LPS single-rotor shredder for long pipes

LPS single-rotor shredder for long pipes

Large-diameter plastic pipe is one of the most awkward things a recycler is ever asked to process. It is rigid, it is long, it does not compress, it does not stack, and it will not go into a normal shredder hopper. The usual answer is to cut it into short lengths first — with a saw, by hand, one cut at a time — which is slow, labour-intensive work before the actual recycling starts.

The LPS exists so that step can be skipped. Long pipes, large or small in diameter, can be nested inside one another and fed in whole. If cutting them short is not something you want to do, this machine will take them as they are.

Maximum pipe diameter is the specification that matters

Most shredders are chosen on throughput. This one is chosen on geometry first, and throughput second.

The two models accept ⌀630 mm pipe (LPS800) and ⌀1,100 mm pipe (LPS1200). If your largest pipe exceeds that figure, no amount of installed power helps — the pipe physically will not enter the cutting chamber. Check this number against your largest regular diameter before anything else on the page.

It also explains the rotor dimensions, which look extreme next to any other single-shaft machine:

Rotor diameter is ⌀800 and ⌀1,200 mm — roughly double what an SS or YPS single-shaft machine carries. A rotor has to be large enough that the cutting circle can engage a pipe wall presented to it side-on, and the chamber around it has to be large enough for the pipe to enter at all. Rotor diameter here is not about capacity; it is about clearance.

40 rpm: slower than any other single-shaft in the range

The rotor turns at 40 rpm, against 72 rpm on the SS series and 74 rpm on the YPS. That is a deliberate drop of nearly half, and it is what thick-walled pipe demands.

A large-diameter HDPE or PVC pipe has a wall many times thicker than a bottle or a film layer. Cutting through it is a high-force, low-speed operation: the blade has to penetrate and shear a substantial section of solid polymer rather than slice a thin one. Turning slower converts the same installed power into more torque at the rotor, and torque is what gets through the wall.

Slower rotation also keeps friction heat down. Thick PE that is worked too fast softens at the cut face, and softened material smears and welds instead of chipping cleanly.

Multiple motors, not one large one

Drive is 37 kW × 2 on the LPS800 and 45 kW × 3 on the LPS1200. Splitting the drive across two or three motors rather than fitting one very large one is a normal choice at this torque level, and it brings two practical advantages: torque is applied at more than one point along a long rotor rather than all at one end, and the motors themselves are standard frame sizes that are straightforward to source and replace anywhere in the world.

Knife count rises steeply with the machine: 60 inserts on the LPS800, 168 on the LPS1200. That is nearly a threefold increase for a 50% longer rotor, because the larger machine has both more length and a much larger circumference to populate.

Where it sits in a pipe recycling line

The LPS is the first stage, not the whole plant. The layout above shows the normal arrangement: shredder with its hydraulic station, a belt conveyor taking the shred away, and a granulator or crusher downstream bringing the material to final flake size.

That two-stage split is deliberate. The LPS is built for clearance and torque, which makes it the only machine on the line that can accept a whole pipe — but those same characteristics make it the wrong machine for producing fine, uniform flake. Once the pipe has been reduced to manageable pieces, a faster crusher with a screen does that job far more efficiently. Asking one machine to both swallow a ⌀1,100 mm pipe and produce 10 mm flake would compromise both ends.

Quoted capacity is 800–1,200 kg/h for the LPS800 and 1,500–2,000 kg/h for the LPS1200, measured on PE pipes. Wall thickness and pipe diameter both move the real figure, since a thick-walled pressure pipe is considerably more work per kilogram than a thin-walled drainage pipe.

Nesting, and what it does for throughput

Feeding pipes whole is one thing; feeding them efficiently is another. A single ⌀200 mm pipe lying in a ⌀1,100 mm chamber leaves most of the cutting circle doing nothing, and the machine is then limited by how fast an operator can put the next pipe in rather than by what the rotor can cut.

Nesting solves that. Smaller pipes are slid inside larger ones before the bundle goes to the infeed, so a single pass presents several walls to the blades instead of one. On a mixed-diameter stock this is the difference between running at rated capacity and running at a fraction of it, and it costs nothing but a moment of sorting at the infeed.

Two things follow for anyone planning the operation. Sort incoming pipe by diameter at the yard rather than at the machine, because nesting is quick when the sizes are already grouped and slow when they are not. And remember that a nested bundle is heavier and stiffer than a single pipe — feeding handling should be planned for the bundle, not for the individual length.

What condition the pipe arrives in

Two very different feedstocks come to this machine and they lead to different plants.

Production offcuts and reject pipe are clean, of known polymer, and often of consistent wall thickness. Shredding and granulating may be all that is needed before the material goes back into the process. This is the simplest case and the one where the shortest line pays back fastest.

Post-consumer and excavated pipe is another matter. Drainage and sewer pipe comes out of the ground carrying soil, grit and sometimes concrete residue, and all three are abrasive. Grit does not stop the shredder — a 40 rpm rotor takes it in its stride — but it consumes blade edges steadily and it will be there in the shred afterwards. Material in this condition needs washing between shredding and any attempt to sell or reprocess it, and the tooling budget should assume faster wear than clean offcuts would suggest.

Worth checking before the machine is specified: whether metal is likely in the stream. Excavated pipe sometimes arrives with clamps, couplings or embedded fixings still attached, and those are worth removing at the yard rather than discovering them at the rotor.

See it running in a line

Frequently asked questions