Which factors determine the total cost of ownership (TCO) of an industrial mixer over 10 years?
The total operating costs of an industrial mixer, also known as total cost of ownership or TCO, cover far more than the purchase price. They take into account all costs from planning, procurement and commissioning through ongoing operation to modernisation, decommissioning and possible residual value. A robust TCO analysis combines investment costs with operating costs as well as indirect costs arising from downtime, product losses or regulatory requirements.
Acquisition and integration
Initial costs include the purchase price of the mixer as well as the costs for the drive, control system, sensors, safety equipment and required peripherals. Added to this are transport, installation, assembly, electrical installation, commissioning and acceptance. Depending on the plant, further costs arise for engineering, project management and integration into existing process lines, controls or supervisory systems.
Special designs can increase the investment. These include, for example, ATEX designs, pressure-resistant or vacuum-resistant construction, hygienic designs, special surfaces, particular sealing systems or corrosion-resistant materials such as duplex, Hastelloy or titanium. However, higher acquisition costs can be economically worthwhile if they reduce maintenance, product losses, cleaning effort or downtime risks in the long term.
Energy and auxiliary equipment
Energy consumption is an important TCO factor, but not the largest cost block for every mixing task. Relevant are the mixer's power consumption, the mixing time, the efficiency of the motor and gearbox, and the plant's utilisation. What is particularly meaningful is the energy per batch, per kilogram or per tonne of product under comparable process conditions.
With heated, cooled, vacuum-operated or inerted plants, auxiliary equipment can account for a considerable share of total energy demand. This includes heating and cooling systems, vacuum pumps, condensers, filters, compressed-air supply and inert gas supply. The assessment should therefore consider the entire process and not just the electrical power of the mixing drive.
Maintenance, spare parts and consumables
Ongoing costs include preventive maintenance, inspections, repairs, spare parts and external service work. Particularly relevant components, depending on the design, are shaft seals, bearings, gearboxes, mixing tools, linings, discharge elements and sensors. Their wear affects not only the direct spare-parts costs but also the plant's availability.
Recurring costs also arise from lubricants, barrier media, hydraulic oils, cleaning agents, process water, filter elements and, where applicable, inert gases. With abrasive, corrosive, toxic or high-purity products, these items can carry particular weight. Condition monitoring can help to monitor critical components more specifically and plan maintenance better. However, it does not replace regular inspection and expert assessment.
Cleaning, product changes and product losses
Cleaning and changeover are often important cost drivers with multi-product plants. Particularly in the food, pharmaceutical and fine chemical industries, dry cleaning, wet cleaning, CIP, WIP, drying, release analytics and documentation can cause considerable time and resource expenditure.
Good cleanability, geometries with minimal dead space, suitable surfaces and extensive residual discharge reduce product losses and shorten changeover times. The economic benefit is particularly high with expensive raw materials, small batches, frequent recipe changes or stringent requirements for avoiding cross-contamination.
Failure costs and plant availability
Unplanned downtime often causes high indirect costs. In addition to the repair itself, there is lost production, personnel waiting time, delivery delays, batch losses and, where applicable, rework. The scale of these costs depends on the mixer's position within the process chain. If the mixer is a bottleneck or part of a continuously operated plant, even a brief failure can have significant consequences.
Metrics such as mean time between failures and mean time to repair are helpful for the assessment. Also decisive is how quickly spare parts are available, whether service personnel can be deployed at short notice, and whether the operation has sufficient planned maintenance windows. High process reliability and reproducible mixing quality reduce the risk of scrap, rework and raw-material losses.
Personnel, training and organisation
TCO also includes costs for operation, cleaning, training, internal maintenance and external service providers. Complex plants with many manual interventions, frequent changeovers or high documentation requirements cause greater personnel effort. Automation, clear operating concepts and readily accessible components can reduce this effort.
Compliance, qualification and documentation
In regulated industries, additional costs arise for technical documentation, qualification, validation, calibration, recurring inspections and audits. Depending on the industry, requirements from GMP, ATEX, pressure equipment law, mechanical engineering, hygiene rules or customer-specific quality systems can be relevant.
Changes to control software, recipe management or data acquisition can likewise require a documented change control process. This effort should already be taken into account at the procurement stage, particularly if the plant is operated in a validated or safety-critical environment.
Modernisation, decommissioning and residual value
Modernisation can become necessary within ten years. Typical examples are control system upgrades, adaptations to new safety requirements, the replacement of components that are no longer available, conversions for new products, or automation retrofits. A modularly built and well-documented plant facilitates such adaptations.
At the end of the service life, costs arise for dismantling, decontamination, cleaning and disposal. These are offset by possible residual values from resale, reuse of components, or the material value of highly alloyed materials.
A robust TCO calculation should compare several scenarios. These include different utilisation rates, energy prices, maintenance intervals, downtime risks, product values and residual-value assumptions. The purchase price is only one item here. The economically best mixing plant is often the one that, over its entire service life, delivers high availability, low product losses, short changeover times and plannable maintenance costs.
