Process control in SUGAR INDUSTRY

In the respect of Sir Hira lal Soni

GROUP MEMBERSJunaid korai 14CH03Imtiaz Bhurt 14CH17Faisal Bhangwar 14CH30Abdul Haseeb 14CH34Muhammad Saleh 14CH41Abdullah Gopang 14CH51

Instrumentation in sugar industryInstrumentation is the art and science of

measurement and control of process variables within a production or manufacturing area. The process variables used in industries are Level, Pressure, Temperature, Humidity, Flow, pH, Force, Speed etc.

When a device is designed to perform without the need of human inputs for correction it is called automatic control 

Goal InstrumentationInstrumentation and control engineers works

with the goal of improving.

Productivity,Optimization,Stability,Reliability,Safety,Continuity.

SensorsSensor measure the physical quantity and

converts into signal which can be observed by observer or by an instrument.

E.g, thermocouple measure the temperature and converts it into the voltage which can be observed by voltmeter.

Process steps in sugar industry Cutting or slicing

Juice Extraction

Clarification (juice purification)

Evaporation

Crystallization

Centrifugaling

Drying and Screening

CUTTING or SLICINGThe cane is cut into small pieces.

Here, We control the flow rate of cane towards the cutter & the size of pieces.

& the flow rate is depend upon capacity of the cutter.

Juice extractionHere the juice is extracted from sugar cane

Juice extraction is the process of squeezing the juice from the cane under a set mills using high pressure between heavy iron rollers. Those mills can have from 3 up to 6 rolls.

Before , entering in the rollers there is electric magnetic drum which removes the metallic parts present in raw material.

Juice extractionIts actioning is provided by steam turbines ,

electric motors or hydraulic devices.

Juice extraction During grinding, hot water is sprayed on to

the sugarcane to dissolve any remaining hard sugar. The smaller pieces of cane are then spread out on a conveyer belt.

Roller Mill

Juice clarificationIn juice clarification tank , a PH detector is

fitted which measure the PH of the juice .

Sugar cane juice has a pH of about 4.0 to 4.5 which is quite acidic. Calcium hydroxide, also known as Milk of lime or limewater, is added to the cane juice to adjust its pH to 7.

Here the Controlling Variable is PH maintaing.

PH measuring methodsMeasuring PH by using indicator.

Hydrogen electrode method.

Semi-conductor sensor method.

PH imaging.

PH Meter

Juice clarification

Evaporator• Generally the evaporators are used to

remove the water percentage from the Juice,

• three vacuum-boiling cells or bodies are arranged in series so that each succeeding body has a higher vacuum (and therefore boils at a lower temperature).

• The syrup leaves the last body continuously with about 65 percent solids and 35 percent water.

Controlling variable in EvaporatorThe controlling variable in Evaporator are

Feed flow rateConcentration (composition)TemperatureSteam flow rate

Evaporator

Crystallization & CentrifugingThis syrup is further concentrated under

vacuum in a vacuum boiling pan until it becomes supersaturated.

This method boils the sugar liquors in three stages, called A-, B- and C-.

The mother liquor from the first crystallization step (A-product) is again crystallized in vacuum pans and then passed through continuous sugar centrifuges

Crystallization & CentrifugingThe mother-liquor is again crystallized in

vacuum pans for  sufficient to exhaust molasses (called massecuite).

Then the massecuite is re-heated in order to reduce its viscosity and then purged in the C-produced centrifugals.

The remaining mixture is a thick mass of large crystals, which is sent to a centrifuge to spin and dry the crystals. The dried product is raw sugar

Controlling VariablesFeed controllingBrix ValueConcentration (Composition)Temperature

DryerDryer removes the Moisture content from

sugar Granulators.

Controlling variables areFeed flow rate,Hot air flow rate,Moisture

Dryer

ScreeningHere the sieve separates the regular and

irregular granulators.

The irregular crystals are recycled to the Crystallizer.

Regular crystals go towards to the Packing section

Solid level measuring sensorsVibrating point level sensorsUltrasonic level sensors.Laser sensorsLoad cellRadar sensorsMicrowave level sensorsfloat level sensorsoptical level sensors