Glow Plug Test


Glow Plug Test

Date: 2/24/08

 

Online Discussion of Heating Element Start Up: http://listserv.repp.org/pipermail/gasification_listserv.repp.org/2009-February/013180.html

 

Description:

A set of diesel glow plugs were purchased and tested to explore their potential to start the GEK with minimal hassle.

 

Plugs where choosen to be commonly available (Bosch 0250202254/ Ford F2TZ-12A342-A): a "factory replacement for 1988 to 1994 Ford and IH (Navistar) Trucks and Vans" (ebay)

 

Individual power consumption is roughly 50 W (when glowing red in open air).

Plugs can not handle direct connection to a 12V car battery, they will overheat. Recommended circuit pending.

 

Shown below is video from ignition of a wood pellet in open air (behaviour in packed material is less impressive).

Images from ignition of a wood pellet in open air. Ignition was near instantanous (0.25 sec after contact).

Video of ignition (download [mp4, 384k])

 

Video of ignition of charcoal with air flow and glow plug (download [mp4, 824k])

 

Charcoal was at air equilibrium moisture content. Torch used to minimize CO emission. Full ignition not shown in video. Ignition of wood pellets was also tested with the same arrangement.

 

Discussion:

The open air ignition of the wood pellet is promising. As a packed bed with air flow, char appears to ignite faster via the glow plug than a bed of wood pellets (not shown).

 

The glow plug was integrated into a "wand". The obvious dangers associated with an exposed element advocate for a stationary perminent itegration into the GEK. One potential design is to mount the plug/tube assembly coaxially centered with the cowling. For a fixed mount the optimal vertical position that will avoid overheating of the element will need to be determined. The assembly could also be mounted to provide manual vertical adjustment and fixing with a set screw if a suitable permenant vertical position is not found.

 

A circuit may need to be developed to maintain a constant temperature of the element (e.g. fully stopping current after combustion is started and [potentially over-]heating the element).