Technical Cement Forum

Flame

David — Fri, 31 Oct 2008 20:35:01 GMT

hey to all;

We are facing high shell temperatures in two areas in our kiln shell, i want to change the postition of the burner pipe by pushing it in or taking it out but the problem is that i dont know the length of the flame inside the kiln. what i mean because i dont know the length of the flame i am not sure if i push the burner pipe in the flame will be close to the high temperature area or not. How i can know the length of the flame inside the kiln? i need to know it to know shall i push or take the burner. ANY HELP PLEASE \

thanks

Flame Length

Cement man — Tue, 26 Aug 2008 00:38:47 GMT

Hey everyone;

What is the length of the flame inside the kiln? how can we determine the length of the flame? i know that alot of factors affect the length of the flame like swirl, primary air pressure, ID fan and etc. but Is there any formula collect all these factors to determine the length of flame (Gas, Oil, & Coal)?!!

Best Regard

Fan performance curve

xxxx — Sat, 07 Nov 2009 03:00:47 GMT

IF THE FAN INLET TEM. IS CHANGED FROM 370 TO 230 DEG.

WHAT CHANGES TO BE MADE IN THE FAN CURVE TO CHECK THE PRESENT OPERATING CONDITIONS?

SHOULD I MAKE A CORRECTION FOR VOLUME IN FAN CURVE

ONLY DENSITY CORRECTION TO BE INCORPORATED IN FAN SHAFT POWER & PRESSURE

CHANGE IN DENSITY WRT TEMP. TO BE INCORPORATED IN ALL THAT IS

VOLUME,PR.,KW.

I THINK ONLY CORRECTION IN PRESSURE & KW IS REQUIRED & NO CORRECTION IN VOLUME IS REQUIRED FOR CHANGE IN TEMP. TO DRAW A NEW FAN CURVE WITH NEW TEMP.

PLEASE SUGGEST

RAJESH

flame optimisation

technical cement forms — Tue, 01 Jul 2008 16:55:03 GMT

Dear sir,

How to check whether the flame is optimised properly.I normally adjust the flame by adjusting the axial or swirl pipes or adjust the axial or swirl dampers. Do you think the flame will change effectvely by adjusting the axial, swirl pressure slightly say by increasing the pr from 190 mbar to say 200 mbar? The other question which is the correct burner pipe position ??Say some 50-100 mm inside the kiln or face to face with the tip of the kiln, Leaning slightly towards material side is good or placing it kiln axis is better?? How to adjust the flame to reduce sulphur/alkali concentration?Pl advice

Mathameticle model

jatin — Tue, 28 Aug 2007 06:26:31 GMT

Does anybody has mathamaticle model for double string preheater.

Just wanted to know the expected parameters at various stages.

thanks,

jatinder...

Mr Ted,

hongminh — Sat, 07 Nov 2009 03:02:14 GMT

Hi Ted Krapkat,

How are you today?

Could you sent to me your email?

I have any questions it is waitting your support.

Thanks inadvance.

HongMinh.

Ring Formation

Raj Sahu — Wed, 14 Oct 2009 06:28:51 GMT

What are the possible reasons for ring formation and subsequent boulder formation inside a kiln?

Cooling of Cement

NG — Wed, 21 Mar 2007 06:20:44 GMT

We want to install Cement Cooler to cool cement before filling in the silo. Request to suggest some suppliers for such the Cement Cooler.

Trace Heating for fine coal hopper

prdp.ks — Sat, 31 Oct 2009 15:37:18 GMT

Dear All,

Is the trace heating in fine coal duct Hopper before coal dosing system have any significant when ambient temperature ranging 4-45 degree Cent, if yes then what kind of heating element system are prefered i.e

pad heating system
tubiler heating system

and what is the philosphy for heating control, while answer these question please assume moisture content in fine coal as per BS1236.

regards

Prdp.ks

Alk / SO3 ratio

electron1539 — Sun, 01 Nov 2009 17:23:36 GMT

Dear experts ,

I used to use this equation for calculate the Alk/sulfate molar ratio :

Na2O + K2O - Cl / SO3

with consideration the molecular wt.

but i found that some companies use the equation without Cl

Alk / sulfate = Na2O + K2O / SO3

which one is correct to use and why ?

