Heat conducting oil heating system for die plate of a dicer
Patent Information
- Application Number
- CN202522062149.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-23
- Publication Date
- 2026-08-21
- Estimated Expiration
- 2035-09-23
AI Technical Summary
在现有技术中已知的热油排放方案中，常常需要就地排放大约1桶(约200L)200℃的热油，在排放过程中常常需要操作人员监护整个排放过程，且排放过程中可能会存在热油泄漏或从排放管中喷出的情况，这使得排放操作人员暴露在被200℃热油烫伤和吸入热油挥发物的风险之中，存在严重的安全隐患和环境污染隐患
[0017]根据本实用新型实施例的导热油加热系统采用了一种改进的导热油排放装置，该导热油排放装置包括密封地连接在切粒机模板的排放管和油箱之间的压力管线，使得可以将切粒机模板内的残余热油直接压回油箱中，从而允许重复利用这些热油，减少了危废排放，节约了生产成本，且还避免了热油向周围环境的泄漏以及因采用临时排放装置带来的环境污染隐患。另外，由于压力管线属于压力容器，因而可以利用氮气加压系统实现对切粒机模板以及周围管路内的吹扫，从而实现对残余热油的完全排空，且整个排空过程更高效、更安全且更环境友好。
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Figure CN224659829U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pelletizer technology, and more specifically to a heat transfer oil heating system for pelletizer die. Background Technology
[0002] A pelletizer (also known as a pelletizing system) is a key piece of equipment in the field of plastics processing and engineering technology. It is mainly used to form molten polymers or plastic raw materials into pellets of specific shapes. The core working component of a pelletizer includes the pelletizing die, through which molten polyethylene, for example, is extruded, and then cut into pellets by rotating cutters. In polyethylene plants, the pelletizing die requires hot oil (or heat transfer oil) to maintain its temperature during operation. When the pelletizer is not in use, such as before each die replacement, the hot oil in the die flow channel and surrounding annular pipes must be drained. In existing hot oil drainage schemes, approximately one barrel (about 200L) of 200°C hot oil is often drained on-site. During the drainage process, operators often need to monitor the entire process, and there is a risk of hot oil leakage or spraying from the drain pipe. This exposes drainage operators to the risk of burns from 200°C hot oil and inhalation of hot oil volatiles, posing serious safety and environmental pollution hazards.
[0003] Furthermore, existing technologies typically rely on opening vent valves on pipelines to discharge residual hot oil using static pressure differences. This means that the discharge facility cannot completely prevent hot oil leakage into the surrounding environment. Moreover, because the entire discharge process is relatively complex and the hot oil is discharged solely by gravity, the process is slow and requires a long discharge time.
[0004] Therefore, an improved hot oil discharge scheme for the heat transfer oil heating system of a pelletizer die is needed to improve the safety and economy of hot oil discharge within the pelletizer die. Utility Model Content
[0005] The purpose of this utility model is to solve at least one of the above-mentioned problems and / or other problems existing in the prior art.
[0006] To achieve the above objectives, this utility model provides a heat transfer oil heating system for a pelletizer die. The heat transfer oil heating system includes an oil tank for supplying heat transfer oil, an oil pump fluidly connected to the oil tank, an oil inlet pipe for fluidly connecting the outlet end of the oil pump to the pelletizer die, and an oil return pipe for fluidly connecting the inlet end of the oil pump to the pelletizer die, so that the heat transfer oil circulates through the pelletizer die to maintain the working temperature of the pelletizer die. The heat transfer oil heating system also includes a heat transfer oil discharge device, which includes a discharge pipe fluidly connected to the pelletizer die and a pressure line for sealingly connecting the discharge pipe to the oil tank.
[0007] In one embodiment, the heat transfer oil heating system further includes a heater disposed on the oil inlet pipeline for further heating the heat transfer oil pumped from the oil tank via the oil pump.
