Step-by-step direct-acting valve and step-by-step direct-acting pneumatic ash conveying system

Abstract

The invention relates to the technical field of thermal power plant pneumatic ash conveying, and provides a step-by-step direct-acting valve and a step-by-step direct-acting type pneumatic ash conveying system.The step-by-step direct-acting type pneumatic ash conveying system comprises an ash conveying pipeline, a gas accompanying pipeline and a plurality of step-by-step direct-acting valves; the plurality of step-by-step direct-acting valves are sequentially arranged along the ash conveying pipeline; the lower ends of the connecting pipelines of the plurality of step-by-step direct-acting valves are communicated with the ash conveying pipeline; main valve air inlets of the multiple step-by-step direct-acting valves are all communicated with the auxiliary air pipeline; a control gas outlet of the downstream step-by-step direct-acting valve in the ash conveying direction of the ash conveying pipeline is communicated with a control gas inlet of the upstream adjacent step-by-step direct-acting valve through a control gas pipe; when the main valve opening and closing end cover in any step-by-step direct-acting valve is in an opening state, the control pistons in all step-by-step direct-acting valves located on the upstream of the step-by-step direct-acting valve in the ash conveying direction of the ash conveying pipeline are in the opening state. The conveying capacity at the blocked position can be enhanced, and the gas source gas amount can be saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pneumatic ash conveying in thermal power plants, in particular, and more particularly to a step-by-step direct acting valve and a step-by-step direct acting pneumatic ash conveying system. BACKGROUND

[0002] In existing thermal power plants, the fly ash generated after coal combustion is conveyed to the ash storage by the pneumatic ash conveying system, that is, the fly ash generated after coal combustion enters the corresponding silo pump through each ash bucket, the outlet of each silo pump is connected to the ash conveying pipeline, and after the fly ash enters each node of the ash conveying pipeline, the fly ash in the ash conveying pipeline is blown to the ash storage by the upstream air source.

[0003] In the actual ash conveying process, due to the long line and many curved sections of the ash conveying pipeline, the ash conveying pipeline is often blocked, which causes the fly ash to be unable to be smoothly conveyed to the ash storage. The traditional method for preventing the ash conveying pipeline from being blocked is to add air supplement points along the ash conveying pipeline. This method has certain improvement on the blocking of the ash conveying pipeline, but it cannot accurately control the air supplement points, resulting in large gas consumption, which conflicts with the situation that the amount of gas required for conveying increases after the economic coal is burned in the power plant, and the amount of gas itself is insufficient.

[0004] Energy saving and environmental protection is the top priority for coal-fired power plants to carry out work. How to solve the conveying difficulty, prevent the ash conveying pipeline from being blocked, accurately supplement air and save gas is a major problem faced by the pneumatic conveying system at present. SUMMARY

[0005] According to the above technical problems, a step-by-step direct acting valve and a step-by-step direct acting pneumatic ash conveying system are provided.

[0006] The technical means adopted by the present application are as follows:

[0007] The first aspect is a step-by-step direct-acting valve, comprising a main valve and a check valve; the main valve comprises a main valve body, a main valve opening and closing end cover, a main spring, a main piston and a pneumatic control mechanism; the upper end of the main valve body is provided with a main valve air inlet; the inside of the upper section of the main valve body is provided with a main air inlet channel arranged in the vertical direction and a secondary air inlet channel arranged in the horizontal direction, the main air inlet channel and the secondary air inlet channel are in communication with each other, and the main air inlet channel and the main valve air inlet are in communication with each other; the inside of the middle section of the main valve body is provided with a main spring mounting chamber, a connecting channel and a main piston mounting chamber arranged in parallel in the horizontal direction, the main spring mounting chamber and the main piston mounting chamber are in communication with each other through the connecting channel, the main spring mounting chamber is in communication with the main air inlet channel, and the main piston mounting chamber is in communication with the secondary air inlet channel; the inside of the lower section of the main valve body is provided with a main air outlet channel arranged in the vertical direction and a secondary air outlet channel arranged in the vertical direction, the main air outlet channel and the connecting channel are in communication with each other, and the main piston mounting chamber and the main air outlet channel are in communication with each other through the secondary air outlet channel; the lower end of the main valve body is provided with a main valve air outlet, and the main valve air outlet and the main air outlet channel are in communication with each other; the main valve opening and closing end cover is slidably installed in the main spring mounting chamber, and the two ends of the main spring are pressed between the main valve opening and closing end cover and the end of the main spring mounting chamber away from the connecting channel; when the main valve opening and closing end cover is blocked at the communication between the main spring mounting chamber and the connecting channel under the elastic force of the main spring, the main valve opening and closing end cover is in a closed state; the main piston is slidably installed in the main piston mounting chamber and separates the main piston mounting chamber into a first main piston chamber and a second main piston chamber, the first main piston chamber and the connecting channel are in communication with each other, the secondary air inlet channel and the secondary air outlet channel are in communication with each other through the second main piston chamber, the main piston abuts against the main valve opening and closing end cover through the connecting channel, and the main piston seals the communication between the first main piston chamber and the connecting channel; when the main valve opening and closing end cover moves away from the communication between the main spring mounting chamber and the connecting channel under the thrust of the main piston, the main valve opening and closing end cover is in an open state; the pneumatic control mechanism is arranged in the main valve body; the pneumatic control mechanism is provided with a control gas outlet and a control gas inlet, and the control gas outlet and the control gas inlet are located on the outside of the main valve body; when the main valve opening and closing end cover is in an open state, the control gas outlet outputs control gas; when the control gas inlet receives control gas, the pneumatic control mechanism allows the main piston to not exert thrust on the main valve opening and closing end cover, i.e., allows the main valve opening and closing end cover to be in a closed state; the check valve is provided with a check valve air inlet, and the check valve air inlet and the main valve air outlet are in communication with each other.

