Ball Mill Optimiztion

How can I make dynamic separator more efficient e fficient ?. Juan Pedro Esperón Ingeniero Quimico I heard reducing anchor of blades b lades one can obtain more final product from reject of dynamic separator and increase production without changing 1 day strenght. What do you think about it ?     

Like Comment (10) Share Follow March 22, 2012

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suresh suresh deolalkar  Director at Deolalkar Consultants three factors govern the performance1 speed 2 air/material ratio 3 angle/no of blades on rotor . designer of separator can advise you on specific problem o o o

Like Flag as inappropriate March 23, 2012

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 bhargava  bhargava rao Tech Manager at Al Ghurair You have two factors to adjust to improve the efficiency 1, static blade adjustment 2. RPM of rotor. Only upto certain RPM of rotor, seperator is efficient. Over that seperator

efficiency comes down. Additional deflectors can be p rovided to improve the efficiency. However, consultation with supplier is better. o o o

Like Flag as inappropriate March 23, 2012

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Jagrut Jagrut Upadhyay Process Consultant at PEC Consulting (Penta Engg. Corp.) St. Louis, Missouri. Dynamic separators need to be operated with max air flow in order to maintain desired air velocity across the separator. In addition to above points, look for PERFECT seal  between rotor and the static part of the separator. This plays a vital role. o o o

Like (1) Flag as inappropriate March 23, 2012

Eduardo Sánchez likes this

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Rana Rana shahid section incharg kiln utility and cement mills at Hail cement company i am agree with bhargava rao and maintain wear tear of blades and roto and its parts o o o

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Like Flag as inappropriate March 24, 2012

Hussain Hussain Khan at ACC Cement Company Please once check separator seal, baled position and air damper position also. o o o

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Craig Craig Puljan Maintenance Manager at Lehigh Southwest Cement Company Hello Juan, I agree with what Jagrut is saying. Please run your fan to achieve maximum airflow through the separator and then adjust the rotor speed (RPM's) upwards in order to achieve the sharpest particle size distribution. Doing this should show some kind of  production increase as you are getting particles out of the system o o o

Like Flag as inappropriate March 26, 2012

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Craig Craig Puljan Maintenance Manager at Lehigh Southwest Cement Company that can then be replaced by fresh feed. I hope you are successful! Kindest regards! o o o

Like Flag as inappropriate March 26, 2012

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LUIS LUIS FUENTES PRODUCTION MANAGER at CEMEX UK Dear Juan Pedro....I think these are the steps...maybe you already check them...but in case not...these are in my opinion... 1.- Calculate the tromp curve, circulating charge. to decide if your eficiency is ok. 2.- Check if the air flow trough the mill and the separator is ok...measure with pitot. 3.- check if your using the right charge in the mill, and the right level of media. 4.- check if your diaphram intermediate and exit are ok, blockage, etc...if you have cyclons, static separator, bag filters if they are in good conditions... 5.- check if the residue of size of the cement is well measured and calculated or if the clinker characteristics are ok, clinker dusty, low uality of clinker, free lime, poor C3S, etc require more finest in the cement mill and consequ ence the TPH of the mill reducing sometimes... 6.- Check if the amount of water (in case you are using is ok) the spraying and the temeperatures in the mill are ok? 7.- check if you have false airs in the separator system....holes, gaps.,etc. 8.- check if the mechanical equipment is in good conditions, blades, vibrations, temperatures, oil, speed, dampers, etc... o o o

Like Flag as inappropriate March 26, 2012

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Jagrut Jagrut Upadhyay Process Consultant at PEC Consulting (Penta Engg. Corp.) St. Louis, Missouri. Hello Juan, Thanks to Craig for specifically mentioning about sep arator's speed. I would also like to offer following comments, which might be useful. It is generally accepted that high efficiency separators lead to a good performance of grinding circuits and considerable saving of energy, The cause for a production increase through the improvement of separator efficiency can b e analysed as follows:

