NEW EXPERIENCE WITH SOLEXSUGAR COOLER

THURSDAY 6 APRIL 2017

Jean-Marc Reichling

TODAY WHAT IS THE SITUATION

➢Headquarters: Calgary, Alberta, Canada➢More than 850 installations since 1989 worldwide in different industries➢ Offices in Europe: Arnhem (NL) After sale service & quality control;

Couvin (BE) ; Bremen DE) ; Prague (CZ) , London (U.K) Moscow (RU)➢Office in South America : Brazil Sao Polo , China➢ Agent Worldwide: India ; South America, Thailand, Malaysia, Morocco

THE SOLUTION : INVENT THE FIRST

INDIRECT BULK SOLID FLUID HEAT EXCHANGER

TODAY WHAT IS THE SITUATION ?

SOLEX WORLD LEADER IN

BULK LIQUID HEAT

EXCHANGER

SOLEX DRYER

SOLEX HIGH TEMPERAURE

COOLER

SOLEX HEATER

FIRST LIQUID BULK SOLID HEAT EXCHANGER

Low Power

Consumption

Little Emissions

Product Moves

by Gravity

Almost no

Moving Parts

Small Foot Print

FIELD OF APPLICATIONS

TYPE OF SUGAR PLANT

Sugar Beet Plant

Sugar Cane Plant

Sugar Refinery

SUGAR BEET AND SUGAR CANE PRODUCTION

WORLDWIDE

SUGAR DEMAND AND SUGAR PRODUCTION

WORLDWIDE

TYPE OF SUGAR : SUCROSE C12H22O11

CUSTOMISES SOLUTION TO MEET CUSTOMERS

PROCESS CONDITIONS

Every Installation is customising for the particular plant parameters.

Each unit is designed to maximise energy recovery

Operation is optimised for lowest energy consumption

Modular design provides flexibility to meet existing plant layout.

Use of ThermaPro Quantum software to get the exact profile temperature of any particles at any position.

Vertical gravity feed design results in low operation and maintenance costs

TYPICAL SCHEMATIC

TYPICAL PROCESS CONDITIONS

REFINED CRYSTAL

SUGAR

➢ Design Flow Rate 75 t/h

➢ Sugar Crystal Size 0.35-0.65 mm

➢ Sugar Moisture < 0,04 %

➢ Sugar Inlet 55°C

➢ Sugar Outlet 30°C

➢ Cooling Water (from Chiller) 20°C

➢ No Air Injection Required

TYPICAL INSTALATION

MODULAR DESIGN

TYPICAL PROCESS CONDITIONS

Customers

Packaging –

1kg; 5kg;25kg;50kg

Big Bags 500Kg

Moisture 0.2 – 1.0 %

Temperature 50 – 60°C

Sugardrying

Sugarcooling

Sugar maturation cell

Moisture 0.03 – 0.05 %

Temperature 28 – 35°C

CAKING & CAKING ???

Caking During storage (Silos) or in the package.

Caking is a phenomenon in which sugar crystals give up bound moisture resulting

in supersaturation of the” crystal surface and consequent crystalisation. At the point

of contact between crystals this surface crystallisation cause intercrystalline

bridging. The sugar then ceases to be free flowing and is refered to as “Caked” (Peter

Rein 2nd edition Cane sugar Engineering)

Caking inside a cooler.

If the temperature of the surface of the heat exchanger is lower as the dew point of

the air surrounding the product this will cause the product ( the fines even more) to

cake on the plates

The tendency for the moisture to migrate either from the product to the air or from

the air to the product is defined by the critical relative humidity (CRH) of the product

The condensation mechanism is predictable and can be eliminate by choosing the

appropriate condition in the cooler (Temperature of cooling water and controling the

air parameters T° and RH) (Neville Jordisson: Not as easy as it looks Nitroigen +Syngas 2008)

CAKING OF WHITE SUGAR AND HOW TO

PREVENT IT MOHAMED MATHLOUTHI1,2 AND BARBARA ROGER (2000)

➢ Maturation. Period needed for Water activity of sugar crystals in storage cells to equilibrated with

surrounding air (equilibrium relative humidity (ERH),

➢ The amount of fine particles (<250 µm). These particles play a role as a cement of the cohesion in

case of caking. When the moisture migrates, the fines, which are hygroscopic, absorb water and form

a cement between the sugar crystals (Thus either removed the fines by screening or even better

optimized the crystallization process).

