Air filter testing device with extremely small flow

Abstract

The utility model provides an air filter testing device with extremely small flow, which takes a pipeline, a large air filter and a fan as basic structures, and comprises the following structures that a branch is externally connected to an original air filter testing device, and a small air filter, a flow meter, an absolute filter and a vacuum pump are sequentially connected to the branch through the pipeline. The small air filter is a test sample piece; the flow meter is used for detecting the air flow in the branch pipeline; the absolute filter is used for collecting dust penetrating through the air filter; and the vacuum pump is used for sucking air and providing flow required by an experiment. According to the invention, the existing equipment is modified, so that the cost is reduced to meet new test requirements; meanwhile, the original pipeline is not changed, and the test of the large air filter can be completed; in addition, the device is simple in arrangement, and is suitable for testing small flows of air filters of various styles, sizes and shapes.

Description

Technical Field

[0001] This application belongs to the field of aerodynamics and testing devices, and relates to an air filter testing device with extremely low flow rate. Background Technology

[0002] An air filter, or simply air filter, is a device that removes particulate impurities from the air. Cars typically have an air filter installed in front of the engine to filter impurities from the air; without one, impurities would enter the engine, accelerating wear and tear on components.

[0003] An air filter testing device is a specialized device used to evaluate the filtration efficiency, pressure drop, and dust holding capacity of air filter elements under different conditions. It is widely used in automobiles, industrial equipment, HVAC systems, and air purifiers to ensure the normal operation of equipment and air quality. The air filter testing device measures the filtration performance of the filter element by simulating the airflow, dust concentration, and particle size distribution in the actual working environment. The main working principles include: (1) Airflow generation: A controllable airflow is generated by a fan or air generator to simulate the airflow under actual working conditions. (2) Dust injection: A certain concentration of test dust is injected into the airflow to ensure that particles of different sizes are evenly distributed in the airflow. (3) Particle monitoring: The number and particle size distribution of particles before and after the filter element are monitored in real time by a precision particle counter or optical detection equipment to calculate the filtration efficiency. (4) Pressure drop measurement: The pressure drop when air passes through the filter element is measured using a differential pressure sensor, that is, the pressure difference of air before and after the filter element, to evaluate its impact on airflow resistance. (5) Dust holding capacity test: The dust holding capacity of the filter element is evaluated by long-term dust injection, and the changes in filtration efficiency and pressure drop are observed as the dust holding capacity increases.

[0004] The current air filter testing bench has a testing capacity of 1m. 3 / min~50m 3 / min. This covers air filter testing for traditional gasoline vehicles and trucks, but with the rapid popularization of new energy vehicles, more and more low-flow air filters need to be tested (for suspension filters and breather valve filters, the test flow rate needs to be 0.2m). 3 / min~0.5m 3 The existing air filter test bench cannot meet the requirements ( / min). Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this application is to provide an air filter testing device with extremely low flow rate.

[0006] The technical solution of this application is as follows:

[0007] One of the technical solutions of this application provides an air filter testing device with extremely low flow rate, based on a pipeline, a large air filter, and a fan. The device includes the following structure:

[0008] An external branch is connected to the existing air filter testing device. The branch is connected in sequence to a small air filter, a flow meter, an absolute filter, and a vacuum pump via pipes.

[0009] Furthermore, the small air filter is a test sample, and its performance is to be tested. The efficiency of the test sample is determined by its filtration efficiency, which is calculated using the formula: (1 - absolute filter increment / total ash addition) x 100%.

[0010] Furthermore, the small air filter includes, but is not limited to, the following types: cotton filter cartridge, metal mesh filter, paper filter, activated carbon filter, coalescing filter, cyclone or inertial separator, and electronic filter.

[0011] Furthermore, the flow meter is used to detect the air flow rate in the branch pipe;

[0012] Furthermore, the flow meter is a small-flow air flow meter, including but not limited to the following types: thermal mass flow meter, ultrasonic flow meter, vortex flow meter, differential pressure flow meter, and capacitive flow meter.

[0013] Furthermore, the absolute filter is used to collect dust that passes through the air filter, because the filter paper on the air filter cannot block all dust particles of all sizes, so a filter element with higher filtration efficiency needs to be installed at the air outlet.

[0014] Furthermore, the absolute filter is an absolute air filter, specifically the Freudenberg MF95 absolute filter.

[0015] Furthermore, the vacuum pump is used to draw in air, providing the flow rate required for the experiment.

[0016] Furthermore, in air filter testing equipment, the selection of a vacuum pump is typically based on equipment requirements, such as pumping speed, vacuum level, stability, and application environment. The vacuum pumps include, but are not limited to, the following types: liquid ring vacuum pumps, reciprocating vacuum pumps, slide valve vacuum pumps, rotary vane vacuum pumps, dry screw vacuum pumps, and scroll vacuum pumps.

[0017] Furthermore, the flow meter and vacuum pump are used together to control the required test flow rate.

[0018] Furthermore, in the branch circuit, the pipes between the flow meter, absolute filter, and vacuum pump all use 8mm gas pipes.

[0019] Furthermore, in the branch circuit, the diameter of the diversion pipe is the same as the diameter of the air outlet and air inlet of the small air filter.

[0020] Adding a small vacuum pump and flow meter ensures stable flow. Additionally, the testing standards (QC / T 32 and ISO 5011) define the ash concentration for the ash addition test as 1 g / m³. 3 This device can also meet the concentration requirements in the standard.

[0021] Furthermore, assume the fan is set to a flow rate of 10.02 m³ / s. 3 / min, concentration is 1g / m 3 The vacuum pump flow rate is set to 0.02 m³ / h. 3 / min, so the ash concentration added to the large air filter is 1g / m³. 3 x 10m 3 / min=10g / min, the ash concentration for the small air filter is 1g / m 3 x 0.02m 3 / min=0.02g / min, which meets the requirements of the testing standard.

