Cement Division

he RSP facilities firing of fuel (upto 60% of total requirement ) before kiln, to achieve calcinations degree upto 95% and thus helps in increasing capacity of the total system substantially, without increasing heat load on the kiln. The RSP system mainly consists of the Swirl burner (SB), Swirl Calciner (SC), Mixing Chamber (MC) and Adjustable Orifice (AO).

• Swirl Burner (SB)
  Fuel is introduced vertically in the burner and primary air from the cooler enters tangentially. This part of the calciner helps in providing stable burning of fuel, with relatively high air/fuel ratio.
• Swirl Calciner (SC)
  The oxygen rich hot air tapped from cooler, enters tangentially in this furnace. Material from second stage (from bottom) cyclone is fed at the feed points as shown. The swirling action provides longer retention time and achieves complete combustion of fuel at nearly stoichiometric fuel / air ratio. The presence of oxygen rich air helps in rapid combustion of fuel. These conditions help in rapid calcinations of the raw meal fed to the calciner.
• Mixing Chamber (MC)A duct (CD) connects the SC to MC. The hot gas from kiln gets mixed with the hot gases with material coming from SC, in the MC. The material gets lifted and enters the bottom stage cyclone. The MC provides further retention time and helps in accelerating the calcination upto 95% before the material gets separated in the bottom stage cyclone and is fed to the kiln.
• Adjustable Orifice (AO)
  This device installed at kiln inlet before MC helps in adjusting velocity of the air entering MC and balances quantity of the air passing through kiln and that passing through the duct taking air from cooler to SC.

Salient Features

• Smaller kiln size for the same capacity, or higher output from the same kiln size. (Doubling of the capacity is normal).
• Lower heat consumption.
• Use of low grade, high ash coal at relatively coarse particle size is feasible
• Non conventional fuels can be used in the calciner efficiently.
• No coating formation in the SC & MC since the decarbonation is achieved at a temperature below 1000°C.
• Combustion in presence of oxygen rich air in SC ensures complete combustion at nearly stoichiometric fuel air ratio, which is the main criterion for stable operation.
• Low pressure preheater cyclones help in lowering the pressure drop at preheater fan inlet and thus saving in power consumption.

The six stage preheater helps in achieving better heat consumption.

JMC rotary kilns are mainly known for their constructional strength. Those parts which are subjected to high mechanical stresses such as kiln shell, tyres, supporting rollers bearings kiln drive are designed to withstand the most hostile conditions and are constantly being modified and kept technically upto date.

Rotary Kiln & Pre-heater tower : The kiln shell is fabricated from IS-2062 Tested plates. The unit consists of tyre rings, Girth gear, Gear guard, Inlet and outlet seal, supporting Roller assembly feed & discharge hood etc.

Tyres are made either in the form of a loose ring or they are fixed to the kiln shell in a toothed form. The toothed tyre attachment reduces the deformation of the kiln shell, and therefore also that of the refractory lining, to a minimum. Kilns with toothed tyres have particularly low lining wear. The bearings for supporting the roller are compact and robust in design and are interchangeable. Cooling is achieved by water circulation.

Salient Features

• Most efficient pneumatic inlet seal.
• Modern graphite block outlet seal.
• Hydraulic thruster for adjusting the kiln position.
• Modern three channel coal burner for efficient combustion of coal.

JMC has completely indigenized the grate coolers design. JMC has supplied grate coolers for various plants which are working satisfactorily. In its effort to modernize, JMC is in touch with the recent trends in grate cooler design and has already taken steps to bring the modern features, so the recuperation efficiency is improved, total cooling air requirement is reduced and as a result, total specific power consumption for the cooler is reduced.

JMC also offers planetary coolers which are simple in design, do not require separate dedusting, drive and also make the total system compact.

Drying chamber can be provided before first chamber. The grinding length of the mill can be suitably divided in two chambers by a control diaphragm which allows fines toriove to the second chamber and large particles get further ground in the first chamber. The grinding media grading can thus be optimized to suit the particle size. Lifting liners are provided in the first chamber. Classifying liners are provided in the second chamber.

This mill can be used in open circuit without separator with larger L/D ratios.

Deep Bucket conveyors using the double strand roller chain are specially designed to handle abrasive and hot materials (such as clinker from grate cooler) on a horizontal & inclined profile with the lowest power consumption. Till date such large installations have been supplied by JMC.

JMC offers bucket elevators of chain & U-link design as per the DIN Standard. Both centrifugal discharge (for free flowing, granulator material) and central discharge (for lumpy and sticky material) can be offered for capacities ranging from 10m3 / hr to 400 m3/hr.

Vertical pneumatic (VP) conveyor is a unique pneumatic conveying equipment offered by JMC for conveying fine powders vertically at heights as high as 100M. Due to its features such as no moving parts (and hence practically no maintenance), relatively low power consumption as compared to the pneumatic screw pumps, possibility to design a control system based on differential pressure and very low capital cost, the VP Conveyor is extremely popular in Indian Industry.

The low pressure compressed air enters the conveying pipe of the VP CONVEYOR at a high velocity through a nozzle.

The fluidized material around the conveying pipe combines with the air in the gap between nozzle and conveying pipe and is carried upward along with the air stream.

As the material fed from the top of the vessel builds its height in the vessel, the air pressure develops gradually and the discharge rate increases automatically and stabilizes, depending upon the height of the material allowed to be achieved in the conveying vessel. The same procedure is reversed while stopping the operation. As such, no separate shut-off device or seal is required, as the custom of material in the vessel itself acts as a sealing element for avoiding the back pressure.

This equipment uses the principle of transporting the powders under gravity in fluidized condition. JMC P.G. Conveyors are known for its optimum design and very low power consumption.

JMC Rotary air locks are known for high sealing efficiency & robustness. Precision machining is adopted to achieve the best sealing effect.