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

Abstract

The present application relates to the technical field of pneumatic ash conveying of thermal power plants, and provides a step-by-step direct-acting valve and a step-by-step direct-acting pneumatic ash conveying system, wherein the step-by-step direct-acting pneumatic ash conveying system comprises an ash conveying pipeline, an accompanying gas pipeline and a plurality of step-by-step direct-acting valves; the step-by-step direct-acting valves are arranged along the ash conveying pipeline in sequence; the lower ends of the connecting pipelines of the step-by-step direct-acting valves are in communication with the ash conveying pipeline; the main valve gas inlets of the step-by-step direct-acting valves are in communication with the accompanying gas pipeline; the control gas outlets of the step-by-step direct-acting valves downstream along the ash conveying direction of the ash conveying pipeline are in communication with the control gas inlets of the step-by-step direct-acting valves adjacent thereto upstream through a control gas pipeline; when the main valve opening and closing end cover in any step-by-step direct-acting valve is in an open state, the control pistons in all the step-by-step direct-acting valves upstream along the ash conveying direction of the ash conveying pipeline from the step-by-step direct-acting valve are in an open state. The present application not only can enhance the conveying capacity of the blocked part, but also can save the gas amount of the gas source.

Description

Technical Field

[0001] This invention relates to the field of pneumatic ash conveying technology for thermal power plants, and more particularly to a step-by-step direct-acting valve and a step-by-step direct-acting pneumatic ash conveying system. Background Technology

[0002] In existing thermal power plants, the fly ash produced after coal combustion is transported to the ash silo through a pneumatic ash conveying system. That is, the fly ash produced after coal combustion enters the corresponding silo pump through each ash hopper, and the outlet of each silo pump is connected to the ash conveying pipeline. After the fly ash enters each node of the ash conveying pipeline, it is blown to the ash silo by the upstream air source.

[0003] In actual ash conveying processes, due to the long length and numerous bends in the ash conveying pipelines, blockages frequently occur, preventing fly ash from being smoothly transported to the ash silo. The traditional method for preventing blockages in ash conveying pipelines is to add air replenishment points along the pipeline. This method can improve the blockage situation to some extent, but it cannot accurately control the air replenishment points, resulting in high air consumption. This conflicts with the increased demand for gas for conveying after power plants burn economical coal types, leading to insufficient gas supply.

[0004] Energy conservation and environmental protection are of paramount importance to coal-fired power plants. How to solve the transportation difficulties, prevent ash conveying pipeline blockage, and at the same time accurately replenish gas and save gas consumption are major challenges currently facing pneumatic conveying systems. Summary of the Invention

[0005] In response to the aforementioned 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 employed in this invention are as follows:

[0007] In a first aspect, a step-by-step direct-acting valve includes a main valve and a check valve; the main valve includes 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 inlet; the upper section of the main valve body is provided with a main air intake channel arranged vertically and a secondary air intake channel arranged horizontally, the main air intake channel and the secondary air intake channel being interconnected, and the main air intake channel being interconnected with the main valve inlet; 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 horizontally, the main spring mounting chamber being interconnected with the main piston mounting chamber through the connecting channel. The main valve body is connected to the main intake channel via the main spring mounting chamber and the auxiliary intake channel via the auxiliary piston mounting chamber. The lower section of the main valve body contains a vertically arranged main exhaust channel and a vertically arranged auxiliary exhaust channel. The main exhaust channel is connected to the connecting channel, and the main piston mounting chamber is connected to the main exhaust channel via the auxiliary exhaust channel. The lower end of the main valve body has a main valve outlet, which is connected to the main exhaust channel. The main valve opening / closing end cap is slidably mounted in the main spring mounting chamber, and both ends of the main spring are pressed against the end of the main spring mounting chamber furthest from the connecting channel, thus connecting with the main valve opening / closing end. Between the closed end caps; when the main valve opening and closing end cap is sealed at the connection 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 cap is in the closed state; the main piston is slidably installed in the main piston mounting chamber and divides the main piston mounting chamber into a first main piston chamber and a second main piston chamber. The first main piston chamber is interconnected with the connecting channel, and the auxiliary intake channel is interconnected with the auxiliary exhaust channel through the second main piston chamber. The main piston abuts against the main valve opening and closing end cap through the connecting channel, and the main piston seals the connection between the first main piston chamber and the connecting channel; when the main valve opening and closing end cap is pushed away by the main piston... When the main valve is away from the connection point between the main spring mounting chamber and the connecting channel, the main valve opening and closing end cover is in the open state; the pneumatic control mechanism is located inside the main valve body; the pneumatic control mechanism is provided with a control air outlet and a control air inlet, both of which are located on the outside of the main valve body; when the main valve opening and closing end cover is in the open state, the control air outlet outputs control air; when the control air inlet receives control air, the pneumatic control mechanism causes the main piston not to apply thrust to the main valve opening and closing end cover, that is, to keep the main valve opening and closing end cover in the closed state; the check valve is provided with a check valve inlet, which is connected to the main valve outlet.

