Pressure loss alarm control device

Abstract

A pressure loss alarm control device comprises an explosion-proof case, an intelligent instrument is arranged in the explosion-proof case, a pressure difference transmitter and a time relay are electrically connected to the intelligent instrument, and the pressure difference transmitter is provided with two air pressure interfaces which are used for directly measuring the atmospheric pressure difference value in a door bucket and a workshop. The atmospheric pressure difference value is converted into an electric signal through the conversion circuit, and the electric signal is transmitted to the intelligent instrument, so that the intelligent instrument receives the electric signal, filters, identifies and judges the electric signal, converts the electric signal into an atmospheric pressure difference value through the conversion circuit, displays the atmospheric pressure difference value, and compares the atmospheric pressure difference value with an alarm value for calculation; if the atmospheric pressure difference value is lower than the alarm value, a timing signal is automatically output to the time relay, and if the atmospheric pressure difference value is higher than the alarm value, output of the timing signal is stopped.

Description

Technical fields:

[0001] This utility model relates to a pressure loss alarm control device. Background technology:

[0002] In the production workshops of pharmaceutical and chemical plants, some toxic and polluting harmful gases are generated. These harmful gases need to be purified into clean and harmless gases by professional equipment in the workshop before being discharged into the atmosphere. This requires the workshop to be well-sealed to trap the harmful gases inside. However, there are inevitably doors and windows in the workshop, so it is impossible to completely seal them. In particular, workers need to open the doors when entering and leaving the workshop, which may cause harmful gases to leak out.

[0003] To prevent the leakage of harmful gases, a vestibule is added outside the workshop entrance, and a positive pressure ventilation system is installed inside the vestibule. The positive pressure ventilation system is generally equipped with two sets of fans: a main fan and a backup fan. The positive pressure ventilation system sends air into the vestibule, making the atmospheric pressure inside the vestibule higher than the atmospheric pressure inside the workshop. The positive pressure ventilation system is activated before the workshop starts production. When workers open the door to enter or exit the production workshop, the air in the vestibule will enter the production workshop under the action of atmospheric pressure, thereby preventing the leakage of harmful gases from the production workshop.

[0004] When a positive pressure ventilation system malfunctions or the door is not fully closed, the atmospheric pressure inside the vestibule drops, causing it to lose its protective function. To prevent this, pressure sensors are usually installed inside the vestibule to measure the pressure. However, this method only measures the pressure inside the vestibule, not the pressure inside the workshop. The measured value is compared with atmospheric pressure, not the pressure inside the workshop. If the pressure inside the workshop increases while the pressure inside the vestibule remains constant, the pressure difference between the two will decrease. Existing pressure sensors cannot detect and provide timely feedback on this situation. Utility model content:

[0005] This utility model provides a pressure loss alarm control device with a reasonable structural design. Based on the cooperation of multiple functional components, it can measure the pressure difference between the atmospheric pressure inside the vestibule and the atmospheric pressure inside the production workshop. Based on the measurement result of the pressure difference and the detection time, it determines whether to issue an audible and visual alarm. If the atmospheric pressure difference is less than the set value and continues for a period of time, the pressure loss alarm controller will issue an audible and visual alarm and simultaneously interlock to start the backup fan of the positive pressure ventilation system to increase the air supply to maintain the atmospheric pressure difference, thereby avoiding detection omissions, ensuring the stable operation of the positive pressure ventilation system, and solving the problems existing in the prior art.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0007] A pressure loss alarm control device includes an explosion-proof enclosure. Inside the enclosure is an intelligent instrument, which is electrically connected to a differential pressure transmitter and a time relay. The differential pressure transmitter has two air pressure interfaces for directly measuring the atmospheric pressure difference between the vestibule and the workshop. The atmospheric pressure difference is converted into an electrical signal by a conversion circuit and transmitted to the intelligent instrument. After receiving the electrical signal, the intelligent instrument filters, identifies, and judges it, and then converts the electrical signal back into an atmospheric pressure difference value through the conversion circuit and displays it. It then compares and calculates the difference with the alarm value. If the atmospheric pressure difference is lower than the alarm value, a timing signal is automatically output to the time relay. If the atmospheric pressure difference is higher than the alarm value, the timing signal is stopped.

