A method for controlling the flow of casting liquid for pellet casting propellant

Abstract

The present invention provides a method for controlling the flow of casting liquid for granulated propellant, in which the discharge port of a one-way valve is fixed at the other end of a hose, and the feed port of the one-way valve is connected to a casting liquid container through a hose with a valve. The present invention aims at the characteristics of liquid filling gap flow in the granulation and casting process of bipropellant, and adopts the principle of preventing reverse flow with a portable one-way valve, so that the casting liquid flows and stops along the direction required by the process. The method of the present invention can effectively improve production efficiency, ensure production safety, and reduce labor intensity, and is of great significance to the field.

Description

Technical Field

[0001] The invention belongs to the technical field of propellant manufacturing, relates to a particle casting propellant, and in particular to a method for controlling the flow of a casting liquid material of a particle casting propellant. Background Art

[0002] The pellet casting process has flexible charging forms, which can realize free-loading charging and shell-bonded charging. The size of the charge column is not limited, and special-shaped charge columns with complex structures can be cast. Therefore, it is widely used in the preparation and production of modified double-base propellant charges. The pellet casting process is a key process for propellant forming. Its process principle is to use the difference in vacuum degree to press the casting liquid from the storage tank through the pipeline into the mold of the casting tank, so that the liquid fills the gaps between the medicine particles in the mold, thereby obtaining a solid-liquid mixture with a higher uniformity.

[0003] The schematic diagram of the casting process is shown in Figure 1 ,from Figure 1 It can be seen that the casting pipeline is an important channel connecting the casting mold and the liquid tank. The casting liquid needs to flow through the casting pipeline into the mold to complete the casting operation. Figure 2 , the specific operations are as follows:

[0004] First, before the casting operation begins, the casting pipeline is connected and fixed to the bottom cover of the mold. Currently, personnel use copper wire and explosion-proof pliers to complete the operation. During this process, neither personnel nor tools come into contact with hazardous materials.

[0005] Second, under the condition of human-machine isolation, the liquid is pressed into the casting mold through the casting pipeline through the vacuum pressure difference between the liquid tank and the casting tank. In order to prevent incomplete plasticization of the medicine particles and affect the propellant molding quality, the liquid casting height usually exceeds the upper part of the medicine particles by about 1 cm.

[0006] Third, after the casting process is completed, in order to prevent the liquid from flowing back, the pipeline at the mold end needs to be closed first. Currently, personnel use copper wire and explosion-proof pliers to complete the operation. The liquid pipeline is bent 180° and then fastened with copper wire. Since there is casting liquid in the pipeline, there is a squeezing effect on the liquid during the tightening process, which is very dangerous.

[0007] During the pipeline closure process, personnel need to enter the site, open the casting tank operation window, and use tools to bend and tighten the pipeline filled with casting liquid. The process of tightening the copper wire with pliers may cause the material to explode. Therefore, this method has problems such as high safety risks, low efficiency, and high labor intensity.

[0008] In order to solve the above problems, a Chinese invention patent with application publication number CN 108438296A provides a device and method for automatically tightening and cutting a cable tie. The method uses a motor to automatically tighten the cable tie. However, the cable tie cannot be effectively installed and positioned, and it is difficult to achieve complete human-machine isolation in the pipeline closure link of the pellet casting propellant process. In addition, the tightening process still cannot avoid mechanical stimulation of the material, posing a safety risk. Summary of the invention

[0009] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for controlling the flow of casting liquid for particle casting propellant, so as to solve the technical problem that the production efficiency of the control method in the prior art needs to be further improved.

[0010] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0011] The invention discloses a method for controlling the flow of casting liquid of a particle casting propellant. The method adopts a one-way valve to realize the flow control of the casting liquid.

[0012] Specifically, the method comprises the following steps:

[0013] Step 1: Fix the assembled mold in the casting tank, and fix one end of a 3-5 cm hose on the tail pipe of the bottom cover of the mold.

[0014] Step 2: fix the discharge port of the one-way valve to the other end of the hose, and connect the feed port of the one-way valve to the casting liquid container through a hose with a valve.

[0015] Step three, turn off the casting pipeline switch and perform vacuum treatment on the casting tank and liquid container for 4 hours respectively.

