|
Zircoat
with its high concentration of Zirconia, resists harsh chemical
attacks at high and low temperatures. Around 3mm thick Zircoat
coating can work wonders at ambient to 1800° C temperature.
5mm thick Zircoat coating offers as good a protection and
insulation as a 130mm thick insulation fire brick. Zircoat
prevents leakage of hot gases from heating chambers, thus
maximum heat energy is preserved, wear and tear on the Zircoated
surface is minimised and coating lasts longer.
Zircoat has unlimited applications and is used in the following
areas where continuous and high temperature heating is found
hazardous, specially in the heating chambers constructed with
conventional materials.
|
| |
|
 |
Ceramics / Glass
|
| |
Aluminium, brass and
other nonferrous metals
|
| |
Chemicals and fertilizers
|
| |
Pulp and paper
|
| |
Natural and other gases
|
| |
Petroleum and hydrocarbon
|
| |
Iron and steel
|
| |
Marine and shipping
|
| |
Cement
|
| |
Sugar
|
| |
Coating of kiln furniture,
graphite and carbon crucibles. Zircoat coating will
be of great benefit to use in the above areas as well
as in domestic boilers, induction furnaces, rotary kilns,
chimneys, ducts, etc., where fuel oil, gas or electricity
are used for heating purpose.
|
| |
|
|
 |
|
Nonferrous Metal Industry
Zircoat is excellent for use
in ferrous and nonferrous metal and other alloy industries.
In aluminium, brass and its alloy industries, alumina refractory
bricks which come in contact with molten aluminium or other
nonferrous metals get corroded faster because their alumina
content gets leached out. Zircoat which contains higher percentage
of Zirconia in its residual is incompatible with molten metals.
Therefore 3 to 5mm thick Zircoat coating on the face of refractory
brick linings acts as a barrier and an armour to molten metals
which arrests leaching of bricks, thus considerably enhancing
the life of the heating chambers
|
| |
|
Iron & Steel Industry
|
| |
 |
In cast iron and steel
industry, apply around 6mm thick Zircoat between ganister
and steel shell of the heating chambers of the cupola
and accordingly suitable thickness coating for patching
receivers, ladles, funnels, spouts etc., and over refractory
bricks in reheat furnaces, soaking pits, open hearth
floors, furnace doors, sloping floors etc.
Zircoat is used as a lubricant in the preparation of
steel ingots for better quality and better finish of
steel plates, castings etc.
|
|
|
Zircoat acts as a barrier and as an armour coat on the linings
of electric furnace, producing special grade steels.
|
| |
|
Chemical Industry
|
| |
|
In many chemical processes,
corrosive waste gases and chemicals at high temperature
cause havoc to the steel structures, such as chimneys,
ducts, furnace shells etc. Waste gases usually contain
oxides of sulphur and vanadium. Even at low temperature,
the area of acid-resistant bricks collapses because
the cement mortar decays under the attack of sulphuric
acid. In such cases, Zircoat coating increases the life
of heating systems considerably due to its resistance
to acids and waste gases. The service life of chimneys,
steel shells and ducts can be extended multi folds if
coated with Zircoat.
|
|
|
|
Fertilizer Industry
|
| |
|
Generally frequent breakdowns
are experienced in high temperature lones. In chemical
processing units 3 to 5mm thick Zircoat will work as
a barrier coat between heat transfer walls and corrosive
chemical gases. This prevents costly breakdowns.
|
|
| |
|
Town and Natural Gas Industry
|
| |
|
A process called cyclic
process, carries out the conversion of waste chemicals
from oil refineries to industrial heating gas or town
gas. Waste refinery gases and heavy naphtha are heated
up for a few minutes in converters, where temperature
suddenly rises from 105 to 980°C.