[0008] The time relay is used to receive the timing signal from the smart instrument and start timing. When the time reaches the set time, the time relay will output an alarm signal to the flashing buzzer and output a linkage signal to the standby fan.

[0009] The flashing buzzer is installed on the door panel of the explosion-proof enclosure, and a power switch knob is also provided on the door panel to control the power on and off of the equipment.

[0010] An air switch is provided on the smart meter, and the air switch is electrically connected and configured to cooperate with the power switch knob.

[0011] A viewing window is provided on the explosion-proof enclosure to allow users to easily view and obtain differential pressure values, alarm values, and alarm status information.

[0012] The smart instrument is fixed inside the explosion-proof enclosure by an instrument bracket.

[0013] The door panel is equipped with handles and hinges for easy access and maintenance.

[0014] An 8-position terminal block is provided inside the explosion-proof enclosure. The 8-position terminal block is used to connect the differential pressure transmitter and the standby fan.

[0015] This utility model adopts the above-described structure, using a differential pressure transmitter to directly measure the atmospheric pressure difference between the vestibule and the workshop. The atmospheric pressure difference is converted into an electrical signal by a conversion circuit and transmitted to an intelligent instrument. Upon receiving the electrical signal, the intelligent instrument filters, identifies, and judges it, then converts the signal back into an atmospheric pressure difference value and displays it. This value is then compared with an alarm value. If the atmospheric pressure difference is lower than the alarm value, a timing signal is automatically output to a time relay; if the atmospheric pressure difference is higher than the alarm value, the timing signal output stops. The time relay receives the timing signal from the intelligent instrument and begins timing. When the set time is reached, the time relay outputs an alarm signal to a flashing buzzer and a linkage signal to the standby fan. The flashing buzzer provides an audible and visual alarm when the pressure difference is abnormal, prompting staff to investigate the problem. The intelligent instrument receives and identifies various electrical signals and performs data calculations, offering advantages such as simplicity, practicality, safety, and reliability. Attached image description:

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure 2 This is a schematic diagram of the internal structure of this utility model.

[0018] In the diagram, 1. Viewing window, 2. Handle, 3. Power switch knob, 4. Hinge, 5. Flashing buzzer, 6. Instrument bracket, 7. Smart instrument, 8. Differential pressure transmitter, 9. Time relay, 10. Air switch, 11. 8-position terminal block. Detailed implementation method:

[0019] To clearly illustrate the technical features of this solution, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0020] like Figure 1-2 As shown in the diagram, the pressure loss alarm control device includes an explosion-proof enclosure. Inside the enclosure is an intelligent instrument 7, which is electrically connected to a differential pressure transmitter 8 and a time relay 9. The differential pressure transmitter has two air pressure interfaces for directly measuring the atmospheric pressure difference between the vestibule and the workshop. The atmospheric pressure difference is converted into an electrical signal by a conversion circuit and transmitted to the intelligent instrument. After receiving the electrical signal, the intelligent instrument filters, identifies, and judges it, and then converts the electrical signal back into an atmospheric pressure difference value through the conversion circuit and displays it. It then compares and calculates the difference with the alarm value. If the atmospheric pressure difference is lower than the alarm value, a timing signal is automatically output to the time relay. If the atmospheric pressure difference is higher than the alarm value, the timing signal is stopped.

[0021] The time relay is used to receive the timing signal from the smart instrument and start timing. When the time reaches the set time, the time relay will output an alarm signal to the flashing buzzer 5 and output a linkage signal to the standby fan.

[0022] The flashing buzzer 5 is installed on the door panel of the explosion-proof enclosure. A power switch knob is also provided on the door panel to control the power on and off of the equipment.

[0023] An air switch 10 is provided on the smart instrument 7, and the air switch 10 is electrically connected and configured with the power switch knob 3.

