Management of the characteristics of the process of pumping fluid in modern pumps is provided in manual and automatic modes. Depending on the requirements for operation, it may be necessary to take into account certain parameters. For example, the user can adjust the delivery volumes and intensity of the function. At the same time, there are separate types of equipment specially designed for point maintenance of certain environments. These include dosing pumps used in the food, pharmaceutical and chemical industries.
Features of the dosing pump
Dosing units provide the possibility of volumetric pressure pumping of liquids, suspensions and emulsions. At the same time, most of these pumps can serve both neutral and aggressive media. For this reason, their use is common in the chemical industry. Depending on the characteristics of the material used in the flow path, the specific purpose of the equipment is also determined. The main difference from traditional household units is that dosing pumps allow you to adjust the pressure level from the point of exit to the inlet of the working medium. In this case, the absolute value of the inlet pressure exceedsthe equivalent of the saturated vapor of the pumped liquid. Among the main technical and operational characteristics of such equipment is the ability to work with media of a certain kinematic viscosity and the diameter of the nozzle passage.
Hose Metering Pumps
This kind of metering pump is designed to work with liquids and pasty substances. The principle of operation is based on the mechanical action on the working channel, which is most often represented by a strong but flexible tube. That is, in the process of work, mechanical pressure is exerted on the hose with the medium, as a result of which the liquid is pushed out to the outlet. Rollers rolling along a circle are used as a physical activator. By design, dosing pumps of this type are a device that includes flexible pipes and a hose with a set of rollers. Also, the infrastructure part is provided by the track into which the tube line is laid. It is in it that the physical impact occurs.
Membrane units
This is a volumetric pump, in which the function of the working body is performed by a flexible plate fixed at the edges of the structure. To a certain extent, it also acts as a piston. The membrane bends during operation, which leads to a displacement of the liquid. In this case, the force effect can be different. For example, it is practiced to use mechanical drives, hydraulics and pneumatic devices that deform the plateby changing the pressure in the working cavity. Due to the absence of gearboxes and motors, dosing pumps are considered the safest and most reliable. This is especially important in the maintenance of flammable liquids, since the function of the unit has no preconditions for the formation of a spark.
Plunger Models
This is a kind of reciprocating hydraulic machines. The valve distribution system does not allow the use of such units for reverse action, which distinguishes them from other volumetric devices. The reverse movement of the piston on the pipeline causes the valve to close, which prevents the medium from leaking into the channel. At the same time, the valve on the discharge side opens and the liquid flows through it to the receiving point. During operation, the dosing plunger pump provides an uneven fluid flow rate, which causes its main drawback. The spasmodic effect is compensated in various ways, including by introducing several piston elements into the design.
Marking units
If, according to the design, the units are made in accordance with the requirements for a specific form factor, then in terms of functional content and mechanism controls, manufacturers develop common standards. Thus, the LP dosing pump provides for manual control of the transfer of liquid from the moment the unit stops. If the system is provided with the possibility of automatic and remote control, then the equipmentNDE designation is assigned.
Also, manufacturers indicate the dosing index, which averages 1-2.5. There are also devices that do not have this indicator at all. As a rule, models with an initial index do not have a heating jacket, and the highest level of dosing accuracy is characterized by the presence in the design of a supply for a barrier or flushing fluid. This classification also applies to all types of units. For example, an LP dosing plunger pump may have both the first accuracy index and the second.
Manufacturer Reviews
Dosing models in the families of pumping equipment occupy a separate niche due to the specifics of their application. This is not a household segment, therefore, such units are not widely used by the manufacturers themselves. Development in this direction is carried out by large specialized companies, including Etatron and Grundfos. In the assortment of the first manufacturer, the eOne Basic modification gained popularity. This is a membrane unit, whose users note the presence of a well-thought-out intelligent control system with the possibility of high-precision power regulation. Grundfos dosing pumps, and in particular diaphragm representatives of the DME series, are no less worthy. The owners of such equipment emphasize the reliability, successful execution of ball-type valves, as well as the function of an electronic unit that allows you to adjust the dosing accuracy.
Conclusion
The segment of dosing pumping equipment can be classified as industrial, since such devices are more often used in enterprises, service organizations, etc. This also explains the high requirements for the execution of the structural part. Reliability, safety and stability are the main qualities that modern dosing systems must have. Pumps of this type operate in intensive operation, so manufacturers tend to increase the resource of the element base. Among the negative factors, not only the ordinary wear of mechanical parts is distinguished. For example, membrane aggregates have practically no rubbing components. But the flow part in contact with aggressive media must be protected from chemical attack.
