Real-time monitoring device for oxygen content in limited operation space
The real-time monitoring device consisting of an oxygen concentration meter and a fan in a confined working space solves the problem of large human factors in the existing technology, realizes automatic monitoring of oxygen content and ventilation, and ensures work safety.
Patent Information
- Application Number
- CN202422577973.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2034-10-24
AI Technical Summary
In the prior art, the oxygen content monitoring method in a confined working space is greatly affected by human factors, which can easily lead to safety accidents and cannot effectively ensure the safety of workers.
A real-time monitoring device including an oxygen concentration meter, a fan, a transfer switch, a contactor and a thermal relay was designed. The oxygen concentration meter was used to monitor the oxygen content in real time, and an alarm was automatically issued when the oxygen content exceeded the standard and the fan was started for ventilation, eliminating the influence of human factors.
It has achieved effective monitoring of the oxygen content in confined working spaces, timely discovered and dealt with the risk of excessive oxygen content, eliminated potential accidents, and ensured the safety of workers.
Smart Images
Figure CN223413752U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a device for real-time monitoring and controlling the oxygen content in a confined working space, belonging to the technical field of safety devices. Background Art
[0002] When working in confined spaces (such as tunnels and caves), the oxygen content within the workspace is crucial to worker safety. According to confined space standards, the oxygen concentration within the workspace should be between 19.5% and 23%. Working in an oxygen-deficient space (less than 19.5%) or an oxygen-enriched space (more than 23%) poses a threat to worker safety and can easily lead to accidents. Therefore, real-time monitoring of oxygen levels within confined workspaces is essential. Existing monitoring methods involve workers using an oxygen concentration meter to measure the oxygen content. When the oxygen concentration exceeds the 19.5%-23% range, a fan is activated for ventilation. However, this monitoring method is significantly affected by human factors. If workers lack safety awareness or forget to monitor due to heavy workloads, accidents can easily occur, failing to ensure worker safety. Therefore, it is essential to design a device that can effectively monitor oxygen levels in confined workspaces. Utility Model Content
[0003] The purpose of this utility model is to address the shortcomings of the existing technology and provide a real-time monitoring device for the oxygen content in a confined working space, so as to effectively monitor the oxygen content in the confined working space, eliminate potential safety hazards, and ensure the personal safety of workers.
[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:
[0005] A real-time monitoring device for oxygen content in a confined working space comprises an oxygen concentration measuring instrument, a blower, a transfer switch and a contactor. The probe of the oxygen concentration measuring instrument is placed in the confined space. One end of a normally open contact in the oxygen concentration measuring instrument is connected to the live wire of an AC power supply, and the other end is connected to the neutral wire of the AC power supply via a contactor control coil. The motor of the blower is connected to a three-phase AC power supply via a main contact of the contactor.
[0006] The above-mentioned real-time monitoring device for oxygen content in a confined working space also includes a stop button, a start button and a transfer switch connected between the oxygen concentration measuring instrument and the live wire of the AC power supply. The common end of the transfer switch is connected to the live wire of the AC power supply, and the normally open end of the transfer switch is connected to the normally open contact in the oxygen concentration measuring instrument. After the normally open contact of the start button is connected in parallel with the first auxiliary normally open contact of the contactor, one end is connected to the normally closed end of the transfer switch through the normally closed contact of the stop button, and the other end is connected to the neutral wire of the AC power supply through the contactor control coil.
[0007] The above-mentioned real-time monitoring device for oxygen content in a confined working space also includes a fan operation indicator light and a fan stop indicator light. One end of the fan operation indicator light is connected to the neutral wire of the AC power supply, and the other end is connected to the common end of the transfer switch through the second auxiliary normally open contact of the contactor; one end of the fan stop indicator light is connected to the neutral wire of the AC power supply, and the other end is connected to the common end of the transfer switch through the auxiliary normally closed contact of the contactor.
[0008] In the above-mentioned real-time monitoring device for oxygen content in a confined working space, a thermal relay is installed on the motor of the fan, and the auxiliary contacts of the thermal relay are connected in series with the contactor control coil.
