1. IN FEBRUARY 2015, LOUISE FORDHAM VISITED ITALCEMENTI’S
DEVNYA CEMENT PLANT, BULGARIA, WHERE A BRAND NEW
STATE-OF-THE-ART PRODUCTION LINE HAS BEEN INSTALLED.
M
y first glimpse of Italcementi’s Devnya Cement
plant was from the sky; the plant’s lights
blinking in the dusk as I descended upon the
city of Varna along Bulgaria’s Black Sea Coast. Whilst
the city’s beaches, Roman Baths and historic sights are
among some of the key draws for tourists, the area is
also an attractive home for industry.
PLANT TOUR:
DEVNYA
CEMENT
44 /45

2. May 2015
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May 2015
46 World Cement
Varna West Port serves vessels of up to 50 000 t
and provides access to the Black Sea markets and
beyond. Devnya Cement plant’s proximity to
the port is just one of a number of reasons why
it is said to be strategically located. The plant,
explains Devnya Cement’s Manufacturing Manager,
Teodor Petsov, “is a pearl”: cement and clinker are
transported a short distance by truck for export
from the port, which also allows for the import of
slag, coal and petcoke; the local area is abundant
in high quality raw materials; a well-developed
railway network enables extensive and cost-effective
transport of raw materials, cement and clinker; the
site even has its own dedicated natural gas pipeline,
although this is now only used for startups.
Another reason why the plant could be described
as a pearl is, of course, the e160 million investment
in a new, state-of-the-art production line. Already
the largest cement manufacturer in Bulgaria, this
investment will enable Italcementi to strengthen
its presence in domestic and export markets whilst
utilising best available technologies to increase
the Devnya Cement plant’s operational efficiency
and reduce its environmental footprint. The
modernisation project includes a dry process line with
the capacity to produce up to 4000 tpd of clinker and
1.7 million tpy of cement.
The EPC contract for the project was awarded to
CBMI Construction Co. Ltd, part of the Sinoma Group,
in the spring of 2012, and the construction phase
commenced shortly after. The kiln started up in
October 2014 and it will be fully operational in late
spring 2015.
During my visit to the plant in early February,
Teodor Petsov and Gabriele Pierantoni,
Commissioning Manager, Italcementi – CTG, kindly
took the time to talk me through the new line.
Based on the Italcementi Group Technical Centre’s
knowhow, Devnya Cement has selected leading
equipment from a wide range of suppliers to ensure
maximum efficiency and innovation in each area of
the plant.
The new production line
Raw material handling, storage and grinding
Limestone is sourced from a nearby quarry, which
is operated by a separate entity. The limestone,
which has a very high purity, arrives via five
revamped belt conveyors with a total length of
3 km. Sand and marl are supplied from sites in
close proximity to the plant, and iron silicate is
purchased from another facility. These materials
are also of a consistently high quality, meaning
that little has to be done to them when they
arrive onsite. The existing raw material storage
and crane operating system remain in place,
providing a total storage capacity of 80 000 t. New
additions to the raw materials department include
a marl crushing system supplied by Bedeschi and
a crossbelt online analyser from PANalytical.
The latter will be linked to FLSmidth’s QCX/
BlendExpert™ to allow for automatic adjustments
to the raw mill mix.
For grinding, a new Loesche vertical roller mill
LM 48.4 has been installed. Schenck Process was
chosen to supply all seven weigh feeders, while
Aumund provided four bucket elevators: one to
feed the preheater tower, one to feed the homo
silo, the third on standby, and a chain elevator
for the raw mill. The 13 000 t capacity homo silo
itself is also new, supplied by IBAU HAMBURG.
FLSmidth Pfister was chosen to supply a double
raw meal dosing system.
Pyroprocessing
The new 5-stage preheater is of CBMI design,
with an inline, low-NOX
calciner. The 3-pier kiln
is 68 m long with a 4.6 m dia., and lined with
Tongda-supplied refractory. A gas analyser from
The revamp means that the Devnya Cement plant, pictured
here by night, can produce up to 4000 tpd of clinker and
1.7 million tpy of cement.
