Single-tube-pass strip falling devolatilization device suitable for heat transfer of high-viscosity polymer
By using a single-pass design with a heat transfer oil return chamber in the center of the annular heat exchanger tube bundle, the problem of low heat transfer efficiency of high-viscosity polymers is solved, achieving efficient heat transfer and simplifying the structure, thus reducing equipment costs.
Patent Information
- Application Number
- CN202422715736.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-08
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2034-11-08
AI Technical Summary
Existing technologies are unable to efficiently transfer heat to high-viscosity polymers, making it difficult to remove light phase substances, which affects product quality. Furthermore, traditional strip devolatilizers are complex in structure and expensive.
The single-pass strip devolatilizer achieves single-pass flow of heat transfer oil by setting a heat transfer oil return chamber in the center of the annular heat exchange tube bundle, which simplifies the structure and increases the heat exchange area.
It improves heat transfer efficiency, reduces the residence time of polymers in the devolatilizer, reduces the risk of coking and blockage, and lowers equipment costs.
Smart Images
Figure CN223746993U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the field of heat transfer and chemical industry separation, concretely relates to a single tube pass drop bar devolatilizer suitable for high viscosity polymer heat transfer for the heating devolatilization process of PEO and other high viscosity polymers. BACKGROUND
[0002] The current polymer production process generally includes multiple steps such as reaction, polymerization and devolatilization. The devolatilization process refers to the process of removing unreacted low-boiling organic small molecules by flash evaporation under high temperature environment by taking advantage of the boiling point difference between low-boiling organic small molecules and polymers. In this process, as the content of organic small molecules in the system gradually decreases, the viscosity of the polymers in the molten state will gradually increase, and accordingly, the flowability of the polymers deteriorates, and the heat transfer performance decreases sharply. Therefore, relying solely on the traditional tube heat exchanger, the laminar flow heat transfer process in the tube is difficult to transfer heat to the organic small molecule substances wrapped in the polymers in the tube, which will make it difficult to remove light phase substances from the polymer product, affecting the quality of the final product.
[0003] However, the forced disturbance of high-viscosity fluid heat transfer by stirring devices such as scrapers can increase the heat transfer efficiency to some extent, but the high-viscosity polymers will have a wall sticking phenomenon. Once the local high temperature overheating lasts for a long time, the polymers will produce thermal plasticity, and even carbonization. At the same time, forced stirring by rotary machines also has the disadvantages of small heat transfer area, high manufacturing and maintenance cost, and small processing capacity.
[0004] The drop bar devolatilizer is a high-efficiency heat exchange equipment suitable for high-viscosity liquid heat transfer using heat transfer oil as the heating medium. In the equipment, the heat pipe of the drop bar heating core adopts a double tube pass design: the tube bundle is divided into two passes, the inner circle and the outer circle, and the inner circle heat exchange tube and the outer circle heat exchange tube are respectively connected with two heat transfer oil inlet and outlet cavities. The space enclosed by the inner circle heat exchange tube is used as a high polymer inlet channel. This design has two disadvantages: first, the space enclosed by the inner circle is too large, causing the polymer to stay in the inner circle space for too long and easily accumulate; second, the heat exchange tube is designed in double passes, and a partition is needed in the tube chamber, making the equipment structure complex. For example, patent CN116753750B discloses a devolatilization preheating device and method suitable for high-viscosity polymers. Based on the traditional drop bar devolatilizer, the patent changes the upper tube chamber partition structure and tube opening position, and sets a tapered distributor with a narrow top and a wide bottom in the polymer containing space. The polymer enters from the center and exchanges heat with the heat exchange tube by the thrust provided by the distributor. The setting of the distributor reduces the volume of the inner cavity, but the patent still continues the design idea of the double tube pass drop bar heat exchange tube, and the structure is still relatively complex.
[0005] Therefore, it is crucial to develop a new structure of drop bar devolatilizer with simple structure and efficient mass transfer for polymer production. The utility model discloses a novel falling strip devolatilizer
[0006] The utility model discloses a novel falling strip devolatilizer, which has the characteristics of high mass transfer efficiency, simple structure, low maintenance cost and the like.
[0007] The utility model discloses a technical scheme that is as follows:
[0008] A single-tube-path novel falling strip devolatilizer suitable for high-viscosity polymer heat transfer, comprising a separation chamber and a falling strip heating chamber in the central cavity of the separation chamber.
