Sugar Melter Application in Sugar Factory | Sugar Melter design Calculation

In this article discussed about the role of sugar melter in sugar industry process house and its capacity and design calculation. Also provided online calculator for its capacity calculation.

Sugar Melter Capacity Calculation | Sugar Melting  Feed Liquor Calculation

The sugar melter simply can be defined as it a equipment in which dissolving of sugar takes place. Generally the sugar plants can be classified as Raw sugar plant, Refined sugar plant and white( Suphited ) sugar plants. All these type of sugar plants sugar melter is one of the essential equipment in process house.

According to sugar melter application it is called mainly two types.

  • B and C sugar mellter or low grade sugar melter
  • Raw Sugar melter

B & C sugar mellter:

According to boiling scheme adopted in sugar process, some or total low grade sugars i.e B sugar and C double cured sugar may be remelted. Its melt diverted to high grade massecuites.

B Massecuites cured in continuous centrifugals or high gravity batch machines. The B sugar can be used directly as a seed for A massecuite boiling and excess B sugar pumped to sugar melter for remelting the sugar and it is used in A boiling.

For C massecuites double purging is absolutely essential to reduce the colour load on final massecuite. The sugar after second purging is dissolved in a melter and melt used in “A” boiling.

For B and C sugar melting purpose using hot water, clear juice or syrup for melting

Raw Sugar Melter:

Affination process is the first step of refined sugar making. This process helps to remove as much of the molasses film surrounding the raw sugar. The affinated  sugar sent to raw sugar melter to prepare melt for further process. For less colour of raw sugar can be directly sent to melter without affiniation process.

Raw sugar melting purpose using hot water or sweet water (low brix water) for melting

Sugar melter design parameters

There are two basic approaches to equipment for sugar melter

1. Horizontal cylindrical vessel with a horizontal rotating stirrer ( Horizontal sugar melter)

2. The second type is using number of vertical tanks in series or compartments in the same vessel and having top mounted stirrers in each tank ( Vertical sugar melter)

The Sizing of melter mainly depends on

  • Size of the crystal to be melt
  • Final melt brix requirement
  • Temperature of the melter ( melt temperature )

For B and C sugar having the crystal size in the range of  150 to 350 micron. According to Peter Rein recommendations  15 to 20 minutes holding volume required for at 70 brix and 70 oC temperature.

For Raw sugar having the crystal size in the range of  250 to 650 micron So for raw sugar melter required minimum 25 to 30 minutes holding volume required for at 70 brix and 70 oC temperature.

Calculation of melter feed requirement and its vapour line sizing

Example – 1: ( Using Clear juice for both magma and melter)
S.No Particulars UOM Values Remarks
Required Data
1 Crushing Capacity TCH 230
2 B sugar  % cane % 5 4.5 to 6 %
3 C sugar % cane % 1.5 1 to 2 %
4 Rory & Powder sugar % 1 0.5 to 1.5 %
5 Brix of sugar % 95 90 to 98
6 Magma mixer oultet brix % 90 88 to 92
7 Final Melt Brix % 65 60 to 70
8 Clear Juice
% 14 Clear juice brix
9 Vapour temperature oC 110 Consider 1st vapour
10 Velocity of vapour m/sec 30 Consider 1st vapour
11 Clear Juice inlet temperature oC 90
12 Melt outlet temperature oC 75 70 to 80 oC
13 Inlet Magma Temperature oC 45 40 to 50 oC
Calculation part
1 Specific heat of Melt (Cp ) Kcal/oC 0.65
2 Latent heat of vapour (λ ) Kcal/kg 532.51 As per the steam table
3 Specific Volume of Vapour M3/kg 1.210 As per the steam table
Magma
4 Quantity of B seed + C seed T/hr 17.25 230 x (5+1.5+1)%
5 Clear juice required for Magma T/hr 1.135 [(17.25 x 95) – (17.25 x 90)] / (95 – 14)
6 Final Qty of magma T/hr 18.385 17.25 + 1.135
Melter for B and C sugar
7 Clear juice required for melting T/hr 9.01 [(18.385 x 90) – (18.385 x 65)] / (65 – 14)
8 Total Melt Quantity ( Q ) T/hr 27.397 18.385 + 9.01
9 Vapour required T/hr 1.003 Q Cp ∆T / λ
M3/sec 0.337 1.003 x  1000 x 1.210 / 3600
0.405 20 % extra
10 Dia of the vapour pipe mm 131 SQRT(0.405/(0.785*30)))*1000
11 Melt holding volume required M3 9.132 27.392 x 20 / 60 (20 min. retention time

Note : In the above calculation clear juice temperature ( heat value) not consider. While using the clear juice vapour requirement for melter is very less and some times almost requirement is zero.

