The development and application effect of intensive mixer

Keywords:

intensive mixer

Source: internal company

Most of our briquetting plants use cylindrical mixers and simple wheel mixers for mixing of raw materials. But its mixing efficiency is low, so in recent years, new pelletizing plants and some old plants have turned to a powerful mixer.

1. The structure of the intensive mixer

1.1 Transmission part: The transmission part is composed of motor, hydraulic coupling, reducer and gear coupling, etc.

1.2 The rotor assembly: The whole shaft erected in the two end plates of the load bearing, spindle welded fixed groove, through the bolt welded head rake teeth rake rod and fixed groove coupling together.

1.3 Cylinder assembly: The Cylinder body is rolled from common steel plate and welded with inlet and outlet and accident discharge port, the bottom is placed horizontally and connected to the foundation through foundation bolts.

1.4 The transmission base is made of ordinary steel plate welded together and fixed on the same level foundation as the Cylinder by ground bolts.

2. The main performance parameters of the intensive mixer

Specification: Φ1600×3500mm

Processing capacity: 170t/h

Spindle speed: 83.3r/min

material residence time: 60s

drive motor: JS126 a 4225kw, 1475r/min

hydraulic coupling: YOX560, 1500r/min

reducer: parallel shaft cylindrical gear, NZL545 type, speed ratio 18

3. The intensive mixer mixing efficiency measurement

3.1 Mixing efficiency measurement

The following table shows the data of material mixing for the test :

Sampling location	Components	Specimen No. and data
Sampling location	Components	1	2	3	4	5	6	7	8	9	10	C	R
Pre-mix	SiO₂	4.03	4.69	4.63	4.38	5.49	5.09	4.56	4.56	4.46	4.37	4.63	1.46
	CaO	0.33	0.31	0.33	0.30	0.24	0.31	0.31	0.26	0.30	0.26	0.30	0.09
	Fe	68.7	67.8	68.2	68.2	67.9	68.2	68.6	68.5	68.5	68.2	68.33	0.90
After wheel mix	SiO₂	4.06	4.59	4.62	4.30	5.35	5.06	5.46	4.50	4.50	4.36	4.58	1.31
	CaO	0.32	0.31	0.32	0.30	0.31	0.31	0.24	0.26	0.25	0.26	0.29	0.08
	Fe	68.6	68.2	67.7	68.2	68.2	67.9	68.6	68.5	68.6	68.3	68.28	0.90
After intensivemix	SiO₂	6.6	6.56	5.95	6.10	6.00	5.90	6.05	6.10	5.90	6.25	6.14	0.70
	CaO	0.24	0.24	0.25	0.27	0.31	0.25	0.25	0.25	0.31	0.25	0.26	0.07
	Fe	66.8	67.0	66.80	66.7	66.4	66.6	66.5	66.6	66.8	66.5	66.67	0.60

Note: C is the average content of the component, and R is the extreme difference, which is the difference between the maximum and minimum values.

3.2 Mixing efficiency analysis

The quality of the mixing operation can be measured by the mixing efficiency η and the average uniformity factor m of the mixture, which is calculated as follows:

In the formula C1......Cn is the content of a component of the sample, C is the average content; n is the number of samples; M1......Mn is the uniformity coefficient of each sample; Mmix, Mmax is the minimum and maximum value of the uniformity coefficient; Md is the uniformity coefficient of samples greater than 1, Mi is the uniformity coefficient of samples less than 1; M is the average uniformity coefficient, its value is closer to 0, the better; η is the mixing efficiency, its value is closer to 1 ,the better. Md is the homogeneity coefficient of the specimen greater than 1, Mi is the homogeneity coefficient of the specimen less than 1; M is the average homogeneity coefficient, its value is closer to 0, the better; η is the mixing efficiency, its value is closer to 1, the better.

The data measured in front of the above formula is calculated after the mixing effect is included in Table 2. it is obvious from Table 2 that the mixing efficiency η and the average uniformity coefficient m of the powerful mixer is more ideal, according to the information we have, it is equivalent to the mixing effect of the two-stage cylinder mixer. While the effect of wheel mixing is very poor, its data show that it does not meet the production requirements for mixing. In addition, from the data in Table 1, especially the value of the extreme difference R shows that the powerful mixing is much better than the wheel mixing.

Categories	Efficiency codes	Measurement items
Categories	Efficiency codes	SiO₂	CaO	Fe
Pre-mix	η	0.7341	0.7273	0.9869
Pre-mix	M	0.0713	0.2833	0.0040
After wheel mix	η	0.7589	0.7500	0.9869
After wheel mix	M	0.0568	0.0965	0.0035
After intensive mix	η	0.8939	0.7742	0.9911
After intensive mix	M	0.0303	0.0769	0.0022

4. Conclusion

4.1 The intensive mixer is a kind of ideal mixing equipment newly adopted in the pelleting process in China in recent years. Its technology is reasonable, the mixing effect is good, and the equipment has passed the standard.

4.2 With a intensive mixer instead instead of wheel or cylinder mixer can improve the mixing effect, promote and stabilize the production of pellets, improve production and quality.