[0008] Further, the pneumatic control mechanism comprises an exhaust air filter, a control spring mounting chamber, a control gas inlet channel, a breathing hole, a control gas outlet channel, a control piston and a control spring; the exhaust air filter is arranged in the upper section of the main valve body; the control spring mounting chamber is arranged in the middle section of the main valve body in the vertical direction, and the control spring mounting chamber is in communication with the exhaust air filter; the control gas inlet channel is arranged in the middle section of the main valve body in the horizontal direction, and the control gas inlet is in communication with the control spring mounting chamber through the control gas inlet channel; the breathing hole is arranged in the middle section of the main valve body in the horizontal direction, and the control spring mounting chamber is in communication with the first main piston chamber through the breathing hole; the control gas outlet channel is arranged in the lower section of the main valve body in the horizontal direction, and the control gas outlet is in communication with the auxiliary exhaust channel through the control gas outlet channel; the control piston is slidingly mounted in the control spring mounting chamber, and the control spring is compressed between the exhaust air filter and the control piston; when the control piston is blocked at the communication position of the control spring mounting chamber and the control gas inlet channel under the elastic force of the control spring, the control piston is in the closed state; when the control piston is away from the communication position of the control spring mounting chamber and the control gas inlet channel under the pressure of the control gas, the control piston is in the open state.

[0009] Further, the upper end of the main valve body is provided with an air filter mounting port, and the inner portion of the upper section of the main valve body is provided with an air filter adjusting screw hole; the air filter mounting port is in communication with the control spring mounting chamber through the air filter adjusting screw hole; and the exhaust air filter is threadedly fitted in the air filter adjusting screw hole through the air filter mounting port.

[0010] Further, the exhaust air filter comprises an air filter nut, a pre-adjusting screw plug and a filter screen; the inner portion of the upper section of the air filter nut is provided with an air filter exhaust channel, and the outer side of the lower section of the air filter nut is threadedly fitted with the air filter adjusting screw hole; the pre-adjusting screw plug is threadedly fitted with the inner side of the lower section of the air filter nut; the filter screen is arranged in the air filter exhaust channel; and the two ends of the control spring are compressed between the pre-adjusting screw plug and the control piston.

[0011] Further, the main valve further comprises a main spring adjusting screw plug; the outer side of the middle section of the main valve body is provided with a screw plug mounting port, and the inner portion of the middle section of the main valve body is provided with a screw plug adjusting screw hole arranged in the horizontal direction; the screw plug mounting port is in communication with one end of the main spring mounting chamber away from the connecting channel through the screw plug adjusting screw hole; the main spring adjusting screw plug is threadedly fitted in the screw plug adjusting screw hole through the screw plug mounting port; and the two ends of the main spring are compressed between the main spring adjusting screw plug and the main valve opening and closing end cover.

[0012] Further, the main valve further comprises a trace air adjusting rod; the upper end of the main valve body is provided with an adjusting rod mounting port; the upper section of the main valve body is internally provided with an adjusting rod screw hole arranged in the vertical direction, and the adjusting rod mounting port and the secondary air passage are in communication with each other through the adjusting rod screw hole; and the trace air adjusting rod is threadedly connected in the adjusting rod screw hole through the adjusting rod mounting port and can extend into the secondary air passage through the adjusting rod screw hole.

[0013] Further, the secondary air passage is provided with a pressure gauge.

[0014] Further, the check valve comprises a check valve body, a check valve ball and a check valve spring; the check valve air inlet is arranged at the upper end of the check valve body; the interior of the check valve body is internally provided with a check valve passage arranged in the vertical direction, and the check valve passage and the check valve air inlet are in communication with each other; the lower end of the check valve body is provided with a check valve air outlet, and the check valve air outlet and the check valve passage are in communication with each other; the check valve ball is slidingly installed in the check valve passage, and the two ends of the check valve spring are tightly pressed between the check valve air outlet and the check valve ball; when the check valve ball is blocked on the check valve air inlet under the elastic force of the check valve spring, the check valve is in the closed state; when the check valve ball is away from the check valve air inlet, the check valve is in the open state.

[0015] Further, the connecting pipeline and the air outlet ball valve arranged in the vertical direction are further included; the upper end of the connecting pipeline and the check valve air outlet are in communication with each other, and the air outlet ball valve is arranged on the connecting pipeline.

[0016] The second aspect is a step-by-step direct-acting pneumatic ash conveying system, which comprises an ash conveying pipeline and an air accompanying pipeline, and further comprises a plurality of step-by-step direct-acting valves according to any one of the first aspect; the plurality of step-by-step direct-acting valves are arranged in sequence along the ash conveying pipeline; the lower end of the connecting pipeline of each of the plurality of step-by-step direct-acting valves is in communication with the ash conveying pipeline; the main valve air inlet of each of the plurality of step-by-step direct-acting valves is in communication with the air accompanying pipeline; the control gas outlet of the step-by-step direct-acting valve downstream of the ash conveying direction of the ash conveying pipeline is in communication with the control gas inlet of the step-by-step direct-acting valve adjacent to the upstream thereof through a control gas pipeline; when the open end cover of the main valve in any one of the step-by-step direct-acting valves is in the open state, the control piston in all the step-by-step direct-acting valves upstream of the step-by-step direct-acting valve along the ash conveying direction of the ash conveying pipeline is in the open state.

