12.2	20.5	18	0.3	11.2	2.3	0.1	28.6
2	3.2	2.3	16.2	29.9	8.0	0.4	4.6	1.5	0.2	33.7
3	4.5	3.8	15.9	25.2	15.0	0.4	9.3	2.1	0.2	23.7
4	0.7	1.1	5.1	7.7	36.8	0.0	38.4	0.7	0.0	9.5
5	0.8	0.9	4.1	6.5	39.6	0.0	39.0	0.5	0.0	8.6
6	0.7	0.9	4.8	7.3	37.8	0.1	39.9	0.6	0.0	7.9