The new 3-pier kiln (68 m long x 4.6 m dia).
ITECA is located at the back-end of the kiln and
two further gas analysers from ABB can be found
at the preheater outlet and at the C5 exit for the
calciner. For clinker cooling, Devnya Cement has
opted for an IKN Pendulum Cooler®
with a surface
area of 100 m2
. Four roller crushers are located at
the cooler exit and three Aumund pan conveyors
subsequently transport the clinker to the storage
area.
The new line allows for increased emissions
control and monitoring. To meet stringent
NOX
emission limits, an SNCR system with ammonia
injection from Yara has been installed. Although
the plant was still in the testing stage at the time
of my visit, the SNCR system was already up and
running and the plant was in line with the EU’s
Integrated Pollution Prevention and Control (IPPC)
permit. This is also true of dust emissions. The
new line features 6.5 m long PFTE filter bags from
AAF, with pulse jet cleaning technology and high
temperature resistance. The plant is equipped
with a continuous emissions monitoring system.
Reducing heat
The modernisation project has significantly
reduced heat consumption, which can largely be
attributed to the gas circuit CTG has designed for
the plant. According to Teodor, the gas circuit at
Devnya is one of the most sophisticated within
the Italcementi group. Gabriele explains: “It is
sophisticated because we designed the gas circuit
in order to minimise losses and maximise the
heat usage to the overall burning line. We have
quite wet raw materials, with high moisture in
the spring and autumn, so when the raw mill is
running we use 100% of the heat coming from
the preheater and we also take the exhaust air
from the cooler.” From the cooler vent fan, the
hot air runs through an underground tunnel to
the raw mill department where it is split into
different branches, regulated by dampners. The
air can either be used in the raw mill, directed
to the bag filter or used for drying in the coal
mill. Commissioned in 2001, the coal mill also
formed part of the existing plant. However, when
the new line was set up it was connected to the
cooler via the hot air duct, drastically lowering the
amount of heat consumed during coal grinding.
Whereas the cooler now meets all of the mill’s hot
air needs, hot gas generators were also required
under the old system.
It is not just heat consumption that
Devnya Cement has worked to reduce as part
of this investment. There is no continuous
consumption of water on the new line. To meet
any water requirements that may arise, e.g. for
occasional use in the conditioning tower or for
any firefighting purposes, a new water treatment
facility has been installed for rainwater.
Table 1. Equipment and suppliers
Equipment Supplier, capacity and notes
Quarry
Transport from
quarry
3 km belt
Raw material
storage
80 000 t, operated with 3 OWHC
Online analyser CNA Sodern
Blending/homogenising
Silos IBAU HAMBURG, 13 000 t useful
capacity
Grinding
Mill type Vertical raw mill, Loesche LM 48.4
Drying (raw
materials)
Integrated circuit mixing hot gases
from preheater and cooler exhaust air.
Availability of a dedicated HGG (LOMA
type) for first startup
Drying (coal) From new kiln cooler exhaust air.