How amixon® assesses energy efficiency, TCO and payback of an industrial mixer
The cost-effectiveness of an industrial mixer is not decided by the purchase price alone. What matters are the costs and losses over the entire planned service life. This includes investment and integration, energy, product losses, cleaning and changeover times, maintenance, spare parts, downtime risks, personnel effort, quality assurance and possible modernisation.
amixon® therefore views total cost of ownership as an interplay of process performance, plant availability and long-term usability. The focus is particularly on factors that can be influenced through design and process engineering: a product-appropriate energy input, short mixing and discharge times, extensive residual discharge, good cleanability, low wear rates and long-term spare-parts availability.
The economically best solution is not necessarily the plant with the lowest purchase price or the lowest installed motor power. What is decisive is whether the mixing plant works reproducibly over many years, limits product losses, enables short changeover times and creates plannable operating and maintenance costs.
Energy consumption matched to the mixing task
General figures for energy consumption per tonne of product are of only limited value for industrial mixers. The real energy demand depends on the recipe, batch size, fill level, mixing time, product properties, temperature, viscosity and the required energy input.
Depending on the design and mixing task, amixon® mixers operate at low circumferential speeds. The low-speed mode of operation can reduce friction, impact stress and dynamic loads. With sensitive or free-flowing powders, a large-volume product circulation can achieve the required mixing quality with a comparatively low energy input.
Here the focus is not on the lowest possible power, but on the power input appropriate to the mixing task. Too little energy can lead to insufficient homogeneity. Too much energy can damage particles, raise the product temperature and unnecessarily increase energy consumption. The mixing task should therefore be fulfilled reproducibly with the lowest technically sensible energy input.
The Gyraton® silo mixer GM is designed for large-volume batches of up to approximately 100 cubic metres. Its mixing principle enables the homogenisation of large product quantities with a comparatively low installed drive power. This means that energy demand per batch can be limited, particularly with large quantities of free-flowing bulk material. The actual power consumption is assessed with the specific product, the intended fill level and the required mixing time.
Product loss, residual discharge and changeover times
With high-value raw materials, small batches or frequent recipe changes, product losses and cleaning times are often major TCO factors. Every residual quantity in the mixer causes not only a direct loss of value. It can also extend cleaning, complicate the release of a subsequent batch and increase the risk of cross-contamination.
The amixon® AM and KS series are designed for extensive residual discharge. ComDisc® discharge tools support the removal of residual product from the mixing chamber. The discharge rate actually achievable, however, always depends on the product. Moisture, particle shape, cohesion, bulk density, abrasiveness and adhesion tendency significantly influence the residual quantity.
Extensive residual discharge can be economically relevant particularly with high-value powders, active ingredients, additives or recipes involving small batches. The specific dischargeability should be assessed with the original product as part of a trial.
Mixing chambers with minimal dead space, product-appropriate discharge elements and good accessibility of product-contact surfaces simplify dry or wet cleaning. This allows changeover times to be reduced and the plant's productively usable time to be increased. This can have a positive effect on OEE, throughput, personnel effort and overall cost-effectiveness.
Maintenance, availability and service life
amixon® mixing technology is designed for robust construction, low dynamic loads and good accessibility for inspection and cleaning. The mixing tool is supported exclusively at the top. This means a product-contacted lower shaft passage can be dispensed with. This reduces a potentially maintenance-intensive area within the mixing chamber.
The combination of low-speed operation, low-wear construction and long-term available design documentation can reduce maintenance effort and spare-parts risks. Selected wear parts can already be provided with the initial delivery. The targeted stocking of critical components helps to limit unplanned downtime.
For modernisation, conversions or spare-parts needs, amixon®'s design, manufacturing and service support the plant's long-term use. amixon®'s own control over drawings and manufacturing facilitates the identification of components as well as the assessment and, where necessary, re-manufacture of individual parts.
Robust data instead of general catalogue values
The economic assessment of a mixing plant should be based on measured process data. In the amixon® pilot plant, mixing tasks are investigated with the original product. Mixing time, power consumption, dischargeability, product protection, cleaning effort, changeover times and reproducibility can be assessed in the process.
The amixon® pilot plant at the Paderborn site has more than 30 test units in different sizes available. Additional pilot plants exist in Japan, India, Thailand, China, South Korea and the USA. The trials are carried out with realistic fill levels, batch sizes and the intended temperature and pressure conditions.
The results are documented and form a basis for selecting the size, defining process parameters and the cost-effectiveness calculation. Scale-up to the target size is carried out on the basis of the respective mixing task and, for critical processes, should be confirmed through suitable trials.
TCO as an overall process
amixon® does not assess energy efficiency in isolation as the drive's power consumption. What is decisive is the overall process comprising mixing time, energy input, product loss, residual discharge, cleaning, maintenance, spare-parts supply, plant availability and long-term usability.
An amixon® mixing plant can bring its economic advantages to bear particularly where high-value products are processed, product changes occur frequently, residual quantities are critical, or long service lives are expected. The basis for a robust TCO, ROI and payback calculation is therefore not general catalogue values, but documented trial data with the original product and realistic process conditions.