VALVES MAINTAINING CONTROL OVER ACTIVE MEDIA.
Companies are having to contend with ever-stricter standards when it comes to compliance with specified limits within production and logistics processes. In particular, the amended version of the First General Administrative Regulation pertaining to the Federal Immission Control Act of 18 August 2021 (Technical Instructions on Air Quality Control – TA Luft) is presenting enterprises with new challenges.
The challenge of Containment
Actually, the matter is quite simple: just make sure that nothing related to your production processes escapes to the outside.Easier said than done. How do you appropriately isolate pipes, silos, containers, mixers and packaging systems from one another and from the surrounding atmosphere, while ensuring that the specified limits can be reliably adhered to even in the case of superimposed pressure?When it comes to alternating product carriers such as mobile contai-ners (IBCs) or big bags, in particular, docking systems with appropriate safeguards are an essential prerequisite.
Critical Interfaces
Alongside specific docking tasks, existing systems and those to be implemented in the future are also faced with a multitude of shut-off and dispensing processes for which the deployment of safe isolation valves is imperative.
Among the critical interfaces in this case are usually transfer points at which solid materials are to be transferred to a dif ferent pressure level. lf, for instance, the product is transferred from a silo or storage tank,
scales or a mixer into the reactor or the feed pipe with a different pressure level, the butterfly valve must ensure zero leakage. This applies to both positive pressure and vacuum applications.
An additional difficulty is posed by cleaning processes in which the discharge or metering device – usually a rotary valve – has to be opened to the outside.
Cycle lock with inerting system, ex-decoupling.
Cycle Locks and Regulatory Compliance
Cycle locks consist of two butterfly valves that are joined to one another via a container – in the simplest case, with a section of pipe. This unit can be designed as an explosion-decoupled safety system in accordance with EN 13 849-1, thus also ensuring safe product discharge even in dust explosion class 3 (KSt > 300 bar* m/s).
Material is contained, i.e. does not escape to the outside, during the transfer process, the cleaning processes or even in the event of an explosion. The prerequisite is that the two valves comply with the regulations of TA Luft and, if applicable, are approved as explosion pressure-resistant parts in accordance with EN 14 460, etc. The requirements of components and assemblies pursuant to the Federal Immission Control Act must be taken into consideration by the manufacturer or distributor. The design must enable the operator to adhere to limit values and ensure safe operation.
According to current estimates, around 50,000 production systems in Germany are subject to the new TA Luft regulations in force since 2021.
Advanced Valve Technology for Modern Applications
EBRO ARMATUREN has further refined its shaft sealing in response to these more stringent requirements. The valves can be used individually or, as outlined here, in EBRO cycle locks.
Thus, operators and plant engineers can rely on a device that meets no fewer than three important criteria for systems with corresponding requirements:
- Type testing for ATEX up to zones 0 and 20, approval in IECEx•
- Deployment also possible with active substances; can be cleaned when completely closed against the external atmosphere
- Type testing as an explosion-decoupled safety system at performance level ‚D‘ with a test pressure of > 15.4 bar
ViDos® valves are based on proven standard valves with an elastomer or PTFE liner.
In addition to the classic task of controlling or regulating the product flow, this valve is also used as a metering device for bulk solids. For this purpose, a linear vibrator whose pulses are conducted directly into the valve disc is integrated within the valve. In this context, product flow is set in motion and maintained by means of the disc‘s vibration. Bridging is effectively prevented, while the even rate of discharge enables high repeatability.
The volumetric flow can be easily throttled without running the risk of product flow coming to a halt. In this case, it must be ensured that alveolar fractions of the dosed products are unable to escape to the outside during either ongoing operation or maintenance and cleaning work.
This vastly simplifies directly loading scales or containers positioned on load cells. The valve is first opened completely in order to feed in the majority of the desired quantity as quickly as possible.
Shortly before the desired quantity has been achieved, the valve is closed partially and the vibration kicks in. The remaining quantity can now be infed in fine flow. The valve then securely seals the container.
The vibrating dosing valve undertakes metering tasks
Containment and Sustainability
However, the encapsulation of products within a production
system is by no means a one-way street. lnvitations to tender,
particularly for the sensitive processes involved in battery cell production, include requirements that also have to rule out the product being adversely affected by potential sources of both external and internal contamination.
Thus, minimising abrasion is a key issue, not only in the pharmaceuticals and fine chemicals industries. Complete isolation of the product flow from the external atmosphere goes hand in hand with the need to ensure that no non-ferrous metals are present. Demands to entirely prevent the entry of metal ions are not uncommon either.
In itself, containment is a broad term that requires specifying on closer analysis. Depending on their requirements, operators and plant engineers have access to a range of suitable discharge and metering systems based on butterfly valves. Criteria such as a low total cost of ownership, the overall energy footprint and full recyclability are also gaining in importance.