➢ It is advised to have a sugar with M.A. >0.63 mm and C.V.< 30 with less than 5% of fines (250 µM).

CAKING IN SUGAR

➢ Caking is caused by moisture migration through the sugar caused by the

temperature gradient between the sugar and ambient conditions

➢ When the moisture migrates, the fines, which are hygroscopic, absorb water

and form a cement between the sugar crystals

➢ In order to assure a high sugar quality during storage in silos or in bags,

must control the residual moisture, crystal size, and uniformity of the sugar

storage temperature

➢ Typically cooled to within 5ºC of ambient minimizing risk of agglomeration

MOISTUREMIGRATION

TEMPERATURE GRADIENT

micro-crystal growth

HYGROSCOPICPRODUCT

WATER COOLEDPLATES

HUMIDITYIN VOID SPACE

CONDENSATION

CAKING ON PLATES ×

THE SECRET TO LONG TERM OPERATING PERFORMANCE

WHAT CAUSES CAKING ?

ADD PURGEAIR TO LOWER

DEWPOINT

CORRECTWATER TEMP

PROFILE

ELIMINATECONDENSATION

NO CAKING

PURGEAIR

✓

THE SECRET TO LONG TERM OPERATING PERFORMANCE

PREVENTING THE CAKING MECHANISM

AIR INJECTION TO PREVENT CAKING

Model calculates minimum air flowrate & required dew point of the air base on

CRH of the product

Graph of dew point & water temperatures in cooler

CONTROL PROCESS CONDITIONS/ SOLEX MODULES

PRODUCT IN

VENT

PRODUCT OUT

COOLING WATER IN

COOLING WATER OUT

PLANT

CONTROL

SYSTEM

GATE FEEDER

ACTUATOR

POSITIONERINSTR. AIR

PURGE AIR

INCLOSED LOOP

TEMPERED

WATER

CIRCUIT

TEMPERED

WATER

MODULE

PLANT

COOLING

WATER

IN/OUT

TYPICAL INSTALLATION SUGAR COOLER AND

MODULE FOR HOT COUNTRIES ( AIR INJECTION )

TEST WITH AMORPHOUS SUGAR BRAZIL

➢ Product: Amorphous: Spontaneous crystallization in the crystallization pan without

the addition of seeds . Irregular Crystals.

➢ Size: 0,38 mm

➢ Bulk Density: 750-775 Kg/m³

➢ Particle Size : 0, 38mm

➢ Moisture : 0,2%

Challenge : Cooling the sugar and avoid scaling on the plates of the cooler.

PILOT TEST WITH AMORPHOUS SUGAR BRAZIL

• The first run, performed without the use of air, showed a build-up of product on the top half of each plate.

• Air was injected for all the subsequent runs and good results were observed. The pilot unit was emptied to inspect the

plates at the end of each runs and no signs of accumulation were observed. The plates remained very clean

Run

number

Water

temperature

°C

Air

Product

temperature

In °C

Product

temperature

Out °C

Product

feed rate

kg/h

Run

time

min

Caking

on

plates

Notes

1 35 No 65 57 600-800 40 YCaking observed on top half of the

plates. Good mass flow

2 35 Yes 60 50 600 30 N*

No caking but sticky patches

observed due to previous was.

Good mass flow

3 30 Yes 55 42 500 45 N No caking. Good mass flow

4 25 Yes 55 33 400 75 N No caking. Good mass flow

5 25 Yes 65 31 200-300 60 N

No caking. Good mass flow.

Reduced flow rate for a better

cooling

Test conditionsProduct type: Amorphous sugar with a moisture content of 0.2%.Cooling water: Water module used (at 2300 L/h) with temperature controller.Dry air purge: Testing with and without air injection.Product flow rate: 400-800 kg/h.

