Container Washing - Frequently Asked Questions
Rotajet are the experts in container washing equipment. With 30 years’ experience, Rotajet have the knowledge to answer the questions you have about container washing. If you can’t find what you’re looking for in our container washing FAQs, please contact our team and we would be happy to answer your queries.
Cleaning an IBC
To ensure that you are achieving a repeatable cleaning quality as well as showing your due diligence, it is important to regularly check the IBC to ensure it has been completely decontaminated. This is a simple offline process and can be achieved by following several different processes.
One method used across the industry is by conducting a swab test with a product like the 3M™ Clean-Trace™ or conductivity of pH tests. These provide you with a colour coded, qualified result in 10 minutes or less, making them a fast and effective test.
Yes, it is possible to utilise solvents in your container washing process however the machine must be manufactured to remove the possibility of ignition by adhering to ATEX legislation. Rotajet offer a full range of ATEX equipment including IBC reconditioning lines. All ATEX installations are CE marked and adhere to the standards set by the ATEX directive. It is the responsibility of the client to conduct a full ATEX study to ensure your facility is suitable to house the operation.
Rotajet offer full ATEX design studies alongside the manufacturing process if you wish to have assistance to fulfil your obligations within the ATEX directive.
To fully clean an IBC, it must go through three distinct container washing processes. Firstly, to remove labels and stubborn stains on the exterior surfaces the vessel must be pressure washed in a station such as the RJ-IWE. Next, to remove the bulk of the contamination, typically a chemical wash stage is incorporated into the line either as a standalone system (RJ-IW/1C) or as part of a two-stage wash and rinse (RJ-IW/2). Finally, a freshwater rinse is used to flush any remaining chemicals or contamination from the system.
A table is included below to show typical cycle times for each possible configuration. It is important to note that this can vary depending on the contamination and dosing percentage as well as if optional heating is included.
6 – 11 min
The energy required to clean an IBC is entirely dependent on the type and level of contamination present. A table is included below showing the power requirements for each component stage and typical cycle times for the container washing process are included for each.
Drying an IBC
Drying an IBC can be problematic for two reasons. Firstly, the internal shape of the IBC can leave water in “puddles” in the base of the IBC after washing. As the thermal dryer will only evaporate the surface of the water it can take an extended period to dry which is why we typically include a wet vac station.
Secondly, as an IBC is typically made from HDPE, if extremely high temperatures are used to drive off the water, the bottle will deform or even melt, rendering the IBC useless. A RJ-DIBC thermal dryer operates at 130°C, well below the HDPEs melt point.
A RJ-DIBC uses compressed air at a volume of 200-900L/min to dry an IBC. This will typically dry an IBC in approximately 6 minutes at 130°C.
Thermally drying any object demands high energy input due to the need to generate and maintain a high temperature of expelled air. Thanks to the efficiency of the design, this is kept to 3.7kW/230V.
The consumption of energy for a thermal dryer can be reduced by utilising heat generated by processes at your facility through a heat exchanger. The introduction of a vacuum station prior to the thermal dryer can vastly reduce energy consumption as well as decrease cycle times by removing any puddles that have formed in the cavities of the IBC.
Pressure testing an IBC
IBCs can contain any liquid from water to diesel and are transported worldwide. Leakages not only increase spends, but the materials held within them can also represent a major health and safety risk; presenting an expensive clean-up operation. Pressure testing an IBC means that you can be sure when refilling that no cracks or punctures are present.
IBCs are required to be fully tested at a minimal interval of 2.5 years as well as receive a full inspection. It is however best practice to test each IBC during the reconditioning process as many buyers will not accept un-tested IBCs. More information regarding UNECE requirements for testing IBCs can be found here.
Due to the HDPEs thermostability, it will begin to flex at temperatures far below its melt point. The additional flexibility will alter the results of the pressure test and may give false readings. Rotajet typically install the RJ-IPT after it has been rinsed with cold water and before the thermal drying stage to ensure the bottle is cool before testing.
If an IBC fails a pressure test, it is regarded as unusable in its current condition and therefore is not refilled. Although repairing an IBC with plastic welding is possible, typically the IBC bottle is removed, and a fresh bottle is fitted inside the protective cage in a process called “debottling”. The spent bottle is then typically recycled by size reducing, cleaning, drying, and bagging the plastic granulate. Rotajet produce fully integrated plastic recycling lines including standardised machinery for processing IBCs, drums, and small containers.
Effluent produced from a reconditioning system is always a primary consideration when designing a new process. How effluent is handled depends on many factors: a breakdown of options is laid out below, but for individual advice please contact our technical team here.
- Right to discharge – Depending on the country your are operating in, your local authority and the contamination and wash liquors used, it may be possible to gain the right to discharge the waste from your process directly down the drain.
- Tankering – If the effluent contains VOCs or POPs, it may not be possible to discharge the waste directly into the sewage system due to the potential harm to the environment and/or the human health.
- Water treatment – The most comprehensive option for dealing with the effluent produced by the system is to integrate it into a water treatment facility. In many cases this may already be present within your operation, however Rotajet do offer the fully functioning water treatment facility as an optional extra for an RJ-IW-Auto.
- Solvent Distillation – If you are washing using solvents, this can be configured into a closed loop system with solvent distillation to recover the spent solvent.
Unless you are dealing with solvent based contamination, the RJ-IW-Auto uses water to clean the IBC in the exterior wash, interior wash, and rinse stations. Each station delivers water, with or without chemical dosing. The cycle time of each station will affect the total amount of water used.
The water consumption of the line can be reduced from these levels if a recirculation system is added as an optional extra.