Jumbo Sized Reactor for Bio-pellets
Jumbo Sized Reactor for Bio-pellets
I recently decided to try out the latest rage in nitrate/phosphate reduction - bio-pellets The vendors of the pellets (I purchased mine from Warner Marine) all recommend approx. 1/2 liter of pellets per 100 gallons of water to be filtered. I usually stick with recommended amounts - I always like to err on the side of caution - so, for my system, I need around 2-1/2 to 3 liters of pellets. Current general opinion seems to be that the pellets require a fluidized media reactor for maximum effectiveness. That's a bit of a problem as there are no (affordable) fluidized media reactors on the market that are large enough to hold four liters.
So what to do? Well, I happened to have a 24" long piece of 6" cast acrylic tubing that had originally been intended as the neck for a DIY skimmer that never materialized. It was perfect for a jumbo sized DIY reactor, instead. Add to that some 3/8" black and 1/4" clear acrylic sheet, a few 1/4"-20 nylon thumb screws, a length of 1/4" silicone o-ring stock (all of which I had laying around as extras from previous projects), and just about all the material requirements, for the reactor, were taken care of. The only parts I had to purchase were a few 3/4" Sched-40 PVC fittings and two circular sewing grids from Jo-Ann's.
How does a fluidized reactor work?
Before I start on the description of the reactor build, it might be good to describe how a fluidized media reactor functions - skip this paragraph if this is not new to you. The term fluidized media comes from the fact that the media - such as sand, carbon, GFO, or in this case bio-pellets - is forced into a fluid like (ergo fluidized) tumbling motion by the flow of water through the reactor. This can only take place if the water entering the reactor (in sfficient volume and force) is first sent to the bottom of the reactor ad then flows up through the media. The drawing illustrates this principle:
Of course, in addition to the reactor, a pump is required to move the water from the system, through the reactor, and back to the system.
A little about the design
This reactor would be holding a relatively large amount of media. Add that to the fact that bio-pellets are fairly heavy, and one can assume that there will have to be a strong current through the reactor in order to cause the pellets to enter into a fluidized motion. Taking this need for more water flow into consideration, I dimensioned all the fittings a size larger than the 1/2" I usually use. I assumed that 3/4" water lines would suffice to get the 2-1/2 to 3 liters of pellets moving sufficiently.
I"ve been building fluidized reactors for years using the same basic and very practical design. It"s seen on many commercial reactors and with good reason. The design is straight forward, comparatively simple to build, and functions very well.
And the component parts
The top consists of a keyhole flange made of 3/8" cast acrylic sheet. I like to use black, but any color will do. I use a template whenever I need to make a keyhole flange. Years ago, I made a set of flange templates - one for every standard size of acrylic tubing, from 2" all the way up to 12". The templates are made from 1/2" MDF and minimize the effort necessary to complete a flange. Using a template and my router table, I can complete one in less than half an hour.
I used 3/4" female threaded couplings for both IN and OUT through-leads. That way, later, I can change out, or realign, the 90deg elbows for straight couplings if that better suits the installation conditions.
BTW: anytime I have a need to glue acrylic to PVC, I use the two part epoxy glue Weld-On 40. It is extremely strong and fairly easy to work with. I say fairly easy because you do have to put a little effort into mixing it up accurately, as the instructions call for a 20 to 1 mix - resin to hardner.
Viewed from the bottom, you can see the fittings used below the top flange. The longer of the two (water in) is a 3/4" slip coupling. When the top is placed on the reactor, it engages (slips over) the central water feed tubing that leads to the bottom of the reactor. The "water out" lead just ends in a short stub (just a slice of a normal 3/4" coupling added for strength) beneath the top flange.
continued on next post...
Jumbo Sized Reactor for Bio-pellets
I recently decided to try out the latest rage in nitrate/phosphate reduction - bio-pellets The vendors of the pellets (I purchased mine from Warner Marine) all recommend approx. 1/2 liter of pellets per 100 gallons of water to be filtered. I usually stick with recommended amounts - I always like to err on the side of caution - so, for my system, I need around 2-1/2 to 3 liters of pellets. Current general opinion seems to be that the pellets require a fluidized media reactor for maximum effectiveness. That's a bit of a problem as there are no (affordable) fluidized media reactors on the market that are large enough to hold four liters.
So what to do? Well, I happened to have a 24" long piece of 6" cast acrylic tubing that had originally been intended as the neck for a DIY skimmer that never materialized. It was perfect for a jumbo sized DIY reactor, instead. Add to that some 3/8" black and 1/4" clear acrylic sheet, a few 1/4"-20 nylon thumb screws, a length of 1/4" silicone o-ring stock (all of which I had laying around as extras from previous projects), and just about all the material requirements, for the reactor, were taken care of. The only parts I had to purchase were a few 3/4" Sched-40 PVC fittings and two circular sewing grids from Jo-Ann's.
How does a fluidized reactor work?
Before I start on the description of the reactor build, it might be good to describe how a fluidized media reactor functions - skip this paragraph if this is not new to you. The term fluidized media comes from the fact that the media - such as sand, carbon, GFO, or in this case bio-pellets - is forced into a fluid like (ergo fluidized) tumbling motion by the flow of water through the reactor. This can only take place if the water entering the reactor (in sfficient volume and force) is first sent to the bottom of the reactor ad then flows up through the media. The drawing illustrates this principle:
Of course, in addition to the reactor, a pump is required to move the water from the system, through the reactor, and back to the system.
A little about the design
This reactor would be holding a relatively large amount of media. Add that to the fact that bio-pellets are fairly heavy, and one can assume that there will have to be a strong current through the reactor in order to cause the pellets to enter into a fluidized motion. Taking this need for more water flow into consideration, I dimensioned all the fittings a size larger than the 1/2" I usually use. I assumed that 3/4" water lines would suffice to get the 2-1/2 to 3 liters of pellets moving sufficiently.
I"ve been building fluidized reactors for years using the same basic and very practical design. It"s seen on many commercial reactors and with good reason. The design is straight forward, comparatively simple to build, and functions very well.
And the component parts
The top consists of a keyhole flange made of 3/8" cast acrylic sheet. I like to use black, but any color will do. I use a template whenever I need to make a keyhole flange. Years ago, I made a set of flange templates - one for every standard size of acrylic tubing, from 2" all the way up to 12". The templates are made from 1/2" MDF and minimize the effort necessary to complete a flange. Using a template and my router table, I can complete one in less than half an hour.
I used 3/4" female threaded couplings for both IN and OUT through-leads. That way, later, I can change out, or realign, the 90deg elbows for straight couplings if that better suits the installation conditions.
BTW: anytime I have a need to glue acrylic to PVC, I use the two part epoxy glue Weld-On 40. It is extremely strong and fairly easy to work with. I say fairly easy because you do have to put a little effort into mixing it up accurately, as the instructions call for a 20 to 1 mix - resin to hardner.
Viewed from the bottom, you can see the fittings used below the top flange. The longer of the two (water in) is a 3/4" slip coupling. When the top is placed on the reactor, it engages (slips over) the central water feed tubing that leads to the bottom of the reactor. The "water out" lead just ends in a short stub (just a slice of a normal 3/4" coupling added for strength) beneath the top flange.
continued on next post...
Feel free to continue to add anything as time goes on.
For those of you who are not aware of the fact, Mark was kind enough to allow me to dedicate a photogallery to his beautiful coral pictures on my site (check it out - it's 
