A combined fire and pressure vacuum relief valve

Abstract

The present invention provides a combined fire-resistant pressure vacuum relief valve, which includes a pressure valve seat. A threaded connector is provided at the bottom end of the pressure valve seat, and a mounting plate is threadedly connected to the surface of the threaded connector. An anti-rain cover bracket is fixedly sleeved outside the bottom end of the pressure valve seat, and an anti-rain cover is installed outside the anti-rain cover bracket. The pressure valve seat is located inside the anti-rain cover. A positive pressure end and a negative pressure end are provided at the top end of the pressure valve seat. The positive pressure end includes a counterweight plate and a pressure end valve disc. The bottom of the pressure end valve disc is designed as an embedded groove, and the counterweight plate is pressed on the surface of the pressure end valve disc, so as to form an effective seal between the pressure end valve disc and the pressure valve seat. The combined fire-resistant pressure vacuum relief valve of the present invention can enable the pressure relief at the pressure end and the vacuum relief at the vacuum end to pass through two different channels respectively. Through the independent flow channel design, the problem of flow dead corners in the composite flow channel is eliminated, and the generation of turbulent flow and eddy current in the valve is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of relief valves, in particular to a combined fire-retardant pressure vacuum relief valve. Background Art

[0002] The currently used combined fire-blocking pressure vacuum relief valve has the following disadvantages:

[0003] 1. The current mainstream combined fire-blocking pressure / vacuum relief valve cavity structure is generally a composite flow channel design. The composite flow channel has a dead angle of flow, which will cause disturbance and turbulence in the valve. Disturbance and turbulence will directly lead to design defects such as flutter and partial lifting of the valve disc during the opening process.

[0004] 2. Under normal working conditions, the discharge volume at the pressure end is higher than that at the vacuum end. The positive pressure throat diameter of the current combined fire-blocking pressure / vacuum relief valve is smaller than the negative pressure throat diameter. This will cause the discharge volume at the pressure end to be smaller than that at the vacuum end. If the pressure end discharge is satisfied and the vacuum end discharge volume is insufficient, flutter will occur.

[0005] 3. The composite flow channel causes excessive pressure loss at the negative pressure end, which indirectly leads to poor stability of the valve plate vacuum opening.

[0006] 4. The current combined fire-blocking pressure / vacuum relief valve adopts a side inlet and outlet airway design. The side inlet and outlet airway causes the fire-blocking element to be installed on the side. In order to prevent rain, a rain cover is usually added to the fire-blocking element. The cover design can prevent rain, but when the wind on the reverse side continues, it will also be collected into the flow channel by the rain cover, directly leading to the formation of back pressure. Back pressure will cause the valve to be unable to open when it needs to be discharged, directly leading to new safety hazards and risk points for the storage tank. Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] In view of the shortcomings of the prior art, the present invention provides a combined fire-blocking pressure vacuum relief valve, which solves the problems that the existing combined fire-blocking pressure / vacuum relief valve composite flow channel design is prone to flow dead corners, poor vacuum end opening stability, easy to cause back pressure formation, and poor sealing.

[0009] (II) Technical solution

[0010] To achieve the above objectives, the present invention is realized through the following technical solutions: A combined fire-resistant pressure vacuum relief valve, comprising a pressure valve seat, a threaded connector is provided at the bottom end of the pressure valve seat, an installation plate is threadedly connected to the surface of the threaded connector, a rain shield support is fixedly sleeved outside the bottom end of the pressure valve seat, a rain shield is installed outside the rain shield support, the pressure valve seat is located inside the rain shield, a positive pressure end and a negative pressure end are provided at the top end of the pressure valve seat, the positive pressure end includes a counterweight plate and a pressure end valve disc, the bottom of the pressure end valve disc is designed as an embedded groove, the counterweight plate is pressed on the surface of the pressure end valve disc, so that an effective seal is formed between the pressure end valve disc and the pressure valve seat, a vacuum end valve seat is embedded in the groove at the lower surface of the pressure end valve disc, the negative pressure end includes a crank counterweight mechanism, a lifting valve rod, and a vacuum valve disc, the upper surface of the vacuum valve disc is designed as an embedded groove, the lifting valve rod is connected to the center of the vacuum valve disc through a nut, the crank counterweight mechanism is located at the top of the lifting valve rod, and the crank counterweight mechanism forms an effective seal between the vacuum valve disc and the vacuum end valve seat under a downward acting force.

