Waste heat recovery system for catalyst drying

Abstract

This utility model discloses a waste heat recovery system for catalyst drying, including a steam condensate tank and a hot water tank located downstream of the steam condensate tank. The hot water tank has an inlet and a first outlet, while the steam condensate tank has an outlet and a first inlet. A steam condensate delivery pipe is provided between the outlet of the steam condensate tank and the inlet of the hot water tank to deliver the steam condensate to the hot water tank for heating. A hot water overflow return pipe is provided between the first outlet of the hot water tank and the first inlet of the steam condensate tank to partially deliver the hot water from the hot water tank to the steam condensate tank to reduce the temperature of the steam condensate. This effectively utilizes the heat of the steam condensate, eliminating the need for additional pipes to introduce low-pressure steam, reducing steam consumption, saving production costs, and allowing the overflowing hot water to return to the steam condensate tank, further reducing the steam condensate temperature and achieving a cycle of secondary utilization of the steam condensate waste heat.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, and specifically to a waste heat recovery system for catalyst drying. Background Technology

[0002] Currently, the method for obtaining hot water in the catalyst drying process is as follows: a certain amount of cold water is stored in a hot water tank, a steam coil is placed in the hot water tank, low-pressure steam enters the coil through a switching valve, and a temperature transmitter controls the opening and closing of the switching valve to maintain it within a suitable temperature range. The polyolefin catalyst production process generates a large amount of steam condensate, which is generally used for circulating water makeup. This steam condensate carries a significant amount of heat, and large-scale makeup water use can cause a sharp rise in circulating water temperature, leading to production fluctuations and increasing circulating water evaporation. If this heat were used to supply hot water for the catalyst drying step, it would reduce steam consumption and lower the condensate temperature, reducing heat loss. The cooled condensate, when used for circulating water makeup, can also reduce water temperature fluctuations, decrease circulating water evaporation, and conserve water resources. Utility Model Content

[0003] One of the main technical problems that this invention addresses is that existing catalyst drying devices cannot effectively utilize the heat in steam condensate.

[0004] To achieve the above objectives, this utility model provides a waste heat recovery system for catalyst drying, including a steam condensate tank and a hot water tank disposed downstream of the steam condensate tank. The hot water tank has an inlet and a first outlet, and the steam condensate tank has an outlet and a first inlet.

[0005] A steam condensate delivery pipe is provided between the outlet of the steam condensate tank and the inlet of the hot water tank to deliver steam condensate to the hot water tank for heating hot water; a hot water overflow return pipe is provided between the first outlet of the hot water tank and the first inlet of the steam condensate tank to partially deliver the hot water in the hot water tank to the steam condensate tank to reduce the temperature of the steam condensate.

[0006] In some embodiments, the system further includes a hot water return pipe and a drying vessel disposed on the hot water return pipe, the hot water return pipe being used to partially transport the hot water from the hot water tank to the drying vessel and back to the hot water tank.

[0007] In some embodiments, the hot water tank has a second outlet, one end of the hot water return pipe is connected to the second outlet, and the other end is connected to the inlet.

[0008] In some embodiments, at the water inlet, the steam condensate delivery pipe is connected to the hot water return pipe, and a valve body is provided at the interface between the steam condensate delivery pipe and the hot water return pipe.

[0009] In some embodiments, a pump body is provided on the hot water return pipe to pump the hot water into the desiccant.

[0010] In some embodiments, the system further includes a condensate return pipe for the self-circulating transport of condensate from the condensate tank.

[0011] In some embodiments, the steam condensate tank has a second inlet, one end of the steam condensate return pipe is connected to the steam condensate delivery pipe, and the other end is connected to the second inlet.

[0012] In some embodiments, a pump body is provided on the steam condensate delivery pipeline to pump the steam condensate into the hot water tank.

[0013] In some embodiments, the temperature inside the hot water tank is set to 43–47°C.

[0014] In some embodiments, the temperature inside the steam condensate tank is set to 55–65°C.

