Great Benefit from installing The Kemco Witman

inCalcium Carbonate Production Plants

by reducing drying cost and CO2 emissions.

“Kemco Witman” Centrifugal Powered Screw Ejecting Dryer 1

Part 1 : Calcium carbonate

1) Wide applications of Calcium Carbonate:

Rubber

Glass

Paper

Paint

Asphalt filler

Plastic

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2) Typical Calcium Carbonate Production Flow:

1) Running cost a) Kiln drier

Fuel consumption = 30L/ h X Operating hour 166h/ month X fuel cost US$0.65/ L = US$3,237/ month b) Witman

Power = (Main motor 15kW + Heater 30kW) X Operating hour 166h/ month X power cost US$0.18/ kWh = US$1,345/ month2) CO2 emission a) Kiln drier

Fuel consumption = 30L/ h X Operating hour 166h/ month X CO2 emission 2.5kg/ L = 12,450kg/ month b) Witman

Power = (Main motor 15kW + Heater 30kW) X Operating hour 166h/ month X CO2 emission 0.555kg.kWh = 4,146kg/ month

Washing drum

Wet type screen

Kiln dryerφ 2m× 15m

Horizontal impactor

Dedust分级分选

Mill粉碎机

Final product

Ｗｉｔｍａｎ

Introducing "Witman" here can allow replacement of kiln dryer or can drastically reduce its fuel consumption.

Feed 50- 0mmNeeds to be washed and dried to remove silt/ clay.

Feed=>15t/ h =100%)（Moisture content : 15%

9t/ h

1t/ h

After drying process10t/ h =70%)（

Moisture content : 0.8%

Silt 5t/ h =30%)（To be disposed ofas industrial waste

Saving 58%

Saving 67%

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1. Reducing drying cost and CO2 emissions in Calcium Carbonate Production Plants

2. Preferable feed size is <10mm for crushed rock and <5mm for sandy material.

3. Continuous operation.

3) Main concepts for Developing the Kemco Witman:

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1. Continuous operation:Continuous feeding and stable moisture

content of product.2. High dehydration performance (Max. acceleration 1000G) To reduce the moisture content of limestone: 9-5mm material : Down to less than 1.2% 10-3mm material : Down to less than 1.0% 3. An optional heating device is also available.　 To reduce the moisture to less than 1%.4. Compact size.5. Easy maintenance. Easy maintenance via front maintenance door. 　　

4) Main features of the Kemco Witman:

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5) Process flow:

Feed (5.2t/h) + Working water (2.4t/h)

Dehydrate by centrifugal power

Heat (Optional)

Products

Centrifugal dehydration Centrifugal dehydration and heater drying

Feed Feed

Feed

Working water

Working water

Working water

Heat

Heat

Dust

Dusty waterDusty water

Product Product

6

Drain pipe

Feed Hopper

Main Body

V belt cover

Main motor

Chute for product

Model N452K

Vibration absorbing rubber

6) Process flow:

7

脱水成品

Feed

Drain Products

Heat

テーパースリットスクリーン

供給パイプ

Working water

7) Mechanism:

Basket

Screw

Inlet pipe

Reduction gear

Electric Motor

Water Products

Screen

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1) Screw and basket (equipped with screen inside) rotate at high speed (approx. 1,700 rpm) generating the centrifugal force by which the material is dehydrated. 2) The screw turns at a slightly higher speed than the basket. The difference of speed makes screw eject products. Water and small particles come out through screen. 3) The screen mesh size is 0.2mm to 0.3mm.

Screw Screen

8) Main components:

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ﾌｨｰﾄ 量゙と製品水分の関係

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

4 4.5 5 5.5 6

(t/ h)ﾌｨｰﾄ 量゙

(%)

製品

水分

offﾋｰﾀonﾋｰﾀ

Model N452K

Feed: Lime stone:5-0mm9) Performance:

Feed volume (t/h)

Mois

ture

(%

)Co-relation: Feed volume (t/h) and moisture content

Heater off

Heater on

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NF=5.2t/ h 2.4t/ h加水量：

1052.51.20.60.30.150.0750

10

203040

50607080

90100

mm篩目（ ）

通過

百分

率（％

）

原料

脱水製品

排水側微砂

※1 ． JIS A 1102 　骨材のふるい分け試験による測定結果

10) Size distribution:

Feed: Lime stone:5-0mm

Feed

Products

Fine particle in drain water

Sieve mesh size (mm)

New feed: 5.2t/h, Working water:2.4t/h

%

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In addition to a reduction of moisture; Improvement of color, due to elimination of silt, is also noted.

Feed ProductMoisture: 10% 1%

11) Comparison – Before & After:

Feed: Limestone: 5-0mm

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Model Capacity Motor

N-452K 5 to 10 t/h 15kW

N-570-K 10 to 20 t/h 30kW

Maximum permissible feed size is 10mm

12) Model line ups and capacity:

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13) Dimensions:

14

Model N452K

A minimum 200kgs of sample feed is required per sample test.

Drain pipe

Air blower

Feed hopper

Chute

Heat inlet

Conveyer

Witman

Conveyer

Hopper

Electric motor

14) Test plant:

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