Constraints inside a container
Container plants are limited in width, height and weight. Usable water depth is usually lower than in a concrete basin, and there is little headroom for lifting. That changes the membrane choice: modules need to fit the internal width with room for piping, and cartridges should come out without a large crane. Zyramic Swing cartridges lift out individually, which suits builders who want service from a roof hatch rather than through a full module pull.
Custom sizing: we cut, weld and assemble in Poughkeepsie, NY, so cartridge and module sizes can often be tailored to your existing tanks. Tell us your tank dimensions, or see custom sizes.
Sizing for a moving target
Containerized plants often serve camps, construction sites, emergency response and remote industry, where flow and load change quickly. A conservative design flux, real equalization volume and a cleaning plan that a part-time operator can follow help keep a compact plant stable. Fine screening is especially important, because a single rag event in a small tank affects a larger share of the membrane area.
Build, rent or replace
We supply modules to container plant builders, rent modules for US temporary projects, and make replacement flat-sheet membranes for containers already in the field. See the compare page for how Swing, Palisade and ceramic modules differ.
| Mild backwash (special cases only) |
|---|
| Backwashing is not a standard Swing operating mode and is not meant for routine use. Swing has been pressure-tested to 14.5 psi (1 bar) and held without breaking. If a site is in a bind even after relaxation and CIP, contact us; we may be able to work out a special mild-backwash procedure. |
Worked sizing example
Take a containerized plant for a 250-person camp at about 13,209 gpd (50 m³/day):
| Item | US | Metric | Note |
|---|---|---|---|
| Average flow | 13,209 gpd | 50 m³/day | about 9 gpm (2,083 L/h) |
| Design flux (gross) | 8.8 gfd | 15 LMH | Zyramic design guidance |
| Derate for relaxation and cleaning | ~20% | ~20% | |
| Net flux | ~7.1 gfd | ~12 LMH | |
| Membrane area needed | ~1,869 ft² | ~174 m² | average flow ÷ net flux |
| Swing-8 cartridges | ~14 | ~14 | 135 ft² (12.5 m²) each |
| Peak factor | ~2.5 | ~2.5 | |
| Peak flow | ~33,022 gpd | ~125 m³/day | extra area, short-term higher flux, or equalization |
This is an illustration only; a real design also checks temperature, MLSS, redundancy and the cleaning schedule.
Tips for a smooth project
- Size for peak hour as well as average flow
- Invest in good fine screening up front
- Use temperature-corrected flux for cold-weather design
- Plan lifting access so modules come out easily
Next step
Most projects start with a short call or an email with flows and a sketch. We send back a preliminary module layout and a quote, then refine it with your engineer once the process design is firm. If you are still comparing processes, we'll help you choose the right approach for your site.
Sizing considerations
To give a useful recommendation we usually need:
- Container internal width, height and water depth
- Design and peak flow, and how fast the load changes
- Operator availability and remote monitoring
- Lifting method available on site
- Climate: freeze protection or heat
Most relevant product: Swing MBR. See also replacement membranes, rentals and how to choose.
Why engineers look at Zyramic flat-sheet modules
| Item | Details |
|---|---|
| Smaller sheets, less wear and tear | each sheet flexes less in service, and a damaged unit affects less area. |
| Strong wide membrane welds | designed to resist delamination over the membrane's life. |
| Thick, robust membrane | about 250 microns including support. |
| Assembled in Poughkeepsie, NY | of domestic and imported components. In our Poughkeepsie shop we cut and weld membrane sheets to plates, build module frames and assemble complete modules. For funded projects, tell us your domestic-content requirements and we'll review what we can document. |
| Buy, rent or replace | new modules, rentals and pilots for US projects, and replacement membranes that fit many existing cassettes. |
Performance and life depend on pretreatment, design flux and operation; flux figures are Zyramic design guidance, sized to each project.
Frequently asked questions
Will your module fit a 20 ft or 40 ft container?
Swing modules are available in several deck and column combinations, so most container layouts can be accommodated. Send internal dimensions for a fit check.
Can cartridges be replaced without removing the whole module?
Yes, Swing cartridges are designed to be swapped one at a time.
Do you build the container plant?
No. We supply membranes and work with the builder or integrator.
Are rentals available for temporary container plants?
Yes, for US projects.
How much flow can one container treat?
It depends on biology, depth and membrane area. Container plants commonly range from small camp systems to a few hundred cubic meters per day; larger flows use several containers.
What about freezing climates?
Insulated containers, heat tracing and indoor equipment are typical. Cold water also lowers flux, so we size for the coldest expected mixed liquor temperature.