In this article, we take a closer look at the features of a continuous scale. Whether grain, coffee, plastic granules or other bulk materials, as soon as you want to load, dose or mix them, it is essential to record the weight. Of course, you could fill the bulk goods into containers and then weigh them, but is this really efficient and time-saving? You have probably asked yourself this question many times and answered it yourself. So what better, more efficient and precise way is there to measure bulk goods quickly?
Continuous scales as a solution
The answer from our side is quite clear: you are looking for a continuous scale from Hense Wägetechnik. You are probably more familiar with an impact plate scale. However, as this only measures the impact impulse of the products and is therefore heavily dependent on the properties of the product, we recommend a continuous scale in the form of our FlowSlide measuring system. A continuous scale is suitable for virtually any flowable bulk material. However, the products that flow through the continuous weigher must have a non-caking property. If caking bulk materials are nevertheless passed through a continuous weigher, they falsify the measurement result, obstruct the channel and thus reduce the throughput. The advantages of a continuous weigher can be seen very quickly. They can also be easily integrated into existing systems. Due to its relatively small size, you are guaranteed to find a place to mount the continuous scale. Our system is also available in baby, normal and maxi sizes. The function of such a scale is just as quick and easy to explain as the operation of the scale itself. The bulk material flows from a vertical downpipe directly into the continuous weigher and hits a specially shaped chute. While the product to be measured flows over the curved chute, the bulk material itself generates a certain centrifugal force which acts on the chute. The mass of the bulk material can be determined via a calibratable load cell based on this throughput measurement. A change in bulk density or grain size is easily compensated for by this measurement technology and has virtually no effect on the measurement accuracy. This is possible because the friction of the bulk material along the measuring chute cancels each other out. The calculation is performed by an electronic evaluation system. The measuring range of such a system is between 30 kilograms per hour and 300 tons per hour. This means that both particularly light and very heavy bulk materials can be weighed.
FlowSlide - our continuous scale
Together with Hense Wägetechnik, you can start planning the integration of a continuous scale immediately. We will be happy to support you. Through an intensive and individual consultation, we will find the right measuring system together and at the same time inform you about all costs, advantages and disadvantages. This will enable you to quickly assess our system. Once you have decided on one of our systems, we will immediately start planning and preparing a quotation. If we do not have the required continuous weigher in stock, our production department with its high-precision 5-axis machine will ensure that your order is completed quickly. Optional extras such as various additional connections, WLAN or dosing contacts can also be integrated. Our technical team then carries out the direct installation in your system. The display unit can of course be integrated into a control panel as required, but wall mounting is also possible. Good planning is crucial to ensure that your system only has to interrupt work for a short time. But we are also as flexible as possible when it comes to installation times and adapt to your wishes. Once the system has been successfully installed, it is immediately put into operation by our specialists and checked for correct operation. If required, we will carry out a further calibration and possibly also a verification. This is followed by training on how to operate the display panel and control the continuous scale.
Installation of the FlowSlide continuous scale
We explain in a video what needs to be considered when commissioning a FlowSlide:
Practical examples of a continuous scale
Dosing of coffee blends
One project that we were able to implement thanks to our smallest continuous scale, the Baby FlowSlide, is the dosing of coffee beans for a test roasting plant. In order to carry out these measurements, we were looking for a particularly compact measuring system with a low output of 20 to 100 kilograms per hour. Our Baby FlowSlide impressed with its precision, maintenance-free operation and particularly compact design. The functionality was tested by our customer in numerous preliminary trials. As cocoa beans are an abrasive product, a special Hardox material was used for the slide. This should further minimize wear. Thanks to the Baby FlowSlide system, our customer can now weigh coffee beans even more accurately and thus generate new types of coffee.
Loading crystalline citric acid
This customer wanted to use our FlowSlide system to speed up the truck loading of crystalline citric acid and make it safer. As the granules flowed unevenly, the final result was falsified. The results were checked using a truck scale. The amount of work involved in under- or overloading trucks was enormous. Thanks to our Flow Slide continuous scale, we were able to reduce the tolerances enormously despite the critical inlet conditions. This means that truck drivers can now save themselves a trip to the truck scales. This also saves a lot of working time, because reloading or blowing back the granulate takes time and causes considerable additional work. As citric acid tends to form deposits in the downpipes, an automatic cleaning system has also been included. Air nozzles ensure that the measuring chute is cleaned. During this cleaning process, the measured value is frozen for approximately three seconds. This enabled us to achieve a tolerance of 0.5 percent.