[0015] The above technical solution involves two pipelines between the hot water tank and the steam condensate tank: a steam condensate delivery pipeline connects the outlet of the steam condensate tank to the inlet of the hot water tank, used to transport the steam condensate to the hot water tank for heating; a hot water overflow return pipeline connects the first outlet of the hot water tank to the first inlet of the steam condensate tank, used to partially return the hot water in the hot water tank to the steam condensate tank to lower the temperature of the steam condensate. This effectively utilizes the heat of the steam condensate, eliminating the need for additional pipelines to introduce low-pressure steam, reducing steam consumption, saving production costs, and preventing excessive evaporation caused by overheating of the steam condensate, thus reducing heat loss and water waste, achieving a cycle of secondary utilization of the waste heat from the steam condensate. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the waste heat recovery system for catalyst drying according to this utility model.

[0017] Explanation of reference numerals in the attached figures

[0018] 1. Hot water tank; 101. Inlet; 102. First outlet; 103. Second outlet; 2. Steam condensate tank; 201. Outlet; 202. First inlet; 203. Second inlet; 3. Steam condensate delivery pipe; 4. Hot water return pipe; 5. Hot water overflow return pipe; 6. Steam condensate return pipe; 7. Pump body; 8. Valve body. Detailed Implementation

[0019] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0020] To address the problem that existing catalyst drying devices cannot effectively utilize the heat in steam condensate, this invention provides a waste heat recovery system for catalyst drying, comprising a steam condensate tank 2 and a hot water tank 1 located downstream of the steam condensate tank 2. The hot water tank 1 has an inlet 101 and a first outlet 102, and the steam condensate tank 2 has an outlet 201 and a first inlet 202.

[0021] A steam condensate delivery pipe 3 is provided between the outlet 201 of the steam condensate tank 2 and the inlet 101 of the hot water tank 1 to deliver steam condensate to the hot water tank 1 for heating hot water; a hot water overflow return pipe 5 is provided between the first outlet 102 of the hot water tank 1 and the first inlet 202 of the steam condensate tank 2 to partially deliver the hot water in the hot water tank 1 to the steam condensate tank 2 to reduce the temperature of the steam condensate.

[0022] like Figure 1 As shown, the principle of the waste heat recovery system for catalyst drying is as follows: Two pipes are set between the hot water tank 1 and the steam condensate tank 2: a steam condensate conveying pipe 3 is set between the outlet 201 of the steam condensate tank 2 and the inlet 101 of the hot water tank 1, which is used to convey the steam condensate to the hot water tank 1 to heat the hot water; a hot water overflow return pipe 5 is set between the first outlet 102 of the hot water tank 1 and the first inlet 202 of the steam condensate tank 2, which is used to partially transport the hot water in the hot water tank 1 back to the steam condensate tank 2 to reduce the temperature of the steam condensate.

[0023] This method effectively utilizes the heat from steam condensate, eliminating the need for additional pipelines to supply low-pressure steam, reducing steam consumption, saving production costs, and ensuring a stable supply of hot water for the catalyst drying process. Furthermore, the overflowing hot water returns to the steam condensate tank 2, lowering the steam condensate temperature and preventing excessive evaporation caused by overheating, thus reducing heat loss and water waste. This achieves a cycle of secondary utilization of steam condensate waste heat. Compared to conventional methods, this solution requires less investment and eliminates the need for a remote control system, making it particularly suitable for hot water supply during the drying process of polyolefin catalysts.

[0024] Actual testing has shown that the waste heat recovery system for catalyst drying of this invention can stably control the temperature inside the hot water tank 1 within the range of 43-47℃, reducing the steam condensate temperature from 80℃ to 60℃, thus reducing heat loss and water waste. Compared to existing technologies that use coils to heat the hot water tank 1 with steam, this waste heat recovery system completely eliminates the need for steam input, saving all steam, simplifying the structure, and reducing production costs. Specifically, it can save approximately 105 tons of steam per year.

