Introduction: Screen Printing Washout Booth & Filter System
The photo above is my initial design for the filtration system.
I am a Screen Printer and I needed a large booth to washout my screens in that also filtered out all the gunk from the wastewater. I use eco-friendly chemicals but I still wanted to make sure I kept those chemicals out of the drain.
You can buy large washout booths and filter systems but even for the low end ones I was looking at spending at least $2000.00.
So I searched online for weeks looking for anyone that had built a custom washout booth (full size, I kept seeing washout booths made out of those $50 garage sink basins that aren't big enough for even a smaller sized screen printing frame. The frames I use are 20x24 inches. Even harder to find were custom built filtration systems...so I designed one myself.
What you see in the photos is the combo washout booth/filtration system. When I built this I was mostly focusing on the washout basin/backsplash and drain and then the filtration system. The 2x4s that I built the frame out of could and probably will be replaced with something that looks nicer. It worked and I had orders so I started using it.
I am posting the design plans for the washout booth itself right after doing this. This tutorial is for the filter system underneath the washout booth drain. The rest is pretty straight forward. I just installed a basic shower drain into a large cement mixing tub and then used corrugated plastic sheeting as the backing to keep the chemicals and water from splashing out. The tutorial for that part is the Washout Booth & Filter system (part 1)
Some background, when I started out I didn't understand the first thing about water filtration. I had to do a lot of research on what a "micron" was and what gallons per minute (GPM) really meant when it came to maintaining a filter system over a long period of time. I had to give myself a crash course on plumbing, water pressure, etc.
So you will hear me refer to microns in this tutorial. A micron is a measurement for a water filters ability to filter out a certain size of particle. The larger the micron the larger the holes are in the water filter and it will let more particles through while catching the big particles. Water filters can be made from a wide variety of materials. if you go online you can find filters that are carbon filters, pleated (look kind of like a cylinder of folded paper), polypropylene, and string or fiber cartridges. Each has its pros and cons as far as how long it will last, how much water pressure it can handle, etc. With the exception of carbon filters, which are mostly for taste and don't really filter out much (at least in terms of screen printing drain gunk)
So the best way I decided to filter my washout booth waste was to build a system of 5 filters of decreasing size.
Phase 1: Large particles--when you reclaim a screen the emulsion normally comes off in chunks and those larger chunks are easier to filter out with screen mesh. I created a filter using some 255 tpi screen mesh I pulled off an old screen (that I broke when trying to reclaim it) and glued it around some PVC pipe cut to size. I will get to that in the tutorial.
Phase 2&3: I bought a small piece of swamp cooler fabric that is double sided, I dark green rougher side that catches larger particles and a light blue side that catches smaller ink particles
Phase 4: 25 micron filter/filter housing. At this stage the wastewater gets pumped through my sump pump into the first filter housing.
Phase 5: 10-15 micron filter/filter housing. This is the final stage and the smallest particles get scrubbed from the wastewater and then exits and runs out the drain hose into the drain.
Adjustments: I used the 10 inch filter housings to test and see if the set up worked after I designed it. I am going to switch to at least one 20 inch filter housing and then bump up the microns. Its doing its job now, but I have to swap out the filters much more frequently than if I had been using say a 75 micron filter and a 25 micron filter that were 20 inches.
Step 1: Materials
You will need:
1. PVC cutting tool (I just use a regular handsaw)
3. hole saw attachments for drill. 1" and 3" hole size for the bulkhead fittings
4. PVC cement and primer
5. plumbing tape
6. plumbers wrench (I got a nice red one from walmart, it wasn't too pricey either)
7. Sump pump Simer 2305-04 Geyser II 1/4 HP Submersible Utility Pump is the one I used
**well ventilated area for that pvc cement and primer that stuff is strong and you don't want to breathe the vapors.**
1. (2ct) 18 gallon Medium sized tote. I used the ones made by Sterilite or Rubbermaid because they were made out of a strong heavy duty plastic that didn't crack when I cut into it. You can use bigger bins but only wider, the height can't get much higher or it will make the washout booth too tall.
****EDIT: I am trying to find or build some sort of bin that will hold full sized screen printing screens, then you could just stack a couple of screens on top of each other for your phase 1-3 filters in the back tank, which would be way easier than swamp cooler fabric and having to glue screen fabric over pvc pipe!***
1. PVC Pipe. Sizing to what you need. Example the filter housings I used had 3/4" fittings, so I had to buy 3/4" pipe and fittings. The sump pump had a different size so I had to buy some pipe in that size and reducer fittings for 3/4" pipe.