[0017] Compared with the prior art, the present application has the following advantages: 1. In this invention, the gas-tracing pipeline supplies gas to the main valve inlet of the step-by-step direct-acting valve. When there is no blockage and the pressure in the ash conveying pipeline is normal, the gas sequentially passes through the main inlet channel, the auxiliary inlet channel, the second main piston chamber, and the auxiliary exhaust channel to reach the check valve inlet. Since the pressure in the ash conveying pipeline is normal, the gas directly pushes the check valve ball away from the check valve inlet. However, the pressure in the second main piston chamber is insufficient to cause the main piston to push the main valve opening / closing end cover away from the connection between the main spring mounting chamber and the connecting channel. Therefore, a small amount of gas sequentially passes through the check valve channel and the connecting channel. The ash conveying pipeline is connected to the main pipeline. Each step-by-step direct-acting valve provides a small amount of air to the ash conveying pipeline and operates independently. When a blockage occurs in the ash conveying pipeline and the pressure rises, the air in the step-by-step direct-acting valve at the blockage point passes sequentially through the main air inlet channel, the auxiliary air inlet channel, the second main piston chamber, and the auxiliary exhaust channel to reach the check valve inlet. Due to the increased pressure in the ash conveying pipeline, the air cannot directly push the check valve ball away from the check valve inlet. The pressure in the second main piston chamber increases, causing the main piston to push the main valve opening / closing end cover away from the main spring mounting chamber and the connecting channel. At the connection point, in addition to the aforementioned paths, the air also travels through the main intake channel, main spring mounting chamber, connecting channel, and main exhaust channel to reach the check valve inlet. At the check valve inlet, both the air volume and pressure increase, causing the air to push the check valve ball away from the inlet. The air then sequentially passes through the check valve channel and connecting pipe into the ash conveying pipeline, with a relatively large volume. This creates a fluidization zone at the blockage point, reducing the conveying pressure and enhancing the conveying capacity at the blockage point. Furthermore, the increased pressure within the main valve body also causes the air to be exhausted via the control air. The air inlet and control air pipe enter the control air inlet channel of the upstream step-by-step direct-acting valve, pushing the control piston of the upstream step-by-step direct-acting valve away from the connection between the control spring mounting chamber and the control air inlet channel. Then, the air enters the first main piston chamber of the upstream step-by-step direct-acting valve through the breathing hole, increasing its pressure and preventing the main piston of the upstream step-by-step direct-acting valve from pushing the main valve opening and closing end cover away from the connection between the main spring mounting chamber and the connecting channel. Therefore, the upstream step-by-step direct-acting valve still provides a small amount of supplemental air to the ash conveying pipeline, thereby saving the amount of air source.

[0018] 2. In this invention, the exhaust air filter is threaded into the air filter adjustment screw hole via the air filter mounting port, and the spring force of the control spring is adjusted by screwing the exhaust air filter in or out.

[0019] 3. In this invention, the pre-adjustment plug is first screwed into the designated position inside the air filter nut, and then the air filter nut is screwed into the designated position inside the air filter adjustment screw hole. The spring force of the control spring is adjusted by the cooperation of the pre-adjustment plug and the air filter nut. In addition, the filter screen can prevent external dust from entering the main valve body.

[0020] 4. In this invention, the main spring adjusting screw plug is threaded into the adjusting screw hole of the screw plug installation port, and the two ends of the main spring are pressed between the main spring adjusting screw plug and the main valve opening and closing end cover. The spring force of the main spring is adjusted by screwing in or out the main spring adjusting screw plug.

[0021] 5. In this invention, the micro-intake adjustment rod is threaded into the adjustment rod screw hole through the adjustment rod mounting port and can extend into the secondary intake channel through the adjustment rod screw hole. The amount of air in the secondary intake channel can be adjusted by screwing the micro-intake adjustment rod in or out.

[0022] 6. In this invention, a pressure gauge is provided on the secondary intake channel to detect whether the main valve is open and the pressure when the main valve is open.

[0023] 7. In this invention, when the outlet valve is in the open state, air can enter the ash conveying pipe through the connecting pipe; when the outlet valve is in the closed state, air cannot enter the ash conveying pipe through the connecting pipe. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is an external structural diagram of a step-by-step direct-acting valve according to the present invention; Figure 2 This is a top view of a step-by-step direct-acting valve according to the present invention; Figure 3 for Figure 2 AA section view; Figure 4 for Figure 2 BB cross-sectional view; Figure 5 for Figure 2 A magnified view of a portion of point M; Figure 6 for Figure 4 A magnified view of a portion at point N; Figure 7 This is an overall structural diagram of a step-by-step direct-drive pneumatic ash conveying system according to the present invention; In the figure: 1-main valve; 2-back check valve; 3-connection pipeline; 4-outlet ball valve; 5-ash conveying pipeline; 6-accompanying gas pipeline; 7-control gas pipeline; 8-inlet pipeline; 9-ash conveying direction; 101-main valve body; 102-main spring adjusting nut; 103-control gas inlet; 104-exhaust air filter; 105-pressure gauge; 106-micro-inlet adjusting rod; 107-main inlet; 108-main inlet channel; 109-vice inlet channel; 110-main spring mounting chamber; 111-connection channel; 112-main piston mounting chamber; 113-main exhaust channel; 114-vice exhaust channel; 115-main outlet; 116-main spring; 117-main valve opening and closing end cover; 118-main piston; 119-control gas exhaust channel; 120-control gas outlet; 121-control gas inlet channel; 122-control spring mounting chamber; 123-breathing hole; 124-control piston; 125-control spring; 201-back check valve body; 202-back check valve ball; 203-back check valve spring; 204-back check valve inlet; 205-back check valve channel; 206-back check valve outlet; 1041-filter nut; 1042-pre-adjusting nut; 1043-filter screen; 1044-adjusting scale; 1121-first main piston chamber; 1122-second main piston chamber. DETAILED DESCRIPTION

[0026] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0027] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The description of the at least one exemplary embodiment is actually only illustrative, but not intended to limit the present application and its application or use in any way. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0028] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or their combinations.

[0029] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims, along with full equivalents thereof.

