Adsorption and steam treatment integrated equipment for low-odor bio-based polyether
By separating multiple functional cavity in the same box, an integrated equipment for adsorption steam treatment for low-odor bio-based polyether was designed, which solved the problem of separate and large land in the prior art equipment, realized the functions of deodorization, acid removal and filtration, and was compact in structure, which was easy to transport and use.
Patent Information
- Application Number
- CN202422261535.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-09-14
AI Technical Summary
In the prior art, the polyether treatment equipment is a separate equipment, connected by pipes, occupying a large area of land and is inconvenient for transportation, and there is a lack of an improved technology to solve this problem.
An integrated equipment for adsorption steam treatment for low-odor bio-based polyethers is designed. By separating the adsorption chamber, ion exchange chamber and high-temperature steam treatment chamber in the same box, the functions of deodorization, acid removal and filtration are achieved. The integrated structure is adopted to reduce the number of equipment and the area of the equipment.
The effects of deodorization and acid removal are achieved, and filtered through a filter mesh is carried out, reducing the floor area and transportation difficulty of the equipment, and the structure is compact, making it easy to use and replace materials.
Smart Images

Figure CN223042460U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of chemistry, in particular to polyether treatment equipment, and specifically to an adsorption and steam treatment integrated equipment for low-odor bio-based polyether. Background Technique
[0002] Polyether is an organic polymer, which is prepared by the addition polymerization reaction of an initiator with ethylene oxide, propylene oxide, butylene oxide, etc. in the presence of a catalyst. The largest output of polyether is made with glycerol (glycerol) as the initiator and epoxides (usually PO and EO are used together). By changing conditions such as the feeding method, dosage ratio, and feeding order of PO and EO, various general polyethers are produced.
[0003] The development of bio-based polyether began with the improvement and innovation of traditional polyether materials. Traditional polyether materials are mainly prepared from petroleum. Although they have good physical properties, there are many problems in terms of sustainable development and environmental protection. When liquid bio-based polyether is subjected to acid removal treatment, generally through several steps of adsorption, ion exchange, steam high-temperature treatment, and filtration, the particulate matter in the polyether is adsorbed by activated carbon, and then the acid is removed through ion exchange and high-temperature treatment of steam, and the impurities in the polyether are filtered through a filter to complete the treatment of the odor, impurities, and acid removal of low-odor bio-based polyether. However, at present, the adsorption, ion exchange, steam high-temperature treatment, and filtration equipment are separate equipment, connected by pipelines, occupying a large space and being inconvenient for transportation. Therefore, an improved technology is urgently needed to solve the above problems existing in the prior art. Content of the Utility Model
[0004] The purpose of the utility model is to provide an adsorption and steam treatment integrated equipment for low-odor bio-based polyether. On the one hand, it realizes deodorization, and on the other hand, it realizes acid removal and filtration. And it adopts an integrated structure, which is completed in the same box body, with the advantages of no need for pipeline connection, compact structure, greatly reduced occupied area, convenient transportation, and overall easy to use and convenient for material replacement, so as to solve the problems raised in the above background technique.
