Safe handling of powders and dusts for Covestro AG

High requirements when working with powders: In the handling of chemical raw materials in the powdery or dusty state, increased safety requirements apply to the design of workplaces to protect employees. Contact with the skin or inhalation of material emissions can be hazardous to the health of employees. Accordingly, when redesigning the research area where employees work with powder blends, Covestro placed great emphasis on employee protection. The special challenge: In addition to optimal employee protection, the intended work steps of weighing, screening and mixing should be as efficient and ergonomic as possible. This was to be done in three work areas that Covestro had defined together with the project engineers of DENIOS AG. Not least because DENIOS was able to meet all the workstation requirements, they decided to implement the project for the market leader from Bad Oeynhausen.

Pollutant capture with ejector technology: The DENIOS solution consists of a weighing area, a sieve area and a walk-in enclosure to accommodate an intensive mixer. In the weighing area, chemicals from some larger containers are transferred to smaller units and small quantities are weighed. A DENIOS worktable ensures the efficient collection and extraction of arising emissions.

The introduction of the substances to be processed in the work table via a lateral vertical slide. A mobile, electronic lifting device helps the user to handle and load larger containers.

Also in the screening area, where a vibrating sieve is used, a DENIOS worktable is used. However, this worktable is here without worktop and equipped with a double swing door. The weighed substances are screened in this area. The worktable also captures the emissions that occur during this step using ejector technology and sucks them off in the rear wall.

The two work tables of the Premium type are designed according to Part 3 of EN 14175. This section of the European Standard EN 14175 regulates the establishment of type-examination procedures for the assessment of the safety and performance of the air flow and the retention capacity of fume cupboards.

Through special nozzles on the front edge of the worktop and in the ceiling area, air-directing jets, so-called ejectors, are directed to the suction bar in the rear wall. The resulting air currents drive vapors and dusts towards the back wall, where they are specifically and safely extracted. Thus, all emissions are safely removed with a minimized air requirement. The ejector technology is predestined for processes that require a draft-free environment.

The intensive mixer needed for the last step is underlaid in a DENIOS free workplace with gullwing doors. The previously screened materials are mixed here. During this process, dusts can form and stir up in the environment. The cabin is used for the safe extraction of these emissions, analogous to the work tables used in the weighing and screening area. The front doors not only increase employee safety, but also reduce the noise level of the mixer. Both the worktables and the free workstation are connected to the customer exhaust air system and can be operated separately due to special controls. To meet the high quality requirements of Covestro's research, all three systems are made entirely of stainless steel.