[0030] In the description of the present application, it is to be understood that the orientation or positional relationships indicated by terms such as "front", "back", "up", "down", "left", "right", "lateral", "vertical", "horizontal", "top", "bottom", and the like are based on the orientation or positional relationships shown in the drawings, and are merely intended to facilitate the description and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be construed as limiting the scope of protection of the present application. The orientation terms "inner", "outer" refer to the inner and outer relative to the contour of the components themselves.

[0031] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper", and the like can be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0032] In addition, it should be noted that the use of the terms "first", "second", and the like do not have a special meaning, and are used only to facilitate the distinction between corresponding parts, and therefore cannot be construed as limiting the scope of protection of the present application.

[0033] Example 1: As Figures 1 to 6As shown, a step direct-acting valve includes a main valve 1 and a check valve 2; the main valve 1 includes a main valve body 101, a main valve opening and closing end cover 117, a main spring 116, a main piston 118 and a pneumatic control mechanism; the upper end of the main valve body 101 is provided with a main valve air inlet 107; the inside of the upper section of the main valve body 101 is provided with a main air inlet channel 108 arranged in a vertical direction and a secondary air inlet channel 109 arranged in a horizontal direction, the main air inlet channel 108 and the secondary air inlet channel 109 are in communication with each other, and the main air inlet channel 108 is in communication with the main valve air inlet 107; the inside of the middle section of the main valve body 101 is provided with a main spring mounting chamber 110, a connecting channel 111 and a main piston mounting chamber 112 arranged in parallel in a horizontal direction, the main spring mounting chamber 110 and the main piston mounting chamber 112 are in communication with each other through the connecting channel 111, the main spring mounting chamber 110 is in communication with the main air inlet channel 108, and the main piston mounting chamber 112 is in communication with the secondary air inlet channel 109; the inside of the lower section of the main valve body 101 is provided with a main air outlet channel 113 arranged in a vertical direction and a secondary air outlet channel 114 arranged in a vertical direction, the main air outlet channel 113 is in communication with the connecting channel 111, and the main piston mounting chamber 112 is in communication with the main air outlet channel 113 through the secondary air outlet channel 114; the lower end of the main valve body 101 is provided with a main valve air outlet 115, and the main valve air outlet 115 is in communication with the main air outlet channel 113; the main valve opening and closing end cover 117 is slidingly installed in the main spring mounting chamber 110, and the two ends of the main spring 116 are pressed between the end of the main spring mounting chamber 110 away from the connecting channel 111 and the main valve opening and closing end cover 117; when the main valve opening and closing end cover 117 is blocked at the communication position of the main spring mounting chamber 110 and the connecting channel 111 under the elastic force of the main spring 116, the main valve opening and closing end cover 117 is in a closed state; the main piston 118 is slidingly installed in the main piston mounting chamber 112 and separates the main piston mounting chamber 112 into a first main piston chamber 1121 and a second main piston chamber 1122, the first main piston chamber 1121 is in communication with the connecting channel 111, the secondary air inlet channel 109 is in communication with the secondary air outlet channel 114 through the second main piston chamber 1122, the main piston 118 abuts against the main valve opening and closing end cover 117 through the connecting channel 111, and the main piston 118 seals the communication position of the first main piston chamber 1121 and the connecting channel 111; when the main valve opening and closing end cover 117 is away from the communication position of the main spring mounting chamber 110 and the connecting channel 111 under the thrust of the main piston 118, the main valve opening and closing end cover 117 is in an open state; the pneumatic control mechanism is arranged in the main valve body 101; the pneumatic control mechanism is provided with a control air outlet 120 and a control air inlet 103, and the control air outlet 120 and the control air inlet 103 are located on the outside of the main valve body 101; when the main valve opening and closing end cover 117 is in an open state, the control air outlet 120 outputs control air;When the control gas inlet 103 receives the control gas, the pneumatic control mechanism makes the main piston 118 not apply the thrust force to the main valve opening and closing end cover 117, that is, the main valve opening and closing end cover 117 is in the closed state; the non-return valve 2 is provided with a non-return valve gas inlet 204, and the non-return valve gas inlet 204 and the main valve gas outlet 115 are in communication with each other.

[0034] Specifically, the design stiffness of the main spring 116 is 100 N / mm, the middle diameter of the main spring 116 is 22 mm, the wire diameter of the main spring 116 is 5 mm, the effective number of turns of the main spring 116 is 6 turns, and the free height of the main spring 116 is 50 mm; the selected end form of the main spring 116 is two ends and tight and ground, and the support number of turns is 1 turn; the material of the main spring 116 is carbon spring steel wire (GB4357) C.

[0035] In this embodiment, as shown in Figure 4 The pneumatic control mechanism includes an exhaust air filter 104, a control spring mounting chamber 122, a control gas inlet passage 121, a breathing hole 123, a control gas exhaust passage 119, a control piston 124 and a control spring 125; the exhaust air filter 104 is arranged in the upper section of the main valve body 101; the control spring mounting chamber 122 is arranged in the middle section of the main valve body 101 in the vertical direction, and the control spring mounting chamber 122 and the exhaust air filter 104 are in communication with each other; the control gas inlet passage 121 is arranged in the middle section of the main valve body 101 in the horizontal direction, and the control gas inlet 103 and the control spring mounting chamber 122 are in communication with each other through the control gas inlet passage 121; the breathing hole 123 is arranged in the middle section of the main valve body 101 in the horizontal direction, and the control spring mounting chamber 122 and the first main piston chamber 1121 are in communication with each other through the breathing hole 123; the control gas exhaust passage 119 is arranged in the lower section of the main valve body 101 in the horizontal direction, and the control gas outlet 120 and the auxiliary exhaust passage 114 are in communication with each other through the control gas exhaust passage 119; the control piston 124 is slidingly installed in the control spring mounting chamber 122, and the two ends of the control spring 125 are pressed between the exhaust air filter 104 and the control piston 124; when the control piston 124 is blocked at the communication between the control spring mounting chamber 122 and the control gas inlet passage 121 under the elastic force of the control spring 125, the control piston 124 is in the closed state; when the control piston 124 is away from the communication between the control spring mounting chamber 122 and the control gas inlet passage 121 under the pressure of the control gas, the control piston 124 is in the open state.