[0008] In one embodiment, the heat transfer oil heating system further includes a first annular pipe fluidly connected to the oil inlet pipe and a plurality of inlets within the pelletizer template, the first annular pipe including a plurality of first flow channels fluidly connected to each of the plurality of inlets; the heat transfer oil heating system further includes a second annular pipe fluidly connected to the oil return pipe and a plurality of outlets within the pelletizer template, the second annular pipe including a plurality of second flow channels fluidly connected to each of the plurality of outlets.
[0009] In one embodiment, the heat transfer oil discharge device includes a first discharge pipe and a second discharge pipe that are fluidly connected to the first annular pipeline and the second annular pipeline, respectively, and a first pressure line and a second pressure line that are fluidly connected to the first discharge pipe and the second discharge pipe at their respective first ends; wherein, the first pressure line is fluidly connected to the oil tank at its second end, and the second pressure line is fluidly connected to the first pressure line at its second end at a position between the first end and the second end of the first pressure line.
[0010] In one embodiment, a discharge valve is provided on both the first discharge pipe and the second discharge pipe. The discharge valve is configured to be closed when the heat transfer oil heating system is in operation and open when the heat transfer oil heating system is in discharge mode.
[0011] In one embodiment, the heat transfer oil heating system further includes a first nitrogen pressurization line and a second nitrogen pressurization line respectively connected to the oil inlet line and the oil return line; wherein, the heat transfer oil heating system is also provided with a first vent valve and a second vent valve, one end of the first vent valve being fluidly connected to the first nitrogen pressurization line and the other end being fluidly connected to the oil inlet line; one end of the second vent valve being fluidly connected to the second nitrogen pressurization line and the other end being fluidly connected to the oil return line; wherein, the first vent valve and the second vent valve are configured to be closed when the heat transfer oil heating system is in the working state, and open when the heat transfer oil heating system is in the venting state.
[0012] As one implementation, a pressure reducing valve is provided on both the first and second nitrogen pressurization lines to ensure that the nitrogen pressure does not exceed a predetermined pressure threshold.
[0013] In one embodiment, isolation valves are provided on both the oil inlet pipeline and the oil return pipeline. The isolation valves are configured to open when the heat transfer oil heating system is in operation and close when the heat transfer oil heating system is in discharge mode, so as to allow nitrogen in the corresponding nitrogen pressurization pipeline to flow toward the pelletizer die and prevent nitrogen from flowing toward the oil pump.
[0014] In one embodiment, the pressure pipeline is a metal pressure pipe with a first diameter; the oil inlet pipeline and the oil return pipeline have a second diameter; wherein the first diameter is smaller than the second diameter.
[0015] In one implementation, the first pipe diameter is 1 inch and the second pipe diameter is 6 inches.
[0016] In one embodiment, the oil inlet line and the oil return line are fluidly connected to the pelletizer template near the top of the pelletizer template; the pressure line is fluidly connected to the pelletizer template near the bottom of the pelletizer template.
[0017] The heat transfer oil heating system according to an embodiment of this utility model employs an improved heat transfer oil discharge device. This device includes a pressure pipeline sealed between a discharge pipe and an oil tank connected to the pelletizer die. This allows residual hot oil within the pelletizer die to be directly pumped back into the oil tank, enabling reuse of the hot oil, reducing hazardous waste emissions, saving production costs, and preventing leakage of hot oil into the surrounding environment and the environmental pollution hazards associated with temporary discharge devices. Furthermore, since the pressure pipeline is a pressure vessel, a nitrogen pressurization system can be used to purge the pelletizer die and surrounding pipelines, achieving complete drainage of residual hot oil. The entire drainage process is more efficient, safer, and more environmentally friendly. Attached Figure Description
[0018] The features and advantages of this utility model will become clear from the following detailed description provided with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and therefore should not be considered as limitations on this utility model, wherein:
[0019] Figure 1 A schematic diagram of a heat transfer oil heating system for a pelletizer die according to an embodiment of the present invention is shown; and
[0020] Figure 2 A schematic diagram of a heat transfer oil heating system for a pelletizer die according to an improved embodiment of the present invention is shown. Detailed Implementation
[0021] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.
