A chlorinator of the floating type includes a cannister (1) having oppositely disposed side walls (3 and 4) and a pair of oppositely disposed end walls (5 and 6) is provided with coupling means in the form of ribs (21) disposed on the outer surfaces of the end walls and float means (2) having a central aperture (13) therein whose axis is vertical includes a generally circular central part (13, 14) and a pair of diametrically opposed segments (15 and 16) each of which includes a peripheral part (15a and 16a) each of which in turn includes clearance portions and coupling portions on which a plurality of coupling ribs are formed so that the cannister may be inserted into the aperture formed in the float means with its coupling means adjacent the clearance portions and which then may be rotated about its vertical axis to cause its coupling ribs to engage the coupling ribs (17 and 20) formed on the peripheral portions (15a and 16a) of the segments (15 and 16), an inwardly projecting protrusion (11, 12) is provided on one of the side walls (3) and projects far enough inward to prevent chlorinator sticks stacked one atop the other from clearing the inward protrusions until a predetermined degree of dissolution of such stick occurs after which the stick may fall downwardly in the cannister thus allowing sticks disposed thereabove to move downwardly thereby to regulate the rate at which chlorine is supplied to the body of water in which a chlorinator floats.

A chemical pellet dispensing device for wells includes a housing defining a pellet chamber and having an inclined bottom wall. A pellet dispensing tube which opens through the bottom wall communicates with the well. A false bottom wall maintains the level of pellets within the chamber below the open end of the pellet dispensing tube. A pellet conveying member is movable along the bottom wall between a position below the level of pellets in the chamber for receiving a pellet to a position in registration with the pellet dispensing tube for depositing a pellet therein. The pellet conveying member is driven by a power source actuated in response to fluid flow from the well. A pellet dislodging slip clutch is interposed between the power source and pellet conveying member. A mechanism is provided for adjusting the rate at which pellets are dispensed into the well.

An apparatus for processing a silver halide photographic material in a processing vessel containing a processing solution in which a solid agent is fed into the vessel to keep the property of the processing solution within a predetermined level. A feeding device to feed the solid agent from a storage container to the processing vessel includes a feeding port through which the solid agent is fed into the processing vessel and a open-close mechanism to open or close the feeding port

Bacteria in tablet form is introduced into a home sewage treatment system. The system uses ground temperature to promote bacteria activity to aid in sewage denitrification. The tablets are periodically dispensed with a power-driven dispenser that periodically drops a tablet below ground into the system.

An apparatus for processing a photosensitive material includes a device to replenish a tablet of a solid processing agent into a processing tank in which a cross-section of the tablet is shaped in a circle. A container in which plural tablets are accommodated is detachably mounted on the device. The plural tablets are accommodated in such a manner that an outer circumference of each tablet is contacted with that of the others.