[0036] Specifically, the control spring 125 has a design stiffness of 1 N / mm, a middle diameter of 5 mm, a wire diameter of 0.6 mm, an effective number of turns of 10 turns, and a free height of 20 mm; the control spring 125 has a selected end form of two ends and is tight and ground flat, and the support number of turns is 1 turn; the control spring 125 is made of carbon spring steel wire (GB4357) C.

[0037] In the embodiment, as shown in Figure 4 and Figure 6 , the upper end of the main valve body 101 is provided with an air filter mounting port, the inner upper section of the main valve body 101 is provided with an air filter adjusting screw hole, and the air filter mounting port and the control spring mounting chamber 122 are in communication with each other through the air filter adjusting screw hole; the exhaust air filter 104 is threadedly fitted in the air filter adjusting screw hole through the air filter mounting port.

[0038] In the embodiment, as shown in Figure 5 and Figure 6 , the exhaust air filter 104 includes an air filter nut 1041, a pre-adjusting screw plug 1042, and a filter screen 1043; the inner upper section of the air filter nut 1041 is provided with an air filter exhaust passage, and the lower section of the air filter nut 1041 is threadedly fitted with the air filter adjusting screw hole; the pre-adjusting screw plug 1042 is threadedly fitted with the inner lower section of the air filter nut 1041; the filter screen 1043 is arranged in the air filter exhaust passage; and the two ends of the control spring 125 are pressed between the pre-adjusting screw plug 1042 and the control piston 124.

[0039] Specifically, the top surface of the air filter nut 1041 is provided with an adjusting scale 1044, including 1.0 MPa, 1.2 MPa, 1.8 MPa, 2.0 MPa, 2.2 MPa, 2.5 MPa, and the like.

[0040] In the embodiment, as shown in Figure 3 , the main valve 1 further includes a main spring adjusting screw plug 102; the outer middle section of the main valve body 101 is provided with a screw plug mounting port, the inner middle section of the main valve body 101 is provided with a screw plug adjusting screw hole arranged in a horizontal direction, and the screw plug mounting port and the one end of the main spring mounting chamber 110 away from the connecting channel 111 are in communication with each other through the screw plug adjusting screw hole; the main spring adjusting screw plug 102 is threadedly fitted in the screw plug adjusting screw hole through the screw plug mounting port; and the two ends of the main spring 116 are pressed between the main spring adjusting screw plug 102 and the main valve opening and closing end cover 117.

[0041] In the embodiment, as shown in Figure 3As shown, the main valve 1 further comprises a trace air adjusting rod 106; the upper end of the main valve body 101 is provided with an adjusting rod mounting port; the upper section of the main valve body 101 is internally provided with an adjusting rod screw hole arranged in the vertical direction, the adjusting rod mounting port and the secondary air passage 109 are in communication with each other through the adjusting rod screw hole; the trace air adjusting rod 106 is threadedly fitted in the adjusting rod screw hole through the adjusting rod mounting port and can extend into the secondary air passage 109 through the adjusting rod screw hole.

[0042] In this embodiment, as shown in Figures 1 to 4 As shown, the secondary air passage 109 is provided with a pressure gauge 105.

[0043] In this embodiment, as shown in Figure 3 As shown, the check valve 2 comprises a check valve body 201, a check valve ball 202 and a check valve spring 203; the check valve air inlet 204 is arranged at the upper end of the check valve body 201; the inside of the check valve body 201 is internally provided with a check valve passage 205 arranged in the vertical direction, the check valve passage 205 and the check valve air inlet 204 are in communication with each other; the lower end of the check valve body 201 is provided with a check valve air outlet 206, the check valve air outlet 206 and the check valve passage 205 are in communication with each other; the check valve ball 202 is slidingly installed in the check valve passage 205, the two ends of the check valve spring 203 are pressed between the check valve air outlet 206 and the check valve ball 202; when the check valve ball 202 is blocked on the check valve air inlet 204 under the elastic force of the check valve spring 203, the check valve 2 is in the closed state; when the check valve ball 202 is away from the check valve air inlet 204, the check valve 2 is in the open state.

[0044] Specifically, the design stiffness of the check valve spring 203 is 1.8 N / mm, the diameter of the check valve spring 203 is 18 mm, the wire diameter of the check valve spring 203 is 1.8 mm, the effective number of turns of the check valve spring 203 is 10 turns, and the free height of the check valve spring 203 is 45 mm; the selected end form of the check valve spring 203 is two ends and tight and flat, and the support number of turns is 1 turn; the material of the check valve spring 203 is carbon spring steel wire (GB4357) C.

[0045] In this embodiment, as shown in Figure 1 and Figure 3 Further comprising a connecting pipeline 3 and an air outlet ball valve 4 arranged in the vertical direction; the upper end of the connecting pipeline 3 and the check valve air outlet 206 are in communication with each other, and the air outlet ball valve 4 is arranged on the connecting pipeline 3.

[0046] The opening pressure of the control piston 124 is set to 0.22 MPa; the corresponding main spring 116 is stressed by 625 N and compressed by 6.25 mm; the check valve spring 203 is stressed by 9 N and compressed by 5 mm; and the control spring 125 is stressed by 3 N and compressed by 3 mm.

[0047] Example 2 The opening pressure of the control piston 124 is set to 0.20 MPa; the corresponding main spring 116 is stressed by 575 N and compressed by 5.75 mm; the check valve spring 203 is stressed by 9 N and compressed by 5 mm; and the control spring 125 is stressed by 3 N and compressed by 3 mm.

[0048] The remaining parts are the same as those of Example 1 and will not be repeated here.

