Product Description
Centrifugal machine
It is a solid /liquid separation equipment , in the stevia refining process , the centrifugal machine is applied to separte the solid material from the stevia glycoside -content liquid .
Here there are different capacity of the centrifugal machine , and generally Model SS800 centrifugal machine is especially used in thie refining step .
Centrifugal machine of refining process of stevia extraction line
Step 1. Put crude stevia extract into mixing tank which contains ready- made solution of ethanol , mix it , then wait some period of time for static crystallization , when crystallization is ready , it is put to centrifugal machine for separation of solid material from liquid state , the crystallized products is placed in plastic bags , and the mother liquid will be concentrated and be filtered for dry products.
Step 2 , When the crystallized products is sufficient , it will be dissolved in ethanol solution , after a period of time , solid substance will be obtained from liquid , and when the solid substance is collected in enough quantity , it will be put to evaporator with pure water so as to recycle ethanol , and when the ethanol is fully collected , then lower pressure and distill , and when the density is ok , filter it with small press filter , dry it and obtain high reb-a products .
One Stop Service for Buildup of Stevia Extraction Line
China has 30 years of history of stevia industry , up to now , there are more than 20 industrial extraction plants, and yearly production capacity reach 10,000 tons of crystallized powder stevia products , the overcapacity problem has already occurred . However, looking around the world , in some countries or regions the stevia industry is a new industry or just in beginning stage , under this context ,we have already formed an experts team which are composed of some qualified specialist , these specialist are those from who have many years of experience in stevia crop growing , stevia leaf extraction , research and development , new products development , marketing ,etc, with this working team , we are aimed to introduce the Chinese stevia industry into the overseas investors , with our 3 decades of expertise , we would help the overseas investors to grow the stevia , set up stevia extraction plant , overall , promote the stevia industry worldwide , and let the stevia products benefit all the people on the whole world .
We are committed to worldwide clients : one stop service is provided , offer feasibility report , production process design , best selection of equipments , and professional after-sale service, GMP certified workshop design , etc.
Successful example :
Annual production capacity of 50 tons stevia extraction project for Mexico.
In 2012, we were introduced to a Mexican company which is engaged in the stevia cultivation and related products development , and since then we both parties have established friendly business relationship , the Mexican enterprise had a plan to set up a stevia extraction plant in Mexico , upon the request of Mexican enterprise , we offered the stevia process expertise and core equipment to the Mexican party , through 3 years of intense cooperation , the plant of yearly production capacity of 50 tons has been established , and in this March , 2016 , it has already been put into operation , and the crystallized stevia extract have already come out of the plant .
Stevia Extraction Process Chart .
DRY STEVIA LEAF ￫ SOKAGE ￫ PRECIPITATION ￫ PRESS FILTRATION ￫ RESIN ABSORPTION ￫ DE-ABSORPTION ￫ DE-SALT ￫DE-COLOR ￫ EVAPORATION OR CONCENTRATION ￫ ETHANOL RECYCLE ￫ MEMBRANE SEPARATION ￫ FILTRATION WITH CARBON ACTIVE ￫ ULTRAFILTRATION ￫ SPRAY DRYING￫INSPECTION ￫ PACKING
Description of Stevia leaf extraction process flow chart
STEP NO. 1 , Steeping section :
Put dry stevia leaf into soaking tank with hot water ( city water warmed by vapor ) , after a period of time , the liquid will be pumped to storage tank by self -suck pump ,, here the liquid would be named as raw liquid . Generally , the stevia leaf will be washed for 3 till 4 times , and when the stevia leaf is washed in fifth or sixth time , the water could be used for new stevia leaf .
STEP NO. 2 , Precipitation section ;
No.1. The raw liquid will be pumped to precipitation tank which is of hot water( note ; city water is warmed by vapor ) ;
No.2. Reaction process : calcium hydroxide solution ( Ca(OH)2 is added , then the solution of( FeCl3) is added too ,to mix the liquid . And when the ph value is satisfied , then the liquid will stay half hour , then be pumped to another tank ( i.e. Called mature liquid ) .
