INTRODUCTION & WORKING PRINCIPLE:
SINGHASINI 3 / 5 – ROLLER MILL with integral separator provide an automatic comparatively dust free complete system for medium to fine grinding and classification of MINERALS / ORES.
The grinding operation in Singhasini 3 / 5 Roller Mill is performed on the principle of attrition and compression, which results due to the centrifugal force generated from the suspended Rollers running inside a stationary Bull Ring.
The MINERAL to be pulverized enters the grinding chamber through an automatic feeder and falls onto the mill floor whereby it is scooped up by steel ploughs into the nip space between the rollers and the bull ring where grinding takes place.
A constant quantity of air is circulated through the mill and system. The air from centrifugal blower enters the mill through a series of tangential ports round the base of grinding chamber and sweeps the fine and medium fine MINERAL to the classifier above the grinding chamber leaving no ground material in the chamber and allowing the rollers to work efficiently crushing the coarse MINERAL.
The Classifier separates the Pulverized MINERAL and coarser particles return back to the grinding chamber for further size reduction. Fine MINERAL is carried by air to the cyclone air separator where air and ground material are separated and collected. The clean air is returned to the blower for close circuit grinding operation.
For providing dustless operation, the mill is operated under negative pressure and is equipped with dust collection system where surplus air in the circuit is vented and fine dust is collected in the dust collector bags.
DESCRIPTION:
The following are the main parts of the Roller Mill:
1. Grinding Chamber.
2. Classifier.
3. Cyclone Air Separator & Tank.
4. Centrifugal Blower.
5. Dust Collector and connecting pipes.
6. Automatic Feeder.
01. Grinding Chamber:
Fitted with a main vertical shaft carrying a heavy duty M.S. Fabricated Spider from which roller assembly (3 / 5 nos.) is suspended. These Rollers run on their own anti-friction bearing while traveling around the Bull Ring. Cast Ploughs are firmly attached near the bottom end of the main shaft.
The Grinding Chamber Bottom of the Roller Mill is of Heavy Duty Cast Iron provided with tangential ports through which air enters the mill. A replaceable alloy steel Bull Ring is fitted in the Grinding Chamber Bottom against which the Rollers revolve.
The Grinding Chamber top of the Roller Mill is of Heavy Duty Cast Iron. For access to the Rollers & inside of the mill, an Inspection door is provided. An automatic star feeder is attached to the Grinding Chamber top for feeding the MINERAL. Supports for the Bracket are also provided on the top that secure Cast Iron Bracket in between which the main shaft runs on anti friction heavy duty bearings.
The main shaft is made out of alloy steel, accurately machined, upon which the Spider and plough is fixed. The 3-Rollers are suspended on Spider. The drive end of the main shaft consists of a heavy-duty gearbox.
02. Classifier:
Singhasini Roller Mills are equipped with Whizzer type of Classifier for separation of coarse MINERAL particles from that of fine.
The fineness of MINERAL can be controlled by setting the R.P.M. of the Classifier Wheel and / or adjusting the gap in between the impeller blades of the classifier wheel and that of its body.
The Classifier is made out of heavy-duty mild steel plate, driven through a Bevel Gear arrangement. The R.P.M. can varied depending upon the fineness and production required. Higher the R.P.M., higher the fineness – lower the production.
03. Cyclone Air Separator & Air Lock Valve.
Cyclone is connected to the Classifier via bend and pipe. The function of the Cyclone is to separate the grinded MINERAL from the air. At the discharge end of the Cyclone, a rotary Air Lock Valve is provided along with gearbox. The Mineral Powder is continuously discharged from the Air Lock Valve. Cyclone, Classifier & Cyclone pipe and its bend are fabricated out of heavy-duty mild steel sheet.
04. Centrifugal Blower:
The Centrifugal Blower is suitably designed, made of thick M.S. plate lined inside with suitable type of liners having independent V-belt drive. The Blower Impeller is of special design statically & dynamically balanced.
05. Dust Collector & Connecting Pipes:
The function of the open type of dust collector is to filter out excess air from the mill and arrest very fine dust particles in the Dust Collector Bags.
06. Automatic Star Feeder:
An Automatic Feeder is provided for feeding the raw Mineral Lumps in the Mill. The Mineral Lumps is put into the Hopper. It is Rotary type having cast iron body. It is designed to take care of the quantity and size of feed material and provided with Paul & Ratchet mechanism and a gearbox.
Technical Specification
Size Output Kgs/Hr 200 Mesh Output Kgs/Hr 325 Mesh Main Mill (H.P.) Blower (H.P.) Classifier (H.P.) Air Lock Valve (H.P.) Automatic Feeder (H.P.)
Size No. 1 500 to 600 250 to 300 15 15 3 1 1
Size No. 2 1200 to 1500 800 to 1000 30 30 5 1 2
Size No. 3 2000 to 2500 1500 to 1600 50 50 7.5 2 2