[0008] Furthermore, the pneumatic control mechanism includes an exhaust air filter, a control spring mounting chamber, a control air inlet channel, a breather channel, a control air exhaust channel, a control piston, and a control spring; the exhaust air filter is located inside the upper section of the main valve body; the control spring mounting chamber is arranged vertically inside the middle section of the main valve body, and the control spring mounting chamber is interconnected with the exhaust air filter; the control air inlet channel is arranged horizontally inside the middle section of the main valve body, and the control air inlet is interconnected with the control spring mounting chamber through the control air inlet channel; the breather channel is arranged horizontally inside the middle section of the main valve body, and the control spring mounting chamber is connected to the control spring mounting chamber through the breather channel. The control gas exhaust channel is connected to the first main piston chamber; the control gas exhaust channel is arranged horizontally inside the lower section of the main valve body, and the control gas outlet is connected to the auxiliary exhaust channel through the control gas exhaust channel; the control piston is slidably installed in the control spring mounting chamber, and the two ends of the control spring are pressed between the exhaust air filter and the control piston; when the control piston is blocked at the connection between the control spring mounting chamber and the control gas intake channel under the elastic force of the control spring, the control piston is in the closed state; when the control piston is moved away from the connection between the control spring mounting chamber and the control gas intake channel under the pressure of the control gas, the control piston is in the open state.

[0009] Furthermore, the upper end of the main valve body is provided with an air filter mounting port, and the upper section of the main valve body is provided with an air filter adjusting screw hole. The air filter mounting port is connected to the control spring mounting chamber through the air filter adjusting screw hole. The exhaust air filter is threaded into the air filter adjusting screw hole through the air filter mounting port.

[0010] Furthermore, the exhaust air filter includes an air filter nut, a pre-adjustment plug, and a filter screen; the upper section of the air filter nut has an air filter exhaust channel inside, and the outer side of the lower section of the air filter nut is threadedly engaged with the air filter adjustment screw hole; the pre-adjustment plug is threadedly engaged with the inner side of the lower section of the air filter nut; the filter screen is disposed inside the air filter exhaust channel; and the two ends of the control spring are pressed between the pre-adjustment plug and the control piston.

[0011] Furthermore, the main valve also includes a main spring adjusting screw plug; a screw plug mounting port is provided on the outer side of the middle section of the main valve body, and a screw plug adjusting screw hole arranged horizontally is provided inside the middle section of the main valve body. The screw plug mounting port is connected to the 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 threaded into the screw plug adjusting screw hole through the screw plug mounting port; both ends of the main spring are pressed between the main spring adjusting screw plug and the main valve opening and closing end cover.

[0012] Furthermore, the main valve also includes a micro-intake regulating rod; the upper end of the main valve body is provided with a regulating rod mounting port; the upper section of the main valve body is provided with a regulating rod screw hole arranged in the vertical direction, and the regulating rod mounting port is interconnected with the auxiliary intake channel through the regulating rod screw hole; the micro-intake regulating rod is threaded into the regulating rod screw hole through the regulating rod mounting port and can extend into the auxiliary intake channel through the regulating rod screw hole.

[0013] Furthermore, a pressure gauge is installed on the secondary air intake passage.

