There comes a moment when a business will need to make a decision whether they should purchase their own asphalt production plant. The business is best advised to utilize the expertise of their many suppliers to help them decide on the perfect configuration and layout. The first thing to consider is which of the two different types of systems they want, batch or continuous production. What makes these two methods differ and is there one method that is better than the other?
The simple answer to that question is that there is no perfect option. For every single job requirement and for every single site there will be a completely different solution. Therefore, the choice may depend on research, careful analysis, and a consideration of all the factors. This will allow a company to make the best personal choice for their company.
Batch Type Asphalt Plant
In the world today, the most popular type of asphalt plant is a batch plant. It will provide a good level of quality and flexibility in regards to the finished product. A batch plant will depend on a specific type or production. For example, every 39 – 50 seconds an entire batch will be completed. This will be produced after all individual components have been metered and weighed separately.
A batch plant is perfect for a producer who is working with several clients all at once. A batch plant will allow the producer to easily change any specifications while at the same time maintaining a very high level of quality.
Continuous Drum Type Asphalt Plant
With a continuous plant there will be no interruption to the asphalt production cycle as the production is not broken down into batches. All of the mixing of materials will take place inside of the elongated dryer drum. It mixes and dries the material at the same time.
Since a continuous plant has no elevators or mixing tower, it will therefore be considerably simplified which will result in a reduced cost of maintenance. However, because there are no screens in a continuous mix plant it will require precise controls at the start of the production cycle. This will need to happen prior to the aggregates being fed into the dryer and prior to them being discharged from the dryer.
When it comes to bitumen metering a batch asphalt plant has the bitumen metered by weight through a load cell that is located in the weigh hopper. A computer system will ensure that the perfect amount is fed into the mixer. This amount will be calculated by the actual weight of the aggregates and their specifications. In a continuous plant metering is normally volumetric.
A batch plant has double paddles and arms. It therefore often does a better than a continuous plant. This is a very important feature when dealing with any special products such as high RAP content, porous asphalt, or splittmastik. The asphalt mixing time can be varied. It can be shortened or lengthened depending on the mixing quality. On the other hand, a continuous plant has constant mixing action.
The final decision will obviously be left to the owner of the plant but in general a batch plant is used where a client needs flexibility, special formulas, or if they work with various clients. A continuous plant, on the other hand, provides continual production and low operational costs.