A liquid injection device includes a nozzle, a moving element and a control valve. The nozzle has a channel, a bypass passage and a suck back passage. The channel penetrates through the nozzle for injecting a working fluid. The channel has a liquid outlet. The bypass passage has a first opening, a switch-on position and a switch-off position. The suck back passage has a second opening between the first opening and the liquid outlet. The first opening and the second opening communicate with the channel. The moving element is disposed in the bypass passage. The control valve is disposed on the nozzle and controls the moving element to switch between the switch-on position and the switch-off position to open or close the channel. A suck back pump sucks the working fluid remaining between the first opening and the liquid outlet when the moving element is located at the switch-off position.

A modular particle valve comprises a plurality of aligned and abutted valve modules that dispense particle curtain segments. The curtain segments merge to form a particle curtain having a width that is limited only by the number of included valve modules. Each valve module comprises a particle hopper and a movable element abutting the hopper from below. An actuator causes the moveable element to block or partially open a hopper outlet to provide a curtain segment of variable thickness. The resulting particle curtain can have a thickness that is uniform or shaped and adjusted according to environmental changes. The moveable elements have edges that abut without intervening structures, and in embodiments interlock while permitting separate movements thereof. Individual valve modules can be removed and reinstalled without significantly disturbing the remaining valve modules. Embodiments are incorporated into systems that dry seeds or collect solar energy by heating particles.

A liquid agent application apparatus includes an application nozzle that is movable up and down and in a horizontal plane direction with respect to a board, an application valve that switch between a first state in which supply of a liquid agent to the application nozzle is performed and a second state in which the supply of the liquid agent to the application nozzle is stopped, and a control device that controls these. The control device performs control such that the application nozzle is lowered, the application valve is switched to the second state by standing by a predetermined time after switching the application valve to the first state at a predetermined supply start timing, and the application nozzle is raised after a timing at which a tip end of the application nozzle reaches a lowering end and the application valve is switched to the second state.