Steam direct compression heating dealdehyding system
Through the direct steam compression heating technology, the reuse of pressurized secondary steam by using a steam compressor has solved the problem of the dealdehyde process consumed a lot of steam and cooling water in pentaerythritol production, and achieved cost reduction and product quality improvement.
Patent Information
- Application Number
- CN202421601769.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-08
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-07-08
AI Technical Summary
The dealdehyde removal process consumes a lot of steam and cooling water during the existing pentaerythritol production process, resulting in high treatment costs.
The direct steam compression heating technology is used, and the secondary steam is pressurized and heated by a steam compressor and reused, and used as heating steam to reduce the demand for fresh steam and cooling water.
It reduces steam and cooling water consumption, reduces processing costs, and improves product quality and system operation efficiency.
Smart Images
Figure CN223170335U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of aldehyde removal systems, in particular to a steam direct compression heating aldehyde removal system. Background Art
[0002] At present, the production of pentaerythritol mainly relies on the petrochemical industry, and is synthesized through raw materials such as ethylene and propylene produced by petroleum cracking. With the development of the petrochemical industry, the production cost of pentaerythritol has gradually decreased, making its application in various fields widely promoted. In addition, with the improvement of environmental awareness, research on the production of pentaerythritol by biological methods has also made certain progress, and it is expected to achieve a more environmentally friendly production process. As a new type of polyol, pentaerythritol has unique chemical properties and structural characteristics, and can be used to synthesize a variety of new polymer materials, such as polyesters, polyurethanes, epoxy resins, etc. These new materials have broad application prospects in the fields of aviation, aerospace, construction, transportation, etc. Pentaerythritol has good biodegradability and can be used to produce environmentally friendly coatings, inks, adhesives and other products, which helps to reduce environmental pollution. It also has certain biological activities and can be used to prepare pharmaceutical intermediates, biological enzymes and other biomedical products, which has important research value. It can also be used to prepare biofuels, such as biodiesel, bioethanol, etc., which helps to alleviate the energy crisis and reduce greenhouse gas emissions. The preparation process of pentaerythritol involves multiple steps, including aldol condensation, hydrogenation reduction, etc. In the preparation process, a mixture of formaldehyde and water is used as one of the raw materials, and pentaerythritol is generated through chemical reactions. In the production process of pentaerythritol, the aldehyde removal process is also an important link. Aldehyde removal removes free aldehydes in the product to improve the purity and quality of the product. This step has a direct impact on the performance and safety of the final product.
[0003] At present, the aldehyde removal process uses external steam to enter the first-effect aldehyde removal reboiler, evaporates and concentrates the material in the aldehyde removal evaporator, and removes the formaldehyde in the material. The concentrated liquid is transported to the second-effect evaporation and concentration device. The first-effect aldehyde-containing secondary steam is discharged from the top of the aldehyde removal evaporator to the second-effect falling film evaporator and used as the second-effect heating steam to perform secondary concentration on the material. The second-effect secondary steam enters the final condenser and is discharged from the system after being cooled by circulating water. The steam consumption for evaporating one ton of water reaches 0.6t / h, the steam consumption is large, and a large amount of circulating cooling water needs to be consumed, resulting in a high treatment cost.
[0004] In view of the problems existing in the above-mentioned existing treatment process, the present invention draws on the currently popular mechanical steam recompression technology, uses a steam compressor to pressurize and heat up the secondary steam, and then sends it back to the first and second effects respectively for use as heating steam, greatly saving the consumption of fresh steam and cooling water, and greatly reducing the treatment cost. Summary of the Utility Model
[0005] The purpose of the present utility model is to solve the deficiencies existing in the prior art, and a steam direct compression heating aldehyde removal system is proposed.
[0006] To achieve the above purpose, the present utility model adopts the following technical solutions: A steam direct compression heating aldehyde removal system includes a first-effect aldehyde removal evaporator steam compressor, a first-effect aldehyde removal reboiler, a first-effect aldehyde removal evaporator, a first-effect tower bottom liquid external delivery pump, a second-effect falling film evaporator steam compressor, a second-effect falling film evaporator, and a second-effect falling film circulation pump. The first-effect aldehyde removal evaporator steam compressor is fixedly connected to the first-effect aldehyde removal reboiler, the first-effect aldehyde removal evaporator, and the first-effect tower bottom liquid external delivery pump. The second-effect falling film evaporator steam compressor is fixedly connected to the second-effect falling film evaporator and the second-effect falling film circulation pump. The first-effect tower bottom liquid external delivery pump is fixedly connected to the second-effect falling film evaporator.
[0007] As a further description of the above technical solution:
[0008] The steam compressor adopts an integral two-stage steam compressor form.
[0009] As a further description of the above technical solution:
[0010] The steam compressor consists of a first-stage compressor volute, a second-stage compressor volute, a vapor-liquid separation tank, a steam connection pipe, an oil cooler, a base, and a motor.
[0011] As a further description of the above technical solution:
[0012] The steam connection pipe is fixedly connected to the vapor-liquid separation tank.
