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EP-4735839-A1 - A VENTILATION APPARATUS

EP4735839A1EP 4735839 A1EP4735839 A1EP 4735839A1EP-4735839-A1

Abstract

The invention relates to a ventilation apparatus comprising a blower (1) arranged to generate an air flow (AF) along an air duct (2) and an air flow meter arranged to measure the air flow generated by the blower. The air flow meter comprises a differential pressure gauge (3), and a measuring element (4) arranged to extend in the air duct (1) in a transverse direction to the air flow (AF) and to connect to the differential pressure gauge (3). The measuring element (4) comprises a primary air channel (5) and a secondary air channel (6).

Inventors

  • KARKKULAINEN, TIMO

Assignees

  • Verona Shelters Finland Oy

Dates

Publication Date
20260506
Application Date
20240628

Claims (15)

  1. 1. A ventilation apparatus comprising a blower (1) arranged to generate an air flow (AF) along an air duct (2), c h a r a c t e r i z e d in that the ventilation apparatus further comprises an air flow meter arranged to measure the air flow generated by the blower, the air flow meter comprises: a differential pressure gauge (3), and a measuring element (4) disposed inside the air duct (2) on a downstream side of the blower (1), the measuring element (4) is arranged to extend in the air duct (1) in a transverse direction to the air flow (AF) and to connect to the differential pressure gauge (3), the measuring element (4) comprises a primary air channel (5) and a secondary air channel (6), the primary air channel (5) is arranged to open on the upstream side of the air flow (AF) through a primary opening (15), and to form a flow connection to the differential pressure gauge (3) to convey air from the primary opening (15) through the primary air channel (5) to the differential pressure gauge (3), and the secondary air channel (6) is arranged to open on the downstream side of the air flow (AF) through a secondary opening (16) and to form a flow connection from the secondary opening (16) through the secondary air channel (6) to the differential pressure gauge (3).
  2. 2. A ventilation apparatus according to claim 1, c h a r a c t e r i z e d in that the measuring element (4) comprises a wing element (7) arranged to extend away from an outer surface of the measuring element (4) in a plane transverse to the air duct (2) such that the wing element (7) is arranged to separate an upstream side and a downstream side of the measuring element (4), the primary opening (15) is arranged on the upstream side of the measuring element (4) and the secondary opening (16) is arranged on the downstream side of the measuring element (4).
  3. 3. A ventilation apparatus according to claim 2, c h a r a c t e r i z e d in that the wing element (7) is arranged at the measuring element (4) such that it extends along a longitudinal direction of the measuring element (4) and comprises a first wing element area (7a) and a second wing element area (7b), the second wing element area (7b) is arranged to extend further away from the outer surface of the measuring element (4) than the first wing element area (7a), and the second wing element area (7b) is arranged to prevent air flow (AF) flowing along the outer surface of the measuring element (4) at the secondary opening (16).
  4. 4. A ventilation apparatus according to any of claims 1 - 3, characterized in that the primary air channel (5) comprises a primary supply chamber (51), a buffer chamber (52) and a primary supply channel (53), the primary supply channel (53) extending from the primary supply chamber (51) to the buffer chamber (52) such that a flow communication is formed between the primary supply chamber (51) and the buffer chamber (52) through the primary supply channel (53), and the supply chamber (51) further forming a flow connection with the differential pressure gauge (3).
  5. 5. A ventilation apparatus according to claim 4, characterized in that the primary opening (15) is provided in connection with the primary supply channel (53) in the primary air channel (5).
  6. 6. A ventilation apparatus according to claim 4 or 5, characterized in that the primary opening (15) is provided in connection with the primary supply channel (53) in the primary air channel (5) such that the primary opening (15) opens in a transverse direction to the air flow (AF).
  7. 7. A ventilation apparatus according to any of claims 4 - 6, characterized in that the primary opening (15) is provided in connection with the primary supply channel (53) in the primary air channel (5) such that the primary opening (15) is closer to the primary supply chamber (51) than the buffer chamber (52).
  8. 8. A ventilation apparatus according to any of claims 4 - 7, characterized in that the primary supply channel (53) having a smaller volume than the primary supply chamber (51), or the primary supply channel (53) having a smaller volume than the buffer chamber (52), or the primary supply channel (53) having a smaller volume than the primary supply chamber (51) and the buffer chamber (52).
  9. 9. A ventilation apparatus according to any of claims 4 - 8, characterized in that the primary supply channel (53) having a smaller diameter than the diameter of the primary supply chamber (51), or the primary supply channel (53) having a smaller diameter than the diameter of the buffer chamber (52), or the primary supply channel (53) having a smaller diameter than the diameter of the primary supply chamber (51) and the diameter of the buffer chamber (52).
  10. 10. A ventilation apparatus according to any previous claim, characterized in that the secondary air channel (6) comprises a secondary supply chamber (61), a pre-chamber (62) and a secondary supply channel (63), the secondary supply channel (63) extending from the pre-chamber (62) to the secondary supply chamber (61) such that a flow communication is formed between the pre-chamber (63) and the secondary supply chamber (61) through the secondary supply channel (63), and the secondary supply chamber further forming a flow connection with the differential pressure gauge (3).
  11. 11. A ventilation apparatus according to claim 10, characterized in that the secondary opening (16) is provided in connection with the pre-chamber (62) in the secondary air channel (6).
  12. 12. A ventilation apparatus according to claim 10 or 11, characterized in that the secondary opening (16) is provided in connection with the pre-chamber (62) in the secondary air channel (6) such that the secondary opening (16) opens in the direction of the air flow (AF) in the air duct (2) on the downstream side of the air flow (AF).
  13. 13. A ventilation apparatus according to any of claims 10 - 12, characterized in that the secondary opening (16) is provided in connection with the pre-chamber (62) in the secondary air channel (6) such that the secondary opening (16) is furthest away from the secondary supply channel
  14. 14. A ventilation apparatus according to any of claims 10 - 13, characterized in that the secondary supply channel (63) having a smaller volume than the secondary supply chamber (61), or the secondary supply channel (63) having a smaller volume than the pre-chamber (62), or the secondary supply channel (63) having a smaller volume than the secondary supply chamber (61) and the pre-chamber (62).
  15. 15. A ventilation apparatus according to any of claims 8 - 14, characterized in that the secondary supply channel (63) having a smaller diameter than the diameter of the secondary supply chamber (61), or the secondary supply channel (63) having a smaller diameter than the diameter of the pre-chamber (62), or the secondary supply channel (63) having a smaller diameter than the diameter of the secondary supply chamber (61) and the pre-chamber (62).

