Fluid handling – With holder for solid – flaky or pulverized material to be...
Reexamination Certificate
2000-12-15
2001-10-09
Lee, Kevin (Department: 3753)
Fluid handling
With holder for solid, flaky or pulverized material to be...
C422S264000, C422S275000, C422S277000
Reexamination Certificate
active
06298871
ABSTRACT:
DESCRIPTION OF THE INVENTION
The present invention is directed generally to chemical feeders. In particular, the present invention is directed to automatic chemical feeders useful for preparing a liquid solution, e.g., an aqueous solution, of a chemical material such as a sanitizing chemical, and dispensing such solution at or to a location, e g., a body of water, where it is to be used. More particularly, the present invention is directed to a chemical feeder that automatically dispenses controlled amounts of an aqueous solution of a chemical material, e.g., a sanitizing chemical such as 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. Still more particularly, the present invention is directed to a chemical feeder, which has improved flexibility in the delivery rate of dissolved chemical material.
Chemical feeders for producing aqueous solutions of water treating agents are known. Aqueous fluids containing sanitizing agents produced by such feeders have been utilized to disinfect effluent from sewage treatment plants, and for the chlorination of water in swimming pools and hot tubs. Such feeders have been used also for the dissolution and delivery of other water-soluble chemicals to aqueous streams and water systems. Chemical feeders designed to disinfect 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 treatment of the sewage plant effluent.
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 a higher concentration level that is harmful to the user. Consequently, chemical feeders which produce aqueous solutions of sanitizing agents that are used in the treatment of recreational water for bathing, swimming and hot tubs, have been designed to alleviate the shortcomings that typically accompany periodic manual additions of sanitizing agents, i.e., a wide variation in the amount of sanitizing agent added. Examples of chemical feeders for treating aqueous streams and/or bodies of water, e.g., sewage effluent, pools and hot tubs, are described in U.S. Pat. Nos. 3,595,786; 3,595,395; 4,584,106; 4,732,689; 4,759,907; 4,842,729; 5,089,127; 5,427,748; 5,441,711; 5,447,641; 5,932,093; and 6,077,484.
A feature associated with earlier chemical feeder designs is that the variation in chemical material concentrations produced is a direct function of the flow rate of dissolving liquid contacting the chemical material within the feeder, i.e., the higher the flow rate—the higher the chemical material concentration in the dissolving liquid. For example, the introduction of water at a given flow rate into a calcium hypochlorite feeder exemplified by U.S. Pat. No. 5,089,127, produces an aqueous effluent with a given concentration of calcium hypochlorite. Increasing the flow rate of water into the feeder causes more water-solid calcium hypochlorite interaction and/or faster dissolution of the calcium hypochlorite, thereby producing an aqueous effluent with a nearly constant concentration of calcium hypochlorite. In such feeders, the delivery rate of chemical material, e.g., calcium hypochlorite, with increasing flow rate of dissolving liquid, e.g., water, approximates a straight line function. A drawback of such feeders is that the delivery rate of chemical material is too invariant with changes in flow of dissolving liquid.
It would be desirable to develop a new and useful chemical feeder in which the concentration of chemical material product delivered by the feeder was more variable with increasing flow rates of water (or other dissolving liquid) into the feeder, i.e., the delivery rate of chemical material with increasing flow of dissolving liquid is not a straight line function but approximates a parabolic function. Such a feeder would possess a greater turn down variability in the delivery of chemical material as the flow rate is reduced. It would also be particularly desirable that such a new chemical feeder be easy to use, e.g., easy to recharge with chemical treating agent and safe to operate.
In accordance with the present invention, there is provided a chemical feeder comprising:
(a) a housing having a base, side walls extending upwardly from said base and a closed upper end, said base and side walls defining a cavity;
(b) an elongated substantially vertical hollow container within said cavity, said container having side walls, the bottom of which are adjacent to said base and which are spaced from the side walls of the housing, thereby defining a collection zone, which is further defined by the outside walls of the container and the inside walls of the housing (including the closed upper end), the side walls of the container extending through and above the closed upper end of the housing and having a plurality of perforations arrayed around its lower portion; thereby to provide liquid communication between the inside of the container and the collection zone;
(c) at least one canister having a base and side walls for retaining solid chemical material therein, said canister having a plurality of perforations in its lower portion, said perforations in the canister being such as to expose only the lower portion of solid chemical material contained therein, said canister being interposed within the container such that the base of the canister is juxtaposed to or below the top of the uppermost perforations arrayed around the lower portion of the side wall of the container, the base of the canister, the base of the housing and the lower portion of the side walls of the container below the canister base defining a chamber;
(d) means to deliver liquid in which the solid chemical material is soluble to the chamber; and
(e) means for removing liquid containing said chemical material from the collection zone.
In another embodiment of the present invention, the inlet for supplying liquid to the chamber is positioned in the side wall of the container in such a manner as to provide a tangential, cyclonic flow of liquid within the chamber. In a further embodiment of the present invention the canister and the lid for the container are attached to form a single integrated member or unit.
The features that characterize the present invention are pointed out with particularity in the claims, which are annexed to and form an integral part of this disclosure. These and other features of the invention, its operating advantages and the specific objects obtained by its use will be more fully understood from the following detailed description and the accompanying drawings in which preferred embodiments of the invention are illustrated and described, and in which like reference characters designate corresponding parts.
Other than in the operating examples, or where otherwise indicated, all numbers and values, such as those expressing the dimensions of the feeder and flow rates, used in the specification and claims are to be understood as modified in all instances by the term “about.”
REFERENCES:
patent: 3107156 (1963-10-01), Fredericks
patent: 3474817 (1969-10-01), Bates et al.
patent: 3595395 (1971-07-01), Lorenzen
patent: 3595786 (1971-07-01), Horvath et al.
patent: 3598536 (1971-08-01), Christensen
patent: 3864090 (1975-02-01), Richards
patent: 3899425 (1975-08-01), Lewis
patent: 4210624 (1980-07-01), Price
patent: 4331174 (1982-05-01), King, Sr.
patent: 4379125 (1983-04-01), Benninger et al.
patent: 4584106 (1986-04-01), Held
patent: 4732689 (1988-03-01), Harvey et al.
patent: 4759907
Ferguson Richard H.
Pickens Stanley R.
Lee Kevin
Millman Dennis G.
PPG Industries Ohio Inc.
LandOfFree
Chemical feeder does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Chemical feeder, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chemical feeder will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2584566