1m 3 Climate chamber and formaldehyde emission testing methods

Abstract

The application discloses 1m 3 The climate box and the formaldehyde release amount detection method, specifically belong to formaldehyde release amount detection technical field, including casing, the sample tube of containing artificial board sample, flow guide disc and air supply device;The air supply device includes the box of hollow and one end opening, rotation drive motor and fan blade;The fan blade and the output end of rotation drive motor are fixed, and the side opposite to the box and the fan blade is provided with air outlet;The flow guide disc is arranged between the sample tube and the box, and the side corresponding to the sample tube and the flow guide disc is provided with air inlet. 3 The climate box can make the artificial board placed in the sample box be subjected to the carrier gas in different directions, be beneficial to promote the sufficient diffusion of the formaldehyde gas in the sample box, shorten the balancing treatment time of the board and improve the accuracy of formaldehyde detection.

Description

Technical Field

[0001] This invention belongs to the field of formaldehyde emission detection technology, specifically involving 1m 3 Climate chamber and formaldehyde emission testing methods. Background Technology

[0002] 1m 2 The surface area of ​​the sample is placed in a climate chamber where the temperature, relative humidity, air flow rate, and air exchange rate are controlled at certain values. Formaldehyde is released from the sample and mixes with the air inside the chamber. The air inside the chamber is periodically extracted and passed through an absorption bottle containing distilled water. All the formaldehyde in the air dissolves into the absorption liquid. The amount of formaldehyde in the absorption liquid and the volume of the extracted air are measured to calculate the amount of formaldehyde per cubic meter of air.

[0003] Currently, climate chambers used in laboratories, such as those manufactured by Shanghai Qinpei Environmental Protection Technology Co., Ltd., have their carrier gas outlet located on the back of the sample chamber near the bottom (e.g.) Figure 6 The air extraction port is located in the gap formed by the perimeter of the panel and the side of the sample chamber. This climate chamber has the following problem during use: the formaldehyde concentration is higher near the engineered wood panels placed inside the sample chamber, meaning there are localized differences in formaldehyde concentration throughout the sample chamber. This leads to inaccurate measurements of formaldehyde release from the engineered wood panels.

[0004] The Wood Industry Research Institute of the Chinese Academy of Forestry has applied for a Chinese invention patent with patent number CN2019111649530. In the background section, it clearly points out that the existing technology has problems with low uniformity and stability of test samples. Due to the processing technology of wood-based panels, raw materials, and the continuous release of free formaldehyde from the wood-based panels to the outside world, even high-quality wood-based panels will have problems with poor uniformity of glue application and large differences between panels. This can easily lead to uneven formaldehyde release in the sample placement area.

[0005] Therefore, it is necessary to further study how to shorten the existing balancing process time to improve timeliness and obtain accurate data on formaldehyde emission from engineered wood products. Summary of the Invention

[0006] The purpose of this invention is to provide 1m 3 Climate chamber and formaldehyde emission testing method, using 1m 3 Climate chambers allow artificial boards placed inside to be exposed to carrier gases from different directions, which helps to promote uniform dispersion of formaldehyde content within the sample chamber, shortens the equilibration time of the boards, and improves the accuracy of formaldehyde detection.

[0007] To achieve the above objectives, the present invention provides the following technical solution: 1m 3The climate chamber includes a shell, a sample tube for holding artificial board samples, a flow guide plate, and an air supply device; The air supply device includes a hollow box with one end open, a rotary drive motor, and fan blades. The fan blade and the output end of the drive motor are fixed together, and the box body is provided with an air outlet on the side directly opposite the fan blade; the guide plate is set between the sample tube and the box body, and the sample tube is provided with an air inlet on the side corresponding to the guide plate.

[0008] How a climate chamber works: The artificial board to be tested is placed inside the sample tube. In practical applications, a frame can be welded to the sample tube, and the sample can be fixed to the frame. When the power is turned on, the drive motor rotates the fan blades, thereby delivering carrier gas (carrier gas purification can be achieved by removing formaldehyde from the air) towards one side of the guide plate. The carrier gas is then diverted by the guide plate and blown into the sample tube through the through-hole on the side end. The flow rate of the carrier gas can be referenced to the 1m³ / h standard for formaldehyde emission testing of artificial boards and their products used in indoor decoration and renovation, as specified in GB18580-2017. 3 Climate chamber.

[0009] The flow-diverting effect of the guide plate allows the carrier gas to flow into the sample cylinder in different directions, and... Figure 1 Compared to the climate chambers used in laboratories, this method allows formaldehyde released from engineered wood products to mix more evenly with the air. As a result, the formaldehyde release obtained during air extraction testing is closer to the average value, avoiding errors in measurement results caused by large or small local concentrations of formaldehyde in the sample.