Description

A VENTILATION APPARATUS FIELD OF THE INVENTION The present invention relates to a ventilation apparatus especially for civil protection shelters, and more particularly to a ventilation apparatus as described in the preamble of the independent claim. BACKGROUND OF THE INVENTION In the prior art ventilation apparatuses, the air flow meter typically has an adjustable choke inside the measuring funnel in order to achieve a large pressure difference. The choke requires adjustment in order to obtain a sufficiently large pressure difference in the air flow meter. It also makes the structure of the air flow meter more complicated. BRIEF DESCRIPTION OF THE INVENTION An object of the present invention is to provide a ventilation apparatus having an air flow meter which can measure small and large air flows without compromising the stability of the air flow meter and still providing accurate results. The objects of the invention are achieved by a ventilation apparatus which is characterized by what is stated in the independent claim. The preferred embodiments of the invention are disclosed in the dependent claims. The invention is based on the idea of having two separate channels in the air flow meter, which is arranged inside an air duct, and which the channels capture the air flow flowing through the air duct from different sides of the air flow meter, allowing the pressure difference to be measured. A ventilation apparatus according to the invention comprises a blower arranged to generate an air flow along an air duct and an air flow meter arranged to measure the air flow generated by the blower. The air flow meter comprises a differential pressure gauge, and a measuring element disposed inside the air duct on a downstream side of the blower. The measuring element is arranged to extend in the air duct in a transverse direction to the air flow and to connect to the differential pressure gauge. The measuring element comprises a primary air channel and a secondary air channel. The primary air channel is arranged to open on the upstream side of the air flow through a primary opening, and to form a flow connection to the differential pressure gauge to convey air from the primary opening through the primary air channel to the differential pressure gauge. The secondary air channel is arranged to open on the downstream side of the air flow through a secondary opening and to form a flow connection from the secondary opening through the secondary air channel to the differential pressure gauge. In other words, the air flow meter comprising the differential pressure gauge and the measuring element are provided in connection with each other such that the measuring element is placed inside the air duct and the differential pressure gauge gauge extends outside the air duct such that the measurement readings shown by the differential pressure gauge can be seen from outside the air duct. The measuring element comprises the primary air channel and the secondary air channel which are parallel and extend in the measuring element in a transverse direction to the air flow flowing through the air duct. The primary air channel and the secondary air channel are preferably arranged on top of each other in the measuring element such that the air flow meets first the primary air channel and then the secondary air channel. The measuring element is arranged in the air duct such that the air flow passes the measuring element when flowing along the air duct, and preferably the air flow passes the measuring element on both sides of the measuring element as it is arranged to extend in the air duct transverse to the air flow. As the primary air channel is arranged to open on the upstream side of the air flow through a primary opening, then the primary air channel is preferably on the upstream side on the measurement element, and the secondary air channel is on the downstream side on the measurement element as it opens on the downstream side of the air flow. The upstream side of the air flow is the air flow flowing between the blower and the measuring element and the downstream side of the air flow is the air flow that has passed the measuring element in the air duct. According to the invention the measuring element comprises a wing element arranged to extend away from an outer surface of the measuring element in a plane transverse to the air duct such that the wing element is arranged to separate an upstream side and a downstream side of the measuring element. The primary opening is arranged on the upstream side of the measuring element and the secondary opening is arranged on the downstream side of the measuring element. In other words, the wing element is arranged to extend from the outer surface of the measuring element so that the air flow passing by the measuring element along the outer surface of the measuring element meets the wing element which prevents the air flow further flowing along the outer surface of the measuring element. This sta