CA1162048A - Apparatus and method for the reuse and treatment of waste water in fiber glass manufacturing operations - Google Patents

Abstract

ABSTRACT

A method and system of treating water used in the manufacture of fiber glass insulation products which is characterized by maintaining the water in continued motion, so that solids never build up with the consequent clogging of orifices and spray nozzles at any point in the system. Further, water is always discharged in an environmentally acceptable condition at an elevated atmospheric location, and never at ground level, the only ground level discharge from the system being solids which are suitable for dry land fill disposal.

Description

i 1162~48 This invention relates generally to the use, treat-ment and reuse of water employed in the manufacture of fiber glass insulation products. More specifically it is concerned with the treatment of water used (i) in the cleaning of the flights, or chains, which are an intergral part of the forming station in a fiber glass insulation manufacturing production line, (ii) the air scrubbers and, if used, the elèctrostatic precipitator in such a line, and (iii) resin (i.e. binder) contaminated water.

BAC~GROUND OF THE INVENTION

Purification of water used in fiber glass insulation manufacturing processes is an increasingly difficult pro-blem in view of the strict environmental standards imposed on such operations. The need to operate such facilities on~a continuous, three-shift operation plus the prohibition against dt~ping anything except neutralized or pure water into streams or other natural water sources, including potential additives to ground water sources, has generated 20 ~ a ritical need for a safe, highly efficient and reliable system for purifying water and water based liquids used in ::
the fiber glass insulation manufacturing process.
Accordingly, a primary object of the invention is to provide a process and system for purification of water used Ln fiber glass insulation manufacturing processes which is efficient, economical and environmentally acceptable.
Another object is to provide a method and system as above described which treats the water and contaminates in such fashion that no water is discharged from the system c~, ~ .. i ..

to a ground level location, and solid, or semi-solid, contaminates are discharged in a condition suitable for disposal in environmentally acceptable dry land fills.
A further object is to provide a method and system as above described in which the water and water-based fluids under treatm~nt are kept constantly in motion so that the particulate material and the solids (which, in the case of fiber glass, have a specific gravity o~ approximately 2.3) are never allowed to plug or clog orifices or qpray nozzles at any time or place in the system.
Other objects and advantages of the invention will become apparent from a reading of the ~ollowing exemplary description thereof.

DESCRIPTION OF THE INVENTION

Figure 1 is a diagrammatic view of the invention illustrating, in this instance, a single make-up water source servicing foux fiber glass insulation production ~20 Lines;
Figure 2 is a schematic view of the precipitator water recycle portion of the Line 1 of Figure l;
Figure 3 is a schematic view of the precipitator pit, also known as the finish cleaner pit, of Figure 2;
~; ~5 and Figure 4 is a plan view of the precipitator pit of Figure 3, wherein certain parts are illustrated in di~grammatic form.

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~ ~16~V48 The water treatment system of this invention, and its mode of operation in conjunction with a fiber glass insulation manufacturing process, is illustrated in its e~tirety in Figure lo This Figure illustrates the method and system of the invention used in con-junction with, in this instance, four individual fiber glass insulation manufacturing production lines.
It should be understood however that the principles of the invention are applicable to a greater or lesser number of lines, and that the specific example chosen for illustration is intended to be illustrative only.
The essential purpose of this system is to clean the forming chains or flights in the forming station of the fiber glass insulation manufacturing process~
the scrubbers and prPcipitator, if one is used, and the resin-contaminated water so that said water can be reused, particularly in the application of the binder to the insulation at the forming station.
It should also be noted that an essential ~eature 20 ~ of the method and system is the maintenance of a supply of soft water, and the further maintenance of a balance of water added to water removed, along with continuous filtration for solids xemoval. Specifically, it will be noted that at all possible entry points of water into the recycle washwater system, only soft water is admittedO
In this co~mection it should be understood that the terms "soft water" and "city water" have rather well-defined meanings. Specifically, "soft water" indicates ~ 16204~

water softened, as by conventionaI Zeolite softeners, in a water house or other softening syst~m adjacent to the fiber glass insulation manufacturing process.
The term "city water" indicates water which is received at the water softening station, and will of course vary from area to area throughout the country. The definition of other waters will become apparent from their mode of usage hereafter in this specification.
Referring now specifically to Figure 1, it will be noted that a source of city water is indicated at 1, and a source of soft water, here a water softening station, is indicated at 2. In this instance a Zeolite softener will be assumed. It should be noted that soft water has the capability of washing phenols off the components of equipment in the system more efficiently than conventional city water.
Softened water from softening station 2 is admitted into each of the four fiber glass insulation manufacturing production lines, indicated generally as Line 1, Line 2, .
Line 3 and Line 4 in Figure 1. For clarity of description and ease of understanding Lines 4 and 1 will be described in detail, and thereafterr each Line, to the extent it is unique, will be descxibed individually.
Softened water from softening station 2 i5 fed into a hydrolaser indicated at 3. The hydrolaser is, in effectr a high pressure pump. Said pump mayr for example be capable of generating a pressure on the order of 8rO00 pounds. The purpose of this high pressure is to provide a high pressure stream or jet of water for spot washing equipment during the ~ .