Availability of a HGG for startups
Conditioning tower ELEX, 40 m3
/h maximum spraying
capacity
Preheater
Stages 5-stages CBMI design. Availability to
feed 4th
stage in case of extra heat
requirement from raw mill
Calciner In line calciner, Low-NOX
design with
staged combustion. Three raw meal
arrival points from C4, two levels of
tertiary air intake, two levels of burner
with total four burners
Burner Unitherm, Low-NOX
type,
2 x 36 MWth and 2 x 19 MWth
Dedusting
Filters/bags Yes with nuisance bag filters
CEMs Yes
SNCR Supplied by Yara, 900 l/hr capacity
Baghouse Main process bagfilter, AAF pulse jet
type, 6.5 m long bags, PFTE, high
temperature resistant
Rotary kiln
Type/size 4.6 m dia. x 68 m length, girth gear/
pinion drive
Supports 3
Drives 1 drive, 630 kW capacity
Type of shell scanner Centurion TK50 with
WinCem graphic 8, Thermoteknix
Thermal imaging Mirion M215 Spyrometer
Refractories Beijing Tongda
Burner Unitherm Low-NOX
Burner, 90 MWth
capacity

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Fuels
On the day of my visit, Teodor and Gabriele are
in the middle of a 72-hour refuse-derived fuel
(RDF) performance test. The RDF is comprised of
municipal waste from Varna, which arrives via
trucks with moving floor discharge capabilities. A
new RDF reception, storage and feeding facility
has been constructed, with a fully automatic
crane. The dosing system was supplied by
Schenck Process; a swan-neck elevator running
at a 45˚ incline to the calciner. To account for
variations in the RDF and possible high chlorine
content, a bypass system has been installed.
This was provided by ELEX, along with the
conditioning tower and ESP. When running, the
exhaust heat from the bypass can be utilised
by the line’s gas circuit, while the bypass dust is
collected and stored. A dedicated MECHATRON®
system from Schenck Process then feeds the dust
into the finish mills, depending on the type of
cement being produced.
The main burner, a low-NOX
M.A.S®
burner
from Unitherm, has also been designed with the
possibility to switch to alternative fuel use in
the future. At present, the system burns 100%
coal, 100% petcoke or a combination of both.
The plant has two pulverised coal silos – one
for the main burner and one for the calciner
– along with a rotary dosing system from
FLSmidth Pfister. Each silo has a capacity of 160 t.
From the finish mills to dispatch
The plant comprises four finish mills from the
existing plant. Originally Russian-supplied, these
mills were designed with identical specifications
and initially ran on an open circuit. Over
the last decade, however, they have all been
upgraded with 3rd
generation QDK separators
from Christian Pfeiffer, and they are now closed
circuit. The plant sells 10 products – eight grey
cement types and two white cement types.
In fact, one of the finish mills is dedicated
to white cement production to ensure high
quality. Devnya Cement is the only company to
manufacture white cement in Bulgaria.
A grand total of 18 cement silos allow for
a high degree of flexibility when it comes to
loading for packing and dispatch. Cement is
dispatched in 25 kg or 50 kg bags, as well as in
1.5 t big bags and in bulk. There are two 8-spout
rotary packers from Möllers in operation at
the plant, as well as stretch hood equipment
for palletising the 25 kg and 50 kg bags if
desired. The products are transported from the
plant by rail or truck. As previously mentioned,
clinker is also dispatched by Devnya Cement,
some of which is transported to Italcementi’s
Vulkan Cement grinding plant in the south of
the country. A new clinker dispatching facility
Table 1. Equipment and suppliers contd.
Fuel
Type Coal/petcoke/natural gas to the main
burner
Coal/petcoke/RDF to calciner
Storage 2 coal silos,160 t capacity each
Secondary fuels RDF
Bypass system Yes
Filter/gas cleaning ESP on bypass system, closed circuit
on the main process dedusting circuit
Clinker cooler
Type IKN Pendulum Cooler®
Linings Bricks and castable
Exit temperature 70+ amb.
Dedusting 2 cyclones, exhaust air circuit
integrated in the main process circuit
Conveyors 2 Aumund pan conveyors
Clinker grinding/storage
Crusher 4 roller crushers at clinker cooler exit
Dedusting Yes with nuisance bag filters
Conveyors Aumund pan conveyor
Clinker storage 80 000 t operated with OWHC
Cement milling 4 lines in closed circuit
Mill types Horizontal ball mills with 2 chambers,
each of them equipped with
3rd
generation Christian Pfeiffer QDK
separators
Materials handling
Bucket elevators 4, Aumund
Conveyors Belt conveyors for raw mill feeding,
air slide for homo silo feeding
Packing/bagging/
loading
Bulk, bag: 25 kg, 50 kg and 1.5 t BB
Bag packers 2 rotary packers, Möllers, with
8 spouts each
Bags 25 kg and 50 kg 2 ply craft paper
bags
Bulk loading New clinker dispatching to trains and
truck with new silo and bulk loaders
Control systems
Central control/
process control
Siemens PCS7 main control system
with ITALMAT standards
Power/electrical
installation
ABB and Siemens supply
Laboratory
X-ray/XRF New XRF, PANalytical Axios
with five bulk loaders will allow for dispatch onto a
dedicated railway line and truck lane.