[0005] To achieve the above object, the present utility model provides the following technical solution: An adsorption and steam treatment integrated device for low-odor bio-based polyether, comprising a box body, a box cover, a first longitudinal partition board, a second longitudinal partition board, a first baffle, a second baffle, a third longitudinal partition board, a first transverse partition board, a second transverse partition board, a third transverse partition board and a filter screen. A box cover is arranged on the upper surface of the box body. A first longitudinal partition board and a second longitudinal partition board are arranged inside the box body. Overflow grooves are formed in the upper parts of the first longitudinal partition board and the second longitudinal partition board. The inside of the box body is divided into an adsorption chamber, an ion exchange chamber and a high-temperature steam treatment chamber by the first longitudinal partition board and the second longitudinal partition board. A first baffle is arranged inside the adsorption chamber. A second baffle is arranged inside the ion exchange chamber. Flow ports are arranged at the lower parts of the first baffle and the second baffle. A first support perforated plate is connected between the first longitudinal partition board and the first baffle in the adsorption chamber. A second support perforated plate is connected between the second longitudinal partition board and the second baffle in the ion exchange chamber. An activated carbon layer is arranged on the upper surface of the first support perforated plate. An ion exchange resin ball layer is arranged on the upper surface of the second support perforated plate. Third longitudinal partition boards are arranged on both sides inside the high-temperature steam treatment chamber. The inside of the high-temperature steam treatment chamber is divided into a flow chamber, a first steam heating chamber and a second steam heating chamber by two third longitudinal partition boards. The first steam heating chamber and the second steam heating chamber are located on both sides of the flow chamber. The overflow groove at the upper part of the second longitudinal partition board corresponds to the flow chamber. An air inlet is arranged at the lower part of the box body where the first steam heating chamber is located. An air outlet is arranged at the upper part of the box body where the second steam heating chamber is located. The lower parts of the first steam heating chamber and the second steam heating chamber are interconnected by a plurality of connecting pipes. The connecting pipes are arranged between the two third longitudinal partition boards. First transverse partition board, second transverse partition board and third transverse partition board are arranged alternately in the flow chamber. Flow ports are arranged at one ends of the first transverse partition board and the third transverse partition board away from the second longitudinal partition board. A flow port is arranged at one end of the second transverse partition board close to the second longitudinal partition board. Filter screens are arranged in the flow ports of the first transverse partition board and the third transverse partition board. A feed port is arranged at the upper part of the box body where the adsorption chamber is located. A discharge port is arranged at the lower part of the box body away from the feed port and where the flow chamber is located.
[0006] Preferably, in the adsorption and steam treatment integrated device for low-odor bio-based polyether provided by the present utility model, screens are arranged in the overflow grooves at the tops of the first longitudinal partition board and the second longitudinal partition board.
[0007] Preferably, in the adsorption and steam treatment integrated device for low-odor bio-based polyether provided by the present utility model, a material replacement port is arranged on the side wall of the box body at the adsorption chamber and the ion exchange chamber. The height of the material replacement port corresponds to the heights of the first support perforated plate and the second support perforated plate. The material replacement port is provided with a circular visible cover plate.
[0008] Preferably, the present utility model provides an adsorption and steam treatment integrated device for low-odor bio-based polyether. Among them, two cleaning ports are provided at the outer end of the box body and located at the flow cavity. The heights of the cleaning ports correspond to the height of the filter net respectively, and a rectangular visual cover plate is provided at the cleaning port.
[0009] Preferably, the present utility model provides an adsorption and steam treatment integrated device for low-odor bio-based polyether. Among them, a support seat is provided at the bottom of the box body.
[0010] Preferably, the present utility model provides an adsorption and steam treatment integrated device for low-odor bio-based polyether. Among them, small doors are provided at the box cover at both the adsorption cavity and the ion exchange cavity.
[0011] Preferably, the present utility model provides an adsorption and steam treatment integrated device for low-odor bio-based polyether. Among them, thermometer installation ports are provided at the box cover at the first steam heating cavity and the second steam heating cavity.
[0012] Preferably, the present utility model provides an adsorption and steam treatment integrated device for low-odor bio-based polyether. Among them, residual liquid discharge ports are provided at the bottom of the side of the box body at both the adsorption cavity and the ion exchange cavity.
[0013] Preferably, the present utility model provides an adsorption and steam treatment integrated device for low-odor bio-based polyether. Among them, heat insulation plates are laid at the second longitudinal partition at the first steam heating cavity and the second steam heating cavity.
[0014] Compared with the prior art, the beneficial effects of the present utility model are:
[0015] A first longitudinal partition and a second longitudinal partition are arranged inside the box body to divide the box body into an adsorption cavity, an ion exchange cavity and a high-temperature steam treatment cavity. And the high-temperature steam treatment cavity is internally divided into a flow cavity, a first steam heating cavity and a second steam heating cavity by two third longitudinal partitions. Thus, the adsorption, ion exchange and steam treatment of low-odor bio-based polyether can be realized. At the same time, two-layer filtration is carried out in the flow cavity for filtration treatment. On the one hand, deodorization is realized, and on the other hand, impurity filtration is realized. And an integrated structure is adopted, which is completed in the same box body, having the advantages of no need for pipe connection, compact structure, greatly reduced occupied area, convenient transportation, and convenient overall use and material replacement. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a side view structural schematic diagram of the present utility model;
[0017] Figure 2 It is a top view structural schematic diagram of the present utility model;
[0018] Figure 3This is a front view structural schematic diagram of the present utility model.