[0022] The terms "first" and "second" are used below to describe the elements of this application. These terms are used only to distinguish the individual elements and not to limit the nature, order, or number of these elements. The terms "comprising" and "having" are used to indicate an open-ended inclusion and mean that there may be additional elements / components besides those listed.
[0023] As mentioned in the background section, in order to maintain a suitable temperature for the pelletizer die in a polyethylene workshop during operation, a thermal oil heating system (or simply "hot oil system") is needed to supply hot oil to the pelletizer die to maintain the temperature. Typically, a thermal oil heating system includes an oil tank for supplying hot oil (i.e., high-temperature thermal oil with a temperature of approximately 200°C), an oil pump fluidly connected to the oil tank, an inlet pipe fluidly connecting the outlet of the oil pump to the pelletizer die, and a return pipe fluidly connecting the inlet of the oil pump to the pelletizer die. Thus, the thermal oil from the oil tank circulates between the inlet and return pipes through the pelletizer die via the pumping action of the oil pump to maintain the operating temperature of the pelletizer die. The thermal oil heating system also includes a discharge pipe fluidly connected to the pelletizer die, and each discharge pipe is equipped with a discharge valve. For example, when the heat transfer oil heating system is in a stopped state (i.e., no hot oil is supplied to the pelletizer die), if the heat transfer oil heating system is stopped every time the pelletizer die is replaced, the hot oil in the flow channel and the surrounding annular pipe in the pelletizer die can be drained using the discharge pipe.
[0024] Figure 1 A schematic diagram of a heat transfer oil heating system for a pelletizer die according to an embodiment of the present invention is shown. In this embodiment, the heat transfer oil heating system includes a hot oil discharge device, which uses a portable cooler to moderately cool the heat transfer oil flowing out from the pelletizer die and surrounding annular pipes through the discharge pipe before discharging it into an empty oil collection tank. The discharged hot oil is treated as hazardous waste.
[0025] Specifically, such as Figure 1 As shown, the heat transfer oil discharge device used is a temporary discharge device, which is only installed when hot oil discharge is required. This hot oil discharge device includes a cooler 5 fluidly connected to a discharge pipe 4 via a hose, and an oil collection tank 6 fluidly connected to the cooler 5 via a hose. When the heat transfer oil heating system needs to be shut down for hot oil discharge, the isolation valves 8 on the inlet pipe 2 and the return pipe 3 must first be closed, and the aforementioned temporary discharge device must be connected. At this time, the discharge valve 9 on the discharge pipe 4 and the vent valves 7 connected to the inlet pipe 2 and the return pipe 3 respectively are opened, and the hot oil in the pelletizer die 1 and surrounding pipes is discharged to the oil collection tank 6 using the static pressure difference. After discharge is completed, the discharge valve 9 and the vent valve 7 are closed, and this temporary discharge device is removed.
[0026] The heat transfer oil discharge device according to this embodiment generally meets the requirements for hot oil discharge. However, considering that the entire discharge process still requires operator supervision, there is a significant safety risk to the operator. Furthermore, since the oil collection tank is not a pressure vessel, nitrogen cannot be used to purge residual hot oil from the system into the tank. This makes it impossible to completely prevent hot oil leakage into the surrounding environment (e.g., residual hot oil inside the pelletizer die and surrounding annular pipes, residual hot oil at the ends of hoses after discharge, and residual hot oil in the cooler). This residual hot oil will flow onto the ground during equipment dismantling. Additionally, the hot oil is discharged by gravity, resulting in a long discharge time. Moreover, the hot oil discharged into the collection tank will be treated as hazardous waste, thus posing a significant environmental pollution hazard.
