We were discussing “Cements and
its types” and “Clinker grinding process in cement manufacturing unit” in
our previous posts. We have also seen the “Clinker storage system” in our
recent post.
Today we are going to start here one very important
topic i.e. Cement storage, packing and dispatch. We will understand the various
terminologies and engineering concepts used in cement technology with the help
of this category, but first read this article “Clinker cooling technology” and “Cement kiln refractory lining”.
Further we will go for discussion of clinker grinding,
cement packing and dispatch, pollution control and much more facts about cement
technology in our next post in this category of cement technology.
Let us see here, cement storage, packing and dispatch
Storage of Cement
Cement is stored in cylindrical silos of RCC type
construction where air is supplied by various root blowers usually. Silos with
bottom inverted cones are used due to lower specific power consumption.
Earlier
cement was stored in wooden and steel casings. Now days, cement is packed in
bags using either
1. Gunny / jute
bags
2. HDPE bags
with kraft paper lining inside
3. 5 ply kraft paper bag
Jute bags cause the highest spillage / leakage
resulting in reduction in net cement content in transit. But the used jute bags
have higher sale value as these can be re - used for cement packing unlike
paper or HDPE bags.
The packers used are either stationary, which are
very limited in capacity, or Rotary, which have a large capacity.
Now days, electronic weighing devices are used to
ensure proper weighing of the packed bags within acceptable limits.
After cooling of cement
Storage of cement and packing into paper bags
requires a reduction of cement temperature down to 65 C. During conveying from
mill to storage silos, cement temperature is lowered by about 5 - 10 C. Cooling process in silos lasts several
weeks. When storing hot cement in silos, lumps are formed from reaction between
clinker minerals and water of hydration of gypsum.
If hot cement is packed in bags, the paper fibre
deteriorates and the bags often tear apart.
Hence, cement coolers can be used to reduce the
temperature of cement from 110 C to around 65 C by applying cold water at 15 C.
Do you have any suggestions? Please write in comment
box.
We will see other topic i.e. “sources of pollution and control technology” in our next post in the category of Steel and cement
technology.
I am very thankful to Mr. Subrata Bhaumik,
Independent cement consultant, for providing such beautiful information and
contents about cement technology.
Mr. Subrata Bhaumik has more than 50 (Fifty) Years
(1965 - 2016) of Experience in Cement and other related Industry covering more
than 100 assignments in cement plants with capacities ranging from 100 tpd to
10,000 tpd in India and abroad involving visit to 25 countries overseas in
connection with work.
For more detailed information about the original
Author of this content, please click the Author profile link below.
Author Profile
Image courtesy: Google
No comments:
Post a Comment