Clarifications to Queries from EPC Bidders Sugar Plant (Technical Specifications)

Transcription

1 Clarifications to Queries from EPC Bidders Sugar Plant (Technical Specifications) 1. Chapter 4 Technical Specifications Who will provide hot water tank for imbibition water for sugar section? 2. Chapter 4, Technical Specifications, cane unloading trolleys 3. Chapter 4, Technical Specifications, drive for CSDE Kindly specify the requirement instead of putting dependability on other factor, which is beyond control of the contractor 90 kw drive appears to be on lower side. We understand, it would be 150 kw Hot water tank for imbibition water will be in the scope of EPC contractor of this package. EPC bidders are expected to visit both the sites, study the situation and specify / quote for the best suitable cane unloading system to ensure guaranteed performance parameters 90 kw power for CSDE is sufficient. It works like a chopper having little more clearance than chopper. Chopper is generally given with the clearance of 600 to 700 mm for this crushing capacity and CSDE is provided with the initial clearance of 1000 mm and if necessary 1100 mm. 4. Chapter 4, Technical Specifications, drive for cane cutter 250 kw drive appears to be on lower side. We understand, it would be 350 kw. 350 KW drive for cane cutter is acceptable. 5. Chapter 4, Technical Specifications, fibrizor 1830 mm swing dia appears to be on lower side. We understand, it would be 1900 mm. Swing diameter is selected to achieve the tip speed of hammer of m/s at operating speed of motor of 740 rpm, to avoid formation of powder. Swing diameter of 1900 mm will correspond to tip speed of hammer of m/s and acceptable. 6. Chapter 4, Technical specifications, number of hammers of fibrizer shall be 160; Swing diameter of 1830 mm Number of hammers should be 144. What is the swing diameter limit? Will shredder of appropriate specifications be acceptable? Fibrizer as specified or suitable shredder is acceptable. Average PI should be 92% and maximum 94% without powder formation. The preparation shall be of hairy nature and long like fibrous, to achieve better percolation rate in the cane diffuser and better feed ability at the dewatering mill. Number of hammers can be chosen by the bidder to achieve the guaranteed performance. The swing diameter limit of 1830 to 1900 mm is acceptable.

2 7. Chapter 4, Technical specifications, auxiliary Final motion gearing and pinion arrangements 8. Chapter 4, Technical Specifications, Juice Heater Can we give planetary gear box in place of reduction gear box and open gearing? Can we use AC VFD? Due to diffuser based technology, RJ will be heated using press water & scalding heater. Hence RJ temperature will be around 70 Deg C. So, we propose to review number of required juice heater specified in tender document. The planetary gear box in place of reduction gear box and open gearing also can be accepted. AC VFD drive for dewatering mill is not acceptable.. Reduction in heaters is accepted without affecting any performance parameters. 9. Chapter 4, Technical Specifications, capacity of centrifugal machines of 650 kg/charge x 3 numbers a) Capacity of centrifugal machines of 650 kg/charge is very small, it should be changed to 1160 x 5 numbers bigger size and numbers b) We propose 2 x 1250 kg/charge or 2 x 1000 kg/charge instead of 3 x 650 kg/charge to reduce power consumption The sugar process house is designed for 75 TCH and sugar recovery of 10% and peak recovery of 12% cane. As such, centrifugal machines as designed are sufficient. Bigger size machines of 1000 kg/charge x 2 numbers x 22 cycles/charge are acceptable. 10. Chapter 4, Technical Specifications, DSM screen We propose to have Rotary juice screen instead of DSM screen because of technical advantages Due to number of disadvantages of rotary juice screen, the same has not been envisaged. Rotary screens were replaced by DSM screens since 1940 and are universally used in the sugar industry worldwide and are working efficiently. Rotary is not accepted. 11. Chapter 4 Technical specifications Filtrate will be sent to sugar house or distillery? Filtrate shall be treated in the sugar plant itself