[0016] Step 4: Reduce the vacuum degree in the liquid container according to the process regulations, open the casting pipeline switch, and close the casting pipeline switch after the casting liquid fills the medicine particle bed.

[0017] Step 5: restore the pressure in the casting tank and the liquid container to atmospheric pressure, cut off the hose below the feed port of the one-way valve, and transfer the casting mold to the next process.

[0018] The present invention also has the following technical features:

[0019] Preferably, the one-way valve is a portable one-way valve.

[0020] Preferably, the inner diameter of the hose is in the range of 12 mm to 24 mm. The method is applicable to the casting process of granular propellant with various casting flow rates.

[0021] Preferably, the inner diameter of the feed port of the one-way valve is in the range of 8 mm to 20 mm, and the outer diameter of the one-way valve is in the range of 12 mm to 24 mm, which matches the inner diameter of the hose. This method is applicable to various types of one-way valve structures.

[0022] Preferably, the inner diameter of the mold is in the range of 40 mm to 500 mm. The method is applicable to the casting process of pelletized propellants of various common sizes.

[0023] Specifically, the forming process of the pelletized propellant is a gap-filling casting process, in which the casting liquid enters the mold from the bottom under pressure to fill the gaps between the pellet beds.

[0024] Compared with the prior art, the present invention has the following technical effects:

[0025] (I) The method of the present invention adopts a one-way valve structure to realize the flow control of the casting liquid, which provides a subversive idea for the design of the human-machine isolation process in the pipeline closure link of the pellet casting propellant casting process.

[0026] (II) The method of the present invention can effectively improve production efficiency, ensure production safety, and reduce labor intensity, which is of great significance to the field.

[0027] (III) The present invention aims at improving the gap-filling flow characteristics of liquid in the bipropellant granulation casting process, and adopts the principle of preventing reverse flow with a portable one-way valve, so that the casting liquid can flow and stop in the direction required by the process.

[0028] (IV) The method of the present invention can be applied to the process and equipment design of a human-machine isolation process prototype, which is beneficial to the realization of the automated process of pellet casting propellant forming. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the casting process.

[0030] Figure 2 Schematic diagram of the casting process.

[0031] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0032] It should be noted that, unless otherwise specified, all raw materials and equipment in the present invention are raw materials and equipment known in the prior art.

[0033] The overall technical concept of the present invention is: the present invention provides a casting liquid flow control method based on a one-way valve structure. First, the one-way valve prevents the backflow of liquid by a diaphragm check valve, which highly matches the characteristic of the casting process that the liquid only flows in one direction under the drive of the pressure difference, and can use the gravity of the liquid in the mold after casting to achieve sealing; secondly, the one-way valve diaphragm is made of plastic materials such as polyvinyl chloride, and the friction generated during the switching process is small, and there is almost no squeezing effect on the liquid, and the safety risk is relatively low; in addition, the one-way valve is small in size, low in cost, and easy to replace, which is convenient for embedding in the casting pipeline. It can complete the function without external structure matching, and can be transported with the mold to the subsequent workstation. Based on the above characteristics, this casting liquid flow control method has good pipeline sealing effect and process matching.

[0034] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0035] Embodiment 1:

[0036] This embodiment provides a method for controlling the flow of a pellet casting liquid material, the method comprising the following steps:

[0037] Step 1: Fix the assembled Φ40mm sample mold in the sample casting tank, and fix one end of a 3cm long latex hose on the tail pipe of the mold bottom cover.

[0038] Step 2: insert and fix the outlet of a portable one-way valve with an outer diameter of 8 mm into the other end of the hose, and insert the feed port of the one-way valve into the beaker containing the casting liquid through the hose with a valve.

[0039] Step three, turn off the casting pipeline switch and treat the casting tank and liquid container with a vacuum of -0.095MPa for 4 hours respectively.

[0040] Step 4: The ambient pressure of the liquid container is increased to -0.035MPa, and the casting pipeline switch is turned on to allow the casting liquid to fill the medicine particle bed and then the casting pipeline switch is closed.

[0041] Step 5: restore the pressure in the casting tank and the liquid container environment to atmospheric pressure, cut off the hose below the one-way valve feed port, and transfer the casting mold to the next process.