Continuous measurement of glass wool
For the production of ceiling tiles, glass wool, water and other additives must first be mixed. The correct and consistent mixing ratio is of great importance here. As glass wool has a particularly low bulk density and an irregular surface structure, it quickly became clear that conventional weighing systems would soon reach their limits. For example, a conventional belt weigher. This could not be used because the load was too low. We initially carried out a number of feasibility tests with our FlowSlide system together with the customer. We were able to convince the customer with our measuring accuracy and flowability. Only the throughput rate of 80 cubic meters per hour could not be achieved with this system. However, at 300 cubic meters per hour, our Maxi FlowSlide measuring system was quickly able to provide a remedy.
Intermediate conclusion
- A continuous scale is suitable for all bulk materials that have good flowability and cannot cake.
- An illuminated color graphic display serves as a display, and settings can be made via a membrane keypad.
- Our continuous weigher is virtually maintenance-free as there are no moving parts. Only parts that come into direct contact with a bulk material and are subject to heavy use may need to be replaced.
- All FlowSlide systems are pre-calibrated at the factory, can be recalibrated on site and can also be calibrated.
- Only high-quality materials such as stainless steel or Hardox 450 are used.
- Very precise, system accuracy (after on-site calibration) of +/- 0.5 %. This is possible because our evaluation electronics carry out a measurement 250 to 500 times per second.
- Excellent reproducibility +/- 0.1 %
- Measuring range from 200 kg/h to over 500 t/h
- Particle size range from 0 to 80 mm and bulk density from 40 to 7,000 kg/m³
- Dust-tight and resistant to permanent immersion thanks to protection class IP68.
The ultimate practical test
The measuring accuracy of weighing systems (belt scales, continuous scales, etc.) is an important component in every production process and should therefore be urgently scrutinized in every industry. As a production manager, you have certainly noticed these problems on several occasions: Inaccurate weight measurements, losses due to dust formation or gross deviations between target and actual values for quantities and weights of your products. As the manager and head of a company, you are certainly interested in making savings. You would like to have better control over the accuracy of quantities. Nowadays, innovations and new technical and electronic developments are a blessing for the vast majority of companies, as enormous progress has been made in the field of measurement technology in particular. Where in the past only conventional scales could weigh and measure a product at a standstill, nowadays ultra-modern devices are in use that deliver very precise results during ongoing production. To your advantage. The daily problems of measuring technology are in the details, because every product requires its own individual measuring system. For example, it no longer makes sense to install a large scale on which everything is weighed beforehand, especially as many productions are much more complex and products are very different. Ongoing processes have to be monitored, additives added and product lines can change. Perhaps you have been working with weigh-belt feeders or similar systems up to now. But the deviations are still too large and inaccurate for you? Do you need better control? Do you want up-to-date results? The solutions we offer you are straight to the point. Although each individual task poses a new challenge, we calculate the optimum method for you. To give you a better understanding of our FlowSide System from Hense, we will give you some examples of flow scales in practice. These are successfully implemented projects that have been realized with the help of our know-how and have contributed to clearly visible success in the respective companies.
Realized examples with the Hense FlowSide continuous scale
Example 1: Bulk flow dosing
About 300 tons of coal are conveyed by conveyor belt in a plant, to which a certain amount of limestone powder must be added. The dosage depends on the condition of the coal and is between 1000 - 8000 kg / h. The deviation in accuracy should be a maximum of 1 percent. Our solution: The built-in belt weigher measures the main flow of coal. Our Hense FlowSide continuous scale, which you have previously attached to the silo, measures and doses the limestone powder. The Hense FlowSide measuring device is thus able to regulate the limestone silo's screw conveyor in proportion to the flow rate. It is mounted maintenance-free directly on the silo frame and guarantees a measuring accuracy of 1% at the factory, with fine adjustment on site even as low as 0.3%. With additional air pressure, you can prevent deposits on the measuring chute in the Hense FlowSide. Problem solved.
