Metering equipment and metering systems are now an integral part of industrial technology and have played a prominent role in scientific and technological progress. The application of dosing technology is constantly increasing, because the introduction of flow technologies has an enormous potential on the development of modern production. Metering technology also offers promising opportunities for optimization of production processes, in which automatic and targeted distribution of metering quantities of various components is carried out. Today, dosing quantities of different aggregate states and forms (gases, liquids, suspensions, pastes, powders, granulates, etc.) with an infinite number of physical and chemical properties and in a very wide dosing spectrum are moved through dosing systems.
What is a dosing system?
According to the relevant technical literature and normative standards, a dosing device or also a doser is referred to as a device intended for dosing and with the help of which a dosing of a certain amount of material can be performed. This device can ensure a proportional and quantity-controlled supply of the dosing quantity at any time, depending on the production requirements or the conditions under which these devices are operated.
What synonyms are often used?
In connection with dosing plants, systems and dosing units, the term dosing technology or equipment is often used. This is a collective term for technologically advanced metering systems that are subject to continuous further development for the conveying, removal, mixing or withdrawal of different meterable (solid, liquid and gaseous) media or products. In addition to conveyor belts, metering pumps are particularly widespread in metering technology and are used in numerous branches of industry, such as the pharmaceutical, medical, laboratory technology and electronics industries.
How does a dosing system work?
A modern feeder consists not only of measuring devices, as in the case of discrete portion scales, but also of devices that serve to feed the product. The feeder takes over the task of preparing a certain material or volume at a certain time in a defined quantity or a defined mixing ratio. The dosing technology used in the device ensures appropriate dosing of the product medium.
The medium to be dosed is fed to the dosing element by means of the piping system. The metering element is able to regulate the metering process precisely and, if necessary, to stop it. Dosing devices are usually composed of a number of technical components – belt, drum, disc, screw and diaphragm pumps. Feeders come in a variety of technical designs such as screw feed systems and rotary valves.
Dosing equipment also includes dosing pumps of various types (piston, gear and diaphragm pumps), stations and dosing systems, as well as water treatment plants. Complex installations of dosing equipment include all kinds of additional devices: pH sensors and controllers, chlorine sensors, RedOx sensors, containers and tanks for the production of solutions and their subsequent reception by pumps for dosing in piping systems.
What are the different types of dosing systems?
The dosing systems are divided into two main groups – volumetric and gravimetric dosing units. Volumetric dosing units are mainly used for dosing gases, liquids, pastes and less frequently solids. Weighing machines are used for solids and liquids. Another distinguishing feature of dosing units is their discrete and continuous operation.
Gravimetric dosing systems
Gravimetric dosing systems are used for dosing bulk materials, less frequently for liquids. The working ranges are large enough and the dosing ranges from a few grams to hundreds of kilograms. And the output capacity ranges from hundreds of kilograms to several hundred tons per hour. They can be used in conjunction with scales for weighing bulk materials. Scales are usually characterized by a large dosing range and high dosing accuracy. At the same time, however, they have a more complex design and lower productivity than volumetric feeders.
Volumetric dosing systems
Volumetric feeders are used for dosing pastes, liquids, gases, bulk materials. The metering range is from a few cubic centimeters to thousands of cubic meters. Such devices work with an error tolerance of 0.5 – 20% and have a dosing capacity from cubic centimeters to several thousand cubic meters per hour. Metering devices of the indicated types have a high degree of reliability and a relatively simple structure. The advantages of volumetric devices are the simple design and reliability. The disadvantages include a strong influence of external pressure and temperature on the dosing volume and increased susceptibility to errors when working with foaming and gaseous products.
Automated dosing systems
The widespread adoption of continuous technologies and the development of automation tools have enabled continuous automatic dosing with weight and volume dosing systems.
In fact, when there is a need to supply aggressive, toxic and hazardous substances, fully automated dosing stations are often the only and best option. Automation makes it possible to simplify the dosing process of substances, minimize the operator’s risk and possible negative influences, as well as increase the accuracy of the dosing process.
Modern fully automatic dosing systems perform a dosing task autonomously and without operator support. If required, such systems can be remotely controlled and reconfigured by the personnel with computer support. From an output rate of approx. 500 to 600 pieces per hour, it is recommended to switch to a fully automatic dosing system, regardless of the dosing containers. Automated metering is particularly important for precise and low fill levels.
Semi-automatic dosing system
With the help of semi-automatic dosing systems, packaging or dosing processes can be carried out more easily and efficiently. Such equipment is suitable for liquid products as well as for all packaging materials that need to be precisely dosed. Thanks to semi-automatic operation, machine operators benefit from a reduced workload.
Manual dosing system
The manual dosing machine has the finest mechanical dosing devices, which provide accurate to precise dosing. If high dosing capacity is required, a lot of work and force must be applied when operating such machine.
In which industries are the dosing systems used?
Today, dosing systems are an integral part of the dosing of substances of any kind and are used in many branches of industry. The use of dosing systems is widespread in the production of food and beverages. And they are also required without exception for all products to be packaged, such as vitamins, stabilizers and flavors. In addition, dosing systems are actively used in the chemical, cosmetic and pharmaceutical industries for the production of a wide variety of goods.