[0009] The falling strip heating chamber comprises a heat transfer element, an upper tube plate, a lower tube plate, an upper tube compartment, a lower tube compartment and a heat-conducting oil return chamber.
[0010] The annular space between the fin group ring inner side and the heat-conducting oil return chamber is a polymer containing cavity.
[0011] The upper tube compartment is fixed above the upper tube plate, and the lower tube compartment is fixed below the lower tube plate.
[0012] The heat-conducting oil return chamber is located at the central position of the polymer containing cavity and comprises a shell tube and an upper head.
[0013] Further, a first annular partition plate is arranged on the upper head of the return chamber, and the first annular partition plate is sealingly connected with the upper head of the return chamber and the end cover of the upper tube compartment of the heating chamber.
[0014] The separation chamber comprises a separation chamber shell, a light component gas phase outlet and a polymer outlet.
[0015] Further, the separation chamber shell is connected with the upper tube plate of the heating chamber by bolts and needs a jacket for heat preservation.
[0016] Compared with the prior art, the utility model has the advantages that:
[0017] The utility model provides a single pipe course falling strip devolatilizer suitable for high viscosity polymer heat transfer, unlike traditional double pipe course falling strip devolatilizer, the devolatilizer adds the heat conducting oil backflow chamber in the central cavity of annular falling strip heat exchange pipe bundle, realizes that the heat conducting oil enters from the upper pipe chamber of devolatilizer, flows through annular falling strip heat exchange pipe bundle once, then enters pipe bundle head (i.
[0018] The utility model discloses a single pipe course falling strip devolatilizer suitable for high viscosity polymer heat transfer, which has the advantages that:
[0019] The utility model discloses the setting of the backflow chamber in the central space surrounded by falling strip heat exchange pipe, which reduces the space of polymer containing cavity of devolatilizer, makes the residence time of polymer in devolatilizer shorter, and is not easy to coking and blockage. BRIEF DESCRIPTION OF DRAWINGS
[0020] Fig. 1 It is whole structure schematic diagram of the utility model discloses a single pipe course falling strip devolatilizer suitable for high viscosity polymer heat transfer.
[0021] Fig. 2 It is cross section structure schematic diagram of single layer fin of annular falling strip heat exchange pipe bundle 21 in separation chamber.
[0022] Fig. 3 It is structure schematic diagram of annular falling strip heat exchange pipe bundle 21 along the axial direction of heat exchange pipe in the utility model.
[0023] In the drawing, 1 is a separation chamber, 2 is a falling strip heating chamber; 21 is an annular falling strip heat exchange pipe bundle, 22 is an upper tube plate, 23 is a lower tube plate, 24 is an upper pipe chamber end cover, 25 is a lower pipe chamber head, 26 is a backflow chamber, 211 is a heat exchange pipe, 212 is a fin, 213 is a gas-liquid separation chamber, 214 is a polymer containing cavity, 215 is a heat transfer chamber, 261 is a shell pipe, 262 is an upper head, 231 is a through hole, 221 is a gap, 27 is a first annular partition plate, 28 is a second annular partition plate, 29 is a third annular partition plate, N1 is a heat conducting oil inlet, N2 is a heat conducting oil outlet, N3 is a material inlet, and N4 is a material outlet. DETAILED DESCRIPTION
[0024] The utility model is further explained below in combination with the embodiments and the drawings, but is not limited to the scope of the application.
[0025] The utility model relates to a single pipe course drop bar devolatilizer suitable for high viscosity polymer heat transfer (referring to Figs. 1-3 ), including separation chamber 1 and drop bar heating chamber 2 in the central cavity of separation chamber,
[0026] Drop bar heating chamber 2 includes annular drop bar heat exchange tube bundle 21, upper tube plate 22, lower tube plate 23, upper tube compartment end cover 24, lower tube compartment head 25 and heat conducting oil backflow chamber 26,
[0027] The third annular baffle 29, with the second annular baffle 28, and the upper tube compartment end cover form an upper tube compartment space, and are communicated with the upper opening of the annular drop bar heat exchange tube bundle 2,
[0028] The first annular baffle 27 and the third annular baffle 29 are arranged above the upper tube compartment end plate 24, and the inlet N3 of the polymer is arranged above the upper tube compartment end plate 24.