1-1/4" pipe (My sump pump had a 1 1/4" opening with an adapter to 5/8" hose fitting, the adapter leaked so I connected the pipe directly to the 1 1/4" threaded opening)
(1 ct) 1-1/4" Schedule 40 PVC Male Adapter (male side is threaded, female side is slip)
(2 ct) 1-1/4" Schedule 40 PVC 90-Degree Elbow (slip both sides)
(1 ct) 1-1/4" Schedule 40 PVC to 3/4" reducer
(3-4ct) 3/4" Schedule 40 PVC Male Adapter (male side is threaded, female side is slip)
(4) 3/4" Schedule 40 PVC 90-Degree Elbow (slip both sides)
(2ct) 2in Banjo Polypropylene tank bulkhead fittings (Banjo TF200 Polypropylene Bulkhead Tank Fitting, 2" NPT Female)
(OPTIONAL, only if you want to install emergency tank drains in case of overflow or you need to clean drain tanks) (2ct) 3/4in Lifegard Aquatics 3/4-Inch Double Threaded Bulkhead
1 sheet: WEB Eco Filter Replacement Pad, 6 Year (swamp cooler fabric) (SEE PHOTO: Fabric in back tank)
(2 ct) 10 or 20 inch filter housings. Look for Pentek, GE, etc. I used: General Electric GXWH04F Standard Flow Whole House Filtration System with 3/4" in and out flow. They came with mounting brackets too!
(2-4ct) filters. You only need two but they usually come in pairs and I like to have replacements on hand.
Instead of having to plumb the rest of the way to the drain, after the second filter housing I installed a hose adapter and just connected a hose to it and then ran the hose out to the drain. Just try to use a hose that doesn't kink too much and you won't have a water pressure problem. Just to test the water pressure after going through the filters, I connected a 50 ft commercial hose and ran it to the washer drain inside my house from the garage, worked perfectly. Also no leaks! Plumbers tape is awesome!
Step 2: Drain Basin
Okay so this step goes through how to make the basins that hold all the dirty drain water from the washout process until it is pumped through the filtration system.
I made two tanks so that it could hold more drain water, and give me more room to make phase 1 filters, which would be placed in the back tank.
The sump pump goes in the front tank, as far in the front of the tank as possible.
Drill 3" holes through one side of the bins
Take the bulkhead adapters and fit them into the holes, flat side on the inside of the bin, screw them in as tight as you can get it with the plumbers wrench.
then for each bulkhead adapter, attach the schedule 40 2" male adapter into the other side of the bulkhead adapter that is sticking outside of the bin. make sure the fit is tight and thread with plumbers tape
cut a very short piece of 2" PVC pipe and connect both drain tanks to each other by welding (with PVC cement) the two slip sides of the male schedule 40 adapters.
See diagrams for reference.
Step 3: Install Sump Pump and 1-1/4 in Connectors
In this step you will do the 1-1/4in pipe and connectors to move the drain water from the sump pump and out of the drain basins (bins)
Don't weld anything together until you have made sure that all your cuts are correct and everything fits together!
Take your 1/4hp Submersible Utility Pump, and attach the
(1 ct) 1-1/4" Schedule 40 PVC Male Adapter (male side is threaded, female side is slip)
Then cut a piece of 1-1/4 inch Schedule 40 PVC pipe so that the 1st 90-Degree elbow clears the top of the drain basin when attached. (see second photo)
Attach first 1-1/4" Schedule 40 PVC 90-Degree Elbow
Then cut a short piece of Schedule 40 PVC to clear the legs of the washout booth
and attach the second 1-1/4" Schedule 40 PVC 90-Degree Elbow
Now you are ready to insert the 1-1/4" Schedule 40 PVC to 3/4" reducer coupling into the other side of the 1-1/4" Schedule 40 PVC 90-Degree Elbow (see third photo)
Step 4: Connect Your Filter Housings
Take your filter housings and attach the 3/4" Schedule 40 PVC Male Adapter to each end (make sure you line up the In and out correctly for proper water flow)
Now just take the desired length of 3/4" PVC pipe and attach your reducer coupling to the first filter housing, then connect the second filter housing to the first
You can add a garden hose adapter on the Out side of the second filter and then just drain your filtered water out through the hose.