[0014] Furthermore, the check valve includes a check valve body, a check valve ball, and a check valve spring; the check valve inlet is located at the upper end of the check valve body; the interior of the check valve body has a check valve channel arranged vertically, which is connected to the check valve inlet; the lower end of the check valve body has a check valve outlet, which is connected to the check valve channel; the check valve ball is slidably installed in the check valve channel, and both ends of the check valve spring are pressed between the check valve outlet and the check valve ball; when the check valve ball is blocked on the check valve inlet by the elastic force of the check valve spring, the check valve is in a closed state; when the check valve ball is away from the check valve inlet, the check valve is in an open state.

[0015] Furthermore, it also includes a connecting pipe and an outlet valve arranged in a vertical direction; the upper end of the connecting pipe is connected to the outlet of the check valve, and the outlet valve is located on the connecting pipe.

[0016] Secondly, a step-by-step direct-acting pneumatic ash conveying system includes an ash conveying pipeline and an air tracing pipeline, and further includes a plurality of step-by-step direct-acting valves as described in any one of the first aspects; the plurality of step-by-step direct-acting valves are arranged sequentially along the ash conveying pipeline; the lower ends of the connecting pipelines of the plurality of step-by-step direct-acting valves are all interconnected with the ash conveying pipeline; the main valve inlets of the plurality of step-by-step direct-acting valves are all interconnected with the air tracing pipeline; the control air outlet of the downstream step-by-step direct-acting valve along the ash conveying direction of the ash conveying pipeline is interconnected with the control air inlet of its upstream adjacent step-by-step direct-acting valve through a control air pipe; when the main valve opening / closing end cap of any step-by-step direct-acting valve is in the open state, the control pistons of all the step-by-step direct-acting valves upstream of that step-by-step direct-acting valve along the ash conveying direction of the ash conveying pipeline are all in the open state.

[0017] Compared with the prior art, the present invention 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 section 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; Figure 8 This is a photograph of the assembled product of a step-by-step direct-acting valve according to the present invention. In the diagram: 1-Main valve; 2-Check valve; 3-Connecting pipe; 4-Outlet air valve; 5-Ash conveying pipe; 6-Tracing air pipe; 7-Control air pipe; 8-Inlet pipe; 9-Ash conveying direction; 101-Main valve body; 102-Main spring adjusting screw plug; 103-Control air inlet; 104-Exhaust air filter; 105-Pressure gauge; 106-Micro-inlet adjusting rod; 107-Main valve inlet; 108-Main air inlet channel; 109-Secondary air inlet channel; 110-Main spring mounting chamber; 111-Connecting channel; 112-Main piston mounting chamber; 113-Main exhaust channel; 114-Secondary exhaust channel; 115-Main valve outlet; 116-Main spring ; 117-Main valve opening / closing end cover; 118-Main piston; 119-Control air exhaust passage; 120-Control air outlet; 121-Control air inlet passage; 122-Control spring mounting chamber; 123-Breath passage; 124-Control piston; 125-Control spring; 201-Check valve body; 202-Check valve ball; 203-Check valve spring; 204-Check valve inlet; 205-Check valve passage; 206-Check valve outlet; 1041-Air filter nut; 1042-Pre-adjustment plug; 1043-Filter screen; 1044-Adjustment scale; 1121-First main piston chamber; 1122-Second main piston chamber. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0030] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

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

[0032] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0033] Example 1: like Figures 1 to 6 and Figure 8As shown, a step-by-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 / 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 valve chamber 110 is connected to the main piston mounting chamber 112 via the connecting channel 111. The main spring mounting chamber 110 is connected to the main intake channel 108, and the main piston mounting chamber 112 is connected to the auxiliary intake channel 109. The lower section of the main valve body 101 is provided with a main exhaust channel 113 arranged vertically and an auxiliary exhaust channel 114 arranged vertically. The main exhaust channel 113 is connected to the connecting channel 111, and the main piston mounting chamber 112 is connected to the main exhaust channel 113 via the auxiliary exhaust channel 114. The lower end of the main valve body 101 is provided with a main valve outlet 115, which is connected to the main exhaust channel 113. The main valve opening and closing end cover 117 is slidably mounted on... Inside 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 / closing end cap 117; when the main valve opening / closing end cap 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 / closing end cap 117 is in a 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 interconnected with the connecting channel 111, and the auxiliary intake channel 109 is connected to the auxiliary exhaust channel 114 through the second main piston chamber 1122. The main piston 118 is connected to the main valve opening / closing end cap 117 via the connecting channel 111, and the main piston 118 seals the connection between the first main piston chamber 1121 and the connecting channel 111. When the main valve opening / 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 / 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 / closing end cap 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 / closing end cap 117, thus keeping the main valve opening / closing end cap 117 in the closed state; the check valve 2 is provided with a check valve inlet 204, which is connected to the main valve outlet 115.

