Liquid treatment apparatus

A dispensing device for dispensing a chemical agent into a fluid flow, comprising:

• a dispense head having inlet and outlet means for coupling to said fluid flow and defining a flow passageway coupling said inlet and said outlet means;
• a canister engageable with said dispense head and defining a hollow interior cavity;
• said flow passageway in said dispense head including flow entry means for directing fluid flow into said hollow interior cavity and flow exit means for directing fluid flow out of said hollow interior cavity;
• a chemical container assembly within said hollow interior cavity in contact with the fluid flow;
• said chemical container assembly including a foraminous pretreatment sleeve, a rigid, hollow, foraminous support tube within each foraminous pretreatment sleeve and extending to said flow exit means, and a cylindrical chemical container disposed in said support tube so as to be held by said support tube a predetermined spaced distance from said flow exit means;
• said support tube comprising a rigid tube having a continuous array of similarly sized openings formed therein;
• said chemical container assembly defining inlet and outlet holes adjacent its upper end and including an outer cylindrical wall enclosed by upper and lower end walls, with said outer cylindrical wall defining a plurality of said inlet holes formed in a linear array, generally parallel to a central axis of said chemical container and wherein said upper end wall defines said outlet hole;
• and
• said flow exit means comprises a stub portion of said dispense head projecting into said hollow interior cavity so as to be at least partly received in the upper end of said support tube in overlapping relation therewith.