[0019] In the figure: box body 1, box cover 2, first longitudinal partition 3, second longitudinal partition 4, first baffle 5, second baffle 6, third longitudinal partition 7, first transverse partition 8, second transverse partition 9, third transverse partition 10, filter screen 11, overflow tank 12, adsorption chamber 13, ion exchange chamber 14, flow port 15, first support perforated plate 16, second support perforated plate 17, activated carbon layer 18, ion exchange resin ball layer 19, flow chamber 20, first steam heating chamber 21, second steam heating chamber 22, air inlet 23, air outlet 24, connecting pipe 25, feed inlet 26, discharge outlet 27, sieve mesh 28, material replacement port 29, circular visual cover plate 30, cleaning port 31, rectangular visual cover plate 32, support base 33, small door 34, thermometer installation port 35, residual liquid discharge port 36, heat insulation plate 37. Specific embodiments
[0020] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the embodiments and drawings of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model;
[0021] It should be noted that in the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "inside", "outside", "upper", "lower", "both sides", "one end", "the other end", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.
[0022] Please refer to Figures 1-3, the present utility model provides a technical solution: an adsorption and steam treatment integrated device for low-odor bio-based polyether, including a box body 1, a box cover 2, a first longitudinal partition 3, a second longitudinal partition 4, a first baffle 5, a second baffle 6, a third longitudinal partition 7, a first transverse partition 8, a second transverse partition 9, a third transverse partition 10 and a filter screen 11. A box cover 2 is arranged on the upper surface of the box body 1. Inside the box body 1 and perpendicular to the lower surface of the box body 1, a first longitudinal partition 3 and a second longitudinal partition 4 are respectively arranged. Overflow grooves 12 are provided at the upper parts of the first longitudinal partition 3 and the second longitudinal partition 4. Screen meshes 28 are arranged in the overflow grooves 12 at the tops of the first longitudinal partition 3 and the second longitudinal partition 4 to prevent the activated carbon in the adsorption chamber 13 from flowing into the ion exchange chamber 14, and to prevent the ion exchange resin balls in the ion exchange chamber 14 from flowing into the flow chamber 20. The inside of the box body 1 is divided into an adsorption chamber 13, an ion exchange chamber 14 and a high-temperature steam treatment chamber by the first longitudinal partition 3 and the second longitudinal partition 4. A first baffle 5 is arranged inside the adsorption chamber 13 perpendicular to the lower surface of the box body 1. A second baffle 6 is arranged inside the ion exchange chamber 14 perpendicular to the lower surface of the box body 1. Flow ports 15 are provided at the lower parts of the first baffle 5 and the second baffle 6. A first support perforated plate 16 is connected between the first longitudinal partition 3 and the first baffle 5 in the adsorption chamber 13. A second support perforated plate 17 is connected between the second longitudinal partition 4 and the second baffle 6 in the ion exchange chamber 14. The first support perforated plate 16 and the second support perforated plate 17 are both arranged parallel to the lower surface of the box body 1. An activated carbon layer 18 is arranged on the upper surface of the first support perforated plate 16. An ion exchange resin ball layer 19 is arranged on the upper surface of the second support perforated plate 17. A material replacement port 29 is arranged on the side wall of the box body 1 at the positions of the adsorption chamber 13 and the ion exchange chamber 14. The height of the material replacement