[0049] Example 3 The opening pressure of the control piston 124 is set to 0.18 MPa; the corresponding main spring 116 is stressed by 525 N and compressed by 5.25 mm; the check valve spring 203 is stressed by 9 N and compressed by 5 mm; and the control spring 125 is stressed by 3 N and compressed by 3 mm.

[0050] The remaining parts are the same as those of Example 1 and will not be repeated here.

[0051] Example 4 As shown in Figures 1 to 7 A step-by-step direct-acting pneumatic ash conveying system, which comprises an ash conveying pipeline 5 and a carrier gas pipeline 6, further comprises the step-by-step direct-acting valve in Example 1 (set as the first distribution direct-acting valve), the step-by-step direct-acting valve in Example 2 (set as the second distribution direct-acting valve) and the step-by-step direct-acting valve in Example 3 (set as the third distribution direct-acting valve); The first distribution direct-acting valve, the second distribution direct-acting valve and the third distribution direct-acting valve are arranged in sequence along the ash conveying direction 9 of the ash conveying pipeline 5; The lower end of the connecting pipeline 3 of the first distribution direct-acting valve, the lower end of the connecting pipeline 3 of the second distribution direct-acting valve and the lower end of the connecting pipeline 3 of the third distribution direct-acting valve are all in communication with the ash conveying pipeline 5; The main valve air inlet 107 of the first distribution direct-acting valve, the main valve air inlet 107 of the second distribution direct-acting valve and the main valve air inlet 107 of the third distribution direct-acting valve are all in communication with the carrier gas pipeline 6 through the air inlet pipeline 8; The control gas outlet 120 of the third distribution direct-acting valve is in communication with the control gas inlet 103 of the second distribution direct-acting valve through the control gas pipeline 7, and the control gas outlet 120 of the second distribution direct-acting valve is in communication with the control gas inlet 103 of the first distribution direct-acting valve through the control gas pipeline 7; When the main valve opening and closing end cover 117 of any one of the step direct acting valves is in the open state, the control pistons 124 in all the step direct acting valves upstream of the ash conveying direction 9 of the ash conveying pipeline 5 are in the open state.

[0052] Specifically, the included angle between the connecting pipeline 3 and the ash conveying pipeline 5 of the first distribution direct acting valve is 35-40°; the included angle between the connecting pipeline 3 and the ash conveying pipeline 5 of the second distribution direct acting valve is 35-40°; the included angle between the connecting pipeline 3 and the ash conveying pipeline 5 of the third distribution direct acting valve is 35-40°.

[0053] The working principle of the embodiment is as follows: When the embodiment is used, the mixture of compressed air and powder or granular material is conveyed in the ash conveying pipeline 5, and the air pipeline 6 supplies air to the main valve air inlet 107 of the first distribution direct acting valve, the main valve air inlet 107 of the second distribution direct acting valve and the main valve air inlet 107 of the third distribution direct acting valve through the air inlet pipe 8.

[0054] When the ash conveying pipeline 5 is not blocked and the pressure is normal, the air reaches the check valve air inlet 204 through the main air inlet channel 108, the auxiliary air inlet channel 109, the second main piston chamber 1122 and the auxiliary air outlet channel 114 in sequence. Since the pressure in the ash conveying pipeline 5 is normal, the air directly pushes the check valve ball 202 away from the check valve air inlet 204, and the pressure in the second main piston chamber 1122 is not enough to make the main piston 118 push the main valve opening and closing end cover 117 away from the communication position between the main spring mounting chamber 110 and the connecting channel 111. Therefore, a small amount of air enters the ash conveying pipeline 5 through the check valve channel 205 and the connecting pipeline 3 in sequence, and the first distribution direct acting valve, the second distribution direct acting valve and the third distribution direct acting valve all supplement a small amount of air to the ash conveying pipeline 5 and work independently.

[0055] When the blockage pressure rises at the connection between the ash conveying pipe 5 and the third distribution direct acting valve, the gas in the third distribution direct acting valve reaches the check valve inlet 204 through the main air inlet channel 108, the auxiliary air inlet channel 109, the second main piston chamber 1122 and the auxiliary air outlet channel 114 in turn. Because the pressure in the ash conveying pipe 5 rises, the gas cannot directly push the check valve ball 202 away from the check valve inlet 204. The pressure in the second main piston chamber 1122 rises, and the main piston 118 pushes the main valve opening and closing end cover 117 away from the communication between the main spring mounting chamber 110 and the connecting channel 111, so that the gas reaches the check valve inlet 204 through the main air inlet channel 108, the main spring mounting chamber 110, the connecting channel 111 and the main air outlet channel 113 in addition to the above-mentioned path. The amount and pressure of the gas at the check valve inlet 204 both rise, and the gas pushes the check valve ball 202 away from the check valve inlet 204. Then the gas enters the ash conveying pipe 5 through the check valve channel 205 and the connecting pipe 3 in turn and in a large amount, and forms a fluidized region at the blockage, thereby reducing the conveying pressure at the blockage and enhancing the conveying capacity at the blockage. In addition, the pressure in the main valve body 101 of the third distribution direct acting valve rises, so that the gas enters the control air inlet channel 121 of the second distribution direct acting valve through the control air outlet channel 119 of the third distribution direct acting valve and the control air pipe 7, and pushes the control piston 124 of the second distribution direct acting valve away from the communication between the control spring mounting chamber 122 and the control air inlet channel 121. Then the gas enters the first main piston chamber 1121 of the second distribution direct acting valve through the breathing hole 123, so that the pressure in the first main piston chamber 1121 rises and prevents the main piston 118 of the second distribution direct acting valve from pushing the main valve opening and closing end cover 117 away from the communication between the main spring mounting chamber 110 and the connecting channel 111. Therefore, the second distribution direct acting valve still supplies a small amount of air to the ash conveying pipe 5. Similarly, the pressure in the main valve body 101 of the second distribution direct acting valve rises, so that the first distribution direct acting valve also still supplies a small amount of air to the ash conveying pipe 5, thereby saving the amount of air source.