[0009] The above-mentioned real-time monitoring device for oxygen content in a confined working space also includes a first air switch and a second air switch. The first air switch is installed between the main contacts of the contactor and the three-phase AC power supply, and the second air switch is installed between the common end of the transfer switch and the live wire of the AC power supply.
[0010] This new system uses an oxygen concentration meter to monitor oxygen levels in confined spaces in real time. When oxygen levels exceed the specified limit, it automatically issues an alarm, prompting workers to evacuate the area and activating a fan for ventilation. Compared to traditional monitoring methods, this system eliminates the influence of human factors and effectively monitors oxygen levels in confined work spaces, eliminating potential safety hazards and ensuring worker safety. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0012] Figure 1 This is the electrical schematic diagram of the control circuit of the utility model;
[0013] Figure 2 It is an electrical principle diagram of the main circuit of the utility model.
[0014] The numbers in the figure are as follows: M, fan, SA, transfer switch, SB1, stop button, SB2, start button, KH, thermal relay, KH-1, auxiliary contact of thermal relay, YC, oxygen concentration measuring instrument, QF1, first air switch, QF2, second air switch, HG, fan running indicator light, HR, fan stop indicator light, KM, contactor control coil, KM-1, contactor first auxiliary normally open contact, KM-2, contactor second auxiliary normally open contact, KM-3, contactor auxiliary normally closed contact, KM-4, contactor main contact. DETAILED DESCRIPTION
[0015] The utility model aims to solve the shortcomings of the existing technology and provides a real-time monitoring device for the oxygen content in a confined working space. When the oxygen concentration in the working space exceeds the standard, the device can automatically issue an alarm message to prompt the workers to evacuate the site in time and start the forced ventilation equipment in time to ensure the safety of the work in the confined space.
[0016] See Figure 1 and Figure 2 The utility model mainly includes a fan M, a transfer switch SA, a stop button SB1, a start button SB2, a thermal relay KH, an oxygen concentration measuring instrument YC, a first air switch QF1, a second air switch QF2, a fan running indicator light HG, a fan stop indicator light HR and a contactor.
[0017] The motor of fan M is connected to the three-phase AC power supply (L1, L2, L3) in sequence through the thermal relay KH, the contactor main contact KM-4, and the first air switch QF1. The input of the second air switch QF2 is connected to the live wire (L) of the AC power supply, and the output is connected to the common terminal of the transfer switch SA. The normally open contact of the start button SB2 is connected in parallel with the first auxiliary normally open contact KM-1 of the contactor. One end is connected to the normally closed terminal of the transfer switch SA through the normally closed contact of the stop button SB1, and the other end is connected to the neutral wire (N) of the AC power supply through the contactor control coil KM and the auxiliary contact KH-1 of the thermal relay in sequence. One end of the normally open contact in the oxygen concentration measuring instrument YC is connected to the transfer switch S One end of the fan running indicator light HG is connected to the neutral line (N) of the AC power supply, and the other end is connected to the output end of the second air switch QF2 through the second auxiliary normally open contact KM-2 of the contactor; one end of the fan stop indicator light HR is connected to the neutral line (N) of the AC power supply, and the other end is connected to the output end of the second air switch QF2 through the auxiliary normally closed contact KM-3 of the contactor.
[0018] When the common terminal of transfer switch SA is connected to the normally closed terminal, manual control mode is selected. Pressing the start button SB2 energizes contactor control coil KM, locking the normally open terminal of transfer switch SA and starting the fan. Pressing the stop button SB1 de-energizes contactor control coil KM and stops the fan. When the common terminal of transfer switch SA is connected to the normally open terminal, automatic control mode is selected. The normally open contact in oxygen concentration meter YC operates according to the preset upper and lower limits of oxygen concentration in the working space. When the normally open contact closes, the fan starts; when the normally open contact opens, the fan stops.
[0019] When the fan is overloaded and heated, the thermal relay KH is activated, the auxiliary contact KH-1 of the thermal relay is disconnected, and the fan stops running.
[0020] When the first air switch QF1 is closed, power is supplied to the main circuit; when the second air switch QF2 is closed, power is supplied to the control circuit.