)48 manufacturing process. In this instance high pressure soft water from hydrolaser 3 is used to wash the chains of Line 4. After the washing action, the water flows by gravity to the basement or collection pit 5 of Line 4, from whence it again discharges by gravity to sewer 6 which in turn discharges into the lift station in a water house which, for example, includes a pump 7 which is set to pump both water and a small quantity of air so that any "floaters" in the lift station are sucked into the pump and moved along the system.
Pump 7 moves the water to hydrosieves 8 which function to remove solids, such as the fibers, for disposal at a convenient site such as an environ-mentally acceptable dry land fill. Any fbrm of hydrosieve may be employed which serves this function.
The type which includes a series of sloped screens has been found to be effective.
The water from which the solids have been separated drains through the hydrosieves into the screened water tank 9 where it is available for usage in the system.
A pump 10 at the outlet of the screened water tank 9 forces the water through line lOA to each o~
the fiber glass insulation manufacturing systems represented by Line 3 and Line 1. Preliminary, it should be noted that in the event screened water tank 9 receives more water then is re~uired in Lines 1 and 3, a float control switch operates to cause a ..~

I lB20~8 solenoid valve to open so that excess water in screened water tank 9 can flow into the surge tankO A metering pump in the line between the surg~ tank and the lift station then forces water at an appropriate time to the lift station where it is again circulated in the system under the pxessure supplied by pump 7.
Screened water under pressure generated by pump 10 is fed into the chain-wick wire system 12 of Line 3. The used water drains from chain washing station represented at 12 directly into a roughing qcrubber pit. The trash pump in the roughing scrubber pit forces the contents of the roughing scrubber pit into the lift station where the water is again cir-culated under pressure generated by pump 7.
Screened water also is admitted to the suction box, the ducts, the washers and the strippers, all indicated generally at 11, in Line 3. Water discharged from station 11 drains into the roughing scrubber from where it is circulated as heretofore described. It should be noted that one o the primary functions of the trash pump in the roughing scrubber pit is to move sunken material to the lit station so that a build-up of the material having a specific gravity greater then 1.0 never accumulates in the roughing scrubber pit; instead, all liquids and solids are maintained in continual motion.
It will also be noted that soft water is fed into hydrolaser 14 of which the output is used as a spot cleaner of the chains in the production line. The used .j , ,~ . ";

0~8 water drains to the roughing scrubber pit where it is recirculated as heretofore described.
Referring now to Line 1, it will be noted that screened water is admitted to station 15 which is the numeral which designates generally the operations more specifically identified as the suction box, the plenum ducts, and the washers and scrubber. Screened water which has passed through this station then drains into a roughing scrubber pit 16 which functions as a collection station, and which includes a trash pump 17 which functions to convey the sinkers to the lif~
station.
Soft water from softening station 2 is directed to the precipitator pit station 21 through 10at control valve 18. The precipitator pit is illustrated in further detail in Figures 2, 3 and 4 from where it will be noted that a level in a surge pit is ~ain-tained by the float control valve 18. The precipitator ~pit also includes a pump pit, a recirculation ~ump, and a trash sump, as illustrated best in Figure 3.
From Figure 4 it will be noted that screened water which has passed through the screens on the right of the Figure into the screen underflow channel is deposited into the recirculation sump29. In this connection it will be noted that float control valve 18 maintains the level in surge sump 20, as used or fresh water is admitted to the recirculation sump 29- A
pair of recirculating pumps 22, shown best in Figure ~, pulls suction from circulation sump 29, delivers water to I lB2048 precipitator 25 shown in Figure 2, and the forming fans forming ducts station 24 and Rotoclone 28 in Figure l.
Forming air from the forming ducts goes, along with oven gases, to the electrostatic precipitator 25. As above described the water passing through screens 26 goes to re-circulation sump 29. In this connection it should be noted that water pumped to the forming fan and forming ducts 24 drains back to screens 26. A scavenger pump is indicated at 27, the pump drawing from the bottom of the surge sump 20 and delivering to the screening area 26.
It will be noted that soft water rom the source is delivered to the recirculation sump 29 through float control valve 18, illustrated best in Line l of Figure lB.
From the recirculation sump 29, the water pases via a float controlled valve 33 to the Ro~oclone 28. From the Rotoclone 28, the water passes through the time controlled valve 30 to the roughing scrubber pit 16.
Fresh soft water from softener station 2 is used ; to wash the flight sprays 31 and the used water drains into the roughing scrubber pit 16. Soft water also is admitted to the hydrolaser 32 and, after usage, also drains into the roughing scrubber pit 16 for recircula-tion back to the lift station.
Turning now to Line 2 shown at the right side of Figure lB, it will be noted that no screened water is supplied to this sytem. Rather, only soft water from softening station ~ is admitted into this line.
Soft water is fed by float control valve 33 into the Rotoclone 34, the float control valve maintaining the desired level within the Rotoclone. As will be appreciated by those knowledgeable in the art, the Rotoclone cools the air admitted to it, serves as a r .-. 1 '