STEP NO. 3 , Filtration section :
Step 3. 1. Mature liquid filtration . Before filtration , make preparations with the filter , insert the thick and thin filtration cloth , tighten the press filter , turn on the pump and filter valve and let the liquid enter the filter with the specific flowing speed , and the filtered liquid should be transparent without impurity , and then the filtered liquid will be put to storage tank . Each press filter can accommodate 15 till 20 tons of liquid , the press filter will have to be washed from top after use .
Step3. 2 . Clean and Wash the press filter .
Wash the press filter with soft water until there is no sweetening liquid , in the meanwhile , compressed air is also used to blow the filter until there is no liquid inside .
Step3.3. Disassemble the press filter .
Disassemble each aluminum sheet from the press filter so as to clear the sheet one by one , take out of the dirt substance from the sheet .
Step 3. 4. Wash and clean the filtration cloth of the press filter .
After washing the cloth of the press filter , it should be installed properly and tighten it so that there is no leakage . The filtration cloth shall be washed and cleaned once a week ( either thick cloth or thin cloth ) , change of the cloth shall depend on requirement .
Step 3. 5. Wash and clean the tank .
The tank for mature liquid ( mentioned above ) shall be thoroughly cleaned once a week . Before cleaning , the stevia liquid inside shall be filtered until there is no stevia liquid left at last .
STEP NO. 4、Resin Exchange section
Step 4. 1. . Absorption resin regeneration ( i.e. Big Recycle , once a month ) . The absorption resin regeneration or recycle will have to be done after one absorption of work .When the liquid level inside the tank shall keep 10 cm above the the resin , then HCL is added , the flowing speed shall keep under the pressure of 0.1mpa , after that , the liquid will stay one hour , then using soft water , wash until ph value is 3 +or - 0.5 ,loosen resin and alkali lye is added , after that , it will stay another one hour , wash with soft water , and loosen the resin for later use.
( Note : new resin will be treated before use like the above mentioned procedure )
Step 4. 2. De-salt resin and de-color resin recycle or regeneration . Once each half month .
A. ：de-salt resin recycle .
Input alkaline lye , and the pressure inside the tank shall keep 0.05 mpa , wash with de-ionized water , then until ph value is 8.5 + or -0.5 , stop , and loosen the resin . Then input HCL solution , and the pressure inside the tank shall keep under 0.05mpa , wash with de-ionized water . Then wait for further combined washing .
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B. De-color resin recycle .
Input HCL , and keep the pressure of the tank under 0.05 mpa , wash with soft water , until ph value is 3+or -0.5 , stop , and loosen resin , then input alkaline , the pressure inside the tank shall maintain below 0.05 mpa , wash with soft water . When ph value is 7+or -0.5 , wash the de-color tank with de-salt tank simultaneously .
New resin of de-salt and de-color shall be treated before use like the above mentioned method .
C. Small recycle of de-salt resin and de-color resin .
After each work , the recycle of de-salt resin and de-color will be done . In case of recycle of de-salt resin , HCl is used , and in case of recycle of de-color resin , alkaline is used , firstly wash the tank separately .then wash two tanks together . After work , it will be ready for future use.
Step4. 3. Absorption .
When in absorption , one single tank is used for absorption in the beginning , and when there is liquid coming out from the first tank , and the liquid tastes a little sweet , it indicates that the first tank is saturated , but still is not satisfactory , it should be working with another tank , the flowing speed shall keep at 6 till 8 tons per hour , in general , three absorption tanks form a group , when the second tank liquid is sweet , then wash the first tank , the others is the same . And when the third tank is saturated , ( liquid come out with sweet liquid , wash with de-ionized water till it is not warm , open the the cover of tank , and reverse -wash , after each tank work 2 or 3 times , then it should be reverse- washed once .