port 29 corresponds to the heights of the first support perforated plate 16 and the second support perforated plate 17. The material replacement port 29 is provided with a circular visual cover plate 30. The material replacement port 29 is used for replacing the activated carbon and the ion exchange resin balls. The circular visual cover plate 30 is used to achieve sealing on the one hand and facilitate observing the internal use situation on the other hand. Small doors 34 are arranged on the box cover 2 at the positions of the adsorption chamber 13 and the ion exchange chamber 14 for adding the activated carbon and the ion exchange resin balls. Third longitudinal partitions 7 are arranged on both sides inside the high-temperature steam treatment chamber. The inside of the high-temperature steam treatment chamber is divided into a flow chamber 20, a first steam heating chamber 21 and a second steam heating chamber 22 by the two third longitudinal partitions 7. The first steam heating chamber 21 and the second steam heating chamber 22 are located on both sides of the flow chamber 20. The overflow groove 12 at the upper part of the second longitudinal partition 4 corresponds to the flow chamber 20. An air inlet 23 is arranged at the lower part of the box body 1 at the position of the first steam heating chamber 21. An air outlet 24 is arranged at the upper part of the box body 1 at the position of the second steam heating chamber 22. The lower parts of the first steam heating chamber 21 and the second steam heating chamber 22 are interconnected through a plurality of connecting pipes 25. The connecting pipes 25 are arranged between the two third longitudinal partitions 7. Heat insulation plates 37 are laid on the second longitudinal partition 4 at the positions of the first steam heating chamber 21 and the second steam heating chamber 22 to reduce the influence on the temperature in the ion exchange chamber 14.The first transverse partition 8, the second transverse partition 9 and the third transverse partition 10 are arranged alternately in the flow cavity 20, the first transverse partition 8 and the third transverse partition 10 are provided with a flow port at one end away from the second longitudinal partition 4, and the second transverse partition 9 is provided with a flow port at one end close to the second longitudinal partition 4. The first transverse partition 8, the second transverse partition 9 and the third transverse partition 10 are arranged parallel to the lower surface of the box body 1, and the flow ports of the first transverse partition 8 and the third transverse partition 10 are provided with a filter screen 11. Two cleaning ports 31 are provided at the outer end of the box body 1 and located at the flow cavity 20. The height of the cleaning port 31 corresponds to the height of the filter screen 11, and the cleaning port 31 is provided with a rectangular visible cover plate 32 to facilitate the removal of impurities through the cleaning port. 31 for cleaning, the rectangular visual cover 32 is used to achieve sealing on the one hand, and on the other hand, it is convenient to observe the use of the filter screen 11. The box cover 2 is located at the first steam heating chamber 21 and the second steam heating chamber 22, and a thermometer installation port 35 is set. The box body 1 is located at the upper part of the adsorption chamber 13 and the feed port 26 is set. The box body 1 is located at the end away from the feed port 26 and at the lower part of the flow chamber 20. The side of the box body 1 and the bottom of the adsorption chamber 13 and the ion exchange chamber 14 are provided with a residual liquid discharge port 36, so that when cleaning the equipment, the residual liquid can be discharged from the bottom of the adsorption chamber 13 and the ion exchange chamber 14. A support seat 33 is set at the bottom of the box body 1 to achieve overall support.
