SF cleaners with filtration

A filtration pump draws the bath through a filter and returns it to the tank, taking out fine particles, oil and residue continuously.

Dirt that the ultrasound loosens stays in the liquid. In a plain tank it settles on the floor or floats on the surface and comes back onto the next batch; in the SF the closed loop takes it out while the machine works.

A cleaner bath lasts much longer: fewer bath changes, less waste and less downtime for draining and refilling, and the parts come out to the same standard from the first batch to the last.

Read more in the knowledge base

• Filtration and bath life
• ST or SF: when the bath needs its own filtration

Overflow from the cleaning tank runs into a buffer tank, where oil separates and a skimmer takes it off before the liquid goes back.

In the buffer tank, separation plates guide floating oil to one side and heavier dirt settles to the bottom. The liquid is pre-filtered and pumped through the filter back to the cleaning tank, and the level in the cleaning tank stays steady when a basket goes in.

The oil skimmer, a rotating belt, lifts the oil off the surface and drops it into a container for disposal. It runs during the cleaning cycles, so oil cannot build up and the cleaner lasts longer.

Read more in the knowledge base

• Removing oil and grease

The returning liquid flows evenly across the surface and carries floating oil and dirt to the overflow, so parts are lifted out through a clean surface.

Oil and fine particles float. Without a surface flow they lie as a film on the bath, and every basket that comes out passes through it. The laminar flow pushes that film to a collection point before it can settle back onto the parts.

The flow is adjustable, so it can be set to the load: stronger for oily work, gentler for light parts that should stay in place in the basket.

Read more in the knowledge base

• Filtration and bath life

60 W transducers at 28 or 40 kHz, adjustable ultrasonic power and a sweep function that keeps the sound field moving.

The transducer count grows with the tank: 48 on the SF-225, 60 on the SF-310 and 72 on the SF-360, for 2880 to 4320 W of ultrasound, about 12 to 13 W per litre. Two external generators drive each tank and are easy to replace.

Sweep varies the frequency slightly around its set value so standing waves do not form: no zones of weak cavitation and no dead spots in the basket. Keep it on unless a process needs a fixed frequency.

Read more in the knowledge base

• 28 kHz or 40 kHz: which frequency cleans your part?
• Sweep and degas: what the two buttons on a digital generator do

The transducers sit in replaceable boxes of AISI 316 stainless steel instead of being bonded under the tank floor.

AISI 316 resists chlorides and acidic chemistry better than AISI 304. The tank itself is AISI 304 with a 2 mm wall.

If a transducer fails, its box is exchanged as a unit; the tank itself does not have to be rebuilt.

Read more in the knowledge base

• Transducers and generators: what drives the tank
• Tank material and wall thickness

One control cabinet runs time, temperature and filtration: a digital timer from 0 to 999 minutes or continuous, and a digital thermostat.

The timer covers short cycles and long soaks, or runs without stopping for continuous production; the SF is built for 24-hour operation.

Filtration is switched from the same cabinet, so the loop can keep cleaning the bath between batches.

Heating of 6 kW on the SF-225 and 9 kW on the SF-310 and SF-360; the digital thermostat holds the set temperature.

Most cleaners work best warm: oils and greases soften from about 40 to 60 °C, and the chemistry acts faster. Match the temperature to the cleaner's data sheet and keep it lower for soft or glued parts.

Plan the warm-up: a full SF-310 needs at least an hour and a half to go from 20 to 60 °C with 9 kW. The hinged lid keeps the heat in.

Read more in the knowledge base

• Choosing the cleaning temperature
• Energy and running costs of an ultrasonic cleaning tank

The cleaning tank and the buffer tank each have a 1" drain valve; lockable castors carry the whole unit.

Drain the cleaning tank and the buffer tank separately into a container or a waste line. With filtration the bath is changed far less often, and when it is, nothing has to be tipped or bailed out by hand.

The stainless steel basket carries up to 200 kg; the stainless steel lid is hinged. The castors turn in every direction and lock; levelling feet set the unit level.

Read more in the knowledge base

• Daily and weekly maintenance of an ultrasonic cleaner