Comprehensive utilization system for waste heat in formaldehyde production

Abstract

The utility model relates to the technical field of formaldehyde production, in particular to a formaldehyde production waste heat comprehensive utilization system which comprises a formaldehyde production system and a waste heat recovery system, the formaldehyde production system is used for producing and manufacturing formaldehyde, and an oxidation furnace steam pocket and a tail gas boiler system are matched with the formaldehyde production system. The waste heat recovery system is connected with the formaldehyde production system and the formaldehyde matched downstream product production line and used for recovering waste heat of formaldehyde circulating liquid of the formaldehyde production system and fully utilizing the waste heat to the formaldehyde matched downstream product production line. The waste heat utilization rate of the formaldehyde production line is improved, direct discharge of steam is reduced, waste of steam resources is avoided, meanwhile, the industrial chain of the formaldehyde industry is prolonged, steam cost, logistics cost and the like are reduced for downstream formaldehyde products, and the market competitiveness of the formaldehyde and the downstream formaldehyde products is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of formaldehyde production, in particular to a comprehensive utilization system of waste heat from formaldehyde production. Background Art

[0002] A large amount of waste heat is generated during the production process of methanol to formaldehyde. The main locations where waste heat is generated are the oxidation furnace and the tail gas boiler, both of which generate steam; at the same time, the formaldehyde circulating fluid also generates a large amount of waste heat. The steam generated by the oxidation furnace is partially used to heat the materials in its own system, such as the methanol evaporator and the methanol superheater, and the excess steam is directly discharged into the atmosphere. A small number of companies use the steam generated by the tail gas boiler system for waste heat power generation, but most companies directly discharge it into the atmosphere, resulting in heat loss. Although the recovery and utilization of heat in the process of methanol to formaldehyde has been greatly developed, most of it is concentrated in the methanol to formaldehyde system itself and the field of waste heat power generation, and the recovered heat is limited.

[0003] At the same time, the country has put forward higher requirements for the transformation and upgrading of the industrial chain, and various industries are striving to find a better development path. The downstream products of the formaldehyde industry mainly include urotropine, phenolic resin, amino resin, urea-formaldehyde resin, polyformaldehyde, trimethylolpropane, etc. These products use steam for heating reaction, evaporation and crystallization during the production process. If you simply purchase steam from outside for production, the cost will remain high. In addition, these products require a large amount of formaldehyde to be purchased from outside during the production process, which also increases logistics and other transportation costs. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a comprehensive utilization system for waste heat from formaldehyde production, so as to solve the problems proposed in the above background technology that waste heat from steam in the formaldehyde production process is directly discharged, resulting in heat loss; waste heat from formaldehyde circulating liquid in the formaldehyde production system is insufficiently utilized, and the recovered heat is limited; downstream products in the formaldehyde industry need to purchase a large amount of formaldehyde during the production process, resulting in high logistics and transportation costs; and downstream products in the formaldehyde industry need to purchase a large amount of steam during the production process, resulting in high steam costs.

[0005] In order to achieve the above purpose, the utility model is realized through the following technical scheme: a system for comprehensive utilization of waste heat from formaldehyde production, comprising

[0006] Formaldehyde production system, a production line where methanol is converted into formaldehyde through an oxidation furnace, used for the production of formaldehyde;

[0007] The steam drum of the oxidation furnace is matched with the formaldehyde production system, which generates steam, part of which is used by the system itself and part of which is supplied to the downstream product production line of formaldehyde;

[0008] The tail gas boiler system is matched with the formaldehyde production system to treat the tail gas generated by the formaldehyde production line. The tail gas boiler system generates steam to supply the formaldehyde supporting downstream product production line;

[0009] Finished product formaldehyde storage tank, used to store finished product formaldehyde;

[0010] Finished product formaldehyde delivery pump, connected with the finished product formaldehyde storage tank, is used to deliver formaldehyde to the downstream product production line of formaldehyde;

[0011] The waste heat recovery system is connected to the formaldehyde production system and the formaldehyde supporting downstream product production line, and is used to recover the waste heat of the circulating liquid in the formaldehyde production system and transport it to the formaldehyde supporting downstream product production line;

[0012] The formaldehyde supporting downstream product production line is connected to the finished formaldehyde delivery pump and is used for the production of downstream products supporting the formaldehyde production line.

