You know once you have decided to buy that asphalt plant, it will be a tough call. The reasons and parameters to configure the exact required machine can be tough. It can be confusing task deciding the storage tanks, the feeder bins and also the kind of controls required. Sometimes the difference between a portable and a static asphalt mix plant can be confusing. In this blog, we will try and help you with the asphalt plant purchasing process.
Once you have decided to have your own asphalt plant you are now going to make important decisions. The decisions will be related to the size of the machine, the type of the asphalt plant the budget and also the brand to select. Once these decision are taken then we decide on the plant configuration like number of bins, number of tanks, type of pollution control, storage silo, etc.
There are two basic types of asphalt plants:
• Drum mix plant (continuous plant)
• Batch mix plant (tower plant)
Batch Mix Plant
Batch mix plant makes hot mix asphalt in batches. Aggregates are fed into the cold feed bins from where they are taken to the drum for drying and heating. After this they will be taken atop the tower unit via a bucket elevator. On the tower unit they will be separated and stored temporarily into different hot bins. At the same time bitumen and filler material will be transferred to its separate weighing units on top of the tower unit.
Now as per the required proportion, these aggregates will be introduced into a pug mill unit. This process will be followed by addition of bitumen and filler material into the pug mill mixer unit. At the end of the mixing cycle the material will be discharged into the waiting trucks or storage silo.
Key advantages of batch mix plant
The key strength of a batch mix plant lies in the fact that it can make quality hot mix asphalt in any mix design. The end product is quality hot mix asphalt with a high grade of accuracy. It is also possible to add numerous mix material designs and operate with the plant with different mix designs. The components being modular it is possible to add or retrofit components as and when required. This adds to the capability of the batch mixer.
Disadvantages of the batch mix plant
A batch plant spends a lot of time in weighing and transferring the materials. A lot of its energy is spent in this process, and it makes the batch plant require more energy to produce hot mix asphalt. Since the number of steps employed are more, the energy spent is also more. Also the batch plant will require more space and high initial cost for set up.
Drum Mix Plant
A drum mix plant is a very basic type of asphalt plant. It uses a simple technique to make hot mix asphalt. It is a simple and continuous facility to produce HMA continuously. The starting process starts with material feeding into the cold feed bins. From there the aggregates are proportionately taken to the drum for heating as well as mixing process. Inside the drum heating and mixing is done in a single unit. Before the aggregates enter the drum they are weighed collectively and then this weight is sent to the control panel to synchronize the flow of bitumen and filler material.
In the first half of the drum heating is done and mixing is done in the later part of the drum. After thorough mixing with bitumen and filler material, the material will be discharged out into the storage silos or into waiting trucks.
The continuous drum mix plants can be parallelflow type or counterflow type. Parallelflow type means the material flow and burner flame are in the same direction. Counterflow means that the material flow and the burner flame are in the opposite direction.
Key Advantages Of Drum Mix Plant
They key advantage of drum mix plant is that it uses a very simple yet basic process to product hot mix asphalt. By eliminating many processes, a drum mix plant uses less energy to produce hot mix asphalt. Its initial cost of investment is also less and energy required to operate is also less. The maintenance cost is less compared to its batch counterpart. Whereas the overall cost of running and maintenance is relatively less compared to a batch asphalt plant.
If a portable plant is required, a drum plant will be much better as it will employ less number of components. A drum plant will also use less number of components, and hence the cost of transportation will be less.
Disadvantages of Drum Mix Plant
Less accuracy of end product is the key weakness of the drum mix plant. A bag filter type pollution control device cannot be used with a drum mixer. The multiple customization options available in a batch plant may not be available with a drum mix plant.
Style of Asphalt Plants
There are two basic styles of asphalt plants, portable and stationary type. The decision to opt between the two is simple. If the plant needs to move often then a portable asphalt plant is preferred choice otherwise a stationary plant is preferred.
If we compare specifications to specifications, then a portable asphalt plant will be costlier compared to a stationary asphalt plant. If the plant needs to be moved few times in a year, then a mobile type of asphalt plant will be useful. If the shifting of the plant is required to be done once in a few years, then a mobile or portable plant will not be good as the cost of portability will be higher.
In such cases, a plant with skid mounted design will be much better. Atlas also manufactures and supplies skid mounted plants with pre-wired components and easy for installation.
Size And Components of Asphalt Plant
It is very important to analyze the requirement for the asphalt plant and then decide the capacity. It is also imperative to note that a very high capacity plant will not be encouraged. A plant should be reasonable and medium-sized with focus on the inclusion of the critical components.
The plant should not be very small with smaller sized components – this will make things difficult to upgrade in the future. If the plant is medium-sized check if it is possible to upgrade the plant’s capacity by changing few components.
A plant is ideal if it is running at 80% of its capacity and this will make sure that components will perform better and things will last longer. However, you can also opt for a medium sized plant with a storage silo to ramp up the production in advance.
Importance of Proper Component Configuration of Asphalt Plant
Proper and correct component configuration is very important for selection of an asphalt plant. The selection of correct configuration and set of components is critical for the success. Some of the main components that matter are:
• Cold aggregate feeder bins: The configuration of feeder bins is important. It all depends on the number of aggregates that need to be used, and this has to affect the configuration of the bins.
• Size of the bitumen tanks: Bitumen tanks have to be of adequate size. You don’t want to plant for bigger volumes of asphalt without having a good stock of bitumen with you. It is important to have a decent amount of the bitumen storage tank, so that production can go on without any issues.
• Burner configuration: This is very important because in some places different fuel options like natural gas, coal, etc are available as plenty. If the customer is well aware and selected a burner accordingly, he can save a lot of money in the long run.
• Hot mix asphalt storage: The storage of the hot mix asphalt has to be of adequate capacity. If the trucks are less in number the plant should not wait for the next truck. This will ensure continuous production for the plant. The silo can be a very handy tool when continuous production needs to be achieved.
If you are looking for long term solutions, do not hesitate to contact us. We are ready to serve you with customized solutions.
