Hot-Mix Asphalt Plant | Lintec & Linnhoff

1. Hot Hot- -Mix Asphalt Plant Mix Asphalt Plant Asphalt also known as hot mix asphalt is a dark bituminous mixture of sand or gravel and aggregates developed for the purpose of road surfacing applications and various other uses. Creating the perfect consistency to fulfil a specific task is a complex process. Most bitumen hot mix plants have a modern modular design and layout resulting in efficient installation and disassembly on sites. This type of bitumen mixing plant consists of several essential components that make up the whole process in manufacturing high quality

2. bitumen. They include a cold aggregate batching machine, dryer drum, burner, bucket elevator, mixing tower, bitumen tanks, fuel tank, mineral filler, automated control room etc. Bitumen Hot Mix Plant Bitumen Hot Mix Plant The cold aggregate batching units are responsible for storing, batching and feeding aggregate into the drying system. Dryer drum is used for removing the moisture from cold aggregate. Bag fillers are used to remove fine dust particles, which can reduce air pollution levels in the work environment and reduce the stress on greenhouse gas effects. Bucket elevator functions as a transferring system for hot aggregate to reach to the top of a mixing tower. The mixing tower is composed of hot aggregate storage bins, vibrating screen, aggregate, bitumen, filler and hot mix weighing units etc. Fuel tanks are also another essential component in this process, used to store the important fuel for purpose of fuelling the burners. Then there are the mineral fillers which add mineral or additives to the mixer. The automated control rooms are for the operator or engineers to operate the bitumen mixing plant through control panel, in a safe and comfortable environment. Bitumen Mixing Plant Process Bitumen Mixing Plant Process The bitumen batch mix plant process begins when the aggregate is placed in an appropriate bin of the aggregate feeder. With the help of a conveyor, the aggregates are then transferred

3. to a drying drum which is equipped with flights internally to promote drying efficiency. From the dryer, the aggregates are transferred to a vibratory screen, which separates the aggregate according to size, and then moves the aggregate to a separate system which is called a hot aggregate hopper. The required type of aggregate is then conveyed to enter the mixing unit of the asphalt plant, to be able to mix the aggregate with the liquid asphalt previously weighed from the heated storage tank. This is done in order to control the size distribution of the aggregate. Then the asphalt and aggregate are mixed in the optimal proportions according to the specifications required for the final mixture. This hot mixed asphalt mixture is then dropped into a thermal storage bin or truck. An overview into Hot Mix Asphalt and Bitumen Hot Mix Plant An overview into Hot Mix Asphalt and Bitumen Hot Mix Plant Hot Mix asphalt (HMA) paving materials are a composition consisting of size-graded, high- quality aggregate, reclaimed asphalt pavement (RAP), and liquid asphalt cement. This mixture is then heated and combined together in carefully measured quantities to produce HMA or hot mix bitumen. Aggregate and RAP make up over 92 percent by weight of the total mixture. For the production of high-grade HMA, a certain percentage of fine aggregate is essential, at least in the range of 74 micrometres [µm] in physical diameter. Apart from the amount and

4. grade of asphalt cement used, mix characteristics are determined by the types of aggregate and RAP used in relative amounts. Hot mix bitumen with asphalt paving materials can be manufactured by a specific process which involves a series of steps. These include; batch mix plants, continuous mix plants which mix outside dryer drums, parallel flow drum mix plants, and counterflow drum mix plants. This order in the process reflects the chronological order of development and use within the HMA industry. In 1996, an estimated 3600 active asphalt plants in the United States produced approximately 500 million tons of HMA. Out of these 2,300 were asphalt batch plants, 1,000 were parallel flow drum mix plants, and 300 of them were counterflow drum mix plants. About 85 percent of plants being manufactured today belong to the counterflow drum mix design, while 10 percent belong to asphalt batch plant design and 5 percent belong to parallel flow asphalt drum mix plant design. A bitumen hot mix plant can be constructed as a permanent plant, or easily relocated as a skid-mounted plant. Nowadays, most hot mix bitumen plants being manufactured have RAP processing capability and possess the capability to use either gaseous fuels (natural gas) or fuel oil.

5. According to official reports from The Department of Energy and Limited State, between 70 and 90 percent of the HMA is produced using natural gas as the fuel to dry and heat the aggregate.