PILOT TEST WITH RAW SUGAR BRAZIL

.

Typical process conditions with raw sugar.

Test conditions

•Product type: Sugar VVHP with a moisture content of

0.1%.

•Cooling water: Water module used (at 2300 L/h) with

temperature controller.

•Dry air purge: Testing with and without air injection.

•Product flow rate: 200-400 kg/h.

Run

number

Water

temperature °CAir

Product

temperature

In °C

Product

temperature

Out °C

Product feed

rate

kg/h

Run

time

min

Caking

on

plates

Notes

1 30 15 35 33 Too high 10 Y

Motor setting too fast. Unit emptied

seconds. Air was tuned off during the

test. Bridging and caking observed

2 28 0 34 - 0 1 night N*No caking but slight powder residue

observed on the plates, no caking

3 30 15 34.5 32.5 200 45 N No caking. Good mass flow

4 25 15 34.5 31 200 45 N No caking. Good mass flow

5 15 15 34 24.5 200 45 N No caking. Good mass flow

RAW SUGAR COOLER: SAN CARLOS

Ingenio Mayagüez / San Carlos, Cali, Colombia

Process Data

Designed feedrate 15,000 kg/h

Sugar cristals size 0.9 – 1.1 mm

Sugar temperature in 55°C

Sugar temperature out 35°C

Specific heat of sugar 0.31 kcal/kg.°C

Moisture content 0.15%

Bulk density 1150 kg/m3

Cooling fluid Water

Cooling fluid

temperature 25°C

Cooling water flow 20 m³/h

Air injection

Dew Point 20C

Flowrate 1500 m³/h

Construction materials

Heat exchange plates SS304L

Water manifold SS304L

Structural casing SS304L/SS304

Discharge feeder SS304L/SS304

RAW SUGAR COOLER: SAN CARLOS

RAW SUGAR COOLER: SAN CARLOS

REFINERY RAR PORTO➢ Design Flow Rate 30 t/h

➢ Sugar Crystal Size 0.55-0.65 mm

➢ Sugar Inlet 45 °C

➢ Sugar Outlet 30°C

➢ Cooling Water (from Chiller) 20°C

➢ Energy Consumption 15 KW (0.53 KW/ T)

Target: Avoid caking in large bags

Typical process condition at RAR

RAW SUGAR COOLER: SAN CARLOS

Before After

BATCH CONDITIONING OF REFINED SUGAR IN A SILO WITH VERY LOW

RELATIVE HUMIDITY AIR JOSÉ MANUEL CHORÃO RAR PORUGAL

➢ The main objective of sugar conditioning is the removal of the bound water to minimize the probability

of caking during storage or transportation

➢ Four steps are involved in the conditioning process [1]: i) crystallisation of sucrose on the supersaturated film

in contact with the crystal surface; ii) evaporation of water molecules from the film surface to the amorphous

outer layer; iii) diffusion of water across the amorphous layer; iv) diffusion of the water into the interstitial air.

The limiting step is the diffusion of water across the amorphous layer

➢ The minimum conditioning time generally admitted is 24 h (up to 48 h), though a considerable

proportion of the water is removed

RAR : CONDITIONING TEST SILO

BATCH CONDITIONING OF REFINED SUGAR IN A SILO WITH VERY LOW

RELATIVE HUMIDITY AIR JOSÉ MANUEL CHORÃO RAR PORUGAL

➢ The main objective is to reduce the maturation time.

➢ Injection of dehumidified air (Using Membrane) with Relative

humidity less as 2%

➢ Within 6 hours they could reduce the moisture between 15 and

24%

CONCLUSION

➢ In order to guarantee a good sugar quality to the consumer several

parameters must be take into account:

➢ Good control on the moisture of final product

➢ Size distribution and percentage of fines.

➢ Purity of Sugar

➢ Efficient control on the temperature of the sugar before storage

➢ Optimal storage conditions ( Control atmosphere (T) and RH (between 40

and 60% RH)

➢ Correct bagging

➢ SOLEX Can help to guarantee one part of the Puzzle: Uniform temperature

of the sugar before the storage.

THANK YOU FOR YOUR ATTENTION