[0013] Furthermore, the waste heat recovery system includes a water storage tank, a waste heat recovery box, a rack, an insulated water tank and a base. The rack, water storage tank and insulated water tank are all fixed on the base. The rack is provided with a waste heat recovery box. The water storage tank is provided on the left side of the waste heat recovery box. The left end of the waste heat recovery box is connected to the circulating liquid inlet in the formaldehyde production system, the right end of the waste heat recovery box is connected to the circulating liquid outlet in the formaldehyde production system, and the insulated water tank is provided on the right side of the waste heat recovery box.

[0014] Furthermore, a first water inlet pipe is led out from the bottom of the water storage tank, the first water inlet pipe is connected to a circulating water pump, the circulating water pump is connected to a waste heat recovery tank through a second water inlet pipe, and the second water inlet pipe is equipped with a first valve.

[0015] Furthermore, the right end of the waste heat recovery tank is connected to the insulation water tank through a water outlet pipe, and a second valve is installed on the water outlet pipe.

[0016] Furthermore, the water outlet of the thermal insulation water tank is connected to a water pipe, the water pipe is connected to a water delivery pump, and the water delivery pump delivers hot water to a downstream formaldehyde supporting product production line through an external water pipe.

[0017] Furthermore, a heating chamber is arranged on the upper side of the waste heat recovery box, and a plurality of groups of heat conducting rods are evenly and vertically arranged inside the waste heat recovery box, and the upper ends of the heat conducting rods extend into the heating chamber.

[0018] Furthermore, a plurality of groups of circular heat exchange fins are evenly arranged on the heat conduction plate located at the lower part of the waste heat recovery box.

[0019] By adopting the above technical solution, the beneficial effects of the utility model are:

[0020] 1. The formaldehyde produced by the formaldehyde production system of the utility model is directly supplied to the downstream product production line, which saves the logistics costs and other expenses caused by the formaldehyde required by the downstream products and reduces the production cost; the steam generated by the oxidation furnace drum is supplied to the formaldehyde downstream product production line, which reduces the discharge of steam, improves the utilization rate of steam, and reduces the cost of steam required by the downstream products; the steam generated by the tail gas boiler system is supplied to the formaldehyde downstream product production line, which reduces the discharge of steam, improves the utilization rate of steam, and reduces the cost of steam required by the downstream products; the excess heat of the formaldehyde circulating fluid in the formaldehyde production line is recovered by the waste heat recovery system, and part of the generated hot water is used for daily life, and part is supplied to the downstream product production line.

[0021] 2. The utility model improves the waste heat utilization rate of the formaldehyde production line, reduces the direct discharge of steam, avoids the waste of steam resources, and at the same time extends the industrial chain of the formaldehyde industry, reduces the steam cost and logistics cost for formaldehyde downstream products, and improves the market competitiveness of formaldehyde and its downstream products. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0024] Figure 2 This is a schematic diagram of the structure of the evaporation tank in the utility model;

[0025] Figure 3 It is a cross-sectional view of the evaporation tank in the utility model.

[0026] In the figure: 1-formaldehyde production system, 2-oxidation furnace drum, 3-tail gas boiler system, 4-finished formaldehyde storage tank, 5-finished formaldehyde delivery pump, 6-formaldehyde supporting downstream product production line, 7-waste heat recovery system, 71-water storage tank, 711-first water inlet pipe, 712-circulating water pump, 713-first valve, 72-waste heat recovery box, 721-second water inlet pipe, 723-heating chamber, 724-heat conducting rod, 7241-heat exchange plate, 74-frame, 75-insulated water tank, 76-base, 77-water pipe, 78-delivery pump, 79-water outlet pipe, 791-second valve. DETAILED DESCRIPTION

[0027] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0028] See also Figure 1-Figure 3The utility model provides a technical solution: a formaldehyde production waste heat comprehensive utilization system, including a formaldehyde production system 1, an oxidation furnace drum 2, a tail gas boiler system 3, a finished formaldehyde storage tank 4, a finished formaldehyde delivery pump 5, a formaldehyde supporting downstream product production line 6 and a waste heat recovery system 7. The formaldehyde production system 1 is a production line in which methanol generates formaldehyde through an oxidation furnace, which is used to produce formaldehyde. The oxidation furnace drum 2 is matched with the formaldehyde production system 1. The formaldehyde production system 1 generates steam, part of which is used for its own system, and part of which is supplied to the formaldehyde supporting downstream product production line 6. The tail gas boiler system 3 is matched with the formaldehyde production system 1 to treat formaldehyde. The exhaust gas generated by the production line, the exhaust gas boiler system generates steam and supplies it to the formaldehyde supporting downstream product production line 6, the finished formaldehyde storage tank 4 is used to store the finished formaldehyde after production, the finished formaldehyde delivery pump 5 is connected to the finished formaldehyde storage tank 4, and is used to deliver the formaldehyde to the formaldehyde supporting downstream product production line 6, the waste heat recovery system 7 is connected to the formaldehyde production system 1 and the formaldehyde supporting downstream product production line 6, and is used to recover the waste heat of the circulating liquid in the formaldehyde production system 1 and deliver it to the formaldehyde supporting downstream product production line 6, the formaldehyde supporting downstream product production line 6 is connected to the finished formaldehyde delivery pump 5, and is used for the production of downstream products supporting the formaldehyde production line.