This tremendous temperature bounce occurs every couple
of minutes; the thermal shock, thus developed can shatter
the refractory linings in no time, which can cause explosion
of semiburnt gases under pressure-resulting in heavy
losses.
|
|
|
|
12mm thick Zircoat coating on the steel sections of the reacting
areas of gas producing units will considerably increase the
service life of chambers. The coatings can perform satisfactorily
and offer prolonged protection. The life of heat transfer
units of domestic and industrial boilers can be improved further
by applying 3 to 4mm thick Zircoat over the refractory lining.
|
| |
|
Shipping Industry
|
| |
|
In ships, furnaces/boilers
producing heat for generation of steam are fired with
fuel oil. Because of months of nonstop operation of
these furnaces/boilers, refractories get severely damaged
due to the hot corrosive gases developed from fuel oil.
At elevated
temperature, presence of small percentage of sulphur-dioxide,
trioxide, vanadium pentoxide etc. damages refractory
brick work. 3 to 4mm thick Zircoat applied on the refractory
brick lining and also if used as a brick lining mortar,
will enhance the life of furnaces/boilers considerably.
Zircoat is found as an excellent mortar for laying new
refractory brick lining in high and low temperature
furnaces and kilns.
|
|
| |
|
Petroleum and Hydrocarbon Industry
|
| |
|
A huge amount of heat
is vital for smooth and efficient running of a refinery.
260 to 2000° C temperature is employed continuously
to crack down the crude oil and convert it to useful
end products. The refinery runs more economically if
the heating process is kept uninterrupted. Continuous
high temperature corrodes the plant faster. Zircoat
is an ideal remedy to protect the plant from corrosion.
|
|
|
| |
|
Pulp and Paper Industry
|
| |
|
High consumption of thermal
energy is necessary for chemical conversion of wood into paper
pulp and subsequent recovery of unreacted chemicals involves
reliable refractory structures. Regions of high mechanical
abrasion (as in ash flumes, the hoods of lime kilns and boilers
in which heavy fuel oils are burned) often sufferfrom rapid
erosion.
|
|
Severe spalling of refractories
can occur when they are subjected to violent and and
wet fuel comes in contact with hot furnace walls.
In this and in many chemical industries, problem of
normal refractory wear developed from thermal or mechanical
stresses is further aggravated by chemical attacks by
reactive substances present in or produced by pulping
or recovery process. Zircoat refractory coating is exceptionally
stable and durable under conditions of thermal, mechanical
and chemical onslaught encountered in the pulping process.
3 to 4mm thick Zircoat coating can increase the service
life of heating systems by many folds.
|
|
| |
|
Sugar Industry
|
| |
|
In the sugar industry,
plant managers will find Zircoat as an ideal cost-saving
remedy for speedy repairs and maintenance of combustion
chambers in lime kilns, pulp dryers, steam boilers,
gas fired and oil-fired furnaces or wherever sugarcane
waste is burned as a fuel.
Zircoat has proved a reliable, economical and cost-saving
remedy in sugar producing mills. As a rule, plant repairs
are generally carried out before the peak season starts
when sugarcane juice is in abundance.
|
|
|
|
Harvesting of sugarcane keeps
the plant working at optimum capacity for four to five months
at a time. For the rest of the year the plant remains idle
when patching and repairs can be conveniently carried out.
In producing sugar from sugarcane, a large amount of sugarcane
waste is burned as a fuel. This process produces hazardous
chemical gases, which are corrosive at elevated temperatures.
These chemical gases damage most refractories and firebricks,
causing heavy breakdowns, which lead to great financial losses.
Zircoat is found to be the most suitable remedy for speedy
repairs of damaged areas.
|
| |
|
Use of Zircoat in Induction Melting
Furnace
|
| |
|
The refractory brick lining
between electric bobbins and silica ramming is the vital part
of the induction melting system, and sensitive to thermal
shock and physical wear.
Zircoat is used to reinforce these refractory bricks by trowelling
with 3 to 4mm thick coating on outside and 5 to 6mm thick
coating on inside refractory brick walls. Coating has to be
properly dried up to set it hard.
After proper setting of Zircoat, silica sand has to be rammed
in between the steel sleeve and 5mm thick asbestos or mica
sheet to form an average silica wall thickness of 200mm. Melting
of steel starts and the steel sleeve is allowed to melt away
and get dissolved in the molten steel. After removing the
molten metal from the trough, coating of pure silica is formed
on top of the Zircoat coating.