Example – 2: ( Using evaporated syrup for both magma and melter)
S.No Particulars UOM Values Remarks
Required Data
1 Crushing Capacity TCH 230
2 B sugar  % cane % 5 4.5 to 6 %
3 C sugar % cane % 1.5 1 to 2 %
4 Rory & Powder sugar % 1 0.5 to 1.5 %
5 Brix of sugar % 95 90 to 98
6 Magma mixer oulet brix % 90 88 to 92
7 Final Melt Brix % 65 60 to 70
8 Syrup using for melter % 55 Syrup Brix
9 Vapour temperature oC 110 Consider 1st vapour
10 Velocity of vapour m/sec 30 Consider 1st vapour
11 Syrup Juice inlet temperature oC 50
12 Melt outlet temperature oC 75 70 to 80 oC
13 Inlet Magma Temperature oC 40 40 to 50 oC
Calculation part
1 Specific heat of Melt (Cp ) Kcal/oC 0.65
2 Latent heat of vapour (λ ) Kcal/kg 532.51 As per the steam table
3 Specific Volume of Vapour M3/kg 1.210 As per the steam table
Magma
4 Quantity of B seed + C seed T/hr 17.25 230 x (5+1.5+1)%
5 Syrup required for Magma T/hr 2.464 [(17.25 x 95) – (17.25 x 90)] / (95 – 55)
6 Final Quantity of magma T/hr 19.714 17.25 + 2.464
Melter for B&C sugar
7 Syrup required for melting T/hr 49.29 [(19.714 x 90) – (19.714x 65)] / (65 – 55)
8 Total Melt Quantity ( Q ) T/hr 69.00 49.29 + 19.714
9 Vapour required T/hr 2.948 Q Cp ∆T / λ
M3/sec 0.990 2.948 x  1000 x 1.210 / 3600
1.189 20 % extra
10 Dia of the vapour pipe mm 225 SQRT(0.405/(0.785*30)))*1000
11 Melt holding volume required M3 23.000 69.0 x 20 / 60 (20 min. retention time

Note :

1. In the above calculation total syrup requirement is 2.46 + 49.29 = 51.75 T/hr. Here syrup brix having maintained below 55o then available quantity will be sufficient for melting the sugar. Otherwise it may be required some quantity of hot water or clear juice to maintained constant melt brix.

2. While using the clear juice/syrup for melter then it is better to use screener to strain out extraneous matter

3. In the energy conservation point of view some designers using 4th vapour as a heating medium for melter. If  we using 4th vapour then operate melter under vacuum condition or using DCH (Direct Contact Heater) with melt recirculation pump.

Sugar melter automation

The main controlling parameters in the melter is Brix and Temperature.  So two control loops are required in melter automation

1 . Brix transmitter and control valve for feed (sweet water or clear juice or syrup) inlet to maintained the constant melt brix

2. Temperature transmitter and vapour/ steam control valve to maintain the constant melt temperature.

Online Calculator for Sugar Melter Capacity Calculation

 

Sugar Melter Capacity Calculation | Sugar Melting design in sugar factory boiling house | sugarprocesstechRelated Articles:

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Post Author: siva alluri

The aim of this Blog "sugarprocesstech" is Providing basic to advance knowledge in sugar process industry and providing maximum calculation regarding capacity and equipment design online calculators .

1 thought on “Sugar Melter Application in Sugar Factory | Sugar Melter design Calculation

    Aravind

    (September 9, 2018 - 1:39 pm)

    Thank u sir to giving sugar Melter calculation

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