1. Introduction
Ukrainian industry is facing a critical need to reduce energy consumption and improve equipment reliability. Many enterprises still operate belt and chain conveyors installed in the last century. Worn-out gear reducers, inefficient asynchronous motors without frequency regulation and absence of basic monitoring lead to massive electrical energy losses and frequent emergency stoppages.
Equipment aging is accompanied by increased energy efficiency requirements according to European directives and internal market requirements. Requirements of standards series ISO 50001 (Energy Management) and EN 60034-30 (Engine Efficiency Classes) force chief engineers to review approaches to technical maintenance. Modernization of conveyor transport is a necessary step to ensure the competitiveness of the enterprise.
2. Evaluation of Obsolete Systems
Before starting the modernization, it is necessary to conduct an audit of the current state of the conveyor line. Many operators follow the principle "if it is working, do not touch", ignoring the hidden maintenance costs of the outdated machine park. The table below shows the criteria for evaluating outdated drives:
| Evaluation Criterion | Old system | Permissible limit |
|---|---|---|
| Drive transmission | 55% — 68% | At least 92% (IE3/IE4) |
| Vibration level (ISO 10816) | Over 4.5 mm/s (Dangerous status) | Up to 1.8 mm/s |
| Reducer housing temperature | Above 85 °C | Up to 70 °C |
| Frequency of scheduled stops | More than 3 times a month | Less than 1 time per quarter |
| Positioning Accuracy | Missing (no encoders) | ±1 mm |
The main objection from production managers sounds like: "But the old equipment is still working!". A simple calculation shows that the cost of electricity consumed by a 55 kW outdated motor per year exceeds the cost of purchasing a new high-efficiency drive in combination with a frequency converter.
3. Modern Alternatives
Technological development of components allows significantly changing the architecture of conveyor lines. Transition from centralized drives with long cardan shafts and open belt drives to decentralized modular solutions provides a significant increase in reliability.
| Technology | Traditional solution | Modern solution |
|---|---|---|
| Engine | Class IE1/IE2, 78% Efficiency | IE4 class (permanent magnet synchronous), 96% efficiency |
| Reducer | Coupling / cylindrical | Conical-cylindrical modular reducer |
| Motion Control | Direct start through contactor | Vector frequency converter |
| Hydraulics and Braking | Oil-Warmed Hydraulic Couplings | Integrated recovery systems (for example, components HYDAC 1253106) |
Use of high-pressure hydraulic components, such as HYDAC 1253106 valve blocks for braking and load stabilization in inclined conveyors, ensures smooth operation without impact loads on the mechanical part of the reducer.
4. Calculation of Return on Investment (ROI)
Economic justification of modernization is based on real production indicators of an average mining and beneficiation or cement plant in Ukraine. Let us consider modernization of a line with 4 conveyors with total motor power of 220 kW.
- Electricity tariff: 6.00 грн/kW·h (VAT included).
- Working time: 6 000 hours per year (3 shifts, continuous cycle).
- Present power consumption (IE1, old reducers): 220 kW / 0.70 (system efficiency) = 314 kW from the grid.
- Modernized consumption (IE4, modular drives, frequency regulation): 220 kW / 0.93 (efficiency) = 236 kW from the grid.
- Annual energy saving: (314 - 236 kW) × 6 000 h = 468 000 kW·h.
- Energy cost saving: 468 000 × 6.00 UAH = 2 808 000 UAH per year.
- Reduction in maintenance costs and downtime: reduction of 80 hours of unplanned stoppages per year saves approximately 640 000 UAH (taking into account the cost of lost profit and maintenance staff salaries).
- Total annual savings: 3 448 000 грн.
Capital expenditures (CapEx) for the purchase of drives, sensors, hydraulics (including HYDAC units) and installation works amount to approximately 4 200 000 грн. Simple payback period (Payback Period):
4 200 000 / 3 448 000 = 1.22 years (approximately 14.5 months).
5. Implementation Roadmap
In order to avoid long-term production stoppages, the modernization is carried out in stages:
- Design and audit: Laser alignment, load measurement using strain gauges, development of drawings for transition plates for new reducers.
- Pre-assembly of units: Assembly of new motor-reducers and hydraulic stations on the pre-assembly line.
- Short-term installation (during planned maintenance): Removal of old foundation frames, installation of new modular drives (window period: 48-72 hours).
- Startup procedures: Frequency converter setup, vibration and temperature sensor calibration, checking the operation of recovery systems.
6. Technical Problems and Their Solutions
During the integration of new equipment, engineers often encounter geometric incompatibility between new and old mounting positions. The use of standardized modular interfaces allows the production of intermediate adapter plates according to standard ISO 5211 even before the line shutdown begins.
Another problem is harmonic distortion in the network from powerful frequency converters. It is solved by installing active harmonic filters or using drives with low harmonic levels according to the standards EN 61000-3-2.
7. Case Study (Practice Example)
At a cement plant in the western region of Ukraine, the main drive of the raw material inclined conveyor was replaced. Instead of an outdated drive with a hydraulic coupling, a modern set was installed: IE4 motor, conical-cylindrical reducer and hydraulic control block based on HYDAC components.
- Before modernization: MTBF (mean time between failures) was 720 hours; specific energy consumption — 4.2 kWh per ton of transported material.
- After modernization: MTBF increased to 5 400 hours; specific consumption decreased to 3.1 kWh/t.
- Additional effect: Noise level at the workplace decreased from 84 dB to 68 dB, which meets the occupational safety requirements according to DSTU EN ISO 9614.
8. Receiving and Validation
After completion of the installation, a comprehensive test is carried out in accordance with the national and European standards:
- No-load test for 4 hours for temperature control of bearing units (limit: not higher than +65 °C or ΔT ≤ 40 °C relative to ambient).
- Testing under full load for 72 hours of continuous operation.
- Vibration characteristic measurements according to standard ISO 20816-1.
- Testing of emergency switches and break detection sensors.
9. Conclusion
Modernization of conveyor systems is an investment with a predicted payback period less than 1.5 years. Implementation of high-efficiency drives, smart sensors and reliable hydraulic components (such as UNITEC-D E-Catalog) eliminates the risks of emergency stops and reduces the energy consumption of the enterprise. UNITEC-D GmbH supplies a full range of certified components for modernization of industrial equipment in Ukraine according to CE and UkrSEPRO standards.
10. References
- ISO 50001:2018 — Energy Management Systems. Requirements and guidelines for use.
- EN 60034-30-1 — Rotating electrical machines. Efficiency classes for single-speed three-phase asynchronous motors (code IE).
- DS TU EN 61800-5-1 — Electric frequency-controlled power drive systems. Safety requirements.
- Technical documentation of the manufacturer of hydraulic system series HYDAC 1253106.