* to the improved separation characteristics, the amount of fines returned to the mill with the rejects decreases considerably which avoids over grinding and wasting of grinding energy at the mill. This mechanism is facilitated by the intensification of air sweeping through the mill and the temperature reduction inside the mill which can be often observed when using modern high efficiency separators. * virtue of the improvement in cement quality, for the modified particle size distribution, the possibility of reducing the specific surface area of cement a rises. A high surface area of cement promises the possibility of an increase in the production rate. This is due to  possibility of sever over grinding in the mill, especially when grinding aids are not used. * more influence of high efficiency separators on t he properties of the cement would be the reduction of mill  –  inside temperature. In conventional grinding circuits mill  –  inside temperatures were too high, and several types of c ooling procedures were introduced in the circuits. In modern type HESs, a large amount of cooling air can be efficiently introduced in to the circuit. This explains as to why the separator should be maintained in a manner in what it should  be. Alteration of the volume of separating air: As a general rule, the separator achieves the maximum possible throughput and the best  possible efficiency at the maximum volume of separating air. If the volume of separating air is reduced, the product becomes finer, with the throughput and efficiency being lower!! It might in some cases be subsequently found that the volume of separating air is insufficient, so that a fresh air has to be installed in the air duct between the circulating air fan and the separator. If this is done, it should be ensured that that the fan capacity is adequate with regard to volume and pressure. In practical life, you will experience that you can achieve the same residues on a particular sieve, with relatively lower Blaine, when a properly maintained separator is optimized well. o o o

Like Flag as inappropriate March 26, 2012

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Luis Luis Lardizabal Process Engineer in Portland Cement Industry Can you provide a report tests that you have done to know the current condition ?

o o o

Like Flag as inappropriate March 26, 2012

Separator performance without Tromp curve what is the way to judge the separator performance by seive analysis of rejects,feed & fines. what is the normal range of residues on 212,90,63,45,32 mic for better efficiency of a separator in coarse,feed & fines & why?(for cement as well as raw meal) what is the optimum efficiency of a high efficiency separa tor? raj Reply

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138 posts TimePosted 3 years ago lalbatros says

Re: Separator performance xxxx, If you have residues on {212, 90 , 63, 45, 32} µm for feed, coarse and fine, and if your product is not too fine - as compared to 32µm - , then you could evaluate a Tromp curve. If you have less data, you have less chances to evaluate your separator, and vice-versa. However, the main question is: what do you mean by "optimum efficiency"? On a Tromp curve, you can observe the so-called "bypass level". The bypass level indicates how much % of fine particles go to the coarse stream. This measures, of course, and un-wanted behaviour or an "un-efficiency".

If the bypass is 40%, and if the production is 100 t/h, then, naïvely speaking, this means that 40 t/h of good product is returned to the mill. This could be, naïvely, translated as an efficiency of 100/140 = 70% and would indicate that the  production could be increased by 40 t/h if the separator would be 100% efficient. Actually, the impact of the bypass is lower but it increases with the fineness of the product (circulation factor). This can be understood by a model of the complete grinding circuit. My message is: to evaluate a seperator you do need to evaluate the Tromp curve. The least you could get from the Tromp curve is the bypass factor. If you don't have enough information for that, you cannot evaluate the separator. Michel Reply

224 posts TimePosted 3 years ago xxxx says

Re: Separator performance my question is what is the normal range of these residues for coarse,feed & product so that i can compare for any improvement in the system raj Reply

138 posts TimePosted 3 years ago lalbatros says

Re: Separator performance There is no answer to this question. It depends on what you are producing. For "system improvement", is it not enough to c heck the quality of the product and the  productivity t/h ? If your focus is on "separator improvement", then it is all about the Tromp curve. Here is some sample data to illustrate my point:

finish product 3500 Blaines, (P32,P45,P63,P90,P212) = (78%, 90%, 97%, 99.3%, 100%) where P=1-R feed 2450 Blaines, (P32,P45,P63,P90,P212) = (53%, 67%, 80%, 90%, 99.6%) reject 1200 Blaines, (P32,P45,P63,P90,P212) = (23%, 39%, 61%, 79%, 98.9%) Plant Circulating load:

1.8

Separator  bypass: 10% cut diameter: 40µm (x50) (x75= 26µm, x50= 40µm, x25= 63µm) imperfection: 46% (=(x75-x25)/2/x50) Mill residues reduction factors: (= residue mill outlet / residue mill inlet) @32µm = 40% @45µm = 58% @63µm = 76% @90µm = 87% @212µm = 100% (!) (this is calculated from residues and circulating load)

I don't see how you could use these data and compare them to your own data. What is your product? What is the product fineness? What is you circulating load? To evaluate your separator, you need the Tromp curve, even with very few points. The bypass is one point of the Tromp curve that can be evaluated even with few data.