The brick wall is thus reinforced by Zircoat and it becomes
super resistant to wear and sudden break downs due to thermal
shocks. After repeated usage of Zircoat, service life of furnace
can be increased multi folds.
|
| |
 |
| [A] |
Terminals Bobbin |
| [B] |
3 to 4mm Zircoat |
| [C] |
High Grade Refractory Bricks |
| [D] |
5 to 6mm Zircoat |
| [E] |
5 to 6mm Mica / Asbestos Sheet |
| [F] |
Rammed Pure Silica Sand 200mm |
ZIRCOAT INCREASES OUTPUT MANY FOLDS |
|
|
| |
|
Induction Melting Furnaces
|
| |
|
Induction furnaces are used
for melting ferrous and nonferrous rnetals. During the metal
melting process, generally following problems are observed:
|
| |
|
| • |
Rammed silica lining cracks due
to thermal shocks. |
| • |
Slagging of molten metal passage
obstructs free flow of metals. |
| • |
Eroding of silica lining. |
| • |
Faster leaching out of refractory
bricks which came in contact with molten metal. |
| • |
Cracking of bricks and escape of
molten metals. |
| • |
Molten metals getting contaminated
because of leached out constituents from lining
bricks. |
| Zircoat is excellent
to protect the heating system from above problems. |
|
|
|
| |
|
Kiln Furniture
|
| |
|
Life of silicon carbide,
mullite, alumina and cordierite refractory kiln furniture
can be increased considerably by brushing or spraying
with 1 to 2mm thick Zircoat.
|
|
| |
|
Carbon / Graphite Crucibles
|
| |
|
Crucibles are used for melting
of ferrous and non ferrous metals. In metal melting process
these crucibles are severely affected by molten metals at
elevated temperatures, and it is generally experienced that
they fail in just few charges.
Life of these expensive crucibles can be extended considerably
by applying 2 to 3mm thick Zircoat coating on the inside and
outside walls of crucibles.
Since Zircoat is incompatible (unfriendly) with carbon / graphite,
following procedure is suggested for coating the crucibles.
|
| |
|
Form a brushable Zircoat
paste by mixing 5% Sodium Silicate solution in clean
tap water. Ensure that crucible walls to be coated are
rough and clean enough so that the coating adheres well
over them. Apply 2 to 3mm thick Zircoat by brushing
and allow the coated areas to dry out for a couple of
days in warm atmosphere. The first heating of crucibles
should be slower than normal. Around 2mm thick Zircoat
coating can double the life of crucibles.
Caution: Improper drying of Zircoat coated crucibles
may cause cracking/shattering during first heating.
|
|
|
| |
|
Rotary Kilns
|
| |
|
Zircoat is also an ideal
and excellent refractory coating for rotary kilns, chimneys,
ducts etc. 25mm thick Zircoat coating is sufficient for obtaining
superior results. It reduces the gross weight of the rotary
kiln and eliminates the risk of thermal shock damages.
|
| |
|
|
Procedure for application of
Zircoat to Rotary Kilns |
| • |
Weld 6mm dia x 57mm L steel studs to
the inside tubular kiln chamber wall at (12") 305mm
centres. |
| • |
Apply around 25mm thick Zircoat coating
(in convenient small thickness layers) on the bottom half
of the cylinder and fasten a mild steel wire mesh to the
bolts over the coated area and press it tightly. The Zircoat
coated shell has to be heated for around 24 hours at temperature
200°C to completely dry out the moisture and set the
Zircoat hard. |
| • |
After thoroughly drying
out the Zircoat, again apply a second coat of 25mm thick
Zircoat on the surface of wire mesh and repeat a further
layer of wire mesh tightly secured over the coated area,
once again thoroughly dry up the coated area at 200°C
for further period of around 24 hours. This makes total
thickness of Zircoat coating around 55mm above the steel
shell. Again tightly fix up the wire mesh over the coated
area and apply a final coat of around 5 to 6mm to ensure
that the steel studs are totally immersed in Zircoat.
System should be heated up for around 54 to 60 hours
at 200°C and ensure that all the moisture is completely
removed. After that the temperature can be increased
at the usual rate.
|
|
| |
 |
| |
| |
| |