[0022] Furthermore, the aforementioned air filter testing device with extremely low flow rate and its usage method can be applied in the field of aerodynamics, for use in dust filtration on breathing valves or air suspensions.

[0023] Compared with the prior art, this application has at least the following improvements and beneficial effects:

[0024] (1) Modify existing equipment to meet new testing requirements at a relatively low cost.

[0025] (2) The original equipment was not modified and the large air filter test can still be completed.

[0026] (3) It is easy to set up and is suitable for testing small flow rates of air filters of various styles, sizes and shapes. Attached Figure Description

[0027] Figure 1 A schematic diagram of an existing air filter testing device;

[0028] Figure 2 A schematic diagram of the air filter testing device provided in this application;

[0029] Figure label:

[0030] 1 is the fan, 2 is the large air filter, 3 is the pipeline, 4 is the small air filter, 5 is the flow meter, 6 is the absolute filter, and 7 is the vacuum pump. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be described in detail below with reference to specific embodiments. It should be noted that the following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0032] All raw materials used in this invention are not particularly limited in their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0033] Example 1: An air filter testing device with extremely low flow rate

[0034] This embodiment is based on the original air filter testing device ( Figure 1 Based on the existing system (where the blue arrows indicate the airflow direction), an external branch was added. This external branch connects sequentially to the small air filter test sample 4, the flow meter 5, the absolute filter 6, and the vacuum pump 7. Figure 2 (The blue arrows in the diagram indicate the direction of airflow).

[0035] The working principle of the device provided in this embodiment is as follows: Since the flow rate provided by the fan 1 is too large, a diversion port is added to the test pipeline so that the test with a small flow rate can be met.

[0036] The usage method is as follows: First, install and fix the position of the large air filter 2. The diameter of pipe 3 needs to be designed and installed according to the diameter of the air filter outlet. Then, drill a hole at the bottom of the pipe to install the diversion pipe. The diameter of the diversion pipe needs to be consistent with the diameter of the outlet and inlet of the sample to be tested. The pipes between the flow meter 5, the absolute filter 6, and the vacuum pump 7 all use 8mm air pipes. The absolute filter is a Freudenberg MF95 absolute filter, which provides almost 100% removal efficiency for 0.2-micron particles and can withstand large flow surges.

[0037] Example 2: Actual use of an air filter testing device with extremely low flow rate

[0038] The main function of an air filter testing device is filtration efficiency testing: by measuring the concentration of particles of different sizes in the air before and after the air filter element, the filtration efficiency of the filter element is calculated. The filtration efficiency test includes the following steps:

[0039] S1. Weigh the initial weight W1 of the small air filter 4 to be tested;

[0040] S2. Weigh the initial weight W2 of the absolute filter 6;

[0041] S3. Install the small air filter 4 and the absolute filter 6 to be tested into the test device;

[0042] S4. Turn on the fan and vacuum pump, and set the test flow rate required for the experiment. Both the fan 1 and the vacuum pump 7 are air extraction devices.

[0043] S5. Set the ash concentration and termination conditions, and start the ash feeder;

[0044] S6. When the experiment reaches the termination condition and stops, remove the air filter and the absolute filter and weigh them. The weight of the air filter is W3 and the weight of the absolute filter is W4.

[0045] S7. The absolute weight gain of the filter is calculated as: W4 - W2 = W5, and the total ash addition is: W3 - W1 + W5 = W6.

[0046] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A very low flow rate air filter testing device, comprising a pipe (3), a large air filter (2), and a fan (1), characterized in that, The device includes the following structure: An external branch is connected to the original air filter test device, and a small air filter (4), a flow meter (5), an absolute filter (6) and a vacuum pump (7) are connected in sequence through pipes on the branch.

2. The air filter testing device with extremely low flow rate according to claim 1, characterized in that, The small air filter (4) is a test sample, and its performance needs to be tested.

3. The air filter testing device with extremely low flow rate according to any one of claims 1 or 2, characterized in that, The small air filter is selected from any one of cotton filter cartridges, metal mesh filters, paper filters, activated carbon filters, coalescing filters, cyclone or inertial separators, or electronic filters.

4. The air filter testing device with extremely low flow rate according to claim 1, characterized in that, The flow meter (5) is used to detect the air flow in the branch pipe.

5. The air filter testing device with extremely low flow rate according to claim 1 or 4, characterized in that, The flow meter (5) is a small-flow air flow meter, selected from any one of thermal mass flow meter, ultrasonic flow meter, vortex flow meter, differential pressure flow meter or capacitive flow meter.

6. The air filter testing device with extremely low flow rate according to claim 1, characterized in that, The absolute filter (6) is used to collect dust that passes through the air filter.

7. The air filter testing device with extremely low flow rate according to claim 1, characterized in that, The vacuum pump (7) is used to draw in air and provide the flow rate required for the experiment.

8. The air filter testing device with extremely low flow rate according to claim 1 or 7, characterized in that, The vacuum pump (7) is selected from liquid ring vacuum pump, reciprocating vacuum pump, slide valve vacuum pump, rotary vane vacuum pump, dry screw vacuum pump, and scroll vacuum pump.

9. The air filter testing device with extremely low flow rate according to claim 1, characterized in that, The flow meter (5) and the vacuum pump (7) are used together to control the required test flow rate.

10. The air filter testing device with extremely low flow rate according to claim 1, characterized in that, In the branch circuit, the pipes between the flow meter (5), the absolute filter (6) and the vacuum pump (7) all use 8mm air pipes; the diameter of the branch pipe is the same as the diameter of the outlet and inlet of the small air filter.

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