[0027] Therefore, this utility model proposes an improved heat transfer oil discharge scheme for heat transfer oil heating systems. For example... Figure 2 The diagram shown illustrates a heat-conducting oil heating system for a pelletizer die according to another improved embodiment of the present invention. Figure 1 The basic structure of the heat transfer oil heating system is similar. The heat transfer oil heating system includes an oil tank 11 for supplying heat transfer oil, an oil pump 12 fluidly connected to the oil tank 11, an oil inlet pipe 14 for fluidly connecting the outlet end of the oil pump 12 to the pelletizer die 13, and an oil return pipe 15 for fluidly connecting the inlet end of the oil pump 12 to the pelletizer die 13. The heat transfer oil heating system 10 also includes a heater 16 disposed on the oil inlet pipe 14 for further heating the heat transfer oil pumped from the oil tank 11 via the oil pump 12.
[0028] However, with Figure 1 The embodiment shown differs from the one described above in that, according to Figure 2The heat transfer oil heating system of the illustrated embodiment does not employ a temporary discharge device. Instead, it adds pressure lines 23 and 24 to the heat transfer oil heating system for sealingly connecting the discharge pipes 21 and 22 of the pelletizer die to the oil tank 11. In actual installation and use, the oil inlet line 14 and the oil return line 15 are fluidly connected to the pelletizer die 13 at a position near the top of the plant roof, while the pressure lines are fluidly connected to the pelletizer die 13 at a position near the bottom of the pelletizer die 13.
[0029] By using this type of pressure pipeline that connects directly to the oil tank, not only can the leakage of hot oil into the surrounding environment be prevented, but also... Figure 1 The environmental pollution risks associated with using temporary oil collection tanks in the illustrated embodiment.
[0030] The following will be based on references. Figure 2 The specific structure and working process of this improved heat transfer oil heating system are described in detail.
[0031] like Figure 2 As shown, the heat transfer oil heating system includes a first annular pipe 17 fluidly connected to the oil inlet pipe 14 and a plurality of inlets 131 within the pelletizer die 13. The first annular pipe 17 includes a plurality of first flow channels 171, each corresponding to and fluidly communicating with the plurality of inlets 131. Additionally, the heat transfer oil heating system also includes a second annular pipe 18 fluidly connected to the oil return pipe 15 and a plurality of outlets 132 within the pelletizer die 13. The second annular pipe 18 includes a plurality of second flow channels 181, each corresponding to and fluidly communicating with the plurality of outlets 132. These first or second flow channels may, for example, be arranged in... Figure 2 The radial flow channel shown is as described. Thus, the heat transfer oil in the oil tank 11 is pumped by the oil pump through the oil inlet pipe 14, the first annular pipe 17, and multiple first flow channels 171, entering the pelletizer mold 13 through multiple inlets 131. Within the pelletizer mold, it flows to the corresponding multiple outlets 132, then through multiple second flow channels 181 and the second annular pipe 18 into the return oil pipe 15, and finally returns to the inlet end of the oil pump 12, achieving the circulation of the heat transfer oil. Of course, the arrangement and number of the above flow channels can be determined according to actual design requirements.
[0032] To drain and guide the heat transfer oil in the pelletizer die and surrounding annular pipes, this embodiment's heat transfer oil drainage device includes a first drainage pipe 21 and a second drainage pipe 22, respectively fluidly connected to the first annular pipe 17 and the second annular pipe 18. Both the first and second drainage pipes are equipped with drainage valves 25. The heat transfer oil drainage device includes a first pressure line 23 and a second pressure line 24. (The text repeats itself here.) Figure 2As shown, the first pressure line 23 is fluidly connected to the first discharge pipe 21 at its first end and to the oil tank 11 at its second end. The second pressure line 24 is fluidly connected to the second discharge pipe 22 at its first end and to the first pressure line 23 at its second end, located between the first and second ends of the first pressure line 23. Thus, the heat transfer oil discharged into the two pressure lines can converge and ultimately be transported to the oil tank 11 via the first pressure line 23. This discharge method is safer because the pressure lines, discharge pipe, and oil tank are all sealed and fixedly connected, eliminating any risk of hot oil leakage during the entire discharge process. Of course, it should be understood that the connection relationship between the discharge pipe and the pressure lines can have various possibilities; for example, the connection configurations of the first and second pressure lines and the first and second discharge pipes can be reversed, as long as the intended technical objective is achieved.
