MINING Fluidized bed electrical heating systems metso ^ Expect results

Metso has designed and supplied numerous fluidized bed dryers, heaters, calciners, roasters and coolers to the mineral sands industries within Americas, Australia, Africa, and Asia for many years. These plants are fired on gas or liquid fuels and often custom designed to fit within existing buildings and process requirements. A need was identified for an economical and compact design for relatively low thermal energy/throughput mineral sand heaters. Metso designed and built an electrically heated prototype, which was successfully installed and commissioned at Namakwa Sands Ltd in South Africa....

The Metso heater design is based on the fluidized bed principle. To fully appreciate the operation of the heater, a few relevant principles of fluidization need to be understood: A When air is passed up through a loosely packed bed of granular material, either of three states exists, depending on the velocity of the air through the bed. • At low air velocities, the air will percolate through the bed and cause minimum particle movement in the bed. • As the air velocity is increased, the bed will expand and the particles will become mobile within the bed of air or fluidized. • As the air velocity...

Main components of system The fluidized bed electric heater consists of a rectangular steel vessel separated by an air distributor or fluoplate. Ambient temperature air from the fluidizing fan is introduced into the lower portion (or windbox) of the vessel and enters the upper portion (heat exchanger) via tuyeres in the fluoplate. The material to be heated is fed onto the fluoplate where it is fluidized and heated by electrical elements immersed in the bed of material. The heated material is discharged from the heater over a weir for further processing. Typical layout Expansion chamber Cage w/...

Dust collection Primary dust collection consists of a baffle chamber arrangement, which forms an integral part of the heater expansion chamber. The heated dust collected by the baffle chamber is mixed back with the heated bed product. The exhaust gases are then directed to a common baghouse dust collection system. Electrical sandheater

The main advantage regarding the energy efficiency of Metso electric heater lies in very quick response time to fluctuating thermal demand. The electric elements are located in the bed of fluidized material inside a stainless steel tubes. On the outside of the tube the constantly moving bed of mineral receives the heat generated by the elements in a rapid and very efficient process. The heat is virtually directly injected to the moving particles instead of being supplied with the fluidizing air. This approach minimizes the quantity of fluidizing air and at the same time reduces the heat losses...

General model Selection Heater model EH 18 36 48 81 120 165 Feed Rate @ AT=30°C Exhaust air flow @ 100 °C Efficiency @ max Max. Thermal Load Number Of Elements Fan Power: installed Heater Power: installed Weight - empty Weight - running Performance calculated at the following conditions Power Supply Element type installed Ambient temperature Atmospheric pressure Specific heat of solids Max. product temperature 140 oC Feed temperature 70 °C General model dimensions EH 36 48 81

• Metso Minerals Industries Inc. 350 Railroad Street, Danville, PA 17821-2046, USA, Phone: +1 570 275 3050, Fax: +1 570 275 6789 • Metso Minerals Industries, Inc. 2715 Pleasent Valley Road, York, PA 17402, USA, Phone: +1 717 843 8671 • etso Minerals (South Africa) (Pty) Ltd. M Private Bag X2006, Isando, Johannesburg,1600, South Africa, Phone: +27 11 961 4000, Fax: +27 11 397 2050 • Metso Minerals (Australia) Ltd. Level 2, 1110 Hay Street, West Perth, WA 6005, Australia, Phone: +61 8 9420 5555, Fax: +61 8 9320 2500 • Metso Minerals (India) Pvt Ltd 1th floor, DLF Building No. 10, Tower A, DLF Cyber...