[0042] The process operation results show that the one-way valve-based flow control method for pellet casting propellant casting liquid can effectively avoid the pipe tying operation of pellet casting propellant accompanying samples, and the one-way valve is not blocked or leaked during the process.

[0043] Embodiment 2:

[0044] This embodiment provides a method for controlling the flow of a pellet casting liquid material, the method comprising the following steps:

[0045] Step 1: Fix the assembled Φ158mm product mold in the product casting tank, and fix one end of a 5cm long PVC hose on the tail pipe of the mold bottom cover.

[0046] Step 2: insert and fix the outlet of a portable one-way valve with an outer diameter of 12 mm into the other end of the hose, and insert the feed port of the one-way valve into the storage tank containing the casting liquid through the hose with a valve.

[0047] Step three, turn off the casting pipeline switch, and treat the casting tank and liquid storage tank with a vacuum of -0.095MPa for 4 hours respectively.

[0048] Step 4: Increase the pressure in the liquid storage tank to -0.035MPa, open the casting pipeline switch, allow the casting liquid to fill the medicine particle bed, and then close the casting pipeline switch.

[0049] Step 5: restore the pressure in the casting tank and the liquid storage tank to atmospheric pressure, cut off the hose below the one-way valve feed port, and transfer the casting mold to the next process.

[0050] The process operation results show that the one-way valve-based flow control method for pellet casting propellant casting liquid can effectively avoid the pipe tying operation of medium-sized pellet casting propellant products, and the one-way valve is not blocked or leaked during the process.

[0051] Embodiment 3:

[0052] This embodiment provides a method for controlling the flow of a pellet casting liquid material, the method comprising the following steps:

[0053] Step 1: Fix the assembled Φ360mm core product mold in the product casting pit, and fix one end of a 5cm long PVC hose on the oil inlet port on the top of the mold core.

[0054] Step 2: insert and fix the outlet of a portable one-way valve with an outer diameter of 12 mm into the other end of the hose, and insert the feed port of the one-way valve into the storage tank containing the casting liquid through the hose with a valve.

[0055] Step three, turn off the casting pipeline switch, and treat the casting pit and liquid storage tank with a vacuum of -0.095MPa for 4 hours respectively.

[0056] Step 4: Increase the pressure in the liquid storage tank to -0.035MPa, open the casting pipeline switch, allow the casting liquid to fill the medicine particle bed, and then close the casting pipeline switch.

[0057] Step five: restore the pressure in the casting pit and the liquid material storage tank to atmospheric pressure, cut off the hose above the one-way valve feed port, and transfer the casting mold to the next process.

[0058] The process operation results show that the use of a one-way valve-based flow control method for pellet cast propellant casting liquid can effectively avoid the pipe tying operation of large-scale cored pellet cast propellant products, and the one-way valve is not blocked or leaked during the process.

Claims

1. A method for controlling the flow of a pellet casting propellant casting liquid, characterized in that: This method uses a one-way valve to control the flow of casting liquid; The method comprises the following steps: Step 1: Fix the assembled mold in the casting tank, and fix one end of a 3-5 cm hose on the tail pipe of the bottom cover of the mold; Step 2: fix the discharge port of the one-way valve to the other end of the hose, and connect the feed port of the one-way valve to the casting liquid container through a hose with a valve; Step 3: Turn off the casting pipeline switch and perform vacuum treatment on the casting tank and liquid container for 4 hours respectively; Step 4: according to the process requirements, reduce the vacuum degree in the liquid container, open the casting pipeline switch, and close the casting pipeline switch after the casting liquid fills the medicine particle bed; Step 5: restore the pressure in the casting tank and the liquid container to atmospheric pressure, cut off the hose below the feed port of the one-way valve, and transfer the casting mold to the next process; The one-way valve is a portable one-way valve; The inner diameter range of the feed port of the one-way valve is 8mm~20mm; the inner diameter range of the hose is 12mm~24mm; the outer diameter range of the one-way valve is 12mm~24mm, matching the inner diameter of the hose; The inner diameter of the mold ranges from 40 mm to 500 mm.

2. The method for controlling the flow of the pellet casting propellant casting liquid as claimed in claim 1, characterized in that: The forming process of the pelletized propellant is a gap-filling casting process, in which the casting liquid enters the mold from the bottom under pressure to fill the gaps between the pellet beds.

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