[0021] When the contactor control coil KM is energized, the contactor main contact KM-4 closes, the fan starts, and at the same time, the contactor second auxiliary normally open contact KM-2 closes, the fan running indicator HG lights up, the contactor auxiliary normally closed contact KM-3 opens, and the fan stop indicator HR goes out. When the contactor control coil KM loses power, the contactor main contact KM-4 opens, the fan stops, and at the same time, the contactor second auxiliary normally open contact KM-2 opens, the fan running indicator HG goes out, the contactor auxiliary normally closed contact KM-3 closes, and the fan stop indicator HR lights up.
[0022] During operation, the probe of the oxygen concentration meter YC is placed inside the confined space, while the monitoring device is placed outside. Before entering the confined space, the operator manually activates the fan to ventilate the space. After the inspector verifies that the oxygen content in the confined space is acceptable, the operator can enter the space to work. This principle is followed: ventilation first, testing second, and work last. During operation, the selector switch is set to the automatic position (the common terminal of the selector switch SA is connected to the normally open terminal). The oxygen concentration meter YC monitors the oxygen content in the workspace in real time. When the oxygen content falls below 19.5%, the oxygen concentration meter YC sounds an alarm and activates the fan to force-ventilate the confined space. When the oxygen content exceeds 23%, the oxygen concentration meter YC activates the fan to avoid working in an oxygen-rich environment. This allows for timely detection and resolution of risks of excessive oxygen content, eliminates potential accidents, and ensures safe operations in confined spaces.
Claims
1. A real-time monitoring device for oxygen content in a confined working space, characterized in that: The invention comprises an oxygen concentration measuring instrument (YC), a blower (M), a transfer switch (SA) and a contactor. The probe of the oxygen concentration measuring instrument (YC) is placed in a confined space. One end of the normally open contact in the oxygen concentration measuring instrument (YC) is connected to the live wire of the AC power supply, and the other end is connected to the neutral wire of the AC power supply via the contactor control coil (KM); the motor of the blower (M) is connected to the three-phase AC power supply via the main contact (KM-4) of the contactor.
2. The real-time monitoring device for oxygen content in a confined working space according to claim 1, characterized in that: The invention also includes a stop button (SB1), a start button (SB2) and a transfer switch (SA) connected between the oxygen concentration measuring instrument (YC) and the live wire of the AC power supply. The common end of the transfer switch (SA) is connected to the live wire of the AC power supply, the normally open end of the transfer switch (SA) is connected to the normally open contact in the oxygen concentration measuring instrument (YC), the normally open contact of the start button (SB2) is connected in parallel with the first auxiliary normally open contact (KM-1) of the contactor, one end of which is connected to the normally closed end of the transfer switch (SA) through the normally closed contact of the stop button (SB1), and the other end is connected to the neutral wire of the AC power supply through the contactor control coil (KM).
3. The real-time monitoring device for oxygen content in a confined working space according to claim 2, characterized in that: It also includes a fan operation indicator light (HG) and a fan stop indicator light (HR), one end of the fan operation indicator light (HG) is connected to the neutral line of the AC power supply, and the other end is connected to the common end of the transfer switch (SA) through the second auxiliary normally open contact (KM-2) of the contactor; one end of the fan stop indicator light (HR) is connected to the neutral line of the AC power supply, and the other end is connected to the common end of the transfer switch (SA) through the auxiliary normally closed contact (KM-3) of the contactor.
4. The real-time monitoring device for oxygen content in a confined working space according to claim 3, characterized in that: A thermal relay (KH) is installed on the motor of the fan (M), and the auxiliary contact (KH-1) of the thermal relay is connected in series with the contactor control coil (KM).
5. The real-time monitoring device for oxygen content in a confined working space according to claim 4, characterized in that: It also includes a first air switch (QF1) and a second air switch (QF2). The first air switch (QF1) is installed between the main contact of the contactor (KM-4) and the three-phase AC power supply, and the second air switch (QF2) is installed between the common end of the transfer switch (SA) and the live wire of the AC power supply.