[0034] Specifically, the main spring 116 has a design stiffness of 100 N / mm, a mean diameter of 22 mm, a wire diameter of 5 mm, an effective number of coils of 6, and a free height of 50 mm. The selected end form of the main spring 116 is that both ends are tightly closed and ground flat, and the number of support coils is 1. The material of the main spring 116 is carbon spring steel wire (GB4357) C.

[0035] In this embodiment, as Figure 4 As shown, the pneumatic control mechanism includes an exhaust air filter 104, a control spring mounting chamber 122, a control air inlet channel 121, a breather 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 inlet channel 121 is arranged horizontally inside the middle section of the main valve body 101, and the control air inlet 103 is interconnected with the control spring mounting chamber 122 through the control air inlet channel 121. The breather channel 123 is arranged horizontally inside the middle section of the main valve body 101, and the control spring mounting chamber 124 is interconnected with the control spring mounting chamber 125 through the breather channel 125. 23 is interconnected with the first main piston chamber 1121; the control gas exhaust passage 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 passage 114 through the control gas exhaust passage 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 gas intake 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 moved away from the connection between the control spring mounting chamber 122 and the control gas intake 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 mean diameter of 5 mm, a wire diameter of 0.6 mm, an effective number of coils of 10, and a free height of 20 mm. The end configuration of the control spring 125 is selected as having both ends tightly closed and ground flat, with a support coil count of 1. The material of the control spring 125 is carbon spring steel wire (GB4357) C.

[0037] In this embodiment, as Figure 4 and Figure 6 As shown, the upper end of the main valve body 101 is provided with an air filter mounting port, and the upper section of the main valve body 101 is provided with an air filter adjustment screw hole. The air filter mounting port is connected to the control spring mounting chamber 122 through the air filter adjustment screw hole. The exhaust air filter 104 is threaded into the air filter adjustment screw hole through the air filter mounting port.

[0038] In this embodiment, as Figure 5 and Figure 6 As shown, 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 has an air filter exhaust channel inside, 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 disposed 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.

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

[0040] In this embodiment, as Figure 3 As shown, the main valve 1 also includes a main spring adjusting screw plug 102; a screw plug mounting port is provided on the outer side of the middle section of the main valve body 101, and a screw plug adjusting screw hole arranged horizontally is provided inside the middle section of the main valve body 101. The screw plug mounting port is connected to the end of the main spring mounting chamber 110 away from the connecting channel 111 through the screw plug adjusting screw hole; the main spring adjusting screw plug 102 is threaded into the screw plug adjusting screw hole through the screw plug mounting port; 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 this embodiment, as Figure 3As shown, the main valve 1 also includes a micro-intake regulating rod 106; the upper end of the main valve body 101 is provided with a regulating rod mounting port; the upper section of the main valve body 101 is provided with a regulating rod screw hole arranged in the vertical direction, and the regulating rod mounting port is connected to the auxiliary intake channel 109 through the regulating rod screw hole; the micro-intake regulating rod 106 is threaded into the regulating rod screw hole through the regulating rod mounting port and can extend into the auxiliary intake channel 109 through the regulating rod screw hole.

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

[0043] In this embodiment, as Figure 3 As shown, 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 has a check valve channel 205 arranged vertically, which communicates with the check valve inlet 204; the lower end of the check valve body 201 has a check valve outlet 206, which communicates with the check valve... The channels 205 are interconnected; 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.