[0024] A viewing window 2 is provided on the explosion-proof enclosure to facilitate users in viewing and obtaining differential pressure values, alarm values, and alarm status information.

[0025] The smart meter is fixed inside the explosion-proof enclosure by the meter bracket 6.

[0026] The door panel is equipped with a handle 2 and a hinge 4 for easy access and maintenance.

[0027] An 8-position terminal block 11 is provided inside the explosion-proof enclosure. The 8-position terminal block 11 is used to connect the differential pressure transmitter and the standby fan.

[0028] The working principle of the pressure loss alarm control device in this embodiment is as follows: Based on the cooperation of multiple functional components, it can measure the pressure difference between the atmospheric pressure inside the vestibule and the atmospheric pressure inside the production workshop. Based on the measurement result of the pressure difference and the detection time, it determines whether to issue an audible and visual alarm. If the atmospheric pressure difference is less than the set value and continues for a period of time, the pressure loss alarm controller will issue an audible and visual alarm and simultaneously interlock to start the backup fan of the positive pressure ventilation system to increase the air supply to maintain the atmospheric pressure difference, thereby avoiding detection omissions and ensuring the stable operation of the positive pressure ventilation system.

[0029] This application is used to measure the pressure difference between the atmospheric pressure inside the vestibule and the atmospheric pressure inside the production workshop. If the atmospheric pressure difference is less than the set threshold and lasts for a certain period of time, generally less than 25Pa for 1 minute, an audible and visual alarm will be issued, and the standby fan of the positive pressure ventilation system will be interlocked to increase the air supply and maintain the atmospheric pressure difference.

[0030] The overall solution mainly includes an explosion-proof enclosure, inside which is installed an intelligent instrument. The intelligent instrument is electrically connected to a differential pressure transmitter and a time relay. The differential pressure transmitter has two air pressure interfaces for directly measuring the atmospheric pressure difference between the vestibule and the workshop. This atmospheric pressure difference is converted into an electrical signal by a conversion circuit and transmitted to the intelligent instrument. Upon receiving the electrical signal, the intelligent instrument filters, identifies, and judges it, then converts the electrical signal back into an atmospheric pressure difference value and displays it. This value is then compared with an alarm value. If the atmospheric pressure difference is lower than the alarm value, a timing signal is automatically output to the time relay; if the atmospheric pressure difference is higher than the alarm value, the timing signal output stops. The time relay receives the timing signal from the intelligent instrument and begins timing. When the set time is reached, the time relay outputs an alarm signal to a flashing buzzer and a linkage signal to the standby fan. The flashing buzzer is located on the door panel of the explosion-proof enclosure, which also has a power switch knob for controlling the power on and off of the equipment.

[0031] In practical applications, the differential pressure transmitter converts the differential pressure value into an electrical signal and transmits it to the intelligent instrument. Upon receiving the electrical signal, the intelligent instrument converts it back into a differential pressure value and compares it with a set alarm threshold. If the value is higher than the alarm threshold, it continues to receive, convert, and analyze the data. If the value is lower than the alarm threshold, it sends an electrical signal to a time relay. The time relay, upon receiving the signal, begins timing. If the timing reaches the set time, it sends an electrical signal to a flashing buzzer and outputs an interlock signal. When the differential pressure value exceeds the alarm threshold, the intelligent instrument stops outputting electrical signals to the time relay. The time relay, upon detecting the disappearance of the electrical signal, also stops outputting electrical signals to the flashing buzzer and the interlock signal, ensuring the normal and stable operation of the system.

[0032] Preferably, the smart instrument is equipped with an air switch, which is electrically connected and configured to work in conjunction with the power switch knob. The power switch knob can only function after the air switch is closed, thus preventing accidental operation.

[0033] Preferably, a viewing window is provided on the explosion-proof enclosure to facilitate users in viewing and obtaining differential pressure values, alarm values, and alarm status information; the intelligent instrument is fixed inside the explosion-proof enclosure by an instrument bracket to ensure the overall stability of the internal component structure.