[0013] As a further description of the above technical solution:
[0014] One set of the steam connection pipes is provided at each end of the vapor-liquid separation tank.
[0015] As a further description of the above technical solution:
[0016] The steam connection pipe is provided with a first-stage steam outlet, and the other set of the steam connection pipes is provided with a second-stage steam inlet.
[0017] As a further description of the above technical solution:
[0018] The reboiler adopts a vertical tube-sheet form.
[0019] As a further description of the above technical solution:
[0020] The reboiler consists of an upper head, a tube sheet, a preheating steam inlet, a heating steam inlet, a support, a tie rod, a heat exchange tube, a baffle, a condensate outlet, a lower head, a circulation inlet, a circulation outlet, and an exhaust port.
[0021] The utility model has the following beneficial effects:
[0022] The utility model utilizes a high-efficiency steam compressor to compress and recycle the secondary steam generated by evaporation, increasing the enthalpy of the secondary steam. The secondary steam with increased thermal energy is sent into the evaporation chamber for heating, so as to recycle the existing thermal energy of the secondary steam, thereby eliminating the need for additional supplementary live steam. Relying on the internal steam balance of the system, continuous evaporation can be achieved. By means of configuration control, the motor speed of the steam compressor is controlled, and then the system temperature and pressure are controlled to maintain the evaporation balance of the system, enabling the steam compressor to operate under optimal conditions and maximizing economic benefits.
[0023] The steam direct compression heating technology is currently the most advanced evaporator technology in the world. It only requires a very small amount of live steam (a small amount of live steam is required at startup, and almost no live steam is needed during normal operation), greatly reducing the operating costs of enterprises and environmental pollution. Since the compressor is used to provide heat source, the temperature difference is much smaller compared with traditional evaporators, enabling gentle evaporation, greatly improving product quality and reducing scaling. There is no need for a condenser or only a very small area of condenser is required. The structure and process are very simple, with full-automatic operation, continuous operation, safety and reliability, and the whole set of equipment is easy to operate without dead corners. Description of the Drawings
[0024] Figure 1 It is a flow chart of a steam direct compression heating aldehyde removal system proposed by the utility model;
[0025] Figure 2 It is a schematic diagram of the steam compressor of a steam direct compression heating aldehyde removal system proposed by the utility model Figure 1 ;
[0026] Figure 3 It is a schematic diagram of the steam compressor of a steam direct compression heating aldehyde removal system proposed by the utility model Figure 2 ;
[0027] Figure 4 It is a schematic diagram of the steam compressor of a steam direct compression heating aldehyde removal system proposed by the utility model Figure 3 ;
[0028] Figure 5 It is a schematic diagram of the reboiler of a steam direct compression heating aldehyde removal system proposed by the utility model. Detailed Embodiment
[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0030] Referring to Figures 1 - 5 , an embodiment provided by the present invention: A steam direct compression heating aldehyde removal system includes a first-effect aldehyde removal evaporator steam compressor, a first-effect aldehyde removal reboiler, a first-effect aldehyde removal evaporator, a first-effect tower bottom liquid external delivery pump, a second-effect falling film evaporator steam compressor, a second-effect falling film evaporator, and a second-effect falling film circulation pump. The first-effect aldehyde removal evaporator steam compressor is fixedly connected to the first-effect aldehyde removal reboiler, the first-effect aldehyde removal evaporator, and the first-effect tower bottom liquid external delivery pump. The second-effect falling film evaporator steam compressor is fixedly connected to the second-effect falling film evaporator and the second-effect falling film circulation pump. The first-effect tower bottom liquid external delivery pump is fixedly connected to the second-effect falling film evaporator. The aldehyde removal tower of the aldehyde removal evaporator adopts a plate / packed tower design to maximize the aldehyde removal effect and efficiency. The secondary steam at the top of the first-effect aldehyde removal evaporator is pressurized and heated by the first-effect aldehyde removal evaporator steam compressor and used as heating steam. The first-effect aldehyde removal reboiler is provided with a fresh steam supplement port as a standby steam supplement port to compensate for the insufficient secondary steam and insufficient evaporation caused by heat loss. The second-effect falling film evaporator adopts an integrated vertical tube falling film evaporator structure, with a tubular falling film evaporator at the upper part and a vapor-liquid separation chamber at the bottom. The second-effect falling film evaporator adopts an integrated vertical tube falling film evaporator structure, with a tubular falling film evaporator at the upper part and a vapor-liquid separation chamber at the bottom. The secondary steam of the second-effect falling film evaporator is pressurized and heated by the second-effect falling film evaporator steam compressor and used as heating steam. The second-effect evaporator is provided with a fresh steam supplement port as a standby steam supplement port to compensate for the insufficient secondary steam and insufficient evaporation caused by heat loss.