[0033] More advantageously, since both the pressure pipelines and the hot oil tank are pressure vessels, they allow for connection to a nitrogen purging system to efficiently drain residual hot oil from the pelletizer die and pipelines. The entire purging process is more efficient, safer, and more environmentally friendly. For example, see still... Figure 2 The heat transfer oil heating system also includes a first nitrogen pressurization line 31 and a second nitrogen pressurization line 32, respectively connected to the oil inlet line 14 and the oil return line 15. A first vent valve 33 and a second vent valve 34 are respectively connected in series with the first nitrogen pressurization line 31 and the second nitrogen pressurization line 32. One end of the first vent valve 33 is fluidly connected to the first nitrogen pressurization line 31 and the other end is fluidly connected to the oil inlet line 14. One end of the second vent valve 34 is fluidly connected to the second nitrogen pressurization line 32 and the other end is fluidly connected to the oil return line 15. Advantageously, a pressure reducing valve 35 is also provided on each nitrogen pressurization line to ensure that the nitrogen pressure does not exceed a predetermined pressure threshold, for example, the nitrogen pressure can be reduced to 200 kPaG to prevent overpressure in the oil tank containing the hot oil during the nitrogen purging process after pressing. (Reference) Figure 2 Isolation valves 19 are also installed on the oil inlet line 14 and the oil return line 15. They are closed during the discharge operation to prevent more oil in the oil inlet line 14 and the oil return line 15 from flowing into the pellet mill die 13. This ensures that the amount of hot oil that is forced back into the oil tank 11 does not exceed the rated capacity of the oil tank.
[0034] In actual operation, when the heat transfer oil heating system needs to be vented, first close each isolation valve on the inlet and return oil lines and open the vent valve to allow nitrogen in the corresponding nitrogen pressurization line to flow towards the pelletizer die, while preventing nitrogen from flowing towards the oil pump. Then, open the vent valve to allow nitrogen to pressurize the hot oil through the pressure line to the oil tank. Optionally, after complete venting, nitrogen purging can continue for 30 minutes to more effectively reduce residual hot oil.
[0035] As an exemplary embodiment, the first and second pressure lines may be metal (e.g., stainless steel) pressure pipes with a first diameter. The inlet and return lines may have a second diameter. The first diameter is smaller than the second diameter. For example, the first diameter of the stainless steel pressure pipe used as the pressure line may be 1 inch, and the second diameter of the inlet and return lines may be 6 inches. Thus, by using pressure lines with relatively small diameters, the pressure discharge of hot oil can be better achieved.
[0036] As can be seen from the above, the improved heat transfer oil discharge device enables a fully enclosed operation of the entire oil discharge process of the heat transfer oil heating system, preventing operators from being scalded by hot oil and inhaling hot oil volatiles. Since the pressure pipeline does not require frequent disassembly, any spillage or spraying during disassembly is avoided. Furthermore, the hot oil that can be reused in the oil tank reduces hazardous waste emissions and saves production costs. In addition, the pressure pipeline, which is sealed to the discharge pipe and oil tank, eliminates the need for connecting and dismantling temporary discharge devices, reduces hot oil evacuation time, and improves maintenance efficiency.
[0037] Various modifications and variations can be made to the embodiments disclosed above without departing from the scope or spirit of this invention. Other embodiments of this invention will be apparent to those skilled in the art based on the practice of this invention disclosed in this specification. This specification and the examples disclosed herein should be considered illustrative only, and the true scope of this invention is defined by the appended claims and their equivalents.
Claims
1. A heat-conducting oil heating system for a pelletizer die, characterized in that, The heat transfer oil heating system includes an oil tank (11) for supplying heat transfer oil, an oil pump (12) fluidly connected to the oil tank, an oil inlet pipe (14) for fluidly connecting the outlet end of the oil pump to the pelletizer template (13), and an oil return pipe (15) for fluidly connecting the inlet end of the oil pump to the pelletizer template, so that the heat transfer oil circulates through the pelletizer template to maintain the working temperature of the pelletizer template (13); wherein, the heat transfer oil heating system is also provided with a heat transfer oil discharge device, the heat transfer oil discharge device includes a discharge pipe fluidly connected to the pelletizer template (13) and a pressure line for sealingly connecting the discharge pipe to the oil tank.