[0010] by Figure 5 For example, the rotary drive motor is fixed to the mounting plate, and the motor's wires can pass through the mounting plate. The mounting plate is slidably installed inside the housing, and a handle is provided at its outer end. During use, the operator can push the mounting plate into the housing along the handle to install the rotary drive motor.

[0011] As a preferred option, the 1m 3 The climate chamber also includes a drive unit, which includes a drive motor, a rotating output rod, a drive wheel, a transmission wheel, a synchronous transmission rod, a transmission rod, a slide rod, and a slide rail rod; The slide rod is fixed to the bottom of the housing, the slide rail is slidably connected to the slide rod, and the end of the slide rail is fixed to the bottom of the housing; The transmission rod is fixed to the upper end of the housing, and the drive wheel and the transmission rod are meshed and connected for transmission. The output end of the drive motor is a rotating output rod, which is connected to the drive wheel for synchronous rotation. The drive wheel and the driving wheel are synchronously connected via a synchronous transmission rod, and the drive wheel and the guide plate are meshed and rotated together.

[0012] Advantages of the drive unit: The main purpose of the driving device is to ensure that the carrier gas can be mixed more fully and evenly with the formaldehyde released from the sample in the sample cylinder. Therefore, the driving device drives the air supply device to move vertically along the guide plate, and at the same time, it can drive the guide plate to rotate. This allows the carrier gas to move along the upper and lower dimensions of the sample cylinder, so that it can mix more evenly with the formaldehyde released from the artificial board inside the sample cylinder.

[0013] The specific working principle of the drive device is as follows: When the output rod of the drive motor rotates, the drive wheel rotates, which in turn drives the transmission rod meshing with it. This causes the housing to move up and down, and the slide rod and slide rail at the lower end of the housing also slide against each other. Since the drive wheel and the transmission wheel are synchronously driven by a synchronous transmission rod, the transmission wheel also rotates synchronously. The transmission wheel and the guide plate are meshed, thus driving the guide plate to rotate. The guide plate is sandwiched between the transmission wheel and the adaptive guide wheel, which rotates along with the guide plate, primarily serving a supporting function.

[0014] Preferably, the bottom end of the housing is provided with at least one adaptive guide wheel, which is engaged and driven by the side end of the guide plate. Two adaptive guide wheels can be designed, located on opposite sides of the guide plate, forming a triangular structure with the drive wheel, which improves structural stability.

[0015] Preferably, the driving device further includes a main drive belt, a first drive guide wheel, a rotating shaft, a second drive guide wheel, a third drive guide wheel, and a transmission belt; the driving wheel and the first drive guide wheel are synchronously connected via the main drive belt; the two ends of the rotating shaft are respectively fixed to the second drive guide wheel and the first drive guide wheel; the third drive guide wheel and the second drive guide wheel are synchronously connected via the transmission belt, and the third drive guide wheel is meshed with the sample cylinder; correspondingly, the sample cylinder has a transmission tooth on its side.

[0016] As another part of the drive unit, this part has the following advantages: In order to mix the formaldehyde released from the engineered wood products with the carrier gas inside the sample tube, the sample tube is driven to rotate simultaneously with the rotation of the guide plate and the up-and-down movement of the air supply device through the linkage structure of the drive device. This allows the carrier gas to fill every corner of the sample tube and mix evenly with the formaldehyde released from the engineered wood products for gas extraction and detection.

[0017] The working principle of the above part is as follows: When the drive wheel is rotated by the drive motor, it drives the first transmission guide wheel to rotate via the main transmission belt. When the first transmission guide wheel rotates, it drives the second transmission guide wheel to rotate synchronously via the rotating shaft. Since the second and third transmission guide wheels are synchronously driven by the transmission belt, and the transmission teeth on the third transmission guide wheel and the sample cylinder are meshed, the sample cylinder can be driven to rotate.

[0018] Preferably, the drive device further includes an adaptive rotating wheel, which is meshed with the transmission gear and is disposed at the bottom end of the housing.

[0019] The adaptive rotating wheel, not shown in the attached diagram, is actually located on the opposite side of the third transmission guide wheel and on both sides of the sample cylinder, mainly to maintain the balance of the sample cylinder.

[0020] Preferably, a support block is provided at the bottom of the shell, and the contact surface between the support block and the sample tube is an arc shape adapted to it. Since the sample tube has a relatively large volume and mass, in order to ensure the stability of the sample tube during rotation, a support block is further provided at the bottom of the sample tube, which can effectively play a supporting role.

[0021] Preferably, the bottom of the shell is provided with a slide rail, and the open end of the sample cylinder is equipped with a cover. The cover is slidably mounted on the slide rail and is connected to an air outlet pipe. The cover mainly serves a sealing function. During operation, the cover can move vertically along the slide rail. The cover and the sample cylinder are rotatably connected. Specifically, the inner side of the cover is provided with a rotating protrusion, while the open end of the sample cylinder actually has a rotating groove. Figure 1 As can be seen, the actual rotation speed of the sample cylinder is not high. When using it, Vaseline can be applied to the rotating protrusion and the rotating groove to improve the sealing effect.

