CHEMICAL DISSOLVING DISPENSER
A diluent such as water is sprayed from a nozzle through a screen onto water soluble packages of chemical supported on the screen to produce a solution for treatment of a system. The solution falls into a reservoir and is recirculated through the nozzle onto the screen for a duration sufficient to dissolve a load of chemical into solution. The concentrated solution is dispensed to a system. The reservoir can be flushed into the system before recirculating solution to the nozzle for further chemical dissolving. Chemical-containing packages can be loaded at any time without system interruption. Chemical is supplied in powder or solid form.
1 . Apparatus for dissolving chemical into a solution for treatment of a system and comprising:
a reservoir;
a chemical receptacle;
a screen above the reservoir in operable association with the receptacle for supporting chemical thereon;
a spray nozzle oriented to spray a diluent onto said screen, with a mix of diluent and chemical falling from said screen into said reservoir;
a pump for recirculating solution of increasing chemical concentrate from said reservoir to said nozzle for spray onto said screen and for a predetermined time duration; and
a second pump for dispensing solution of diluent and chemical to said system.
2 . Apparatus as in claim 1 further including a first valve for passing diluent to said reservoir when open.
3 . Apparatus as in claim 1 further including a plurality of water soluble packages containing chemical in powder form within said receptacle.
4 . Apparatus as in claim 3 further including a solution level sensor operably associated with said reservoir for signaling when said reservoir is full and said valve closing in response to said signaling.
5 . Apparatus as in claim 4 further including a second backup level sensor for sensing a filled condition of said reservoir and a backup valve for shutting off diluent flow to said reservoir upon failure of said first valve to close.
6 . Apparatus as in claim 1 wherein said screen is disposed at least proximate a lower end of said receptacle.
7 . Apparatus as in claim 6 wherein said chemical is in powered form and is contained in discrete water soluble packages supported on said screen.
8 . Apparatus as in claim 6 wherein said chemical is in solid form.
9 . Apparatus as in claim 1 including a sensor for sensing an empty condition of said reservoir after said dispensing.
10 . Apparatus as in claim 1 wherein said pump for recirculating solution is operable to recirculate solution when no powder is in said receptacle.
11 . Apparatus as in claim 1 wherein said reservoir is disposed in a housing having a vent, and said apparatus further including a filter operably disposed with respect to said vent to capture fumes from said reservoir.
12 . Apparatus as in claim 1 wherein said screen includes a first screen element of one mesh size and a second screen element of a smaller mesh size.
13 . A method of dissolving chemical in powder or solid form into a solution for treating a system, said method comprising:
introducing said chemical into a receptacle;
supporting said chemical on a screen;
spraying water from a nozzle onto said screen and carrying chemical into solution falling from said screen;
collecting said solution in a reservoir;
recirculating solution of increasing chemical concentration from said reservoir to said nozzle and spraying solution onto said chemical through said screen;
continuing said recirculation to dissolve chemical into said solution; and
dispensing solution from said reservoir to a system to be treated.
14 . A method as in claim 13 including recirculating said solution from said reservoir to said nozzle to said screen, and back to said reservoir for a predetermined time and dispensing said solution after said time.
15 . A method as in claim 15 including the step of filling said reservoir with water to a filled condition.
16 . A method as in claim 15 further closing a water inlet valve and first ceasing said filling in response to sensing of said filled condition.
17 . A method as in claim 16 including shutting off water flowing to said reservoir in the event of failure of said first ceasing step.
18 . A method as in claim 14 including ceasing said dispensing in response to detecting an empty reservoir.
19 . A method as in claim 14 including continuing said recirculation in the absence of chemical above said screen.
20 . A method as in claim 13 including introducing chemical to said receptacle in discrete water soluble packages.
21 . A method as in claim 20 including introducing said packages into said receptacle while said water is sprayed onto said screen.
22 . A method as in claim 13 wherein said dispensing step includes intermittently dispensing at least a portion of said solution intermittently.
23 . A method as in claim 22 wherein said dispensing step includes intermittently dispensing portions of up to 25 gallons of said solution at 0.05% to 50% strength.
24 . A method as in claim 23 wherein said dispensing includes dispensing solution at about 50 to 90 degrees Fahrenheit.
25 . A method as in claim 22 wherein said intermittent dispensing is carried out over a period of more than one day.