[0023] Installation method and working principle: Weld the first longitudinal partition plate 3, the second longitudinal partition plate 4, the first baffle plate 5 and the second baffle plate 6 inside the box body 1. At this time, the inside of the box body 1 is divided into an adsorption chamber 13, an ion exchange chamber 14 and a high-temperature steam treatment chamber. Then install the first support perforated plate 16 between the first longitudinal partition plate 3 and the first baffle plate 5 by bolts, install the second support perforated plate 17 between the second longitudinal partition plate 4 and the second baffle plate 6 by bolts, and at the same time install the screen 28 in the overflow grooves 12 corresponding to the first longitudinal partition plate 3 and the second longitudinal partition plate 4. Weld two third longitudinal partition plates 7 at the corresponding positions inside the box body 1 to divide the high-temperature steam treatment chamber into a flow chamber 20, a first steam heating chamber 21 and a second steam heating chamber 22. Then install the connecting pipe 25 at the lower part between the two third longitudinal partition plates 7 to connect the first steam heating chamber 21 and the second steam heating chamber 22 to each other. Next, weld the first transverse partition plate 8, the second transverse partition plate 9 and the third transverse partition plate 10 inside the high-temperature steam treatment chamber to form a flow channel. Finally, install the filter screen 11 at the flow ports at the outer ends of the first transverse partition plate 8 and the third transverse partition plate 10, cover the box cover 2, and complete the installation. Before use, put activated carbon into the adsorption chamber 13 through the small door 34 corresponding to the box cover 2 and support it on the first support perforated plate 16, and put ion exchange resin balls into the ion exchange chamber 14 through the small door 34 corresponding to the box cover 2 and support it on the second support perforated plate 17. During use, the low-odor bio-based polyether enters from the feed port 26, enters between the first longitudinal partition plate 3 and the first baffle plate 5 through the flow port 15 at the bottom of the first baffle plate 5, adsorbs particles through the activated carbon layer 18, then overflows into the ion exchange chamber 14 through the overflow groove 12 of the first longitudinal partition plate 3, enters between the second longitudinal partition plate 4 and the second baffle plate 6 through the flow port 15 at the bottom of the second baffle plate 6, and conducts ion exchange on cations and anions in the polyether through the ion exchange resin ball layer 19 to achieve acid reduction treatment. Subsequently, the solution enters the upper part of the flow chamber 20 through the overflow groove 12 of the second longitudinal partition plate 4, and high-temperature steam enters the first steam heating chamber 21 from the air inlet 23, enters the second steam heating chamber 22 through the connecting pipe 25, and is discharged from the air outlet 24. The flow chamber 20 is heated through the first steam heating chamber 21 and the second steam heating chamber 22, so as to condense the ion-exchanged substances in the polyether and filter them through the filter screen 11. Through the filtration of the filter screens 11 on both sides of the flow chamber 20, the treated polyether is discharged from the discharge port 27. The polyether is successively subjected to adsorption, ion exchange, steam treatment and filtration to achieve the purpose of acid removal.The structure of the utility model is reasonable. A first longitudinal partition 3 and a second longitudinal partition 4 are arranged inside the box body 1 to divide the box body 1 into an adsorption cavity 13, an ion exchange cavity 14 and a high-temperature steam treatment cavity. And the high-temperature steam treatment cavity is internally divided into a flow cavity 20, a first steam heating cavity 21 and a second steam heating cavity 22 by two third longitudinal partitions 7, so as to realize the adsorption, ion exchange and steam treatment of low-odor bio-based polyether. At the same time, filtration treatment is carried out through two layers of filtration in the flow cavity 20. On the one hand, deodorization is realized, and on the other hand, impurity filtration is realized. And it adopts an integrated structure and is completed in the same box body 1, having the advantages of no need for pipe connection, compact structure, greatly reduced occupied area and convenient transportation. And the whole is easy to use and convenient for material replacement.
[0024] For the parts not detailed in the utility model, they are all well-known technologies to those skilled in the art.
[0025] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the utility model rather than to limit them. Although the utility model has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that the technical solutions of the utility model can be modified and equivalently replaced without departing from the spirit and scope of the technical solutions of the utility model, and they should all be covered by the scope of the claims of the utility model.