[0056] When the blockage at the connection between the ash conveying pipe 5 and the third distribution direct acting valve gradually disappears, the opening pressure of the check valve ball 202 of the third distribution direct acting valve gradually decreases, and the pressure in the second main piston chamber 1122 of the third distribution direct acting valve also gradually decreases. When the pressure in the second main piston chamber 1122 of the third distribution direct acting valve is less than the elastic force of the main spring 116, the main valve opening and closing end cover 117 of the third distribution direct acting valve is re-sealed at the communication between the main spring mounting chamber 110 and the connecting channel 111 under the elastic force of the main spring 116. The third distribution direct acting valve returns to the state of supplying a small amount of air to the ash conveying pipe 5.

[0057] The embodiment has novel and reasonable structure, can effectively solve the blockage problem of the ash conveying pipeline 5 in the pneumatic ash conveying system, can realize automatic control compared with the traditional air supplement mode, the air saving amount can reach 30-50%, after the embodiment is applied, the initial ash conveying flow rate can be reduced by 2-3 m / s, the terminal ash conveying flow rate can be reduced to 12-15 m / s, the pipe valve wear is effectively reduced, the workload of the maintenance personnel is greatly reduced, the pneumatic ash conveying system can be safely and stably operated for a long period, the embodiment can reduce the main air inlet pressure of the ash conveying to 0.3 Mpa, reduce the air consumption of the ash conveying (save 30% air), reduce the ash conveying flow rate, and increase the ash-air ratio (35-40), in the ash conveying process, when the pressure in the ash conveying pipeline 5 is increased, the step direct acting valve near the high pressure point of the ash conveying pipeline 5 is opened to supplement air to the high pressure point position, at the same time, the output control air limits the opening of other step direct acting valves, concentrates the gas source flow at the high pressure position, so that the purpose of saving the air amount of the gas source is realized, and the energy saving and environmental protection requirement is met.

[0058] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A step-by-step direct-acting valve, characterized in that, Includes a main valve (1) and a check valve (2); The main valve (1) includes a main valve body (101), a main valve opening and closing end cover (117), a main spring (116), a main piston (118), and a pneumatic control mechanism; The upper end of the main valve body (101) is provided with a main valve inlet (107); the upper section of the main valve body (101) is provided with a main air intake channel (108) arranged vertically and a secondary air intake channel (109) arranged horizontally. The main air intake channel (108) and the secondary air intake channel (109) are interconnected, and the main air intake channel (108) is interconnected with the main valve inlet (107); the middle section of the main valve body (101) is provided with a main spring mounting chamber (110), a connecting channel (111) and a main piston mounting chamber (112) arranged in parallel horizontally. The main spring mounting chamber (110) is interconnected with the main piston mounting chamber (112) through the connecting channel (111). The main spring mounting chamber (110) is connected to the main intake passage (108), and the main piston mounting chamber (112) is connected to the auxiliary intake passage (109). The lower section of the main valve body (101) is provided with a main exhaust passage (113) arranged vertically and an auxiliary exhaust passage (114) arranged vertically. The main exhaust passage (113) is connected to the connecting passage (111), and the main piston mounting chamber (112) is connected to the main exhaust passage (113) through the auxiliary exhaust passage (114). The lower end of the main valve body (101) is provided with a main valve outlet (115), and the main valve outlet (115) is connected to the main exhaust passage (113). The main valve opening and closing end cover (117) is slidably installed in the main spring mounting chamber (110). The two ends of the main spring (116) are pressed between the end of the main spring mounting chamber (110) away from the connecting channel (111) and the main valve opening and closing end cover (117). When the main valve opening and closing end cover (117) is sealed at the connection between the main spring mounting chamber (110) and the connecting channel (111) under the elastic force of the main spring (116), the main valve opening and closing end cover (117) is in the closed state. The main piston (118) is slidably mounted in the main piston mounting chamber (112) and divides the main piston mounting chamber (112) into a first main piston chamber (1121) and a second main piston chamber (1122). The first main piston chamber (1121) is connected to the connecting channel (111). The auxiliary intake channel (109) is connected to the auxiliary exhaust channel (114) through the second main piston chamber (1122). The main piston (118) abuts against the main valve opening and closing end cap (117) through the connecting channel (111). The main piston (118) seals the connection between the first main piston chamber (1121) and the connecting channel (111). When the main valve opening and closing end cap (117) moves away from the connection between the main spring mounting chamber (110) and the connecting channel (111) under the thrust of the main piston (118), the main valve opening and closing end cap (117) is in the open state. The pneumatic control mechanism is located inside the main valve body (101); the pneumatic control mechanism is provided with a control air outlet (120) and a control air inlet (103), both of which are located on the outside of the main valve body (101); when the main valve opening and closing end cover (117) is in the open state, the control air outlet (120) outputs control air; when the control air inlet (103) receives control air, the pneumatic control mechanism causes the main piston (118) not to apply thrust to the main valve opening and closing end cover (117), that is, to keep the main valve opening and closing end cover (117) in the closed state; The check valve (2) is provided with a check valve inlet (204), and the check valve inlet (204) is connected to the main valve outlet (115).

