Abstract: An agent is disclosed that is useful for treating liquid media, e.g., dechlorinating aqueous media. The agent contains at least one salt from the sulfur oxide family, such as sodium sulfite. In the agent, the salt is in mixture with an organic gel forming binder. The mixed material is especially adapted for preparing self-supporting, discrete particles of solid compacted material, e.g., tableted composition. The composition can provide such compacted material not only of desirable strength and hardness, but also of desirably controlled dissolution rate.

Abstract: A feeder device for controlled dissolution of a solid treating agent in a liquid of variable flow rate is designed such that the concentration of treating agent in the effluent liquid can be substantially constant, irrespective of the actual flow rate of the liquid. Further, the value of this concentration may be adjusted to varying levels and adapted to meet specific needs and requirements of the particular liquid system in which this feeder device may be employed. The constancy of concentration of the agent is obtained by the provision of a proportional weir, positioned in connection with a dissolution chamber, useful for maintaining a liquid volume in this dissolution chamber which can be linearly proportional to the flow rate of the liquid therethrough. In this liquid volume, dammed up by the weir, the solid treating agent, generally a substance containing hypochlorite, sulfite, sulphate or permanganate, can be present at least partly as a soluble solid.

Abstract: A pressure feeder for controlled addition of dissolvable agent into a flowing liquid has been designed which provides constant concentration of the agent in the treated liquid. This concentration is independent from the flow rate and the pressure of the liquid and also slugging of the agent at zero flow rate is avoided. A feeder according to the invention comprises a dissolution chamber connectable to a point of slightly increased pressure in the main circuit in which dissolution chamber the liquid is brought in controlled contact with stacked tablets of the agent. A linear weir controls the height of the liquid level in the dissolution chamber such that is proportional to the flow rate. The provision of a holding chamber for treated liquid which is connected to the dissolution chamber incorporates a gas volume that automatically adjusts for pressure differences and enables the liquid level in the dissolution chamber as well as the concentration of the agent in the treated liquid to be pressure independent.