[0044] Specifically, the check valve spring 203 has a design stiffness of 1.8 N / mm, a mean diameter of 18 mm, a wire diameter of 1.8 mm, an effective number of turns of 10, and a free height of 45 mm. The selected end form of the check valve spring 203 is that both ends are tightly closed and ground flat, and the number of support turns is 1. The material of the check valve spring 203 is carbon spring steel wire (GB4357) C.

[0045] In this embodiment, as Figure 1 and Figure 3 As shown, it also includes a connecting pipe 3 and an outlet valve 4 arranged in a vertical direction; the upper end of the connecting pipe 3 is connected to the outlet 206 of the check valve, and the outlet valve 4 is provided on the connecting pipe 3.

[0046] The opening pressure of the control piston 124 is set to 0.22 MPa; the corresponding main spring 116 is subjected to a force of 625 N and a compression of 6.25 mm; the check valve spring 203 is subjected to a force of 9 N and a compression of 5 mm; and the control spring 125 is subjected to a force of 3 N and a compression of 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 subjected to a force of 575 N and a compression of 5.75 mm; the check valve spring 203 is subjected to a force of 9 N and a compression of 5 mm; and the control spring 125 is subjected to a force of 3 N and a compression of 3 mm.

[0048] The rest is the same as in Example 1, and will not be described again here.

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

[0050] The rest is the same as in Example 1, and will not be described again here.

[0051] Example 4: like Figures 1 to 7 As shown, a step-by-step direct-acting pneumatic ash conveying system includes an ash conveying pipeline 5 and an air tracing pipeline 6, and also includes the step-by-step direct-acting valve in Embodiment 1 (set as the first distributed direct-acting valve), the step-by-step direct-acting valve in Embodiment 2 (set as the second distributed direct-acting valve), and the step-by-step direct-acting valve in Embodiment 3 (set as the third distributed direct-acting valve). The first distributed direct-acting valve, the second distributed direct-acting valve, and the third distributed direct-acting valve are arranged sequentially along the ash conveying direction 9 of the ash conveying pipeline 5; The lower ends of the connecting pipes 3 of the first distributed direct-acting valve, the second distributed direct-acting valve, and the third distributed direct-acting valve are all connected to the ash conveying pipe 5. The main valve inlet 107 of the first distributed direct-acting valve, the main valve inlet 107 of the second distributed direct-acting valve, and the main valve inlet 107 of the third distributed direct-acting valve are all interconnected with the air tracing pipe 6 through the air inlet pipe 8. The control air outlet 120 of the third distributed direct-acting valve is connected to the control air inlet 103 of the second distributed direct-acting valve through the control air pipe 7, and the control air outlet 120 of the second distributed direct-acting valve is connected to the control air inlet 103 of the first distributed 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 that valve along the ash conveying direction 9 of the ash conveying pipeline 5 are in the open state.

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

[0053] The working principle of this embodiment: When using this embodiment, compressed air forms a mixture with powder or granular material and is transported in the ash conveying pipe 5. The accompanying air pipe 6 supplies air to the main valve inlet 107 of the first distributed direct-acting valve, the main valve inlet 107 of the second distributed direct-acting valve, and the main valve inlet 107 of the third distributed direct-acting valve through the air inlet pipe 8.

[0054] When there is no blockage and the pressure in the ash conveying pipeline 5 is normal, the gas passes through the main intake channel 108, the auxiliary intake channel 109, the second main piston chamber 1122, and the auxiliary exhaust channel 114 in sequence to reach the check valve inlet 204. Since the pressure in the ash conveying pipeline 5 is normal, the gas directly pushes the check valve ball 202 away from the check valve inlet 204. However, the pressure in the second main piston chamber 1122 is insufficient to make the main piston 118 push the main valve opening and closing end cover 117 away from the connection between the main spring mounting chamber 110 and the connecting channel 111. Therefore, a small amount of gas enters the ash conveying pipeline 5 in sequence through the check valve channel 205 and the connecting pipe 3. The first distributed direct-acting valve, the second distributed direct-acting valve, and the third distributed direct-acting valve all provide a small amount of gas to the ash conveying pipeline 5 and work independently.