[0022] Preferably, sliders are provided on both sides of the cover, and correspondingly, a sliding groove is provided on the slide rail rod, and the cover and the open end of the sample tube are rotatably connected.

[0023] This invention provides a method for detecting formaldehyde emission, which includes the following steps: S01. The carrier gas supplied by the external air pump is purified and then connected to the housing. The formaldehyde content of the carrier gas entering the housing shall not exceed 0.006 mg / m3.

[0024] S02. The carrier gas is blown into the sample cylinder by the air supply device, and the temperature range is controlled at 18~30 degrees Celsius, and the carrier gas flow rate is 0.1~0.5m / s.

[0025] S03. Sampling begins the next day. From the second day to the fifth day, sampling is conducted twice a day, with an interval of more than 3 hours between samplings.

[0026] During sampling, connect the vacuum pump to the outlet pipe of the climate chamber, add 25 mL of distilled water to each of the two absorption bottles, connect them in series, start the vacuum pump, and begin vacuuming at a rate of 2 L / min for 60 min.

[0027] Compared with the prior art, the beneficial effects of the present invention are: 1. By diverting the carrier gas through the guide plate and then sending it into the sample cylinder containing the artificial board, the formaldehyde released from the artificial board can be mixed evenly with the carrier gas, avoiding inaccurate measurement results caused by local formaldehyde content differences in the sample cylinder during gas extraction. Attached Figure Description

[0028] Figure 1 The 1m provided for this invention 3 A schematic diagram of the climate chamber (front view); Figure 2 The 1m provided for this invention 3 Schematic diagram of the climate chamber (back side); Figure 3 The 1m provided for this invention 3 Schematic diagram of the climate chamber (internal structure); Figure 4 for Figure 3 Enlarged view of part A in the image; Figure 5 The 1m provided for this invention 3 Schematic diagram of the climate chamber (internal cross-section); Figure 6 Diagram of existing climate chamber sample boxes used in the laboratory; Figure 7 To use existing climate chamber samples to detect the number of days of complete formaldehyde release from engineered wood products and to generate statistical data; Figure 8 To use the climate chamber samples to detect the number of days of complete formaldehyde release from engineered wood products and to generate statistical data; Figure 9 For comprehensive Figure 7-8 A graph of experimental data.

[0029] In the diagram: 1. Second slide rail rod, 2. Cover, 3. Air outlet pipe, 4. Transmission gear, 5. Sample cylinder, 6. Drive wheel, 7. Rotary output rod, 8. Drive motor, 10. Main transmission belt, 11. Third transmission guide wheel, 12. Transmission belt, 13. Support block, 14. Second transmission guide wheel, 15. Rotating shaft, 16. First transmission guide wheel, 17. Box body, 18. Transmission rod, 19. Transmission wheel, 20. Guide plate, 22. Adaptive guide wheel, 23. Slide rod, 24. First slide rail rod, 25. Synchronous transmission rod, 27. Fan blade, 28. Rotary drive motor, 29. Fixing plate, 30. Force application handle, 31. Housing. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This embodiment addresses the 1m from an application perspective. 3 The climate chamber will be further explained: This embodiment provides a 1m 3 The climate chamber, its main components include: Casing 31 Sample cylinder 5 20 diverter plate air supply device The air supply device includes: a housing 17, a rotary drive motor 28, and a fan blade 27.

[0032] drive unit The drive unit includes: a drive motor 8, a rotating output rod 7, a drive wheel 6, a transmission wheel 19, a synchronous transmission rod 25, a transmission rod 18, a slide rod 23, a first slide rail rod 24, a main transmission belt 10, a first transmission guide wheel 16, a rotating shaft 15, a second transmission guide wheel 14, a third transmission guide wheel, and a transmission belt 12.

[0033] The outer side of sample cylinder 5 is cylindrical, while the internal area for holding the sample is cuboid, with a space of 1m. 3 Among them, the drive motor 8 is a servo motor, which is used to control the drive wheel 6 to rotate clockwise or counterclockwise periodically.

[0034] A guide vane is also provided on the side of the guide plate 20 corresponding to the air inlet of the sample cylinder 5, such as... Figure 4 As shown, there are four wedge-shaped deflectors. Two of them with larger bottom areas are fixed to the deflector plate, and the other two with smaller bottom areas are fixed to the deflector plate, so that the carrier airflow can be blown to different angles along the deflectors after it is released.

