Elspec Equalizers for Sugar Industry Daniel L.K. Ching
Sugar Mills- Fertile Ground for Equalizers • Huge MVar requirements can be expected in Sugar Mills. • Equalizers Enhance Generator Capacities and improve power quality of Sugar Mills • Expect repeat orders from Sugar Mills.
Major Steps in Sugar Processing • Milling Process - Cleaning and Juice Extraction by shredding and pressing. • Purification of Juice – Clarification (use of lime and chemicals) and vacuum evaporation. • Crystallization in vacuum pans producing Messecuite. • Centrifugal process to separate raw sugar from molasses. • Drying and Packaging.
Power Generation in Sugar Mills • Sugar Mills generate their steam and power by burning bagasse. • Steam is generated in the boilers. They are used in refining process and to run steam generators.
Power Generation in Sugar Mills • Sugar Mills with refineries need more power and steam. Diesel generators are sometime used for augmentation. • Numerous Steam Turbine and sometimes Diesel Generators are connected in parallel.
Major Loads in a Sugar Mill • Conveyor drive systems • Centrifugal Baskets • Pumps, compressors • Mill loads such as cane cutters or knives, cane mill etc.
Centrifugal Baskets – Important Machine in Sugar Processing • Machine that separates raw sugar or refined sugar from molasses. • Revolves 1000-1200 rpm per process. • Runs as required by the process. • A Sugar Mill may have 6 to 24 or more depending on the sugar mill’s capacity.
Centrifugal Baskets– Characteristics • Would run every few minutes as the process dictates. • Driven by large motors from 100HP (75kw) to 150 HP (112kW). • Old Systems are started Direct-on line (2 speed), DC Drive or driven by VFD’s (current fed- regenerative or voltage fed). • Very Inductive During Starting.
Centrifugal Baskets- Source of Power Quality problems • Huge kVa and Kvar demands during starting may create PQ problems in terms of voltage dips & frequency variations.
Centrifugal Baskets- Source of Power Quality problems • Logged Data obtained from a Centrifugal basket driven by a VFD
Centrifugal Baskets- Source of Power Quality problems • An Example of Centrifugal Basket coupled to a Regenerative Drive
Centrifugal Baskets- Source of Power Quality problems • Another Centrifugal Basket driven by a regenerative drive. Take note on the impact on frequency by the demand of the starting load.
Impact of Centrifugal Baskets on a Sugar Mill • Low Power Factor • Unstable Frequency • Must generate power at higher voltage (higher kW consumption) • Low efficiency • High Losses • Forced load scheduling • Increase CO2 emissions • Occurrence of Voltage Dips that may trip sensitive equipments
Without EQ, plant engineers had used conventional means but they can never improve their powerhouse PF They tried manual banks but these would constantly be damaged. Conventional Automatic banks are likewise useless in their quest to improve their PF
Other Benefits • Enhanced Generator capacities. • Increased generator rigidity by having stable generated frequency and voltage. • Energy/ fuel savings • Reduces steam demand, thus improve productivity • Increased efficiency • Better PQ
Tips when qualifying a Candidate Using a handheld RMS Power Analyzer may help in qualifying • High %THD in Current may indicate presence of fast changing loads
Summary • Sugar Mills can never improve their Power House Power Factor without Equalizer. • Equalizer is the only Solution !