A sand bath device for heating soil organic matter in multiple zones

Abstract

The present application relates to the technical field of soil organic matter determination experiment, in particular to a sand bath device for heating soil organic matter in multiple zones, aiming at solving the problem of uneven temperature in sand bath heating. It comprises a heating disc, a plurality of detection zones are formed on the heating disc, and a base is fixedly connected to the center of each detection zone; a closed box is detachably connected to the base, a plurality of closed boxes are arranged around the base to form heating units, gaps exist between adjacent heating units and the inner side wall of the heating unit and the adjacent heating disc to form heating spaces, and a containing cavity is formed in the closed box; a heat preservation cover is detachably connected to the top of the heating disc; sand particles are filled in the containing cavity and the heating space, and the heating unit can rotate along the base. The heating disc is divided into a plurality of detection zones, realizing partition and modular heating, the closed box forms a heating unit around the base and can rotate along the base, and the sand particles can be made to move relatively after heating by rotating, so that the solid sand particles are mixed uniformly after heating.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil organic matter determination experiment, and particularly relates to a sand bath device for heating soil organic matter in multiple zones. BACKGROUND

[0002] In a certain soil organic matter determination experiment, it is necessary to verify whether the sand bath pot can correctly analyze the sample in the soil organic matter experiment, and the feasibility of the sand bath pot for digesting the soil organic matter sample experiment; the sand bath is widely used in chemical analysis, soil sample pretreatment, drying and heat balance test and the like due to its simple structure, large heat capacity and low risk of sample contact pollution. Common sand bath forms include a metal disc or a deep groove filled with bulk sand placed on an electric hot plate or a heater, heat is transferred to the sand layer through the bottom or side heating elements, and the sand acts as a solid bulk medium, which can buffer temperature fluctuations and provide a relatively stable temperature field for sample processing to a certain extent.

[0003] In the sand bath heating process for soil and similar solid samples, the temperature in the central region is obviously higher than that in the edge region, which causes the formation of a radial temperature gradient in the sand bath, and the uneven temperature is mainly caused by the following factors: the low thermal conductivity of the sand, the heating element is usually concentrated in the center of the disc bottom or on one side, the heating process is mainly conducted, and there is a lack of effective lateral heat exchange, and the free bulk structure of the sand layer limits the rapid diffusion of heat in the plane; for soil detection or pretreatment steps that require strict temperature control (such as moisture determination, volatile analysis or heat balance processing), the above radial temperature difference will cause inconsistency of sample processing, test data deviation and decrease of repeatability.

[0004] In order to improve the temperature uniformity of the sand bath, several technical solutions have been adopted: one is to set heat-conducting blocks or metal lining plates in the sand bath to improve lateral heat conduction; the other is to use mechanical stirring or forced ventilation to promote heat transfer in the medium during heating, such as the electric sand bath device with sand stirring structure disclosed in patent CN202223399409.4 and the adjustable electric sand bath device disclosed in patent CN202421297375.4, both of which mention the use of stirring structure to achieve temperature uniformity. The above methods improve the local temperature difference to a certain extent, but also have some disadvantages: the addition of heat-conducting blocks or metal lining plates in the sand bath, as well as the stirring structure left in the sand bath, deviate from the purpose of testing the pure sand bath heating experiment, and cannot better test the sample. SUMMARY

[0005] The technical problem to be solved by the present application is that uneven temperature may occur in sand bath heating, which affects the experimental measurement accuracy, and the present application provides a sand bath device for multi-zone heating of soil organic matter, which can divide the heating space of the sand bath into several independent small spaces, and can stir the sand particles in the small spaces to avoid the problem of low temperature at the edge and high temperature at the center of the sand particles.

[0006] The present application provides a sand bath device for multi-zone heating of soil organic matter, comprising:

[0007] A heating pot is provided with a heating disc on the top surface, a plurality of detection zones with equal areas and sequentially adjacent are formed on the heating disc, and a base is fixedly connected to the center of each detection zone;

[0008] A plurality of closed boxes are detachably connected to the base, a plurality of closed boxes in the same detection zone are arranged around the base to form a heating unit, a gap exists between adjacent heating units, the heating unit and the inner side wall of the adjacent heating disc to form a heating space, and a containing cavity is formed in the closed box;

[0009] A heat preservation cover is detachably connected to the top of the heating disc;

[0010] The containing cavity and the heating space are both filled with sand particles, the heating unit can rotate along the base, the base is used for placing a digestion tube, and the heating unit is used for wrapping the digestion tube.

[0011] In the above technical solution, the heating disc is divided into a plurality of detection zones, and sand particles are filled in the heating unit of the detection zone and the heating space, so that partitioned and modularized heating is realized, the temperature of different detection zones can be managed respectively, the direct influence of single heating on the whole disc is reduced, the closed box forms a wrapped heating unit around the base and can rotate along the base, the sand particles can be relatively moved by rotating after heating, so that the solid sand particles are mixed after heating, the radial temperature difference between the center and the edge is significantly reduced, and the heating uniformity of the digestion tube is improved.