AF

Stephenb — Mon, 02 Nov 2009 11:45:52 GMT

Good day Experts.

We are currently making clinker for Type II cement. The AF in the KFS and Clinker are 1.1-1.2% and 0.95-1.1% respectively. We are going to change to Type I and the AF in the KFS and Clinker are expected to be 1.3-1.4% and 1.2-1.3% respectively.

What are the positive AND negative effects on the kiln when the AF is high AND also when it is low.?

Thanks

Roller Press

Madsniggy — Sat, 16 Dec 2006 00:25:19 GMT

Hai friends,

Our cement grinding is the combination of "Roller Press and Single Chamber ball mill. . My question is "Are there any cement plants which grind both slag and clinker simultaneously in the roller press" and if so what are the type of problems are you facing. Do you have any problems such as roller damaging if so how are you over coming them. What is the output of your cement mill while grinding slag cement.

STANDARD SPECIFICATIONS

Stephenb — Fri, 30 Oct 2009 19:01:18 GMT

Good day experts.

Is there any ASTM OR BS-EN standard to manufacture a cement from Type V clinker blended with pozzolan?

Thans

LIQUID PHASE

Stephenb — Mon, 26 Oct 2009 13:39:16 GMT

Good day experts.

Can someone tell me the general effects of a high and low liquid phase, both positives and negatives?

Thanks.

Heat balance excel sheet - detailed calculations

Er.Hussaini — Sun, 25 Oct 2009 06:02:46 GMT

Sharing is caring:

here is my contribution to cement engineers community.An excel sheet (MS excel 2003) that can does heat balance for pyro section of cement industry.This sheet is absolutely leagl as it's my personal work. It's not a copyright property of any organization hence could be shared freely.( you need not pay a single penny)

This copy is just a draft copy based on suggestions i'll improve and upload it again (it has been thoroughly checked)

This excel sheet calculates heat Balance of pyroprocessing


For time being this calculation are done for (MKS System only).
It is assumed that you supply very precise data based on which accuracy of entire heat balance calculations lies.

Calculation procedure:

1) Enter the required data on input page just replace the existing values
2) Go to detailed calculation sheet there you get explanation of entire calculations
3) Heat balance report can be printed on Output page

you can download this excel sheet here:

http://cid-dd94cb2ad5b72728.skydrive.live.com/self.aspx/Public/heat%20balance%20cement%20industry%20excel%20sheet-Er.Raza%20hussaini.xls

For comments/quires/suggestions contact me

mohammedhussaini@live.com

Regards

Er.Raza Hussaini

Asst.Manager

B.tech.,(Chemical engg)

Breaking News: Explosion in Cement Plant

Nael — Mon, 26 Oct 2009 20:37:28 GMT

Hey; Our plant is an offline PC kiln with 5 stages preheater and bypass system. Last week a big explosion happened in our preheater riser duct towards Cyclone-5. The results of this explosion are:

1- Riser duct towards cyclone-5 damaged completely (Bricks and castable pieces found 1000 meter far from the preheater)

2- In several areas bricks and castable damaged.

4- Conditioning tower damaged.

5- Of course we have also small damages in each cyclone, damages in most of riser duct expansion joints and etc.

6- (One thing more) Two bird died.

As you see it is a big accident and maybe the damage of preheater is bigger than we think ... it will be clear later after checking the preheater inside.

How & why this explosion happened! I would like to share with all of you the reasons of this accident to avoid it in the future especially it is the first time (as I know) such type of accident happening in a new and modern cement plant.

Last week and after the annual shutdown; kiln feeding was started (after 24 hours heating) but after few hours the feed was stopped due to upset condition of the kiln (dusty & cold).

3 hours before the explosion: (End of the shift) Kiln operator kept the fire on for heating the kiln again.

2 hours before the explosion: Next Shift Kiln operator wanted to increase the heating rate by increasing the gas flow rate and at the same time increased ID fan rpm from 300 to 500 and again to 300 (in one minute). Here the problem started because when he took this action disturbance happened in hood pressure (+2 to -6 mbar) and as a result flame cut-off (BUT FLAME INDICATOR WAS SHOWING ON). Smoke chamber temperature started dropping. (Note: kiln camera was out of order)

1 hour before the explosion: Smoke chamber temperature still dropping very fast, the kiln operator didn’t observe the cut-off of the flame (due to false indication of flame) so he increased the gas flow more and more and at the same time reduced ID fan to the minimum. (Fresh air damper was 100% close).

