Re: Temp Of Ash
Dear Teus Tuinenburg
i remember you have enlighten one formula for the same which is here for your ref:
Calculating the mixture temperature at the beginning of the pipeline is not difficult.
T(mix) = { Cp * Q(air) * T(air) + Cc * Q(fla) * T(fla) }/ {Cp * Q(air) + Cc * Q(fla) }
or :
T(mix) = { Cp * T(air) + Cc * mu * T(fla) }/ {Cp + mu * Cc }
As Peter stated, this mixture temperature is 371 C
in which :
Cp = specific heat-content of air at constant pressure
Q(air) = Mass flow of air
T(air) = Temperature of air
Cc = specific heat of flyash
Q(fla) = Mass flow of flyash
T(fla) = Temperature of flyash
mu = loading ratio kg-flyash/kg air
Example :
Cp = 0.24 10^3 cal/kg
Q(air) = 4.54 kg/sec
T(air) = 150 degr.C
Cc = 0.2 10^3 cal/kg
Q(fla) = 111.1 kg/sec
T(fla) = 382 degr.C
T(mix) ={ 0.24 * 4.54 * 150 + 0.2 * 111.1 * 382 } / { 0.24 * 4.54 + 0.2 * 111.1 } = 371 C
i was talking about this only which may patronage us to calculate temp of mixture at particular distance
kindly give me the full version of this formula
imay be wrong but iam verymuch keen to enter into this matter and shud comeout with some solution for my client
rahul
AMATUER ■
Re: Temp Of Ash
Now that you know your mixture temperature it is very easy to calculate temp. at any distance all you have to do is get the a figure of heat loss / m of your pipe from ref. books then calculate the heat loss in that distance and that will be your temperature at that point. ■
Re: Temp Of Ash
Dear Rahul,
You have the full version of the formula.The heat energy in the air at Tair + the heat energy
in the fly ash at Tflyash is divided over the air-flyash mixture at Tmix.
As soon as heat energy is lost, f.i. by mixing with cooler air, radiation, cooling through a pipewall, then the temperature drops.
Follow the advice of mr Mantoo and use thermodynamics to calculate your answers.
best regards
teus ■
Teus
Re: Temp Of Ash
Don't forget to put the decimal point in the bulk density .
Simply qualitatively I would say that your client is superficially correct, with or without lagging, the powder temperature will not drop appreciably after 6m. Further down the line there will have been some inter-phase heat transfer & thus a lower temperature of the powder. You have not provided the airflow value so who knows? ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Ash Temperature
For calculation of ash temperatures it is important to know at least exact inlet temperatures. Based on nearly 25 years of experience I would guess that ash temperatures from ESP can varied between 120°C and approx. 160°C; ash temp. from APH about 40 - 60°C higher.
If you take out ash from ESP and APH ashtemperature drops down approx. 30 - 50°C immediately after the ash has passed the cone.
So I would guess that after 6 m pneumatic conveying the ash temperatures (ESP) would not exceed approx. 90 - 130°C. Ash temperatures behind APH are approx. 40 - 50°C higher then ESP-temperatures.
Best regards
Klaus Schneider
KS-Engineering
Cologne, Germany ■
Re: Temp Of Ash
dear Rahul,
Heat will flow from a high temperature to a low temperature.
If you want to calculate the possible heat change in material, you will have to make a heat balance, using temperatures, heat content, heat transfer betwen materials, heat flow in materials, radiation and so forth.
This heat balance of the actual situation wiil result in the answers you need.
Could be quite some (enjoyable) work.
success
Teus ■
Teus
Temp of ash
Dear:- TeusTuinenburg
hi sir hou r u
well iwas going thru your one of the most interested thread ie temperature reduction of mixture(air+solids)
lets impel the discussion
can u help me by giving the formula of calcualating the temp reduction in mixture after 6metre
here is some input which may ease you to implies my problem
1) inlet temp of ash 200 DEg C
2) inlet temp of compressed air 50Deg C
3) Ash flow rate 600Kg/Hr
4) bULK DENSITY 075T/m3
5) Distance to be travelled 6Mtr
What will be the temp of mixture after said distance , reason to ask dis quistion becoz
one of my client claim that temperature of ash is 200DEG consistent at all fields(boiler bank, Esp , APH) of outlet of boiler which i concieved may be impossible rather i would not have imagined the said temp will uniform at each level
awaiting your valuable reply
rahul
SIMMERING FOOD ■