[0025] It should be noted that the number of hot water tank 1 and steam condensate tank 2 in the above system can be set to at least one. When there are multiple hot water tanks 1 and multiple steam condensate tanks 2, the multiple hot water tanks 1 are connected in parallel, the multiple steam condensate tanks 2 are connected in parallel, and each hot water tank 1 is selectively connected to a steam condensate tank 2; when there are multiple hot water tanks 1 and only one steam condensate tank 2, the multiple hot water tanks 1 are connected in parallel and connected to a steam condensate tank 2; when there is only one hot water tank 1 and multiple steam condensate tanks 2, the multiple steam condensate tanks 2 are connected in parallel, and each hot water tank 1 is connected to one of the multiple steam condensate tanks 2.

[0026] In some embodiments, the system further includes a hot water return pipe 4 and a drying vessel disposed on the hot water return pipe 4, the hot water return pipe 4 being used to partially transport the hot water from the hot water tank 1 to the drying vessel and back to the hot water tank 1.

[0027] like Figure 1 As shown, the catalyst drying process needs to be carried out in a drying vessel (not shown in the figure). Therefore, the hot water supply to the drying vessel is achieved by setting up a pipe between the hot water tank 1 and the drying vessel. In order to maximize the utilization rate of hot water, the aforementioned pipe is further extended to connect with the hot water tank 1, thus forming the hot water return pipe 4.

[0028] In some embodiments, the hot water tank 1 has a second outlet 103, one end of the hot water return pipe 4 is connected to the second outlet 103, and the other end is connected to the inlet 101.

[0029] like Figure 1 As shown, the hot water return pipe 4 can be divided into a first section and a second section. The first section is located between the second outlet 103 and the dewatering vessel, and the second section is located between the dewatering vessel and the inlet 101.

[0030] In some embodiments, at the inlet 101, the steam condensate delivery pipe 3 is connected to the hot water return pipe 4, and a valve body 8 is provided at the interface between the steam condensate delivery pipe 3 and the hot water return pipe 4.

[0031] like Figure 1As shown, the condensate can first flow into the hot water return pipe 4 that returns to the hot water tank 1, and then enter the hot water tank 1 together with the hot water therein. This allows the condensate and the returning hot water to be regulated to the same or similar temperature before entering the hot water tank 1, improving the heating efficiency of the hot water in the hot water tank 1. The valve body 8 can be a three-way valve. The valve body 8 can also be replaced by a thermostatic mixer.

[0032] In some embodiments, a pump body 7 is provided on the hot water return pipe 4 to pump the hot water to the desiccant.

[0033] like Figure 1 As shown, the pump body 7 can be positioned close to the second outlet 103 to more accurately control the flow rate of hot water output from the second outlet 103. Specifically, the pump body 7 is installed on a section of pipe between the hot water return pipe 4 and the dewatering vessel (not shown in the figure) above it.

[0034] In some embodiments, the system also includes a steam condensate return pipe 6 for the self-circulation transport of steam condensate from the steam condensate tank 2.

[0035] like Figure 1 As shown, part of the steam condensate is used to heat the hot water in the hot water tank 1, and part is immediately circulated back to the steam condensate tank 2 for recycling. This serves two purposes: firstly, it regulates the flow rate of condensate in the steam condensate delivery pipe 3; secondly, it cools the high-temperature steam condensate in the steam condensate tank 2 in a timely manner, preventing excessive evaporation caused by overheating of the steam condensate, thereby reducing heat loss and water waste.

[0036] In some embodiments, the steam condensate tank 2 has a second inlet 203, one end of the steam condensate return pipe 6 is connected to the steam condensate delivery pipe 3, and the other end is connected to the second inlet 203.

[0037] like Figure 1 As shown, when steam condensate is output from outlet 201, steam condensate delivery pipe 3 and steam condensate return pipe 6 simultaneously perform steam condensate delivery. A valve body 8 is installed on the steam condensate return pipe 6 to regulate the flow rate of the returning steam condensate; the valve body 8 is preferably a ball valve.

[0038] In some embodiments, a pump body 7 is provided on the steam condensate delivery pipe 3 to pump the steam condensate into the hot water tank 1.