[0011] Preferably, the crank counterweight mechanism includes two support rods, two first rotating rods, two second rotating rods, and two counterweight wheels. The two support rods are respectively fixed on the surface of the vacuum end valve seat. One ends of the two first rotating rods are jointly rotatably connected to the lifting valve rod, and the other ends of the two first rotating rods are respectively rotatably connected to the two second rotating rods. The middle positions of the two second rotating rods are rotatably connected to the top ends of the two support rods. The two counterweight wheels are respectively connected to the ends of the two second rotating rods away from the two first rotating rods.

[0012] Preferably, a valve sleeve is fixed at the bottom end of the pressure end valve disc. The valve sleeve is sleeved on the surface of the pressure valve seat. A plurality of first air ports are formed on the surface of the valve sleeve at one time. Two symmetric second air ports are provided at the top end of the vacuum end valve seat. The plurality of first air ports and the second air ports are opened respectively when the pressure end and the vacuum end are opened, so as to form an auxiliary independent flow path.

[0013] Preferably, a plurality of through holes are formed on the surface of the rain shield support to facilitate air intake from the bottom.

[0014] Preferably, fire-resistant elements are longitudinally arranged on the outer side of the valve sleeve, and the fire-resistant elements are connected to the rain shield support to play a fixing role.

[0015] Preferably, two positioning screws are connected to the outer surface of the pressure valve seat. Two strip-shaped openings are symmetrically formed on the surface of the valve sleeve. The two positioning screws respectively penetrate into the two strip-shaped openings and are slidably connected to the strip-shaped openings to prevent the positive pressure valve disc from not being able to reset along a predetermined trajectory.

[0016] (III) Beneficial effects

[0017] The present invention provides a combined fire - resistant pressure - vacuum relief valve, which has the following beneficial effects:

[0018] 1. The combined fire - resistant pressure - vacuum relief valve of the present invention enables the pressure relief at the pressure end and the vacuum relief at the vacuum end to pass through two different channels respectively. Through the independent flow - path design, the problem of flow dead - ends in the composite flow - path is eliminated, and the generation of turbulent flow and eddy current inside the valve is avoided.

[0019] 2. Through the combined design, the present invention enables a single valve to achieve fire - resistance, pressure relief, and vacuum relief. The innovative lower air inlet and outlet channels can achieve multi - position air inlet and outlet, avoiding the back - pressure risk brought by the side air inlet and outlet channels.

[0020] 3. Through the setting of the crankshaft counterweight mechanism, the pressure at the vacuum end is more stable. Under the action of the first rotating rod and the second rotating rod, the two counterweight wheels disperse the force, making the lifting of the valve stem move more stably, and greatly ensuring the sealing effect.

[0021] 4. The present invention can achieve a short reseating pressure differential, and can ensure excellent valve seat sealing performance both before and after pressure relief.

[0022] 5. While providing pressure and vacuum relief, the present invention designs a flame arrester to provide a fire - resistance function. The flame - arrester elements are longitudinally designed and cooperate with the multiple dry through - holes opened on the surface of the rain - proof cover support, effectively eliminating the back - pressure generated inside the breather valve due to the air inlet and outlet channels on the side of the flame - arrester element opposite to the tank top in the horizontal design. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 is the front view of the present invention;

[0025] Figure 3 is a schematic diagram of the opening of the pressure end of the present invention;

[0026] Figure 4 is a schematic diagram of the opening of the vacuum end of the present invention.

[0027] Among them, 1. Rain - proof cover; 2. Crankshaft counterweight mechanism; 21. Support rod; 22. First rotating rod; 23. Second rotating rod; 24. Counterweight wheel; 3. Counterweight plate; 4. Pressure - end valve disc; 5. Vacuum - end valve seat; 6. Vacuum valve disc; 7. Pressure valve seat; 8. Flame - arrester element; 9. Rain - proof cover support; 10. Lifting valve stem; 11. Valve sleeve. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] Embodiment 1:

[0030] An embodiment of the present invention provides a combined fireproof pressure vacuum relief valve. As Figure 1 shown in the structural schematic diagram of the combined fireproof pressure vacuum relief valve, it includes a pressure valve seat 7. A threaded connector is provided at the bottom end of the pressure valve seat 7, and a mounting plate is threadedly connected to the surface of the threaded connector. A rain shield bracket 9 is fixedly sleeved outside the bottom end of the pressure valve seat 7, and a rain shield 1 is installed outside the rain shield bracket 9. The pressure valve seat 7 is located inside the rain shield 1. A positive pressure end and a negative pressure end are provided at the top end of the pressure valve seat 7. The positive pressure end includes a counterweight plate 3 and a pressure end valve disc 4. The bottom of the pressure end valve disc 4 is designed with an embedded groove, and the counterweight plate 3 is pressed on the surface of the pressure end valve disc 4, so as to form an effective seal between the pressure end valve disc 4 and the pressure valve seat 7. A vacuum end valve seat 5 is embedded in the groove on the lower surface of the pressure end valve disc 4. The negative pressure end includes a crank counterweight mechanism 2, a lifting valve rod 10, and a vacuum valve disc 6. The upper surface of the vacuum valve disc 6 is designed with an embedded groove, and the lifting valve rod 10 is connected to the center of the vacuum valve disc 6 through a nut. The crank counterweight mechanism 2 is located at the top of the lifting valve rod 10, and the crank counterweight mechanism 2 forms an effective seal between the vacuum valve disc 6 and the vacuum end valve seat 5 under a downward acting force.

[0031] As Figure 2As shown in the figure, the crankshaft counterweight mechanism 2 includes two support rods 21, two first rotating rods 22, two second rotating rods 23, and two counterweight wheels 24. The two support rods 21 are respectively fixed on the surface of the vacuum end valve seat 5. One ends of the two first rotating rods 22 are jointly rotatably connected to the lifting valve rod 10, and the other ends of the two first rotating rods 22 are respectively rotatably connected to the two second rotating rods 23. The middle positions of the two second rotating rods 23 are rotatably connected to the tops of the two support rods 21. The two counterweight wheels 24 are respectively connected to the ends of the two second rotating rods 23 far from the two first rotating rods 22. A sealing diaphragm is arranged inside the vacuum valve disc 6. A valve sleeve 11 is fixed at the bottom end of the pressure end valve disc 4. The valve sleeve 11 is sleeved on the surface of the pressure valve seat 7. A plurality of first air ports are arranged on the surface of the valve sleeve 11 in sequence. Two symmetrical second air ports are arranged at the top end of the vacuum end valve seat 5. A number of through holes are arranged on the surface of the rain cover support 9. A fire arrestor element 8 is longitudinally arranged outside the valve sleeve 11. The fire arrestor element 8 is connected to the rain cover support 9. Two positioning screws are connected to the outer surface of the pressure valve seat 7. Two strip-shaped openings are symmetrically arranged on the surface of the valve sleeve 11. The two positioning screws respectively penetrate into the two strip-shaped openings and are slidably connected to the strip-shaped openings.

[0032] In the normal state, the valve sleeve 11 is in contact with the pressure valve seat 7. The pressure end valve disc 4 at the top is blocked by the counterweight plate 3 against the pressure valve seat 7 to achieve forward sealing, blocking the flow channel at the pressure end. At the same time, under the action of the gravity of the crankshaft counterweight mechanism, the lifting valve rod 10 is lifted upward, so that the vacuum valve disc 6 presses against the vacuum end valve seat 5 in the reverse direction to achieve sealing, blocking the flow channel at the vacuum end and ensuring good sealing at both places.

[0033] Embodiment 2:

[0034] As Figure 3 Shown is a schematic diagram of the opening of the pressure end of the fire arrestor pressure / vacuum relief valve. When materials are transported into the storage tank during operation, the materials compress the steam space inside the storage tank. When the set pressure is reached, the opening action of the combined fire arrestor pressure vacuum relief valve is as follows: The pressure inside the tank pushes the opening of the pressure end of the combined fire arrestor pressure vacuum relief valve. Along with it, the crankshaft counterweight mechanism 2, the counterweight plate 3, the pressure end valve disc 4, the vacuum end valve seat 5, the vacuum valve disc 6, and the valve sleeve 11 are lifted, so that the first air port of the valve sleeve 11 is communicated with the gap between the pressure end valve disc 4 and the pressure valve seat 7, forming a diversion channel at the pressure end. When the pressure drops to 90% of the set pressure, the valve plate assembly (the counterweight plate 3, the pressure end valve disc 4) moves downward and covers the pressure valve seat 7 again to achieve sealing.

[0035] The combined fire arrestor pressure vacuum relief valve adopts the 10% overpressure valve disc technology. The unique 90° downward skirt design of the pressure end valve disc 4 helps the opening height of the pressure end valve disc 4 reach 1 / 4 of the flow channel diameter, that is, the so-called maximum opening value, after overpressure by 10%.

