Size-selective sample inlet with rotating baffle plate
The rotating baffle plate mechanism addresses the issue of dust deposition on sampling devices by redirecting airflow, enabling extended maintenance intervals and maintaining compliance with standards, thus optimizing maintenance schedules.
Patent Information
- Application Number
- DE202025003265
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2025-10-29
- Publication Date
- 2025-12-31
- Estimated Expiration
- 2035-10-31
AI Technical Summary
At high concentrations of suspended dust in ambient air, a large amount of coarser dust deposits on the baffle plate of sampling devices, necessitating frequent maintenance, which contradicts the extended maintenance intervals enabled by larger filter magazine capacities.
A mechanism within the sampling head rotates the baffle plate by a defined angle after a defined time interval, redirecting airflow to a less dusty area, thereby extending maintenance intervals to 30 days while maintaining gas-tight connections and compliance with DIN EN 12341 (2023-10) standards.
The rotating baffle plate mechanism allows for extended maintenance intervals of 30 days without compromising sampling integrity, ensuring compliance with normative requirements and reducing maintenance frequency.
Smart Images
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Abstract
Description
[0001] Sampling devices for measuring the PM10 and PM2.5 particulate matter fractions in ambient air are comprehensively described in DIN EN 12341 (2023-10). Ambient air is drawn through a size-selective sampling inlet (so-called sampling head) at a known, constant volume flow rate. The relevant PM fraction is collected on a filter for a nominal period of 24 hours, while irrelevant PM fractions consisting of coarser dust are separated in the sampling head on a baffle plate lubricated with silicone paste.
[0002] These sampling devices are typically equipped with an automatic filter changer and storage magazines for both unsampled and sampled filters. The filter magazines usually hold 14 filters, allowing for the removal of sampled filters and the replacement of unsampled filters every 14 days. During this maintenance, the baffle plate in the sampling head is also cleaned and lubricated with fresh silicone paste.
[0003] Recent advancements in sampling equipment have led to larger magazine capacities of up to 30 filters, thus extending the maintenance intervals for removing sampled filters and replacing them with unsampled filters to 30 days.
[0004] The invention described in the claim addresses the problem that, at high concentrations of suspended dust in the ambient air, a large amount of coarser dust is deposited on the baffle plate. As a result, despite the increased magazine capacity, the maintenance intervals cannot be extended to 30 days, since cleaning of the baffle plate in the sampling head is necessary after a shorter period.
[0005] This problem is solved by the features listed in the patent claim.
[0006] The invention achieves the rotation of the baffle plate in the sampling head by a defined angle after a defined time interval. This is accomplished by a mechanism located within the sampling head beneath the baffle plate. After the baffle plate has rotated, the nozzles of the sample inlet point towards an area on the baffle plate that is still free of airflow and therefore less dusty. Repeated rotations allow the maintenance interval to be extended to 30 days.
[0007] The mechanism located within the sampling head and below the impact plate ensures compliance with the normative requirements of DIN EN 12341 (2023-10) and maintains a continuous gas-tight connection between the sampling head and the sampling device. The mechanism is controlled via cable or radio via a control unit. Reference symbol list Weather protection B Air intake C Sampling head housing D nozzles E Outlet to the filter medium F Impact plate G Mechanism for rotation H Actuator
Claims
[1] Size-selective sample inlet with rotating baffle plate is characterized by that the mechanism for rotating the impact plate is located inside the sampling head. [2] Size-selective sample inlet with rotating baffle plate is characterized by that the mechanism for rotating the impact plate is located below the impact plate. [3] Size-selective sample inlet with rotating baffle plate is characterized by that the size-selective sample inlet remains gas-tightly connected to the sampling device during the rotation of the baffle plate. [4] Size-selective sample inlet with rotating baffle plate is characterized by that the control unit rotates the baffle plate only to the point where the nozzles continue to point towards a dust-free area of the baffle plate. [5] Size-selective sample inlet with rotating baffle plate is characterized by that the mechanism for rotating the impact plate is controlled via cable or radio.