Physical properties of emulsified asphalt
Emulsified asphalt is a mixture of two immiscible substances - asphalt and water. Its main characteristics are its storage stability, stability during mixing, surface treatment, viscosity characteristics and curing speed. Many of these properties are affected by particle size and particle distribution in the emulsion. This change will change with the type of asphalt, the equipment used in the production of graded emulsion and the application stability of chemical reagents.
Viking Gear pump Common problems in the application of emulsified asphalt
If it works for a long time or the shutdown time is too long, it will show the separation of water and asphalt (demulsification phenomenon), and asphalt will accumulate in the packing chamber of the pump shaft to bond the pump shaft, which makes it impossible to start the work, and the whole equipment cannot work, so it needs to be disassembled for cleaning. It consumes a lot of manpower and material resources.
If it works at high speed for a long time, the rotor, idler gear and shaft will be worn, which will seriously affect the life and increase the maintenance cost.
Because of the particularity of asphalt application, the wear of flow passage components in the pump chamber will cause instability of flow and pressure, and the application with metering requirements will constitute shutdown for maintenance.
Main reasons for these problems
Because emulsified asphalt is a mixture of two immiscible substances - asphalt and water, its composition and chemical characteristics are very complex. If there is no special plan and speed limit for the gear pump, the main reasons are as follows:
If the pump speed is too high, the high shear force of the gear pump will cause certain separation of water and asphalt, which will lead to demulsification. Generally, large pumps are required to run at reduced speed.
Because the structural planning of the pump is simple, the emulsified asphalt does not form an internal circulation in the gear pump, so that the emulsified asphalt accumulates in the bearing and filler cavity. With the addition of running time and the shutdown of the construction period, the demulsification constitutes a jamming machine.
Main advantages of internal gear pump in asphalt application
Internal gear pump is the main pump type in asphalt production, asphalt storage tank and asphalt pavement machinery industry. The maximum flow of internal gear pump can reach 360m ³/h, with stable flow, accurate measurement, small pulse, compact structure and simple maintenance. There are many kinds of seals that can be selected, such as traditional packing, Viking O-Pro series shaft seal without leakage, etc. There are also many choices of external raw materials and internal parts raw materials, such as cast iron, ductile iron, carbon steel, etc., which greatly meet the customer's requirements for the use of different asphalt. The selection of jacket varieties is also diversified. For example, the thermal insulation jacket can be heated with heat transfer oil, and the electric heating method of the pump body can also be used for heating and insulation. When the pump is used for a period of time, if the flow drops, there is no need to replace the worn parts immediately. The method of adjusting the internal clearance of the gear from the outside can maximize the life of the parts and greatly save costs for users.
Solution of Viking Pump in Application of Emulsified Asphalt
VIKING gear pump It has been used in the asphalt industry for decades, so we have appropriate experience in the application of emulsified asphalt. In view of the characteristics of emulsified asphalt, we have strict regulations on the internal structure improvement planning and speed requirements of the gear pump, so as to ensure that when delivering emulsified asphalt, there will be no emulsion breaking phenomenon, which will cause shutdown.
characteristic:
As far as possible, use large pumps to run at reduced speed to reduce shear force and demulsification.
Strengthen the circulation of emulsified asphalt in the pump, and try to avoid the accumulation of dead corners.
Improved planning has been made in the packing chamber to add smoothness, reduce leakage and frequently replace packing.
A general sealing plan has been made for the packing chamber, and Viking's latest O-Pro technology can be selected to achieve zero leakage.
After special planning, the sealing chamber is actively emptied.
Add gaps in flow passage parts to reduce shear stress.
The specially planned idler gear structure further adds the smoothness of idler gear bushing and idler gear pin, making its service life significantly increased.
A variety of rotor, idler gear and shaft sleeve materials can be selected, making it more suitable for the application of special asphalt.