10 minutes before the explosion: The kiln operator didn’t put in his mind that flame may cut-off so in order to increase the heating he stopped ID fan, due to interlock between ID fan and kiln gas; gas flow stopped and at that time the false flame indication disappeared from the monitor. Immediately he started the gas again and gave order to the kiln field operator to torch the kiln manually.

1 minute before the explosion: Preparing the manual torch took several minutes (Note that at this time gas is on, ID fan is off, and fresh air damper is close). When the torch was inserted to the kiln hood; back fire with dust puffing from the hood injured one person but fortuity his injury was only in his eyes and not serious. After 30 seconds the explosion occurred in the preheater and again fortuity all kiln field stuff were near the cooler and nobody was in preheater or around it (Note that the accident happened after midnight).

I know the kiln operator did very big and crazy mistakes and these mistakes will cost us minimum three months stoppage and millions EUR lost. The kiln operator may be will be terminated and maybe others also but I don’t think only the termination will reduce our lost or give guaranty it will not happen again.

Best Regard

NOx Emission

Raj Sahu — Mon, 26 Oct 2009 03:49:44 GMT

What should be the optimum NOx emission (mg/Nm3) at the back end of the kiln?

Air conveyor

ILA — Sat, 24 Oct 2009 18:15:15 GMT

I need to design and understand all calculations for an airslide system for cement, Could any one help with that topics , Is there any correlation between air slide duct width And long With Amount of air and pressure , How is that . And what is the relations between the flow rate per hour with inclination angle .

Thanks

Grate cooler bed

ILA — Fri, 23 Oct 2009 18:36:37 GMT

Dear Sirs I faced real problem and tha is lower kiln output due to unstable bed on the first part of grate cooler , alternathely high bed level , low no. of strock per 1 min. to hydraulic pistons drives lower rpm and colapsed of the bed and too much fresh air to firing zone and upset kiln opreations , Could any one help .

Clinker granulometry during petcoke.

maddy — Mon, 29 Jun 2009 10:56:47 GMT

Respected all,

I think everyone knows that when ever we use petcoke in the system our Clinker granulometry changes and it becomes finer in size. I have seen a change in this pehnomenon, when we use 5-6% sulphur the clinker is finer and when we use a 2% sulphur petcoke the nodulisation is better. Why is this change, is this only due to sulphur or any other reason. And my other question is what happens to clinker temperature when we use petcoke. With my experience I found that clinker temperature was on higher side. Can one tell how to reduce this (let it be any cooler).

Best Regards,

Maddy

SO3

hongminh — Fri, 26 Jun 2009 08:12:21 GMT

Dir sirs!!!

Can we use a bypass system to eleminate the circulation of SO3?

Best regards.

HongMinh.

cement plant cost

xxxx — Wed, 21 Oct 2009 08:53:44 GMT

what is the cost of a new cement plant of 2 MTPA?

what is the cost of erection for the same & cost of iron for the same?

rajesh

Polymorphic form of alite

Raj Sahu — Tue, 20 Oct 2009 05:16:17 GMT

When and how idiomorphic formation of alite takes place? What will be the effect of idiomorphic form of alite on cement quality?

high free lime

bazarah — Sun, 20 Sep 2009 18:26:03 GMT

Hey Friends;

How do you know the kiln feed is hard to burn? If free lime high in clinker

it may be caused operation process not quality? Our kiln by pass system

Target kiln feed:

LSF: (96 -98.5) %

SM: (1.95 – 2.15)

AM: (1.2 -1.4 )

Residue: 90 ^u : (6 -8 ) %

200 ^u : (0.5 – 1.0 ) %

Clinker:

C3S : (52.0 – 55.0) only!

free lime:(1.90 – 2.30) high

liter weight :1120- 1230

If you have any experience or idea to improve this problem,

we are highly appreciated to receive your sharing.

Thanks in advance

Best regards

Bazarah

Process Buildup

Raj Sahu — Thu, 03 Sep 2009 12:12:18 GMT

Dear friends,

There are generally two reasons for process build-ups problem in any kiln,first is due to sulfur cycle and second is alkali cycle.Which process build-ups is difficult to clean in pyroprocessing section?