2. The heat transfer oil heating system according to claim 1, characterized in that, The heat transfer oil heating system also includes a heater (16) installed on the oil inlet pipe (14) for further heating the heat transfer oil pumped from the oil tank (11) via the oil pump (12).
3. The heat transfer oil heating system according to claim 1, characterized in that, The heat transfer oil heating system further includes a first annular pipe (17) fluidly connected to the oil inlet pipe (14) and multiple inlets (131) in the pelletizer template (13), the first annular pipe including multiple first channels (171) fluidly connected to the multiple inlets one by one; the heat transfer oil heating system further includes a second annular pipe (18) fluidly connected to the oil return pipe (15) and multiple outlets (132) in the pelletizer template (13), the second annular pipe including multiple second channels (181) fluidly connected to the multiple outlets one by one.
4. The heat transfer oil heating system according to claim 3, characterized in that, The heat transfer oil discharge device includes a first discharge pipe (21) and a second discharge pipe (22) which are fluidly connected to the first annular pipe (17) and the second annular pipe (18) respectively, and a first pressure line (23) and a second pressure line (24) which are fluidly connected to the first discharge pipe and the second discharge pipe respectively at their respective first ends; wherein, the first pressure line (23) is fluidly connected to the oil tank (11) at its second end, and the second pressure line (24) is fluidly connected to the first pressure line (23) at its second end at a position between the first end and the second end of the first pressure line.
5. The heat transfer oil heating system according to claim 4, characterized in that, Both the first discharge pipe and the second discharge pipe are provided with discharge valves (25), which are configured to close when the heat transfer oil heating system is in operation and open when the heat transfer oil heating system is in discharge state.
6. The heat transfer oil heating system according to any one of claims 1 to 5, characterized in that, The heat transfer oil heating system further includes a first nitrogen pressurization line (31) and a second nitrogen pressurization line (32) respectively connected to the oil inlet line (14) and the oil return line (15); wherein, the heat transfer oil heating system is also provided with a first vent valve (33) and a second vent valve (34), one end of the first vent valve is fluidly connected to the first nitrogen pressurization line and the other end is fluidly connected to the oil inlet line; one end of the second vent valve is fluidly connected to the second nitrogen pressurization line and the other end is fluidly connected to the oil return line; wherein, the first vent valve and the second vent valve are configured to be closed when the heat transfer oil heating system is in the working state and open when the heat transfer oil heating system is in the venting state.
7. The heat transfer oil heating system according to claim 6, characterized in that, A pressure reducing valve (35) is installed on the first nitrogen pressurization line and the second nitrogen pressurization line to ensure that the nitrogen pressure does not exceed the predetermined pressure threshold.
8. The heat transfer oil heating system according to claim 7, characterized in that, An isolation valve (19) is provided on both the oil inlet line and the oil return line. The isolation valve is configured to open when the heat transfer oil heating system is in operation and close when the heat transfer oil heating system is in discharge mode, so as to allow nitrogen in the corresponding nitrogen pressurization line to flow toward the pelletizer template (13) and prevent nitrogen from flowing toward the oil pump.
9. The heat transfer oil heating system according to any one of claims 1 to 5, characterized in that, The pressure pipeline is a metal pressure pipe with a first diameter; the oil inlet pipeline and the oil return pipeline have a second diameter; wherein the first diameter is smaller than the second diameter.
10. The heat transfer oil heating system according to claim 9, characterized in that, The first pipe has a diameter of 1 inch, and the second pipe has a diameter of 6 inches.
11. The heat transfer oil heating system according to any one of claims 1 to 5, characterized in that, The oil inlet line (14) and the oil return line (15) are fluidly connected to the pelletizer template near the top of the pelletizer template; the pressure line is fluidly connected to the pelletizer template near the bottom of the pelletizer template.