2~4L 8 . g fire stop, keeps the ducts clean and causes pollutant vapor condensation.
Water discharged from the Rotoclone goes via a float control valve 35 through the operating screens 46 and into the precipitator pit 36. It will be noted that float control valve 35 controls the level in surge sump 50, Figure 2, and delivers water to recirculation sump 51. A recirculating pump S2 directs water to the forming fans 53, forming ducts 54 and to precipitator 55.
Each of forming fans 53, forming ducts 54 and precipitator 55 drains onto the screens 46 which removes the fibers and large particulate matter, with the treated water then being recirculated as described immediately hereinabove. The balance of the treated water passes through a meter and float control valve onto screens 87 which in turn drain into the roughing scrubber pit 86 associated with this production line.
Discharge from the roughing scrubber pit is through ~20 pump 82 which delivers the water through a meter 84 to the accumulator tank 830 Soft water is also sprayed onto the flights 60 from which it drains into the screens 46.
Screened water from the precipitator pit also passes from pump 52 through float control valve and an associated meter to surge sump 80. Recirculation pumps 82 force water to the suction box 83, the ' '!
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î 162~48 plenum chamber, the suction ducts and the venturi scrubbers. Water drains from this system onto the screens 87, equivalent to screens 26 shown in Figure - 4. The water then drains to the roughing scrubber sump 86~ Pump 82 forces water to accumulator tank 83 and then into a coagulation and vacuum filtration system which cleans up the water for use in the binder making process. ~
Speciica11y, water passing through accumulator tank 83 goes into a pair of treatment tanks, the oukput of which is passed through vacuum filters, and then collected into the treated water storage tank. As needed, water is drawn from this ~torage tank to be mixed with the binder which goes into the process at thé forming station.
From the above description it will be apparent that a method and system have been provided wherein freshly screened water is continually in motion, and a skimming operation i~ operative to thereby minimize coagulation and prevent blockage of spray tips, ducts, fans and, when used, the electrostatic precipltator.
Other objects and advantages of the invention will become apparent to those skilled in the art : ~: :
25~ from a reading of the foregoing description.
; ~ Accordingly it is intended that the scope of the ;~ ~ invention be limited by the scope of the hereinafter appended claims~ when interpreted in light of the ; pertinent prior art, and not in light of the foregoing exemplary description.

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Claims (2)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a combination in a water treatment system for use in a fiber glass insulation manufacturing process, a source of soft water, a source of screened water located at a screening station means for increasing the pressure head of said soft water so as to enable it to be utilized in inter-mittent demand cleaning applications, means for collecting said used soft water and process impurities contained therein and returning said used soft water to a collecting station preparatory to its subsequent use in the system, means for applying said collected soft water to an electrostatic precipitation water cleaning and collection system, said cleaning and collection system including a recirculation sump, a surge sump, and weir means located in the path of the surge sump which functions to keep floating materials in movement through said cleaning and collection system at all times, means for applying water discharged from the cleaning and collection system into one or more pro-cessing stations in the production system, and means for collecting used water from all stations, including used soft water and used screened water, and transferring said collected used water to the screening station where it is prepared for subsequent screened water applications in the water treatment system, said water treatment system being so arranged that floating materials not designated for removal at specific locations is maintained in motion at all times.

2. In a method of treating water in a fiber glass insulation manufacturing process, the steps of supplying soft water under a substantial pressure head to intermittent demand applications, collecting used soft water together with impurities contained therein at a screening station, screening said used soft water preparatory to reuse in screened water applications, applying screened water to one or more stations, including processing stations, in a fiber glass insulation manufacturing system, collecting said screened water subsequent to application thereof at the stations, including both used soft water and used screened water, transferring said screened collected water to the screening station where it is prepared for subsequent screened water applications in the water treatment system, and applying motion to the water in the system at all points therein so that accumulation of solid material, including particulate matter, and semi-solid materials in restricted flow passages is precluded.