Mill Electrification
The process of juice extraction from prepared cane takes place through a combination of mechanical squeezing & dissolution. For the milling of prepared cane, multiple sets of three or more roller mills are used in sugar industry. It has been observed that due to very high power consumption for juice extraction, the industries are shifting their process of juice extraction from milling to diffusion. In case of diffusion system also preliminary extraction (cane diffusion) and dewatering extraction is required through mills only. So time to time various types of drives get introduced for the efficiency and economy of the mills.
SED introduces the improved mill drive system with lower power consumption due to highly efficient & compact planetary drives:
In SED of mill drive system, top roller of the mill has a drive at either end, directly mounted on its shaft. Each of the other rollers has one drive directly mounted on its shaft. This system is equipped with variable frequency drives to control the mill speed very precisely.
Advantagous Features of SED Planetary Mill Drives - Comparative Analysis
| Features | Conventional Mill Drives (Steam Turbine / DC Drives / Hydraulic drives) | SED Mill Drive System |
|---|---|---|
| Compactness | A huge package system with large and bulky items with more complications | Compact & concise with less weight in comparison to conventional system. |
| Power Consumption | High | Very low |
| Noise Pollution | High | Very low |
| Mill Speed Control | Limitation for mill speed control | Easy to run the mill at 1-4 rpm for better results |
| Maintenance Time & Cost | More & precise maintenance due to various systems involved. | Less & easy maintenance, due to compact & less systems involved . |
| Inventory Cost | Higher inventory cost for number of precise spares. | Less number of equipments and spares result cost saving. |
| Gearing / Efficiency | Multi stage enclosed gearing with open gearing train means less efficiency. | Inline planetary gear box gives higher efficiency +90%. |
| Oil Lubrication System (for open gearing & plummer block bearings) | External | No External Gearing & Plummer block /Bearings required |
| Space Area Requirement | Require more space to accommodate entire system | Directly mounted on the roller shaft, no space required. |
| Civil Construction Cost | Heavy civil work involved. | No civil / steel structure required. |
| Manpower Requirement | Highly skilled manpower is essential for the system | Less skilled man power is required for operation / maintenance. |
| Alignment | Precise workmanship to align. | Easy to Align. |
Performance Parameters of mills – Comparative Analysis
| Mill Parameters | Conventional Mill | Modernized Mills by SED Mill Drive Technology |
|---|---|---|
| Power consumption in kW / T of cane (complete tandem including cane handling, preparation, crushing & bagasse handling) | - | 11-12.5 (1.2-1.5 per mill) |
| P.M.E. (Primary mill extraction) | 60-65% | 73% |
| R.M.E (Reduced mill extraction) | +95% | +96% |
| Final Bagasse pol | 1.6-2% | 1.4-1.8% (In case of diffuser 1.2%) |
| Moisture in Bagasse | 51-52% | Up to 47-48% |
| Smooth crushing at variable loads without any effect of low crushing. | Can run at 4-5 rpm. | Easy to run at 1-4 rpm |
| Breakdown / shutdown time towards drive side | Significant due to lot of components & controls involved. | Nil (only few components involved) |