During an aerial ignition operation, it is important to adjust the concentration of ignition spheres to suit the fuel type and loading. This is accomplished by flying at a steady speed and varying the dispense rate.
Early versions of plastic sphere dispensers varied the dispense rate through a combination of adjusting a two speed motor and controlling the number of feed gates which fed the dispenser mechanism. This system provided the user with a selection of four dispense rates from 44 to 133 spheres per minute (spm). These speeds became known as 2 slow, 2 fast, 4 slow, and 4 fast. It was possible to obtain other speeds but this involved disassembling the dispenser and changing the size of one of the drive sprockets.
To an experienced dispenser operator and burn boss, remembering what speed combination you were on and what would be the next faster or slower combination became a matter of routine with sufficient training. However to a novice operator being trained, it was a bit like learning to stick shift for the first time.
Another problem with the speed control system on these dispensers was the potential for jamming during speed changes. When initially starting the dispenser, the manual instructs the operator to first open the gates before turning on the drive motor. If the motor was turned on before the gates were opened, there would be a chance of a sphere jamming in the mechanism as it tried to fall into the moving shuttle blocks. However, this is exactly the situation which occurs when the machine is running and the operator opens up extra gates to change from 2 fast to 4 slow.
One of the main improvements of the Red Dragon dispenser over these earlier dispensers is its simplified speed control system. Speed changes are accomplished exclusively by changing the drive motor speed. There are seven dispense speeds that correspond to dispense rates of 25 to 175 spm. Speed changes are made by rotating a single knob on the remote control with nearly instantaneous speed change response from the dispenser.
Each numbered speed is 25 spm faster than the previous number. If you want to go faster, you can simply increase speed by one number, or two numbers. If you want to go twice as fast, you simply multiply the speed number by two. For example, speed #2 is twice as fast as #1, #6 is twice as fast as #3, etc.
So how does this benefit the user?
With an easier speed change system, the burn boss is more likely to adjust the dispense rate to correspond to the fuel conditions. For example, during slow aircraft turns, the dispenser can be adjusted to prevent a concentration of ignition at the end of a line. Users with only a few hours of operation on the Red Dragon soon find themselves utilizing all seven speeds during an operation.
Rapid speed change is also a great benefit in a situation where the machine needs to be purged quickly. The operator can close the feed gates and turn the speed selector to maximum. Since the Red Dragon has only three spheres to purge, it can purge the machine in one second on maximum dispense speed. Compare that with the five seconds required to purge earlier dispensers.
Early versions of plastic sphere dispensers varied the dispense rate through a combination of adjusting a two speed motor and controlling the number of feed gates which fed the dispenser mechanism. This system provided the user with a selection of four dispense rates from 44 to 133 spheres per minute (spm). These speeds became known as 2 slow, 2 fast, 4 slow, and 4 fast. It was possible to obtain other speeds but this involved disassembling the dispenser and changing the size of one of the drive sprockets.
To an experienced dispenser operator and burn boss, remembering what speed combination you were on and what would be the next faster or slower combination became a matter of routine with sufficient training. However to a novice operator being trained, it was a bit like learning to stick shift for the first time.
Another problem with the speed control system on these dispensers was the potential for jamming during speed changes. When initially starting the dispenser, the manual instructs the operator to first open the gates before turning on the drive motor. If the motor was turned on before the gates were opened, there would be a chance of a sphere jamming in the mechanism as it tried to fall into the moving shuttle blocks. However, this is exactly the situation which occurs when the machine is running and the operator opens up extra gates to change from 2 fast to 4 slow.
One of the main improvements of the Red Dragon dispenser over these earlier dispensers is its simplified speed control system. Speed changes are accomplished exclusively by changing the drive motor speed. There are seven dispense speeds that correspond to dispense rates of 25 to 175 spm. Speed changes are made by rotating a single knob on the remote control with nearly instantaneous speed change response from the dispenser.
Each numbered speed is 25 spm faster than the previous number. If you want to go faster, you can simply increase speed by one number, or two numbers. If you want to go twice as fast, you simply multiply the speed number by two. For example, speed #2 is twice as fast as #1, #6 is twice as fast as #3, etc.
So how does this benefit the user?
With an easier speed change system, the burn boss is more likely to adjust the dispense rate to correspond to the fuel conditions. For example, during slow aircraft turns, the dispenser can be adjusted to prevent a concentration of ignition at the end of a line. Users with only a few hours of operation on the Red Dragon soon find themselves utilizing all seven speeds during an operation.
Rapid speed change is also a great benefit in a situation where the machine needs to be purged quickly. The operator can close the feed gates and turn the speed selector to maximum. Since the Red Dragon has only three spheres to purge, it can purge the machine in one second on maximum dispense speed. Compare that with the five seconds required to purge earlier dispensers.
No comments:
Post a Comment