2. The step-by-step direct-acting valve according to claim 1, characterized in that, The pneumatic control mechanism includes an exhaust air filter (104), a control spring mounting chamber (122), a control air intake channel (121), a breathing channel (123), a control air exhaust channel (119), a control piston (124), and a control spring (125). The exhaust air filter (104) is located inside the upper section of the main valve body (101); the control spring mounting chamber (122) is arranged vertically inside the middle section of the main valve body (101), and the control spring mounting chamber (122) is interconnected with the exhaust air filter (104); the control air intake channel (121) is arranged horizontally inside the middle section of the main valve body (101), and the control air inlet (103) is connected to the control spring mounting chamber (104) through the control air intake channel (121). 122) They are interconnected; the breathing channel (123) is arranged horizontally inside the middle section of the main valve body (101), and the control spring mounting chamber (122) is interconnected with the first main piston chamber (1121) through the breathing channel (123); the control gas exhaust channel (119) is arranged horizontally inside the lower section of the main valve body (101), and the control gas outlet (120) is interconnected with the auxiliary exhaust channel (114) through the control gas exhaust channel (119); The control piston (124) is slidably installed in the control spring mounting chamber (122), and the two ends of the control spring (125) are pressed between the exhaust air filter (104) and the control piston (124). When the control piston (124) is blocked at the connection between the control spring mounting chamber (122) and the control air intake channel (121) under the elastic force of the control spring (125), the control piston (124) is in the closed state. When the control piston (124) is moved away from the connection between the control spring mounting chamber (122) and the control air intake channel (121) under the pressure of the control air, the control piston (124) is in the open state.

3. A step-by-step direct-acting valve according to claim 2, characterized in that, The upper end of the main valve body (101) is provided with an air filter installation port, and the upper section of the main valve body (101) is provided with an air filter adjustment screw hole. The air filter installation port is connected to the control spring installation chamber (122) through the air filter adjustment screw hole. The exhaust air filter (104) is threaded into the air filter adjustment screw hole via the air filter mounting port.

4. A step-by-step direct-acting valve according to claim 3, characterized in that, The exhaust air filter (104) includes an air filter nut (1041), a pre-adjustment plug (1042), and a filter screen (1043). The upper section of the air filter nut (1041) is provided with an air filter exhaust channel, and the outer side of the lower section of the air filter nut (1041) is threadedly engaged with the air filter adjustment screw hole; the pre-adjustment plug (1042) is threadedly engaged with the inner side of the lower section of the air filter nut (1041); the filter screen (1043) is located in the air filter exhaust channel. The two ends of the control spring (125) are pressed between the pre-adjustment plug (1042) and the control piston (124).

5. A step-by-step direct-acting valve according to claim 1, characterized in that, The main valve (1) also includes a main spring adjusting plug (102); The main valve body (101) has a screw plug installation port on the outer side of the middle section, and a screw plug adjustment screw hole arranged in the horizontal direction is provided inside the middle section of the main valve body (101). The screw plug installation port is connected to the end of the main spring mounting chamber (110) away from the connecting channel (111) through the screw plug adjustment screw hole. The main spring adjusting screw plug (102) is threaded into the adjusting screw hole of the screw plug through the screw plug mounting port; The two ends of the main spring (116) are pressed between the main spring adjusting screw (102) and the main valve opening and closing end cap (117).

6. A step-by-step direct-acting valve according to claim 1, characterized in that, The main valve (1) also includes a micro-intake regulating rod (106). The upper end of the main valve body (101) is provided with an adjustment rod mounting port; the upper section of the main valve body (101) is provided with an adjustment rod screw hole arranged in the vertical direction, and the adjustment rod mounting port is connected to the auxiliary air intake channel (109) through the adjustment rod screw hole; The micro-intake adjustment rod (106) is threaded into the adjustment rod screw hole through the adjustment rod mounting port and can extend into the secondary intake channel (109) through the adjustment rod screw hole.

7. A step-by-step direct-acting valve according to claim 1, characterized in that, A pressure gauge (105) is provided on the secondary air intake passage (109).

8. A step-by-step direct-acting valve according to claim 1, characterized in that, The check valve (2) includes a check valve body (201), a check valve ball (202), and a check valve spring (203). The check valve inlet (204) is located at the upper end of the check valve body (201); the interior of the check valve body (201) is provided with a check valve channel (205) arranged vertically, and the check valve channel (205) is interconnected with the check valve inlet (204); the lower end of the check valve body (201) is provided with a check valve outlet (206), and the check valve outlet (206) is interconnected with the check valve channel (205); The check valve ball (202) is slidably installed in the check valve channel (205), and the two ends of the check valve spring (203) are pressed between the check valve outlet (206) and the check valve ball (202). When the check valve ball (202) is blocked on the check valve inlet (204) by the elastic force of the check valve spring (203), the check valve (2) is in the closed state. When the check valve ball (202) is away from the check valve inlet (204), the check valve (2) is in the open state.

9. A step-by-step direct-acting valve according to claim 1, characterized in that, It also includes a vertically arranged connecting pipe (3) and an outlet valve (4); The upper end of the connecting pipe (3) is connected to the air outlet (206) of the check valve, and the air outlet valve (4) is located on the connecting pipe (3).

10. A step-by-step direct-drive pneumatic ash conveying system, characterized in that, It includes an ash conveying pipeline (5) and a gas tracing pipeline (6), and also includes several step-by-step direct-acting valves as described in any one of claims 1 to 9; Several of the aforementioned step-by-step direct-acting valves are arranged sequentially along the ash conveying pipeline (5); The lower ends of the connecting pipes (3) of several of the step-by-step direct-acting valves are all connected to the ash conveying pipe (5); The main valve inlets (107) of several of the step-by-step direct-acting valves are all connected to the tracing gas pipeline (6); The control air outlet (120) of the downstream step-by-step direct-acting valve along the ash conveying direction (9) of the ash conveying pipeline (5) is connected to the control air inlet (103) of the adjacent upstream step-by-step direct-acting valve through the control air pipe (7). When the main valve opening / closing end cap (117) of any step-by-step direct-acting valve is in the open state, the control pistons (124) of all step-by-step direct-acting valves upstream of the step-by-step direct-acting valve along the ash conveying direction (9) of the ash conveying pipeline (5) are in the open state.

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