FLOW RATE MEASUREMENT DEVICE

• Main Authors: KISHIKAWA NAOYUKI, AKAGI KAZUTO, ARIYOSHI YUJI, KAWAI MASAHIRO, URAMACHI HIROYUKI
• Format: Patent
• Language: English; Japanese
• Published: 20.04.2015
• Subjects: MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METERING BY VOLUME; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To sufficiently reduce the collision energy of dust included in a fluid to be measured and prevent the dust from colliding with a flow rate detection element at high speed, thereby achieving both tolerance to dust and flow rate detection accuracy.SOLUTION: Dust in various particle sizes penetrating a bypass passage 7, especially a relative large dust in particle size of about 100 μm to 200 μm, is reliably collided with a first-stage shape part 731, a second-stage shape part 751, and a plate-like member 9, so as to reduce the speed thereof sufficiently, whereby the dust is made to reach a flow rate detection element 3 in a state in which the collision energy is low. Damage to the flow rate detection element 3 due to collision of the dust can thereby be prevented. Also, the installed position of the plate-like member 9 is optimized and the disturbance of air in a flow rate detection unit 33 is suppressed, whereby flow rate detection accuracy and tolerance to dust are both achieved. 【課題】被計測流体に含まれるダストの衝突エネルギーを十分に低下させ、該ダストが流量検出素子に高速で衝突することを防ぎ、ダスト耐量と流量検出精度を両立させる。【解決手段】バイパス通路７に侵入した様々な粒径のダスト、特に粒径１００μｍ〜２００μｍ程度の比較的大きなダストを、第１段形状部７３１、第２段形状部７５１、および板状部材９に確実に衝突させることにより、その速度を十分に低下させ、衝突エネルギーの低い状態で流量検出素子３に到達させる。これにより、ダストの衝突による流量検出素子３の破損を防ぐことができる。また、板状部材９の設置位置を最適化し、流量検出部３３における空気の乱れを抑制することにより、流量検出精度とダスト耐量を両立させている。【選択図】図２