WÖHWA Waagenbau GmbH
The competitiveness of companies in the bulk solids industry is increasingly dependent on their careful use of energy. Cost pressure and legislation demand energy saving in all areas. In the costs for the production of sand, gravel and ballast, energy costs account for an above-average percentage. Thus the installation of an energy controlling system is becoming increasingly important in the non-metallic minerals processing industry (Fig. 1).
At bauma 2013, Wöhwa Waagenbau GmbH is presenting the WÖHWA ECS21 energy controlling system. The advantage of the ECS21 is that, parallel to recording of the power consumption values, mass flows are recorded and collected fully automatically by means of belt weighers, individual characteristic values are calculated and corresponding measured values are provided later for the purpose of control and regulation. In addition, the ECS21 was specially developed to meet the needs of the bulk solids industry. The fully automatic recording of the consumption levels, mass flow rates as well as calculation and evaluation with the ESC21 enables the operator to realize the greatest possible use with his existing personnel.
ECS21 is an energy controlling system that works completely independently of the conventional control systems of a processing plant. A conventional PC on which an SQL database is installed collects all consumption data of corresponding plant sections and equipment via an Ethernet network (three-phase power measurement with evaluation of measured values on site). Every 30 seconds, a measured value from each of the max. 56 measurement points is archived in an SQL database on the PC. Current measurement data of the belt weighers installed in the plant can be collected via the Ethernet and archived on the same database. The ECS21 software can be freely parameterized by the operator and can be extended with additional measurement points, irrespective of whether individual drives or a complete system is to be measured. The different measurement points are subdivided into seven main groups, e.g. primary crushing (Fig. 2), secondary crushing, etc. Up to seven measurement points on the equipment, e.g. screens, crushers, pumps, dedusting of the appropriate plant section, can then be assigned to the main groups.
With the belt weighers integrated in the ECS21 system, it is possible to determine how much time and energy has been consumed during idle running of the plant and how much energy above a maximum value predefined by the operator has been consumed. In addition, the consumption values from two different periods can be compared. With the ECS21 software installed on the PC, any time intervals can be defined, over which the consumption can be accumulated and the performance curve continuously calculated and shown. The operator can use this evaluation to obtain a clear reading of the different consumption levels and performance curves of the plant sections/equipment. At the same time, definite figures (in kWh/t) can be determined with integration of belt weighers. This completely automatic determination of the consumption data and characteristic values can be used for an energy management system in compliance with DIN EN 50001.
The different consumption levels of the different plant sections and equipment are shown continuously and accumulated over freely selected time intervals. A mass flow value can be attributed to every consumption value of a main group, with which a characteristic value can be automatically and continuously determined by the system.
Different options are available for analysis of the measured values:
• Comparative analysis of time interval A with time interval B
• Maximum value analysis
• Idle running analysis (duration and consumption)
• Determination of consumption peaks
A clear and concise report on the different consumption levels and figures is automatically generated daily, monthly or yearly by the system and stored in a separate archiving directory. This directory can be accessed from elsewhere by means of VPN. With a secondary licence, all analyses can be performed from elsewhere.
Hall B2; Stand 306