[0036] Example 3:

[0037] As Figure 4 shown in the schematic diagram of the opening of the vacuum end of the fire - resistant pressure / vacuum relief valve. When the storage tank transfers materials outwards during operation, the outflow of materials will cause the inside of the storage tank to be in a vacuum state. When the set vacuum value is reached, the opening action of the combined fire - resistant pressure - vacuum relief valve is as follows: The opening of the vacuum end of the emergency pressure - vacuum relief valve is accompanied by the upward lifting of the crank counterweight mechanism 2, which causes the vacuum valve disc 6 to move downward, and the vacuum end of the valve opens. When the vacuum pressure rises to 90% of the set vacuum, under the action of the gravity of the crank counterweight mechanism 2, the vacuum valve disc 6 re - lifts and seats again to seal.

[0038] The present invention has an integrated structure with reliable sealing and can provide longitudinal sealing compensation. The air leakage rate at 90% of the set value should be lower than 0.5 SCFH (0.015 Nm3 / h).

[0039] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A combined fire - resistant pressure - vacuum relief valve, comprising a pressure valve seat (7), characterized in that: A threaded connector is provided at the bottom end of the pressure valve seat (7). An installation plate is threadedly connected to the surface of the threaded connector. A rain shield bracket (9) is fixedly sleeved outside the bottom end of the pressure valve seat (7). A rain shield (1) is installed outside the rain shield bracket (9). The pressure valve seat (7) is located inside the rain shield (1). A positive pressure end and a negative pressure end are provided at the top end of the pressure valve seat (7). The positive pressure end includes a counterweight plate (3) and a pressure end valve disc (4). The bottom of the pressure end valve disc (4) is designed with an embedded groove. The counterweight plate (3) is pressed on the surface of the pressure end valve disc (4), so that an effective seal is formed between the pressure end valve disc (4) and the pressure valve seat (7). A vacuum end valve seat (5) is embedded in the groove on the lower surface of the pressure end valve disc (4). The negative pressure end includes a crankshaft counterweight mechanism (2), a lifting valve rod (10), and a vacuum valve disc (6). The upper surface of the vacuum valve disc (6) is designed with an embedded groove. The lifting valve rod (10) is connected to the center of the vacuum valve disc (6) through a nut. The crankshaft counterweight mechanism (2) is located at the top of the lifting valve rod (10). The crankshaft counterweight mechanism (2) forms an effective seal between the vacuum valve disc (6) and the vacuum end valve seat (5) under a downward acting force; The crankshaft counterweight mechanism (2) includes two support rods (21), two first rotating rods (22), two second rotating rods (23), and two counterweight wheels (24). The two support rods (21) are respectively fixed on the surface of the vacuum end valve seat (5). One ends of the two first rotating rods (22) are jointly rotatably connected to the lifting valve rod (10), and the other ends of the two first rotating rods (22) are respectively rotatably connected to the two second rotating rods (23). The middle positions of the two second rotating rods (23) are rotatably connected to the top ends of the two support rods (21). The two counterweight wheels (24) are respectively connected to the ends of the two second rotating rods (23) far from the two first rotating rods (22); A valve sleeve (11) is fixed to the bottom end of the pressure end valve disc (4). The valve sleeve (11) is sleeved on the surface of the pressure valve seat (7). A plurality of first air ports are formed on the surface of the valve sleeve (11) in sequence. Two symmetric second air ports are provided at the top end of the vacuum end valve seat (5).

2. The combined fire - resistant pressure - vacuum relief valve according to claim 1, characterized in that: A sealing diaphragm is provided inside the vacuum valve disc (6).

3. The combined fire - resistant pressure - vacuum relief valve according to claim 1, characterized in that: A number of through holes are formed on the surface of the rain shield bracket (9).

4. The combined fire - resistant pressure - vacuum relief valve according to claim 1, characterized in that: Fire arresters (8) are longitudinally arranged outside the valve sleeve (11). The fire arresters (8) are connected to the rain shield bracket (9).

5. The combined fire - resistant pressure - vacuum relief valve according to claim 1, characterized in that: Two positioning screws are connected to the outer surface of the pressure valve seat (7). Two strip-shaped openings are symmetrically formed on the surface of the valve sleeve (11). The two positioning screws respectively penetrate into the two strip-shaped openings and are slidably connected to the strip-shaped openings.

Images