Step 4. 4. Resin relief ( or Recycle of absorption resin )
The resin relief process is used with ethanol . During the process , it shall maintain the flowing speed of 1.2~2 tons per hour . Ethanol is used to recycle the resin , the modern technology is that two tanks is formed one group for recycle , when the liquid from the bottom of second tank become green or black green , then it will be connected to de-salt tank , and de-color tank , and when the liquid from the last tank of de-salt and de-color taste a little sweet , it will be put to low density tank , after 2 minutes later , sample the liquid and find out that the liquid is bitter , or lower density ethanol occur , then put it to relief storage tank , here the liquid is named as relief liquid , and when the ethanol is input totally , wash the first tank of absorption with soft water , when the ethanol content of last de-salt tank is 5%+or -,stop washing , loosen the resin , then the de-salt or de-color resin is recycled .
Note : During the process of absorption , de-salt , de-color , when the content of ethanol is 5%+ or - in any tank , then start to wash the next tank .
STEP NO. 5, Concentration section
Step 5. 1. Input stevia liquid ( relief liquid ) . Pump the stevia liquid to concentration tank for recycling ethanol , the dense ethanol is put to one storage tank , and the thin ethanol is put to another storage tank . When the ethanol density inside the concentration tank is 5 degrees plus 1 degree tolerance , lower pressure and distill for ethanol recycle;
Step 5. 2. Ethanol recycle . When the stevia liquid in concentration tank is heated until the temperature is 75 grades ~80 grades Celsius , turn off the vapor valve to prevent the liquid from flowing out , and when the ethanol purity is 40%~45%( to be measured by ethanol gauge ), the liquid shall be placed in thin ethanol storage tank . And when the temperature reach 95 degrees till 105 degrees Celsius , the ethanol recycle is finished .
Step 5. 3. Wash press filter .
When the aluminum sheet is used 5 or 6 times , it shall be dismantled and cleaned , use compressed air to blow the sheet , especially clean the active carbon inside ,and return it to the process of precipitation . Also clean the filtration cloth , afterwards , it shall be installed properly and be tightened .When in case of Dense stevia liquid filtration , the aluminum sheet shall be cleaned after 4 or five uses .
STEP NO. 6. Spray drying
（1）Wash the dense stevia liquid tank and spray dryer by using soft water .
（2）Drain the soft water out of dense liquid tank thoroughly .
（3）Dry the interior of spray dryer until there is no water drops , vapor , etc.
（4）to start dust -elimination pump .
（5）According to practical condition , change filter sponge of blower .
（6）receiving barrel shall be cleaned for later use .
（7）Pump the dense stevia liquid to storage tank .
（8）Turn on the spray dryer for warming up .
（9）When the temperature inside the spray dryer is above 100 degrees Celsius , and the temperature of exit is 90 degrees , the stevia liquid shall be entered , instantly the dry stevia power is formed . ( The final products shall contain moisture of 3~4% )
（10）During spray drying , the temperature of entrance shall keep 175 ~195 degrees Celsius , and the temperature of exit shall be 95 degrees till 105 degrees. .
Refining process
Step 1. Put crude stevia extract into mixing tank which contains ready- made solution of ethanol , mix it , then wait some period of time for static crystallization , when crystallization is ready , it is put to centrifugal machine for separation of solid material from liquid state , the crystallized products is placed in plastic bags , and the mother liquid will be concentrated and be filtered for dry products.
Step 2 , When the crystallized products is sufficient , it will be dissolved in ethanol solution , after a period of time , solid substance will be obtained from liquid , and when the solid substance is collected in enough quantity , it will be put to evaporator with pure water so as to recycle ethanol , and when the ethanol is fully collected , then lower pressure and distill , and when the density is ok , filter it with small press filter , dry it and obtain high reb-a products .
Packing & DeliveryPackage : the centrifugal machine will be packed in wooden case , and to be put on pallet suitable for Centrifugal machine of refining process of stevia extraction line shipping.
Delivery ; 3 months of preparation after receiving payment.