Example 2: The Hense FlowSide replaces weigh belt feeders
At the Pfanni plant in Stavenhagen, a reliable throughput measurement system was needed to measure mashed potatoes and "troka". Previously, this was done by weighfeeders in a compact design. The low bulk density of only 0.2 kg - 0.3 kg/l and a high dust content of the product generated an enormous maintenance effort and an enormous deviation of up to 20 % (!). Our solution: We installed maintenance-free Hense FlowSide bulk flow measuring systems instead of the weighfeeders. The measuring accuracy is again 0.3 % and there are no moving wearing parts. Powdery products are also periodically removed from the measuring chute by additional air nozzles. The measuring range of the FlowSide is between 1 - 80 m³/h. Changes in particle size and bulk density have hardly any influence on the measuring accuracy. The production line can therefore change the product without any concerns. Problem solved again.
Example 3: Starch products from the potato
Over 20 starch products were to be recorded and checked using the measuring system in a production facility in Holland. Once again, the continuous weigher and bulk flow meter replaced the weighfeeder. In addition, an additive was to be added in controlled doses. Our solution: We installed the maintenance-free FlowSide FS10 bulk flow system instead of the weigh-belt feeder. A test phase of 4 months was to convince the customer of the measuring accuracy. The customer weighed and tested more than 25 products during this time. Result: The customer took over the new Hense bulk flow system and ordered another Hense continuous weigher elsewhere. Problem solved with flying colors!
Little effort - great effect
As you can see from the examples, our work is individual and solution-oriented. We work with you and your product to find the best possible solution. Deviations of any kind lead to problems and ultimately to losses. You can solve these in a short time with our continuous scales. The effort and installation costs are relatively low and pay for themselves in no time at all.
What does your problem look like?
You are probably familiar with the following: You have flowing bulk materials and want to measure them as continuously as possible. You probably have mixers, feeders or you want to reliably load silos or silo vehicles with certain quantities. You want high measuring accuracy and little or no maintenance. In addition, the measurements should be independent of the products so that the products can also be changed on the key production lines. Are we about right?
Our solution
The continuous scale and Hense FlowSide measuring system is the perfect solution for all flowing or bulk goods and products. Thanks to a measuring chute, the measuring device calculates the throughput in free fall. The centrifugal force generated here is proportional to the mass and can be converted directly and shown on the display. The measured value is between 30 kg/h and around 300 t/h. This should also cover your measuring task. For smaller throughputs, we offer the Baby-FlowSide, which works with values between 10 - 5000 l/h and successfully measures even bulk solids with a low density or grain size. In any case, talk to our experts who will be happy to help you.
How does the FlowSlide system from Hense work?
Your product falls through a funnel into a circular measuring chute. There it generates the centripetal force, which is proportional to the throughput rate. Due to the special force application, the frictional forces along the measuring chute cancel each other out. The measurement is therefore independent of the particle size, bulk density and elasticity of your product. In other words, the FlowSide measuring device "in free fall" can measure almost any bulk material and many similar products reliably and accurately. To name just a very few examples that the flow scale measures without any problems: rice, peas, raisins, wheat, plastic granulate, herbs or cement. In reality, the list is very, very long and productive. Talk to us about your products. The electronic measuring device evaluates the data from the free fall onto the measuring chute in real time and can immediately show the current quantities on the display.
electronic for flowmeters for measuring mass flow rate and total mass
Although factory adjustment is possible, fine adjustment should always be carried out on site so that the measurement results are even more accurate. Thanks to their small dimensions, the Hense continuous weigher and the FlowSide measuring device can be installed quickly and as required in most places, for example under a silo, in free-fall pipes or at dumping points. So you don't have to worry about long production stops or planning a complete conversion. No. On the contrary: the conversion is quick and gives you even more control over your products or batches and therefore important savings. For the technicians among you, here are a few important facts about the function and design: The grain size range is 0 - 60 mm and a bulk density between 0.04 - 7.0 kg/l. The throughput capacity is between 200 kg/h and around 750 t/h. (The device works according to the formula F= m x v² / r) The integrated sensor C3 - 3000 parts works with a supply voltage of 5-15 VDC (via electronics) and has the high protection factor IP 68 (IP68 = complete protection against contact, protection against ingress of dust/protected against ingress of water when immersed for an indefinite period of time) Note the high system accuracy, which is +/- 0.5 %; and the reproducibility with a value of +/- 0.1 %. The materials in contact with the product are made of stainless steel or Hardox 450, the housing is made of high-quality aluminum - stainless steel or plastic is optional. This means that food and many other products can be measured without any problems. The different products have only a minor influence on the result. The height of the Hense Baby FlowSlide = 395 mm, the FlowSlide = 700 mm, the Maxi FlowSlide =1,050 mm and the Ultra FlowSlide = 1,395 mm. The measuring ranges are divided as follows: 1 / 5 / 25 / 50 / 80 / 150 / 300 / 500 / 650 m³/h. The Hense Baby-FlowSide version measures between 100-5000 l/h. This means that almost any task can be mastered. Individual solutions can be realized for you in any case.