[0039] like Figure 1 As shown, the pump body 7 can be set close to the outlet 201, preferably on a section of the pipeline before the connection between the steam condensate conveying pipeline 3 and the steam condensate return pipeline 6, so as to more accurately control the steam condensate flow rate output from the outlet 201.

[0040] In some embodiments, the temperature inside the hot water tank 1 is set to 43–47°C.

[0041] like Figure 1 As shown, the hot water tank originally stores a certain amount of cold water, and the original temperature of the steam condensate is about 80℃. By setting a steam condensate delivery pipe 3 between the outlet 201 of the steam condensate tank 2 and the inlet 101 of the hot water tank 1, the steam condensate can be delivered to the hot water tank 1 to heat the hot water. The temperature in the hot water tank 1 is finally controlled at 43-47℃.

[0042] In some implementations, the temperature inside the steam condensate tank 2 is set to 55–65°C.

[0043] like Figure 1 As shown, the original temperature of the steam condensate is around 80℃, and the temperature range of the hot water used for catalyst drying in hot water tank 1 is 45±5℃. By setting a hot water overflow return pipe 5 between the first outlet 102 of hot water tank 1 and the first inlet 202 of steam condensate tank 2, some of the hot water in hot water tank 1 can be transported back to steam condensate tank 2 to reduce the temperature of the steam condensate. The temperature in steam condensate tank 2 is finally controlled at 55~65℃.

[0044] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A waste heat recovery system for catalyst drying, characterized in that, It includes a steam condensate tank (2) and a hot water tank (1) located downstream of the steam condensate tank (2), the hot water tank (1) having an inlet (101) and a first outlet (102), and the steam condensate tank (2) having an outlet (201) and a first inlet (202). A steam condensate delivery pipe (3) is provided between the outlet (201) of the steam condensate tank (2) and the inlet (101) of the hot water tank (1) to deliver steam condensate to the hot water tank (1) for heating hot water; a hot water overflow return pipe (5) is provided between the first outlet (102) of the hot water tank (1) and the first inlet (202) of the steam condensate tank (2) to partially deliver the hot water in the hot water tank (1) to the steam condensate tank (2) to reduce the temperature of the steam condensate.

2. The waste heat recovery system for catalyst drying according to claim 1, wherein, The system also includes a hot water return pipe (4) and a desiccant installed on the hot water return pipe (4). The hot water return pipe (4) is used to partially transport the hot water from the hot water tank (1) to the desiccant and back to the hot water tank (1).

3. The waste heat recovery system for catalyst drying according to claim 2, wherein, The hot water tank (1) has a second outlet (103), one end of the hot water return pipe (4) is connected to the second outlet (103), and the other end is connected to the inlet (101).

4. The waste heat recovery system for catalyst drying according to claim 2, wherein, At the inlet (101), the steam condensate delivery pipe (3) is connected to the hot water return pipe (4), and a valve body (8) is provided at the interface between the steam condensate delivery pipe (3) and the hot water return pipe (4).

5. The waste heat recovery system for catalyst drying according to claim 2, wherein, A pump body (7) is installed on the hot water return pipe (4) to pump the hot water into the desiccant.

6. The waste heat recovery system for catalyst drying according to claim 1, wherein, The system also includes a steam condensate return pipe (6) for the self-circulating transport of steam condensate from the steam condensate tank (2).

7. The waste heat recovery system for catalyst drying according to claim 6, wherein, The steam condensate tank (2) has a second inlet (203), one end of the steam condensate return pipe (6) is connected to the steam condensate delivery pipe (3), and the other end is connected to the second inlet (203).

8. The waste heat recovery system for catalyst drying according to claim 1, wherein, The steam condensate delivery pipeline (3) is equipped with a pump body (7) to pump the steam condensate into the hot water tank (1).

9. The waste heat recovery system for catalyst drying according to claim 1, wherein, The temperature inside the hot water tank (1) is set to 43~47℃.

10. The waste heat recovery system for catalyst drying according to claim 1, wherein, The temperature inside the steam condensate tank (2) is set to 55~65℃.

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