[0034] The differential pressure transmitter of this application is equipped with two air pressure interfaces, which can directly measure the atmospheric pressure difference between two spaces. Then, the atmospheric pressure difference is converted into an electrical signal through a conversion circuit and transmitted to the intelligent instrument. Compared with using one pressure transmitter to measure the pressure in the shed or using two pressure transmitters to measure the atmospheric pressure in two spaces and then subtracting them to calculate the atmospheric pressure difference, the differential pressure transmitter has the advantages of low cost, simple use, convenient installation, and accurate measurement.

[0035] The time relay of this application will start timing after receiving a timing signal, and will restart timing after receiving a timing signal again; when the timing reaches the set time, the time relay will output an alarm signal to the flashing buzzer and an output linkage signal to the standby fan. The action is precise and the response speed is fast, which can quickly trigger the standby fan when needed.

[0036] It should be noted that the conversion circuit of this application can be built using an AD converter or a DA converter as the core component.

[0037] In summary, the pressure loss alarm control device in this embodiment of the present invention, based on the coordinated action of multiple functional components, can measure the pressure difference between the atmospheric pressure inside the vestibule and the atmospheric pressure inside the production workshop. Based on the measurement result of the pressure difference and the detection time, it determines whether to issue an audible and visual alarm. If the atmospheric pressure difference is less than the set value and continues for a period of time, the pressure loss alarm controller will issue an audible and visual alarm and simultaneously interlock to start the backup fan of the positive pressure ventilation system to increase the air supply to maintain the atmospheric pressure difference, thereby avoiding detection omissions and ensuring the stable operation of the positive pressure ventilation system.

[0038] The above specific embodiments should not be construed as limiting the scope of protection of this utility model. For those skilled in the art, any alternative improvements or modifications made to the embodiments of this utility model shall fall within the scope of protection of this utility model.

[0039] Any aspects of this utility model not described in detail are known to those skilled in the art.

Claims

1. A pressure loss alarm control device, characterized in that: The control device includes an explosion-proof enclosure, inside which is installed an intelligent instrument. A differential pressure transmitter and a time relay are electrically connected to the intelligent instrument. The differential pressure transmitter has two air pressure interfaces for directly measuring the atmospheric pressure difference between the vestibule and the workshop. The atmospheric pressure difference is converted into an electrical signal by a conversion circuit and transmitted to the intelligent instrument. After receiving the electrical signal, the intelligent instrument filters, identifies, and judges it, and then converts the electrical signal back into an atmospheric pressure difference value through the conversion circuit and displays it. It then compares and calculates with an alarm value. If the atmospheric pressure difference is lower than the alarm value, a timing signal is automatically output to the time relay. If the atmospheric pressure difference is higher than the alarm value, the timing signal is stopped. The time relay is used to receive the timing signal from the smart instrument and start timing. When the time reaches the set time, the time relay will output an alarm signal to the flashing buzzer and output a linkage signal to the standby fan. The flashing buzzer is installed on the door panel of the explosion-proof enclosure, and a power switch knob is also provided on the door panel to control the power on and off of the equipment.

2. The underpressure alarm control device according to claim 1, characterized in that: An air switch is provided on the smart meter, and the air switch is electrically connected and configured to cooperate with the power switch knob.

3. The underpressure alarm control device according to claim 1, characterized in that: A viewing window is provided on the explosion-proof enclosure to allow users to easily view and obtain differential pressure values, alarm values, and alarm status information.

4. The underpressure alarm control device according to claim 1, characterized in that: The smart instrument is fixed inside the explosion-proof enclosure by an instrument bracket.

5. The underpressure alarm control device according to claim 1, characterized in that: The door panel is equipped with handles and hinges for easy access and maintenance.

6. The underpressure alarm control device according to claim 1, characterized in that: An 8-position terminal block is provided inside the explosion-proof enclosure. The 8-position terminal block is used to connect the differential pressure transmitter and the standby fan.

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