[0029] The waste heat recovery system 7 includes a water tank 71, a waste heat recovery box 72, a frame 74, an insulation water tank 75 and a base 76. The frame 74, the water tank 71 and the insulation water tank 75 are all fixed on the base 76. The waste heat recovery box 72 is arranged on the frame 74. The water tank 71 is arranged on the left side of the waste heat recovery box 72. The left end of the waste heat recovery box 72 is connected to the circulating liquid inlet of the formaldehyde production system 1, and the right end of the waste heat recovery box 72 is connected to the circulating liquid outlet of the formaldehyde production system 1. The insulation water tank 75 is arranged on the right side of the waste heat recovery box 72. The working principle of the whole system is: the cold water in the water tank 71 is transported to the waste heat recovery box 72 to be heated by waste heat, and the heated water is transported to the water tank 71 for storage and standby, so as to realize the recovery and utilization of waste heat.

[0030] A first water inlet pipe 711 is led out from the bottom of the water storage tank 71, and the first water inlet pipe 711 is connected to a circulating water pump 712, and the circulating water pump 712 is connected to the waste heat recovery tank 72 through a second water inlet pipe 721, and a first valve 713 is installed on the second water inlet pipe 721. The circulating water pump 712, the first water inlet pipe 711 and the second water inlet pipe 721 facilitate the delivery of cold water in the water storage tank 71 to the waste heat recovery tank 72, and the first valve 713 can be used to adjust the water volume.

[0031] The right end of the waste heat recovery tank 72 is connected to the insulation water tank 75 through the outlet pipe 79, and the outlet pipe 79 is equipped with a second valve 791. After the water undergoes heat exchange, it flows out of the waste heat recovery tank 72 through the outlet pipe 79, and then enters the insulation water tank 75 with the flow rate controlled by the second valve 791. The insulation water tank 75 plays a role in heat preservation to prevent heat loss.

[0032] The outlet of the heat preservation water tank 75 is connected to a water delivery pipe 77, which is connected to a water delivery pump 78. The water delivery pump 78 delivers hot water to the formaldehyde supporting downstream product production line 6 through an external water pipe. This achieves the reuse of waste heat and improves energy utilization efficiency.

[0033] A heating chamber 723 is provided on the upper side of the waste heat recovery box 72. Multiple groups of heat conducting rods 724 are evenly arranged vertically inside the waste heat recovery box 72, and the upper ends of the heat conducting rods 724 extend into the heating chamber 723. The heat in the waste heat recovery box 72 can be absorbed by the heat conducting rods 724 and transferred to the heating chamber 723 to heat the water. By evenly arranging multiple groups of heat conducting rods 724 vertically, the heat conduction area inside the waste heat recovery box 72 can be increased, thereby improving the effect of heat recovery. Such a design can effectively improve the efficiency of waste heat recovery and reduce energy waste.

[0034] A plurality of groups of circular heat exchange fins 7241 are evenly arranged on the heat conducting plate at the lower part of the waste heat recovery box 72. This design is to increase the heat exchange area of ​​the waste heat recovery box 72 and improve the heat transfer efficiency. The circular heat exchange fins 7241 can increase the surface area of ​​heat transfer, so that the waste heat can be more fully recovered and utilized.

[0035] As an embodiment of the present utility model: the formaldehyde production system 1 produces product formaldehyde, which is stored in the finished formaldehyde storage tank 4 and directly delivered to the formaldehyde supporting downstream product production line 6 through the finished formaldehyde delivery pump 5; the steam generated by the oxidation furnace drum 2 is partly used by itself, and partly supplied to the formaldehyde supporting downstream product production line 6; the steam generated by the tail gas boiler system 3 is all supplied to the formaldehyde supporting downstream product production line 6; the waste heat generated by the formaldehyde circulating liquid is recovered by the waste heat recovery system 7, and then supplied to the formaldehyde supporting downstream product production line 6.