Benefit from the intelligent electronics
The measuring device supplied with the FlowSide has an illuminated, color display that allows you to easily and directly read off quantities in kg/h, kg/t absolute and the "trend". It can cope with the most common voltages between 110V - 240V (AC) as well as with a control voltage between 12V -30V (DC) and is therefore ready for immediate use anywhere. Interfaces to RS 232 or RS 485 and the Profibus, Modbus TCP and Profinet make monitoring to a computer and other control units relatively easy. WLAN is integrated and counter pulses can be made available at the outputs. To put it simply: the FlowSide continuous scale measuring device fits easily into any control and monitoring environment and you can have it up and running in a very short time. Links to other units, other output controls or control systems are possible. This allows you to construct an all-round monitoring system that can be displayed on the device or on any monitor at any time.
Monitor your measurements and calculate in real time
Thanks to the many interfaces on the Hense FlowSide measuring device, you are able to call up the current situation and absolute quantity data directly. This data can then be processed immediately on a PC, cell phone or other display device. Work with exact quantities in real time and have a direct overview of your costs. The small deviations make it possible to work precisely and accurately with quantities of bulk goods; the smallest deviations can be observed and ultimately included in your invoice. So you end up with 100% correct quantities, isn't that a word?
How does the fine adjustment of the free-fall scale work?
This is the work of our experts. They know exactly what data to feed into the measuring devices and how to fine-tune the free-fall scale so that you can weigh your products as accurately as possible in free fall. Ultimately, it is a formula from the centripetal force to the mass of the product. But leave this to the Hense employees. They have many years of experience and will help you to find the right system. Are you in?
Why you should switch to Hense FlowSide catchweighers
Here is an overview of the basic advantages of your Hense continuous scale:
- The measurement is almost independent of the grain size and density
- Excellent reproducibility and accuracy (+/- 0.1 % and +/- 0.5 %)
- Capacity: between 200 kg/h and approx. 750 t/h
- Factory pre-calibration possible
- Low maintenance requirements
- Quick and uncomplicated installation
- Stainless steel housing
- Food-safe
- Optional bus types: RS 232 / RS 485 / Profibus / Profinet / Modbus TCP / WLAN / dosing contacts
- wide range of operating voltage (110V-240V AC or 12V-30V DC)
- Input: full bridge strain gauge / inputs for tare & dosing start, etc.
- Outputs: bus interfaces / counter pulse / 4-20mA / cleaning / zeroing
- Operating temperature: -20°C - 80°C (option for higher temperatures)
- Wall mounting or panel mounting possible
- High protection of the devices (IP 67 FlowSide scale / IP 68 measuring device) against dirt, dust and water
Conclusion
Bulk materials are difficult to measure conventionally due to their different properties and densities. Further problems arise with regard to accurate measurement in the flow-through process. Thanks to the FlowSide continuous scale from Hense and its measuring chute, you can weigh your products in free fall. With the Hense continuous scale, you can measure and weigh almost all bulk materials and similar products with a very high degree of accuracy and display them in real time. The small dimensions and quick installation bring a big plus to your monitoring environment. No major production stops or conversion measures are required. The sophisticated interfaces make it possible to connect to existing bus systems, WLAN or directly to a computer. The output of control pulses on the Hense FlowSide measuring device can directly control other units, for example screws, filling systems and much more. You can track all data on your computer if you wish. Benefit from the exact measuring accuracy and say goodbye to inaccurate weigh belt feeders or similar systems. Install Hense continuous weighers and experience a completely new way of monitoring production with exact measurements.
Find out more about the functionality of our system in this external article.
