A new method for evaluating packing efficiency of particle size distribution during coal water slurry preparation

doi:10.21203/rs.3.rs-20660/v1

Download PDF

Research

A new method for evaluating packing efficiency of particle size distribution during coal water slurry preparation

https://doi.org/10.21203/rs.3.rs-20660/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Particle size distribution is a key problem in preparation of coal water slurry . Due to the large number of particles and irregular accumulation of particles, how to evaluate and calculate CWS particles has become an urgent need. In this paper, the volume accumulation of particles is simplified as plane accumulation, and the particle packing gradation model based on the three-particle packing gradation and the four-particle packing gradation is constructed. Based on the classical mathematical principle, the packing voids and packing probability of 5 typical CWS particle sizes were calculated. The packing styles of N 1 N 2 N 3 , N 2 N 3 N 4 and N 3 N 4 N 5 were evaluated and analyzed. The evaluation method of packing index based on ΣP×S min andΣP×S max was established. The results show that the packing efficiency of particles can be quantitatively evaluated by using of cumulative calculation of voids areas and packing probabilities under different packing modes. The evaluation results are consistent to the tendency of CWS concentration. By this method, the particle size distribution of CWS can be controlled and adjusted during both wet milling processes and experimental investigations. Furthermore, the method may be used to other particle packing cases.

Energy Engineering

probability analysis

packing efficiency

void distribution

particle size distribution

coal water slurry

Table 1 Particle size distribution of coal water slurry

Samples	Concentration，wt%	<8mesh,wt%	<14mesh,wt%	<40mesh,wt%	<80mesh,wt%	<200mesh,wt%	<325mesh,wt%
A	59.72	100	99.67	93.19	74.22	45.79	40.08
B	60.42	100	99.76	93.04	72.62	43.87	38.42
C	61.48	100	99.77	93.39	73.29	45.21	38.06
D	55.07	100	99.86	90.9	72.12	46.82	38.25

Table 2 Calculated parameters of samples

	A	B	C	D
W₁,wt%	6.48	6.72	6.38	8.96
W₂,wt%	18.97	20.42	20.1	18.78
W₃,wt%	28.43	28.75	28.08	25.3
W₄,wt%	5.71	5.45	7.15	8.57
W₅,wt%	40.08	38.42	38.06	38.25
M₁	262	272	258	363
M₂	18598	20020	19706	18412
M₃	361245	365311	356798	321474
M₄	886646	846273	1110248	1330745
M₅	126435331	121198738	120063092	120662461
N₁	41	42	41	51
N₂	702	737	730	697
N₃	5072	5110	5031	4693
N₄	9229	8947	10722	12098
N₅	251910	244906	243373	244183

Note: N_i=M_i^2/3,i=1,2,3,4,5.

Table 3 Void areas of three-particle packing gradations

Packing modes	N₁N₂N₃					N₂N₃N₄					N₃N₄N₅
Packing modes	a，μm	b，μm	c，μm	s，μm	S_min，μm²	a，μm	b，μm	c，μm	s，μm	S_min，μm²	a，μm	b，μm	c，μm	s，μm	S_min，μm²
R₁R₁R₁	705	705	705	1057.5	215218	244	244	244	366	25780	104	104	104	156	4683
R₁R₁R₂	705	474.5	474.5	827	111967	244	174	174	296	15136	104	74.5	74.5	126.5	2774
R₁R₂R₂	474.5	474.5	244	596.5	55943	174	174	104	226	8635	74.5	74.5	45	97	1598
R₂R₂R₂	244	244	244	366	25780	104	104	104	156	4683	45	45	45	67.5	877
R₁R₁R₃	705	404.5	404.5	757	69937	244	144.5	144.5	266.5	9447	104	60.5	60.5	112.5	1608
R₁R₂R₃	474.5	404.5	174	526.5	34313	174	144.5	74.5	196.5	5296	74.5	60.5	31	83	909
R₂R₂R₃	244	174	174	296	15136	104	74.5	74.5	126.5	2774	45	31	31	53.5	480
R₁R₃R₃	404.5	404.5	104	456.5	20859	144.5	144.5	45	167	3212	60.5	60.5	17	69	509
R₂R₃R₃	174	174	104	226	8635	74.5	74.5	45	97	1598	31	31	17	39.5	253
R₃R₃R₃	104	104	104	156	4683	45	45	45	67.5	877	17	17	17	25.5	125

