Low cost temperature activated fuel controller utilizing a snap action

bimetal thermostat allowing diesel engines to utilize waste vegetable

oil (wvo) as a fuel

This patent is for a simple, low cost fuel controller used to allow diesel engines to

utilize waste vegetable oil as a fuel. The controller uses a snap action bimetal

thermostat (in a normally open configuration) to close a circuit at a factory pre-set

temperature, which activates a relay and energizes an electronic 3-way solenoid

valve to switch between diesel fuel to wvo fuel (wvo/diesel mixture – hereafter

wvo will refer to either 100% wvo or a blend of wvo and diesel). The 3-way

solenoid valve’s default (non-energized) state routes diesel from the regular tank

to the engine’s injector pump. When energized, the 3-way solenoid valve

switches to the other position, which then changes the routing of the fuel to come

from the alternate wvo tank. The purpose of this controller is to achieve ideal wvo

fuel temperature prior to switching to the wvo tank. Any diesel can use wvo as a

fuel, except the fuel needs to be heated in order to lower the viscosity so that the

diesel engine can achieve complete, efficient combustion. Many existing

controllers utilize a PLC or some means of electronic controls to perform this

switching function. This controller is different in that it solely relies on the use of a

snap action bimetal thermostat to control the switching to the wvo once the

predetermined (and preset) temperature is reached. This significantly reduces

the cost of these controllers. This controller also includes the use of optional,

high temperature controls also based on the same snap action bimetal

thermostats (except these will be in a normally closed configuration) to prevent

overheating of the wvo in certain circumstances. This patent also covers the use

of a snap action bimetal thermostat to control the flow of wvo fuel delivered to an

engine in any way.