[0055] When a blockage occurs at the connection between the ash conveying pipeline 5 and the third distributed direct-acting valve, causing pressure to rise, the air in the third distributed direct-acting valve sequentially flows through the main intake channel 108, the auxiliary intake channel 109, the second main piston chamber 1122, and the auxiliary exhaust channel 114 to reach the check valve inlet 204. Due to the increased pressure in the ash conveying pipeline 5, the air cannot directly push the check valve ball 202 away from the check valve inlet 204. The pressure in the second main piston chamber 1122 increases, causing the main piston 118 to open / close the main valve. Cover 117 is pushed away from the connection between the main spring mounting chamber 110 and the connecting channel 111, so that the air, in addition to the above-mentioned path, will also reach the check valve inlet 204 via the main air intake channel 108, the main spring mounting chamber 110, the connecting channel 111, and the main exhaust channel 113. The air volume and pressure at the check valve inlet 204 increase, and the air pushes the check valve ball 202 away from the check valve inlet 204. Then, the air sequentially enters the ash conveying pipeline 5 via the check valve channel 205 and the connecting pipe 3, and the air volume is relatively high. The large pressure creates a fluidization zone at the blockage point, reducing the conveying pressure and enhancing the conveying capacity at the blockage point. In addition, the increased pressure within the main valve body 101 of the third distributed direct-acting valve causes air to enter the control air intake channel 121 of the second distributed direct-acting valve via the control air exhaust channel 119 and control air pipe 7 of the third distributed direct-acting valve. This pushes the control piston 124 of the second distributed direct-acting valve away from the connection between the control spring mounting chamber 122 and the control air intake channel 121. Then, the air enters the first main piston chamber 1121 of the second distributed direct-acting valve via the breather channel 123, increasing its pressure and preventing the main piston 118 of the second distributed direct-acting valve from pushing the main valve opening / closing end cap 117 away from the connection between the main spring mounting chamber 110 and the connecting channel 111. Therefore, the second distributed direct-acting valve still provides a small amount of supplementary air to the ash conveying pipeline 5. Similarly, the increased pressure within the main valve body 101 of the second distributed direct-acting valve causes the first distributed direct-acting valve to also provide a small amount of supplementary air to the ash conveying pipeline 5, thus saving on the amount of air supplied.

[0056] As the blockage at the connection between the ash conveying pipe 5 and the third distributed direct-acting valve gradually disappears, the opening pressure of the check valve ball 202 of the third distributed direct-acting valve gradually decreases, and the pressure in the second main piston chamber 1122 of the third distributed direct-acting valve also gradually decreases. When the pressure in the second main piston chamber 1122 of the third distributed 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 distributed direct-acting valve is resealed at the connection between the main spring mounting chamber 110 and the connecting channel 111 under the elastic force of the main spring 116, and the third distributed direct-acting valve returns to the state of providing a small amount of air to the ash conveying pipe 5.

[0057] This embodiment features a novel and reasonable structural design, effectively solving the blockage problem of ash conveying pipe 5 in the pneumatic ash conveying system. Compared with the traditional air replenishment method, it can achieve automated control and save 30-50% of air volume. After the application of this embodiment, the initial ash conveying flow rate can be reduced by 2-3 m / s, and the final ash conveying flow rate can be reduced to 12-15 m / s, effectively reducing pipe and valve wear, greatly reducing the workload of maintenance personnel, and enabling the pneumatic ash conveying system to operate safely and stably for a long period of time. This embodiment can reduce the main inlet air pressure of ash conveying to 0.3 MPa, reduce the amount of air used for ash conveying (saving 30%), reduce the ash conveying flow rate, and increase the ash-to-air ratio (35-40). During the ash conveying process, when the pressure inside the ash conveying pipe 5 increases, the step-by-step direct-acting valve near the high-pressure point of the ash conveying pipe 5 opens to replenish air to the high-pressure position. At the same time, the output control air restricts the opening of other step-by-step direct-acting valves, concentrating the air source to fluidize the high-pressure position, thereby achieving the purpose of saving air source volume and meeting the requirements of energy conservation and environmental protection.

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

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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