Hot water/steam weed killing system

A portable backpack mounted weed killing system, comprising:

• housing means adapted for carrying in the manner of a backpack by a user;
• a water storage means in said housing means;
• gas powered heating means in said housing for heating water from said storage means;
• gas supply means in said housing operably connected for supplying gas to said heating means;
• application means including manually actuatable valve means operably connected for selectively distributing heated water or steam from said heating means on weeds;
• electrically actuated outlet valve means disposed upstream of said manually actuatable valve means and operably connected to said application means for allowing distribution of heated water or steam from said heating means only upon actuation of said electrically actuated outlet valve means regardless of the position of said manually actuatable valve means;
• and
• control means operably connected for regulating said heating means and said distribution of heated water or steam, said control means including sensing means for detecting temperature conditions in said heating means, and means for controlling said heating means and said electrically actuated outlet valve means in response to said detected temperature conditions such that distribution of heated water or steam is permitted only after a predetermined temperature level has been reached.

A portable backpack mounted weed killing system, comprising:

• a housing adapted for carrying in the manner of a backpack by a user;
• a water supply reservoir in said housing;
• a gas powered flash heater for heating water from said reservoir, said heater including a tank portion operably connected to said reservoir and a gas burner having an electrical igniter and a thermostatically controlled gas supply valve;
• at least one pressurized gas supply source in said housing operably connected for supplying gas to said heater;
• an application nozzle including a manually actuated valve operably connected to said tank portion for distributing heated water or steam from said heater on weeds;
• a thermostatically controlled electrically actuated outlet valve disposed upstream of said manually actuated valve and operably connected to said application nozzle for allowing distribution of heated water or steam from said tank portion of said heater only after a predetermined temperature level has been reached, regardless of the position of said manually actuated valve;
• and
• a control mechanism operably connected for regulating said heater and said distribution of heated water or steam, said control system including sensors for detecting temperature and pressure conditions in said tank portion of said heater, and means for controlling said igniter, said gas supply valve, and said electrically actuated outlet valve in response to said detected temperature and pressure conditions.