Dry Roller ( Operarional Guide Of Asphalt Plant 3 )

2.2.1: Dry roller:
Working mechanism: The dry roller is mainly consisted of the inlet and outlet material box, roller, vane, the rolled rings, the supported idler, the stop idler, the driven device, framework, legs etc. It receives the cold aggregates that the gradient belt feeder delivery, adopts the dry heating method of roller refluent rotation type, delivery the cold aggregates from one end, install the coal (fuel) burner at the other end, then send into the flame and the hot wind, heat the cold aggregate up to the stipulated temperature; There is about 3.5-4 degrees of obliquity in roller, the obliquity can make sure the aggregates are pushed into the feeding outlet. Moreover, there is installed the deferent spiral vanes and the feeding vanes in the roller, so after the aggregates delivered will be heated 3-5 min., they will be scratched into the feeding outlet and then flow into the stone elevator / hot elevator.
Attentions of Installation and debugging:
The debugging of the dry roller is mainly keeping the roller in suspension state; make the catch wheel and the rolling ring in the state of connection and disconnection. Because the idler is the force object, so it is ok that if only guarantee the idler surface inflicts a component force, which can get over the gravity. There out the four idlers should be along with the rolling direction and lean upward at a certain angle, the specified will be decided according to the suspension situation.

2.2: Burning system
For the burner, the user can select the light oil burner or coal burner.

a. Main composing: burner (including the air-blower, oil pump motor), oil pipeline, the bracket of burner etc.
Fuel burner adopts single-slice computer program control, the button or the touch operation, the photoelectric transducer, the temperature storage and other high-tech electric control systems. The only thing you need to do is pressing the “start” key and can start the oil pump, air blower, auto-ignition, the flameout alarm, the auto-control temperature and display, can self-regulate the needed fuel amount according to the temperature of aggregates. In addition, it is matched with the function of manual, when the automatic control system breaks down, can guarantee the normal operation of the burner through the manual system

b. The coal burning device (Optional):
Main composing: Coal-fired hearth, coal pulverizer, fuel ignition system, hearth bracket, coal pipeline etc.
Main function: Offer the needed hot source to the cold aggregates. The advantages: the cost is very low, the maintaining is convenient.
The operating method: Put the diesel tube into the rear of hearth, turn on the diesel pump and add the diesel oil, now ignite the diesel with the manual ignition pole, preheating about 1 minute later, start the coal pulveriser and add the coal, after the flame in being steady (about 3-5 minutes), shut off the diesel oil pump, now just only heat up the cold aggregates in the dry roller with the burning coal.
The characteristics of this four-passage spiral-flow coal burner: The shade is separate: burning stable, difficult to flameout, wide use; Compound spiral-flow: Burning stressed and fully; Air receiver powder: Dregs-proof and protect the bricks; Adjustable flame: Can regulate the length and thickness of the flame and reach the needed flame shape. This kind of burner aims at solving the five big problems of high-efficient, stable burning, low pollution, dregs proof and erosion, and can overcome such the limitations as the unstable burning, the few suitable coal kinds, serious dregs, heavy pollution, easy to be damaged for the brick and so on.
First of all, it can substitute the oil with the coal, can save the fuel expense of mixer, reduce the operating cost greatly.
Second, the special structure and rational layout of the hearth make the coal can burn fully and steadily and without any storing dregs.
Third, for the mutual function of the one-time spiral-flow wind and the adjustable direct-flow wind, not only can burn high-efficiently and stably but also can be suitable for the various coals’ combustion.
Fourth, It is convenient to regulate online: According to the characteristic of various coals and the dry roller, can adjust the length, thickness and strong or weak of the flame at random, the adjustable range is large.
Fifth, Can improve the service life of the brick greatly because of the burning type of air receiver coal;
The requirements of burning:
1) The heat-generating quantity is bigger than 5000 cal / g
2) The volatile component is bigger than 20%
3) The whole moisture is less than 5%
4) The whole Sulphur component is less than 1%
5) Ash content is less than 10%