[0029] The annular drop bar heat exchange tube bundle 21 includes 4-10 layers of equal number of heat exchange tubes 211 distributed in a ring shape, and a plurality of groups of fins 212 arranged in an alternating manner along the axial direction of the heat exchange tubes 211. Each fin only penetrates through two adjacent columns of heat exchange tubes 211, forms a circular ring, and is arranged in an alternating manner from bottom to top in the axial direction of the heat exchange tubes, that is, a plurality of holes for the heat exchange tubes to pass through are arranged on each fin along the radial direction, the number of each column of heat exchange tubes is 4-10, and one fin can simultaneously penetrate through all the heat exchange tubes in the same column. The annular drop bar heat exchange tube bundle divides the internal space of the separation chamber 1 into three parts: the gas-liquid separation chamber 213 outside the fin group ring, the polymer containing cavity 214 inside the fin group ring, and a plurality of heat transfer chambers 215 formed between the overlapping fins.
[0030] The upper tube compartment end cover 24 is fixed above the upper tube plate 22 through the second annular baffle 28 and the third annular baffle 29, and the lower tube compartment head 25 is fixed below the lower tube plate 23.
[0031] The lower tube compartment head 25 and the lower tube plate 23 form a lower tube compartment space, which is communicated with the lower opening of the annular drop bar heat exchange tube bundle 2; the lower tube plate 23 is provided with a through hole 231 in the center, and the upper part of the through hole 231 is communicated with the heat conducting oil backflow chamber 26;
[0032] The heat conducting oil backflow chamber 26 is composed of an upper head 262 at the upper end and a shell pipe 261 welded to the lower part of the upper head. The upper head 262 is communicated with the heat conducting oil outlet N2; and the shell pipe 261 is welded to the through hole 231 of the lower tube plate 23.
[0033] The first annular baffle 27 is welded on the upper head 262; the diameter of the shell tube 261 is between the diameter of the first annular baffle 27 and the diameter of the second annular baffle 29. The shell tube and the upper tube plate 22 have a gap 221 for the entry of the polymer.
[0034] Further, the separation chamber 1 comprises a separation chamber shell, a light component gas phase outlet N5 and a polymer outlet N4.
[0035] Further, the separation chamber shell is connected to the upper tube plate 22 of the falling bar heating chamber 2 by bolts and needs a jacket for heat preservation.
[0036] The utility model is not applicable to the prior art.
Claims
1. A single tube pass falling strand devolatilizer suitable for high viscosity polymer heat transfer comprising a separation chamber and a falling strand heating chamber in the center of the separation chamber; characterized in that: The falling rod heating chamber comprises a circular falling rod heat exchange tube bundle and a heat conducting oil return chamber arranged in the central cavity of the circular falling rod heat exchange tube bundle, and the upper end of the heat conducting oil return chamber is provided with a heat conducting oil outlet, the upper end of the circular falling rod heat exchange tube bundle is connected with the heat conducting oil outlet, and the lower part of the circular falling rod heat exchange tube bundle is communicated with the heat conducting oil return chamber through a lower tube compartment; and an inlet of the polymer is arranged above the space between the circular falling rod heat exchange tube bundle and the heat conducting oil return chamber.
2. The single pass stripping column according to claim 1, wherein, The falling rod heating chamber further comprises an upper tube plate, a lower tube plate, an upper tube compartment end cover and a lower tube compartment head, the heat conducting oil return chamber is composed of an upper head and a shell tube, the lower end of the shell tube is fixedly sealed with the lower tube plate, the lower tube plate is provided with a through hole in the center, the shell tube is communicated with the lower tube compartment through the through hole, and the space surrounded by the shell tube, the lower tube compartment head and the upper head is a heat conducting oil return cavity.
3. The single pass stripping column according to claim 2, wherein The upper head is located in the space between the upper tube compartment and the upper tube plate.
4. The single pass stripping column according to claim 1, wherein, The circular falling rod heat exchange tube bundle comprises 4-10 layers of equal numbers of heat exchange tubes which are arranged in a ring shape and a plurality of groups of fins which are arranged in a staggered manner along the axial direction of the heat exchange tubes.
5. The single pass stripping column according to claim 4, wherein, The internal space of the separation chamber is divided into three parts by the circular falling rod heat exchange tube bundle, i.e., a gas-liquid separation chamber outside the fin group ring, a polymer containing cavity between the inner side of the fin group ring and the heat conducting oil return chamber, and a plurality of heat transfer chambers formed between the overlapping fins.