Claims
1. An integrated adsorption steam treatment device for low-odor bio-based polyether, characterized in that: The invention comprises a box body (1), a box cover (2), a first longitudinal partition (3), a second longitudinal partition (4), a first baffle (5), a second baffle (6), a third longitudinal partition (7), a first transverse partition (8), a second transverse partition (9), a third transverse partition (10) and a filter screen (11); the box body (1) is provided with a box cover (2) on the upper surface; the box body (1) is provided with a first longitudinal partition (3) and a second longitudinal partition (4); the first longitudinal partition (3) and the second longitudinal partition (4) are provided with an overflow groove (12); the interior of the box body (1) is divided into an adsorption chamber (13), an ion exchange chamber (14) and a high-temperature steam treatment chamber by the first longitudinal partition (3) and the second longitudinal partition (4); the adsorption chamber (13) has a plurality of ion exchange chambers (14) and a plurality of ion exchange chambers (15); A first baffle (5) is provided at the bottom of the ion exchange chamber (14); a second baffle (6) is provided inside the ion exchange chamber (14); a flow port (15) is provided at the lower part of the first baffle (5) and the second baffle (6); a first support orifice plate (16) is connected in the adsorption chamber (13) and located between the first longitudinal baffle (3) and the first baffle (5); a second support orifice plate (17) is connected in the ion exchange chamber (14) and located between the second longitudinal baffle (4) and the second baffle (6); an activated carbon layer (18) is provided on the upper surface of the first support orifice plate (16); an ion exchange resin ball layer (19) is provided on the upper surface of the second support orifice plate (17); third longitudinal baffles (7) are provided on both sides of the high-temperature steam treatment chamber; The interior of the high-temperature steam treatment chamber is divided into a flow chamber (20), a first steam heating chamber (21) and a second steam heating chamber (22) by two third longitudinal partitions (7); the first steam heating chamber (21) and the second steam heating chamber (22) are located on both sides of the flow chamber (20); the overflow groove (12) on the upper part of the second longitudinal partition (4) corresponds to the flow chamber (20); the box body (1) is provided with an air inlet (23) at the lower part of the first steam heating chamber (21); the box body (1) is provided with an air outlet (24) at the upper part of the second steam heating chamber (22); the first steam heating chamber (21) and the second steam heating chamber (22) are connected to each other at the lower part through a plurality of connecting pipes (25); The connecting pipe (25) is arranged between the two third longitudinal partitions (7); the first transverse partition (8), the second transverse partition (9) and the third transverse partition (10) are arranged alternately in the flow chamber (20); the first transverse partition (8) and the third transverse partition (10) are provided with flow ports at one end away from the second longitudinal partition (4); the second transverse partition (9) is provided with a flow port at one end close to the second longitudinal partition (4); the flow ports of the first transverse partition (8) and the third transverse partition (10) are both provided with filter screens (11); the box body (1) is provided with a feed port (26) at the upper part of the adsorption chamber (13); and the box body (1) is provided with a discharge port (27) at one end away from the feed port (26) and at the lower part of the flow chamber (20).
2. The integrated adsorption steam treatment device for low-odor bio-based polyether according to claim 1, characterized in that: Screens (28) are provided in the overflow grooves (12) at the tops of the first longitudinal partition plate (3) and the second longitudinal partition plate (4).
3. The integrated adsorption steam treatment device for low-odor bio-based polyether according to claim 1, characterized in that: A material exchange port (29) is provided on the side wall of the box body (1) and located at the adsorption chamber (13) and the ion exchange chamber (14); the height of the material exchange port (29) corresponds to the height of the first supporting orifice plate (16) and the second supporting orifice plate (17); and the material exchange port (29) is provided with a circular visible cover plate (30).
4. The integrated adsorption steam treatment device for low-odor bio-based polyether according to claim 1, characterized in that: Two cleaning ports (31) are provided at the outer end of the box body (1) and located at the flow chamber (20); the heights of the cleaning ports (31) respectively correspond to the heights of the filter screen (11); and the cleaning ports (31) are provided with rectangular visible covers (32).
5. The integrated adsorption steam treatment device for low-odor bio-based polyether according to claim 1, characterized in that: A support seat (33) is provided at the bottom of the box body (1).
6. The integrated adsorption steam treatment device for low-odor bio-based polyether according to claim 1, characterized in that: The box cover (2) is provided with small doors (34) at the adsorption chamber (13) and the ion exchange chamber (14).
7. The integrated adsorption steam treatment device for low-odor bio-based polyether according to claim 1, characterized in that: The box cover (2) is provided with a thermometer installation opening (35) located outside the first steam heating chamber (21) and the second steam heating chamber (22).
8. The integrated adsorption steam treatment device for low-odor bio-based polyether according to claim 1, characterized in that: Residual liquid discharge outlets (36) are provided on the side of the box body (1) and at the bottom of the adsorption chamber (13) and the ion exchange chamber (14).
9. The integrated adsorption steam treatment device for low-odor bio-based polyether according to claim 1, characterized in that: The second longitudinal partition plate (4) is located in the first steam heating chamber (21) and the second steam heating chamber (22) and is provided with a heat insulation plate (37).