[0035] Meanwhile, the laboratory's existing climate chamber was used to detect the number of days required for complete formaldehyde release from engineered wood products, and the data statistics are available in [link to data]. Figure 7 The climate chamber provided in this embodiment was used to detect the number of days required for complete formaldehyde release from engineered wood products, and the data statistics are shown in [link to documentation]. Figure 8 .Depend on Figure 7 and Figure 8It is evident that using the climate chamber provided in this embodiment, formaldehyde in the same type of engineered wood product is completely released in just 12 days. In contrast, using an existing laboratory climate chamber, the complete formaldehyde release time is 14 days. Therefore, the method described in this embodiment can significantly improve the formaldehyde release rate, thereby enhancing experimental efficiency and accuracy.

Claims

1. 1m 3 Climate chamber, including shell (31), characterized in that, It also includes a sample tube (5) for holding artificial board samples, a flow guide plate (20) and an air supply device; The air supply device includes a hollow box (17) with one open end, a rotary drive motor (28), and a fan blade (27); the output ends of the fan blade (27) and the rotary drive motor (28) are fixed together, and the box (17) and the fan blade (27) are provided with an air outlet on the side opposite to each other; the guide plate (20) is disposed between the sample tube (5) and the box (17), and the sample tube (5) and the guide plate (20) are provided with an air inlet on the side corresponding to each other; It also includes a drive device, which includes a drive motor (8), a rotating output rod (7), a drive wheel (6), a transmission wheel (19), a synchronous transmission rod (25), a transmission rod (18), a slide rod (23), and a first slide rail rod (24); the slide rod (23) is fixed to the bottom end of the housing (31), the first slide rail rod (24) is slidably connected to the slide rod (23), and the end of the first slide rail rod (24) is fixed to the bottom end of the housing (17); the transmission rod (18) is fixed to the upper end of the housing (17), and the drive wheel (6) and the transmission rod (18) are meshed and connected; the output end of the drive motor (8) is the rotating output rod (7), and the rotating output rod (7) and the drive wheel (6) are synchronously rotated and connected; the transmission wheel (19) and the drive wheel (6) are synchronously connected through the synchronous transmission rod (25), and the transmission wheel (19) and the guide plate (20) are meshed and rotated and connected; The drive device also includes a main drive belt (10), a first drive guide wheel (16), a rotating shaft (15), a second drive guide wheel (14), a third drive guide wheel (11), and a transmission belt (12). The drive wheel (6) and the first drive guide wheel (16) are synchronously connected by the main drive belt (10); the two ends of the rotating shaft (15) are fixed to the second drive guide wheel (14) and the first drive guide wheel (16) respectively; the third drive guide wheel (11) and the second drive guide wheel (14) are synchronously connected by the transmission belt (12), and the third drive guide wheel (11) and the sample cylinder (5) are meshed and connected by transmission. Accordingly, the sample cylinder (5) is provided with a transmission tooth (4) on its side. The bottom end of the housing (31) is provided with at least one adaptive guide wheel (22), which is engaged and connected to the side end of the guide plate (20) for transmission.

2. The 1m according to claim 1 3 Climate chamber, characterized in that, The drive device also includes an adaptive rotating wheel, which meshes with the transmission gear (4) and is located at the bottom of the housing (31).

3. The 1m according to claim 1 3 Climate chamber, characterized in that, The bottom of the shell (31) is provided with a support block (13), and the contact surface between the support block (13) and the sample tube (5) is an arc shape that is adapted to it.

4. The 1m according to claim 1 3 Climate chamber, characterized in that, The bottom of the shell (31) is provided with a second slide rail (1), and the opening end of the sample tube (5) is provided with a cover (2). The cover (2) is slidably mounted on the second slide rail (1), and the cover (2) is connected to an air outlet pipe (3).

5. The 1m according to claim 4 3 Climate chamber, characterized in that, Both sides of the cover (2) are provided with sliders, and correspondingly, the second slide rail (1) is provided with a slide groove. The cover (2) and the sample tube (5) are rotatably connected.

6. The 1m described in any one of claims 1-5 3 A method for detecting formaldehyde emission using a climate chamber, characterized in that... Includes the following steps: S01. The carrier gas supplied by the external air pump is purified and then connected to the housing (31). The formaldehyde content of the carrier gas entering the housing (31) shall not exceed 0.006 mg / m³. 3 ; S02, the carrier gas is blown into the sample cylinder (5) by the air supply device, the temperature range is controlled at 18~30℃, and the carrier gas flow rate is 0.1~0.5m / s; S03. Sampling begins the next day. From the second day to the fifth day, sampling is performed twice a day, with an interval of more than 3 hours between samplings. When sampling, the vacuum pump is connected to the outlet pipe of the climate chamber. 25 mL of distilled water is added to each of the two absorption bottles and connected in series. After connection, the vacuum pump is started to begin vacuuming at a rate of 2 L / min for 60 min.

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