3 12. Appendix II List of approved makes In the makes of preferred vendor names like VRL/ SEDL and many other vendors mentioned. If we have our own makes and our own proven vendors, we want to mention our preferred makes. Is it acceptable? 13. Appendix VI Out put: screened & mixed juice MJ 110% cane, MJ % cane 98, Bx 13 Out put: screened & mixed juice MJ 110% cane, it should be more; MJ% cane 98, Bx 13 ClJ% cane Bx 12 shall be more. Vendors as mentioned in the bid document shall be permitted. MJ % 125% is acceptable. Naturally, ClJ % cane will go up proportionately. MJ % C = 98, Brix 13 0 The water balance considered is only indicative. The 14. Appendix VII Indicative water balance in the sugar plant, MJ % C = 98, Brix 13 0 MJ% cane can be considered at 125%. 15. Appendix IX Indicative evaporation system with extensive vapour bleeding. Various juice heatings on different type of vapour bleeding are shown in the schematic diagram All juice heaters shall be of that central type Methods of reduction of steam consumption are yet to be standardized by the technical committee of Govt of India. The evaporation system shown in the EPC bid is indicative as every bidder will design the juice heating and evaporation system differently. Suitable size and type such as Direct contact, standard high velocity vertical, dynamic and vapour line type juice heaters and juice heaters by condensate water shall be provided according to the bidder s proven design for achieving the guaranteed steam and power consumptions specified in the EPC bid. 16. Appendix XIII Preliminary plant layout Are we allowed to change layout of complete factory or packagewise section? The overall layout as indicated in the Appendix stands frozen, changes within each plant can be decided by each EPC contractor with approval of HPCL. Changes will only be accepted if it is not affecting the locations of terminal points for other packages and not affecting other packages.

4 Sr. No. EPC Bid Document 17. Special Conditions Cane preparatory index 92 % is very high figure and impractical to achieve using fiberizor. We recommend to use cane shredder, which can provide PI 90% +. PI required for RME of 98.50% should be average 92% and max 94%, with hair like fibrous preparation. Option of installation of shredder is acceptable. In this case, cane magnet can be installed by replacing cane carrier no. 2 by installation of high speed belt conveyor between cane carrier no. 1 and shredder. 18. Special Conditions Reduced mill extraction 98.5 % is not practical figure to achieve during regular operation of plant. Perhaps there is not a single plant operating at such efficiencies on regular basis. We suggest making it 98 %. RME required for ethanol plant is at 98.50%. In South Africa, more than 2 sugar plants are achieving more than 98.60% RME. 98 is not accepted. 19. Special Conditions Time utilization Time utilization factor depend on many variables, which are beyond control of design & engineering. We request you to take out this parameter from performance guarantee. Efficient cane preparation, efficient cane diffusion, efficient dewatering mill and continuous evaporation system with two separate sets it is possible to achieve down time 2.00% only, hence TUE of 98.00% is possible. 20. Special Conditions Power consumption Because of higher fiber content of cane, it is difficult to get 19 kw/tch Power consumption. We request you to make it 21 kw/tch. Efficient diffusion and only 50% juice for sugar process boiling house (processing only 75 TCH), the operating power required shall be 18 kwh/tch. For the cane crushing of 150 TCH, power requirement will be 2700 KW and for provision of peak-kick loading of 21 kwh/tch; 3150 KW, should be sufficient, to enable to export power to the maximum levels.

5 Sr. No. EPC Bid Document 21. Special Conditions 22. Special Conditions Bagasse moisture 48 % of moisture content is difficult to achieve on regular basis, we request you to make it 49 %. Quality of sugar We request you to change it to With the dewatering pressure drum in the diffuser, installation of unique perforated rake inter carrier between diffuser and dewater mill and very efficient dewatering mill having 6-rollers configuration with perforated all rollers (like lotus), it is possible to achieve bagasse moisture of 49%. 49% is acceptable. Average of 80 ICUMSA & maximum of 100 ICUMSA is acceptable.