In part one of this article, I discussed the PyroShot hand launchers which are used to launch Dragon Egg ignition spheres. In this part, I will discuss the Green Dragon which is soon to be released onto the market by SEI Industries Ltd. It is a new automated launcher that also uses Dragon Eggs.
The Green Dragon started its life as a design concept to modify SEI's Red Dragon aerial dispenser for use with ground based vehicles like ATV's. The idea was to use ignition spheres to replace ATV drip torches. The requirement was being driven by forest service concerns about the variety and safety of ATV torches.
After some preliminary trials, it became evident that a ground based device has operational requirements that are quite different from an aerial sphere dispenser. Most important is the need to operate when attached to a vehicle platform that bounces up and down and may be inclined at a variety of angles to the ground. In contrast, a helicopter is a very stable platform and gravity can be relied upon to move spheres through the dispenser.
As discussed in part one, there is also a practical requirement to propel the spheres away from the machine. The Red Dragon is a dispenser which drops spheres whereas the Green Dragon needs to be a launcher. In some applications, this capability would allow it to replace the flame thrower style torches .
The Green Dragon also needs to be able to launch single shots. Existing aerial dispensers utilize multiple injection chambers in order to meet the high dispense rates required because of the helicopter's speed. When they stop dispensing, multiple spheres already in the process must be cleared. This would be less than ideal if you had to launch a minimum of three or four spheres even if you just needed one.
With all of these factors in mind, the Green Dragon was designed specifically as a ground based launcher, rather than a modified aerial dispenser. It can be attached to a wide variety of "ground" based platforms including a pickup truck, ATV, UTV, and even an airboat. The hopper which contains the unprimed spheres has a pressure feeding system that will deliver spheres to the launcher mechanism even when inclined at a 45° angle or when bumping down a rough cut trail or firebreak.
The launcher mechanism injects the spheres with glycol and then propels them from the machine using a compressed gas system. The range of the projectile can be controlled by adjusting the angle of the barrel and by regulating the gas pressure. The maximum range is 70 yards with a top speed of approximately 40 spheres per minute. The launch speed can be adjusted by the operator to match the vehicle speed and the fuel conditions.
The compressed gas can be any non-flammable gas delivered to the machine at a maximum pressure of 150psi. Two more common supplies are compressed air from a vehicle mounted compressor or carbon dioxide bottles that are used in the beverage industry. The system uses standard industrial air quick connect fittings and includes a regulator for carbon dioxide bottles. A 20lb bottle of carbon dioxide will deliver more than 10,000 shots at a range setting of about 50 yards.
The launcher operation is controlled by a pistol grip hand control. Pulling the trigger once causes the machine to cycle and shoot a single sphere. Holding down the trigger makes the machine cycle continuously until the trigger is released. The launcher can also be switched to automatic mode in which pulling the trigger turns the machine on and it continues to cycle until the trigger is pulled again. There is no need to hold down the trigger for those long blacklines on the edge of a block.
The Green Dragon has completed a year of trials at more than a dozen sites in North America and Australia. It is now in production and has a scheduled product release date for July, 2010.
In the final part of this article, I will take a look at all three launching devices and discuss where they can and can't replace conventional ground based devices.
The Green Dragon started its life as a design concept to modify SEI's Red Dragon aerial dispenser for use with ground based vehicles like ATV's. The idea was to use ignition spheres to replace ATV drip torches. The requirement was being driven by forest service concerns about the variety and safety of ATV torches.
After some preliminary trials, it became evident that a ground based device has operational requirements that are quite different from an aerial sphere dispenser. Most important is the need to operate when attached to a vehicle platform that bounces up and down and may be inclined at a variety of angles to the ground. In contrast, a helicopter is a very stable platform and gravity can be relied upon to move spheres through the dispenser.
As discussed in part one, there is also a practical requirement to propel the spheres away from the machine. The Red Dragon is a dispenser which drops spheres whereas the Green Dragon needs to be a launcher. In some applications, this capability would allow it to replace the flame thrower style torches .
The Green Dragon also needs to be able to launch single shots. Existing aerial dispensers utilize multiple injection chambers in order to meet the high dispense rates required because of the helicopter's speed. When they stop dispensing, multiple spheres already in the process must be cleared. This would be less than ideal if you had to launch a minimum of three or four spheres even if you just needed one.
With all of these factors in mind, the Green Dragon was designed specifically as a ground based launcher, rather than a modified aerial dispenser. It can be attached to a wide variety of "ground" based platforms including a pickup truck, ATV, UTV, and even an airboat. The hopper which contains the unprimed spheres has a pressure feeding system that will deliver spheres to the launcher mechanism even when inclined at a 45° angle or when bumping down a rough cut trail or firebreak.
The launcher mechanism injects the spheres with glycol and then propels them from the machine using a compressed gas system. The range of the projectile can be controlled by adjusting the angle of the barrel and by regulating the gas pressure. The maximum range is 70 yards with a top speed of approximately 40 spheres per minute. The launch speed can be adjusted by the operator to match the vehicle speed and the fuel conditions.
The compressed gas can be any non-flammable gas delivered to the machine at a maximum pressure of 150psi. Two more common supplies are compressed air from a vehicle mounted compressor or carbon dioxide bottles that are used in the beverage industry. The system uses standard industrial air quick connect fittings and includes a regulator for carbon dioxide bottles. A 20lb bottle of carbon dioxide will deliver more than 10,000 shots at a range setting of about 50 yards.
The launcher operation is controlled by a pistol grip hand control. Pulling the trigger once causes the machine to cycle and shoot a single sphere. Holding down the trigger makes the machine cycle continuously until the trigger is released. The launcher can also be switched to automatic mode in which pulling the trigger turns the machine on and it continues to cycle until the trigger is pulled again. There is no need to hold down the trigger for those long blacklines on the edge of a block.
The Green Dragon has completed a year of trials at more than a dozen sites in North America and Australia. It is now in production and has a scheduled product release date for July, 2010.
In the final part of this article, I will take a look at all three launching devices and discuss where they can and can't replace conventional ground based devices.
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