In particular, the present invention is directed to automatic chemical feeders useful for preparing a liquid solution of a chemical material, e.g., a sanitizing chemical, and dispensing such solution at or to a location, e.g., a large body of water, where it is to be used.API CAST STEEL VALVES More particularly, the present invention is directed to a chemical feeder that automatically dispenses controlled amounts of an aqueous solution of calcium hypochlorite in a reliable, efficient and cost effective manner for treatment of water systems, e.g., water treatment plants, potable water supplies, water for industrial or process usage, waste water systems, water systems for cooling towers, run-off water, swimming pools, hot tubs and the like.

Chemical feeders for producing aqueous solutions of water treating agents are well known and have been utilized with processes for the disinfection of effluent from sewage treatment plants, for the chlorination of water in swimming pools and hot tubs, and for the delivery of other water soluble chemicals to aqueous streams and water systems. Chemical feeders designed for the disinfection of effluent from sewage treatment plants have been designed to overcome the drawbacks of previous chlorine treatment systems, which required extensive daily attention by operators in order to achieve acceptable disinfection of the sewage plant effluent.Water Pump Control Valves Chlorine and other sanitizing chemicals are used in swimming pool and hot tub applications to control the growth of algae and other organisms in the water. The concentration of the sanitizing chemical in a body of water, e.g., a swimming pool, must be kept between the concentration level that is effective to eliminate algae and other objectionable organisms and below the concentration level that is harmful to the user. Consequently, chemical feeders used in treating bodies of water, e.g., swimming pools and hot tubs, have been designed to alleviate the shortcomings, e.g., wide variations in treating agent concentration, that typically accompany manual treatment, e.g., manual chlorination and manual chemical addition. Examples of existing chemical feeders for treating aqueous streams and/or bodies of water, e.g., sewage effluent, pools and hot tubs, can be found in U.S. Pat. Nos. 3,595,786; 3,595,395; 4,584,106; 4,732,689; and 4,759,907.

One difficulty associated with some of these prior art designs is that they can result in the build up of pressurized air within the chemical feeder, which may lead to potentially dangerous conditions in the event the chemical feeder ruptures or is inadvertently opened while pressurized.Hydraulic control valves An additional disadvantage of some of the prior art chemical feeders is a build up of chemical residue within portions of the chemical feeder. A build up of chemical residue can detrimentally affect the chemical delivery rate of the feeder, eventually requiring it to be taken off-line and cleaned. These difficulties may significantly increase the amount of maintenance required for operation of a chemical feeder.

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2012-01-09

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