[0031] Among them, the steam compressor adopts an integrated two-stage steam compressor form. The steam compressor consists of a first-stage compressor volute, a second-stage compressor volute, a vapor-liquid separation tank, a steam connection pipe, an oil cooler, a base, and a motor. The steam compressor adopts an integrated two-stage steam compressor, which minimizes the floor area to the greatest extent. A vapor-liquid separator is installed at the connection ports of the first and second stages of the steam compressor. The vapor-liquid separator is equipped with a demister. The steam connection pipe is fixedly connected to the vapor-liquid separation tank. A set of steam connection pipes is provided at each end of the vapor-liquid separation tank. The steam connection pipe is provided with a first-stage steam outlet, and the other set of steam connection pipes is provided with a second-stage steam inlet. The reboiler adopts a vertical shell-and-tube form. The reboiler consists of an upper head, a tube sheet, a preheating steam inlet, a heating steam inlet, a support, a tie rod, a heat exchange tube, a baffle, a condensate outlet, a lower head, a circulation inlet, a circulation outlet, and an exhaust port. The first-effect formaldehyde-removing reboiler adopts a single-pass shell-and-tube heat exchanger, which has the advantages of anti-blocking and anti-coking, and is extremely suitable for the evaporation treatment of formaldehyde wastewater.
[0032] Working principle: The raw material is transported to the top feed pipe of the first-effect formaldehyde-removing evaporator. The upper part of the formaldehyde-removing evaporator adopts a plate tower / packed tower structure. The feed flows downward by gravity from the top of the tower, which is beneficial to the removal of formaldehyde from the material. The bottom of the formaldehyde-removing evaporator is a vapor-liquid separation chamber, which is connected to the first-effect formaldehyde-removing reboiler. The material in the tube side of the first-effect formaldehyde-removing tower reboiler exchanges heat with the heating steam in the shell side. The material in the separation chamber evaporates to generate secondary steam, which contacts the downward spraying liquid of the formaldehyde-removing tower from bottom to top, and separates the raw material formaldehyde therefrom. The separated material at the top of the tower is separated from the formaldehyde-removing evaporator and enters the steam compressor of the first-effect formaldehyde-removing evaporator. After being pressurized and heated, it is transported to the first-effect formaldehyde-removing reboiler for use as heating steam. The condensed water after heat exchange is sent out. The upper part of the second-effect falling-film evaporator adopts a falling-film shell-and-tube evaporator, and the bottom is a separation chamber. The concentrated liquid of the first-effect formaldehyde-removing evaporator is transported to the separation chamber of the second-effect falling-film evaporator through the bottom liquid external delivery pump of the first-effect tower, and is transported to the top of the second-effect falling-film evaporator through the second-effect falling-film circulation pump, forming a thin film from top to bottom, and exchanging heat with the heating steam in the shell side. The material in the tube side evaporates to generate secondary steam and enters the bottom separation chamber. After vapor-liquid separation, the secondary steam enters the steam compressor of the falling-film evaporator. After being pressurized and heated, it is transported to the shell side of the falling-film evaporator for use as heating steam. The distilled water after heat exchange and condensation is discharged out of the system.
[0033] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A steam direct compression heating aldehyde removal system, comprising a first-effect aldehyde removal evaporator steam compressor, a first-effect aldehyde removal reboiler, a first-effect aldehyde removal evaporator, a first-effect tower bottom liquid external delivery pump, a second-effect falling film evaporator steam compressor, a second-effect falling film evaporator, and a second-effect falling film circulation pump, characterized in that, The steam compressor of the first-effect aldehyde removal evaporator is fixedly connected to the first-effect aldehyde removal reboiler, the first-effect aldehyde removal evaporator, and the first-effect bottom liquid delivery pump. The steam compressor of the second-effect falling film evaporator is fixedly connected to the second-effect falling film evaporator and the second-effect falling film circulation pump. The first-effect bottom liquid delivery pump is fixedly connected to the second-effect falling film evaporator.
2. The steam direct compression heating aldehyde removal system according to claim 1, wherein: The steam compressor adopts an integral two-stage steam compressor form.
3. The steam direct compression heating aldehyde removal system according to claim 2, wherein: The steam compressor is composed of a first-stage compressor volute, a second-stage compressor volute, a vapor-liquid separation tank, a steam connection pipe, an oil cooler, a base, and a motor.
4. A steam direct compression heating aldehyde removal system according to claim 3, characterized in that: The steam connection pipe is fixedly connected to the vapor-liquid separation tank.
5. A steam direct compression heating aldehyde removal system according to claim 4, characterized in that: A set of the steam connection pipes is provided at each end of the vapor-liquid separation tank.
6. The direct steam compression heating aldehyde removal system according to claim 5, wherein: The steam connection pipe is provided with a first-stage steam outlet, and the other set of the steam connection pipes is provided with a second-stage steam inlet.
7. A steam direct compression heating and aldehyde removal system according to claim 1, characterized in that: The reboiler adopts a vertical tube-sheet form.
8. A steam direct compression heating aldehyde removal system according to claim 1, characterized in that: The reboiler is composed of an upper head, a tube sheet, a preheating steam inlet, a heating steam inlet, a support, a tie rod, heat exchange tubes, baffle plates, a condensate outlet, a lower head, a circulation inlet, a circulation outlet, and an exhaust port.