In with the new
Italcementi has invested in a new control room,
laboratory and electrical substations, all of which
I had the opportunity to see first-hand. Up in the
control room, I got a glimpse at the main control
system – the PCS7 from Siemens. For kiln monitoring,
the plant has thermal imaging equipment from
Mirion and a Centurion kiln shell scanner from
Thermoteknix. The laboratory is equipped with a
PANalytical Axios XRF analyser and an Epsilon 3
analyser.
Preparing for change
Following the installation of a host of new
equipment and technologies, I ask Teodor and
Gabriele how much training Devnya Cement’s
employees underwent. The answer is impressive:
more than 14 000 hours at an investment of
approximately e250 000. Training commenced
in July 2012 and comprised a number of phases.
Three Italcementi plants in Italy and Spain were
used as a base for training sessions with Devnya’s
production and maintenance staff. This included
basic knowledge training for operators, duty chiefs
and engineers in Calusco, with a further month’s
training for control room operators in Malaga. This
was followed by additional class sessions. During
commissioning in the summer of 2014, all vendors
provided site specific training on the equipment that
they supplied. This training encompassed all relevant
plant personnel, from electrical and mechanical staff
to maintenance and automation engineers.
Gabriele conducted much of the training
himself. After arriving at Devnya Cement as Plant
Process Designer and prior to taking up his current
role as Commissioning Manager, Gabriele was
responsible for training. Plant personnel were
able to take advantage of Italcementi e-learning
programmes, as well as simulator sessions. “We
still have two FLSmidth simulators,” says Gabriele.
“We have used these and now we are seeing the
results.”
In addition to training existing staff,
Devnya Cement ensured that it was fully prepared
for the successful operation of the new line by
implementing a succession plan. A significant
number of young people joined the plant as trainees
a few years ago, so that by the time the new line
started up, they were fully fledged professionals
with 2 – 3 years of experience under their belts.
Whilst the long-term benefits of succession planning
are clear, bringing in young talent also helped
to smooth the transition to the new production
process. “We started way ahead to prepare for
this,” says Teodor. “The stress of switching was less
because the team was already integrated.”
Raising the bar
According to CBMI’s Bulgarian branch – whose
scope of supply comprised civil construction, steel
structure manufacture and erection, mechanical
and electrical installation, and commissioning – the
project included: 8000 t of steel structure; 280 t of
The plant is strategically located with access to the
highway, a well-developed railway network and
Varna West Port.
The investment included the construction of a brand
new laboratory (above) and central control room
(below).

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50 World Cement
pipelines; 600 km of cable; 25 000 m2
of thermal
installation; 24 000 m2
of cladding; 170 000 m3
of
excavation works; 54 000 m3
of concrete; 16 000 m2
of plastering; and the list goes on. More than
120 companies took part in the project and
some 3000 people worked during the new line’s
construction phase. Considering these figures, how
easy is it to plan for such a project and ensure that it
runs smoothly? “It’s not that easy,” answers Teodor.
“You have the Bulgarian local team, the Chinese
contractor, the Italian engineering team and various
suppliers, so pulling off a successful project is not
so easy. There are a lot of parties, a lot of cultures
and a lot of languages.” Yet all those involved have
made it look simple.