[0036] In the waste heat recovery system 7, the left and right ends of the waste heat recovery box 72 are connected to the formaldehyde circulating liquid inlet and outlet. The waste heat of the formaldehyde circulating liquid enters the waste heat recovery box 72, and the cold water is heated by the spiral coil. The heated water is transported to the insulation water tank 75 through the outlet pipe 79 for storage, and then transported to the formaldehyde supporting downstream product production line 6 through the delivery water pump 78 for use.

[0037] This new method uses waste heat recovery and industrial chain perspectives, allowing formaldehyde production companies to not only produce formaldehyde, but also combine their own advantages to make full use of steam waste heat to match corresponding downstream products, thereby improving the utilization rate of waste heat and extending the downstream industrial chain of formaldehyde, achieving waste heat recovery, comprehensive utilization of resources, and transformation and upgrading of downstream products supporting the formaldehyde industry.

[0038] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0039] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A system for comprehensive utilization of waste heat from formaldehyde production, characterized in that: include Formaldehyde production system (1), a production line in which methanol is converted into formaldehyde through an oxidation furnace, for producing formaldehyde; The oxidation furnace drum (2) is matched with the formaldehyde production system (1), and the formaldehyde production system (1) generates steam, part of which is used by the system itself and part of which is supplied to the formaldehyde supporting downstream product production line (6); An exhaust gas boiler system (3) is matched with the formaldehyde production system (1) and is used to treat the exhaust gas generated by the formaldehyde production line. The exhaust gas boiler system (3) generates steam and supplies it to the formaldehyde supporting downstream product production line (6); Finished product formaldehyde storage tank (4), used for storing finished product formaldehyde; A finished product formaldehyde delivery pump (5) is connected to the finished product formaldehyde storage tank (4) and is used to deliver formaldehyde to a downstream formaldehyde product production line (6); A waste heat recovery system (7) is connected to the formaldehyde production system (1) and the formaldehyde supporting downstream product production line (6) and is used to recover the waste heat of the circulating liquid in the formaldehyde production system (1) and transport it to the formaldehyde supporting downstream product production line (6); The formaldehyde supporting downstream product production line (6) is connected to the finished formaldehyde delivery pump (5) and is used for the production of downstream products supporting the formaldehyde production line.

2. The formaldehyde production waste heat comprehensive utilization system according to claim 1, characterized in that: The waste heat recovery system (7) comprises a water storage tank (71), a waste heat recovery box (72), a frame (74), a heat preservation water tank (75) and a base (76); the frame (74), the water storage tank (71) and the heat preservation water tank (75) are all fixedly mounted on the base (76); a waste heat recovery box (72) is arranged on the frame (74); the water storage tank (71) is arranged on the left side of the waste heat recovery box (72); the left end of the waste heat recovery box (72) is connected to the circulating liquid inlet of the formaldehyde production system (1); the right end of the waste heat recovery box (72) is connected to the circulating liquid outlet of the formaldehyde production system (1); and the heat preservation water tank (75) is arranged on the right side of the waste heat recovery box (72).

3. The formaldehyde production waste heat comprehensive utilization system according to claim 2, characterized in that: A first water inlet pipe (711) is led out from the bottom of the water storage tank (71), and the first water inlet pipe (711) is connected to a circulating water pump (712). The circulating water pump (712) is connected to the waste heat recovery tank (72) via a second water inlet pipe (721), and a first valve (713) is installed on the second water inlet pipe (721).

4. The formaldehyde production waste heat comprehensive utilization system according to claim 2, characterized in that: The right end of the waste heat recovery tank (72) is connected to the insulation water tank (75) via a water outlet pipe (79), and a second valve (791) is mounted on the water outlet pipe (79).

5. The formaldehyde production waste heat comprehensive utilization system according to claim 2, characterized in that: The water outlet of the heat-insulating water tank (75) is connected to a water delivery pipe (77), and the water delivery pipe (77) is connected to a water delivery pump (78). The water delivery pump (78) delivers hot water to the formaldehyde supporting downstream product production line (6) through an external water pipe, and part of the hot water is used for daily life.

6. The formaldehyde production waste heat comprehensive utilization system according to claim 2, characterized in that: A heating chamber (723) is arranged on the upper side of the waste heat recovery box (72), and a plurality of groups of heat conducting rods (724) are evenly and vertically arranged inside the waste heat recovery box (72), and the upper ends of the heat conducting rods (724) extend into the heating chamber (723).

7. The formaldehyde production waste heat comprehensive utilization system according to claim 6, characterized in that: A plurality of groups of circular heat exchange fins (7241) are evenly arranged on the heat conducting rod (724) at the lower portion of the waste heat recovery box (72).

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