Table 4 Void areas of four-particle packing gradations

Packing modes	N₁N₂N₃					N₂N₃N₄					N₃N₄N₅
Packing modes	a，μm	b，μm	c，μm	d，μm	S_max，μm²	a，μm	b，μm	c，μm	d，μm	S_max，μm²	a，μm	b，μm	c，μm	d，μm	S_max，μm²
R₁R₁R₁R₁	705	705	705	705	497025	244	244	244	244	59536	104	104	104	104	10816
R₁R₁R₁R₂	705	705	474.5	474.5	334523	244	244	174	174	42456	104	104	74.5	74.5	7748
R₁R₁R₂R₂	705	474.5	244	474.5	196800	244	174	104	174	27718	104	74.5	45	74.5	5097
R₁R₂R₁R₂	474.5	474.5	474.5	474.5	225150	174	174	174	174	30276	74.5	74.5	74.5	74.5	5550
R₁R₁R₁R₃	705	705	404.5	404.5	285173	244	244	144.5	144.5	35258	104	104	60.5	60.5	6292
R₂R₂R₂R₁	244	244	474.5	474.5	115778	104	104	174	174	18096	45	45	74.5	74.5	3353
R₁R₁R₂R₃	705	474.5	174	404.5	153443	244	174	74.5	144.5	21379	104	74.5	31	60.5	3812
R₁R₂R₁R₃	474.5	474.5	404.5	404.5	191935	174	174	144.5	144.5	25143	74.5	74.5	60.5	60.5	4507
R₂R₂R₂R₂	244	244	244	244	59536	104	104	104	104	10816	45	45	45	45	2025
R₁R₂R₂R₃	474.5	244	174	404.5	90271	174	104	74.5	144.5	13957	74.5	45	31	60.5	2508
R₁R₂R₃R₂	474.5	174	174	474.5	82563	174	74.5	74.5	174	12963	74.5	31	31	74.5	2310
R₁R₁R₃R₃	705	404.5	104	404.5	109529	244	144.5	45	144.5	15142	104	60.5	17	60.5	2544
R₁R₃R₁R₃	404.5	404.5	404.5	404.5	163620	144.5	144.5	144.5	144.5	20880	60.5	60.5	60.5	60.5	3660
R₂R₂R₂R₃	244	244	174	174	42456	104	104	74.5	74.5	7748	45	45	31	31	1395
R₁R₂R₃R₃	474.5	174	104	474.5	63830	174	74.5	45	144.5	9181	74.5	31	17	60.5	1541
R₁R₃R₂R₃	474.5	174	174	474.5	82563	144.5	74.5	74.5	144.5	10765	60.5	31	31	60.5	1876
R₂R₂R₃R₃	244	174	104	174	27718	104	74.5	45	74.5	5097	45	31	17	31	857
R₂R₃R₂R₃	174	174	174	174	30276	74.5	74.5	74.5	74.5	5550	31	31	31	31	961
R₃R₃R₃R₁	104	104	474.5	474.5	49348	45	45	144.5	144.5	6503	17	17	60.5	60.5	1029
R₃R₃R₃R₂	104	104	174	174	18096	45	45	74.5	74.5	3353	17	17	31	31	527
R₃R₃R₃R₃	104	104	104	104	10816	45	45	45	45	2025	17	17	17	17	289

Fig.abstract.tif

Download PDF

Version 1

posted

You are reading this latest preprint version

A new method for evaluating packing efficiency of particle size distribution during coal water slurry preparation

Status:

Version 1

Abstract

Figures

Full Text

Tables

Supplementary Files

Status:

Version 1