Environmental advantages and sustainability
goals
In addition to process optimisation benefits, the
upgrade project at Devnya Cement will also help the
plant to reduce its environmental footprint:
ll Application of best available techniques
will increase effectiveness and control over
the production cycle and its impact on the
environment.
ll Compliance with emission limits and conformity
with local and EU environmental legislation.
ll Lower levels of atmospheric emissions.
ll Continuous emissions monitoring of the main
elements: SO2
, NOX
and dust.
ll Preventing fugitive dust emissions and
contamination at loading/unloading points
during the transportation of materials and
products.
ll Installation of high efficiency purifying
equipment.
ll Increased energy efficiency.
As part of the Italcementi Group, which is
a member of the World Business Council for
Sustainable Development, Devnya Cement is
committed to the company’s corporate sustainability
policies. With the aim of finding a balance between
environmental protection, social responsibility
and business growth, these cover the following
areas: safety, quality, human rights, environment,
energy, health and social initiatives. In terms of
environmental protection, Devnya Cement, a
member of the UN Global Compact Network in
Bulgaria, has identified eight key priority areas that
it has pledged to continuously improve upon:
1. Proactively addressing the challenges of climate
change, ensuring reduction of greenhouse gas
emissions, with a focus on renewable energy
sources and efficient use of energy.
2. Responsible use of resources, including fossil
fuels and raw materials.
3. Reduction of water consumption and
maintenance of its quality.
4. Waste management: minimising the generation
of hazardous and other waste, promoting the
reuse and recycling of materials where feasible,
and disposal of waste in a safe and responsible
manner.
5. Employee health and safety.
6. Local impact on land and communities:
developing rehabilitation plans for all its
active quarry operations, caring for existing
biodiversity and fostering conservation of
endangered species.
7. Reporting and communications: conducting
regular environmental audits and ensuring open
and transparent communication.
8. Ensuring that all plants and equipment are
designed, operated and maintained to minimise
environmental risks.
Devnya Cement has received recognition
for its environmental initiatives, such as the
Above: Devnya Cement staff help to paint a local
school; below: a group of volunteers from the
company support the local community following a
devastating flood in Varna in June 2014.
ISO 9001 – Quality Management Certificate, ISO 14001
– Environment Management System, ISO 14064 –
Carbon Footprint Certificate, and ISO 50001 – Energy
Management System.
Leading the way
From my first step into Devnya Cement’s
administration building it was clear how much
emphasis the company places upon health and
safety. Photos of employees line the entrance to the
building. These are the plant’s ‘Safety Champions’,
nominated by their colleagues for their dedication
to health and safety. This is just one of many health
and safety initiatives carried out by the company,
which range from safety incentive programmes
and group targets to teambuilding activities. To
celebrate World Health and Safety Day 2014, for
example, some staff members acted out scenarios to
demonstrate potential risks and the safest means of
response, while others helped with local community
projects.
Italcementi Bulgaria’s work to enhance health
and safety has been recognised on a national
level. For three consecutive years Devnya Cement
and Vulkan Cement featured in the top three
in Bulgaria’s Best National Safety and Health at
Work Awards. Indeed, Devnya Cement’s awards
cabinet is fit to bursting. In December 2014, Devnya
Cement and CBMI received the Building of the
Year Award, which is judged by an expert panel of
the country’s leading architects and construction
engineers. The company was also awarded first
place for ‘Greenest Company 2013’. In early 2015,
Devnya Cement was named ‘Investor of the Year’
by the InvestBulgaria Agency. Serge Schmidt, CEO
of Devnya Cement, was presented with the prize by
Bulgarian President Rosen Plevneliev at an awards
ceremony in Sofia. The new line is one of the
largest investment projects in Bulgaria in the last
25 years. In 2014 alone, it represented an investment
of BGN114 million. Considering Devnya Cement’s
achievements thus far and its continual drive for
improvements, perhaps the plant’s next investment
should be a bigger awards cabinet.
Note
Many thanks to Teodor Petsov, Gabriele Pierantoni,
Veneta Yanyova and Adriana Nikolova-Troanska for
their warm welcome and for kindly taking the time to
meet with me and show me around the new line.