[0012] Preferably, the top of the closed box is provided with a cover, one side of the closed box in the width direction is connected with a convex strip, and the other side of the closed box in the width direction is provided with a clamping groove for clamping the convex strip.

[0013] In the above technical solution, the clamping structure of the cover on the top of the closed box and the convex strip and the clamping groove on the side surface provides convenient disassembly and reliable positioning and locking, so that the closed boxes are not dislocated or loosened during rotation or turning.

[0014] Preferably, the cross section of the closed box is a fan-shaped structure, the closed boxes in the same detection area are arranged in a ring structure around the base, a turning-up rib is fixedly connected to the outer peripheral surface of the closed box, the turning-up rib is an arc-shaped structure, and the center of the turning-up rib is concentric with the center of the closed box.

[0015] In the above technical solution, the fan-shaped cross section and the turning-up rib structure enable each heating unit to turn the sand in a regular circumferential path when rotating around the base, thereby achieving continuous and uniform radial mixing and reducing the formation of temperature uneven areas.

[0016] Preferably, a plurality of turning-up ribs are arranged in parallel along the height direction of the closed box, and the lengths of the turning-up ribs on the closed box gradually decrease from top to bottom.

[0017] In the above technical solution, the design of arranging multiple turning-up ribs in parallel along the height direction and gradually decreasing the lengths of the turning-up ribs from top to bottom enables layered and progressive turning and stirring actions during rotation, thereby promoting the radial and vertical mixing of the sand at the same time.

[0018] Preferably, the end of the turning-up rib away from the closed box is an arc surface, and the end surface of the turning-up rib along the length direction is an inclined surface, which faces the closed box.

[0019] In the above technical solution, the arc surface reduces the impact resistance of the sand, and the inclined surface guides the sand to flow back into the closed box, thereby improving the turning efficiency and reducing the blocking and wear.

[0020] Preferably, the bottom surface of the heat preservation cover is provided with a partition plate, the partition plate is used to divide the bottom surface of the heat preservation cover into a plurality of heating areas, the heating areas correspond one by one to the detection areas, the bottom surface of the heat preservation cover is provided with a plurality of modules, the height of the module is equal to the depth of the heating disc, four modules are arranged corresponding to each heating area, and the modules in each heating area are arranged at four corners, respectively.

[0021] In the above technical solution, the partition plate is arranged on the bottom surface of the heat preservation cover, the partition plate is divided into a plurality of areas corresponding one by one to the detection areas, modules with a height equal to the depth of the heating disc are arranged at four corners of each heating area, and each heating area is aligned with each detection area, thereby reducing the thermal interference between adjacent heating areas and enhancing the heat preservation effect of each area.

[0022] Preferably, the surface of the module along the height direction includes two mutually perpendicular planes and an arc-shaped concave surface, and the rotating path of the turning-up rib passes through the concave surface of the module.

[0023] In the above technical solution, the rotating path of the turning-up rib passes through the concave surface, which can guide the smooth passing of the turning-up rib and provide a falling or transition space for the turned-out sand, thereby reducing the collision and resistance and prolonging the service life of the parts.

[0024] Preferably, the side wall of the partition plate and the concave surface of the module in the same heating area are located on the same circular arc, and the heating area is a circular area.

[0025] In the above technical solution, the side wall of the partition plate and the concave surface of the module are located on the same circular arc, so that the heating area is circular and consistent with the rotation track of the material turning convex rib, thereby bringing a symmetrical and uniform heating area and improving the uniformity and repeatability during rotation mixing.

[0026] Preferably, a threaded line is formed on the inner circumferential surface of the closed box, the threaded lines of the plurality of closed boxes in the same heating unit form a continuous internal threaded line, a sleeve is sleeved on the base wall, an external thread for threadedly connecting with the internal threaded line is connected to the outer circumferential wall of the sleeve, the top thread termination line of the external thread is lower than half the height of the sleeve, a through hole is formed on the heat preservation cover, and a through groove is formed on the bottom surface of the closed box.

[0027] In the above technical solution, the continuous internal threaded line is formed on the inner circumferential surface of the closed box, the sleeve on the base wall is provided with an external thread and can be threadedly connected, thereby forming an adjustable and detachable connection mode, facilitating assembly and positioning and ensuring the stability of rotation transmission; the top termination line of the external thread is lower than half the height of the sleeve, which can limit axial loosening and improve safety.

[0028] Preferably, a type groove is formed on the top surface of the base, a limiting block for clamping with the type groove is connected to the bottom of the sleeve, a plurality of grooves are formed around the through hole on the top surface of the heat preservation cover, and a baffle is rotatably connected in the grooves.

[0029] In the above technical solution, the baffle provides positioning and limiting functions, so that the position of the closed box and the sleeve is accurate during assembly and cannot be deviated during rotation.

[0030] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0031] 1. In the present application, the heating box is divided into a plurality of areas, and the heat preservation cover forms a plurality of heating areas through the partition plate and the module, so that each digestion tube has an independent sand bath heating space, and the sealing of the heat preservation cover can also provide a certain heat preservation effect; after the originally large sand bath heating disc is divided into a plurality of areas, the heat transfer efficiency can be better improved, and the temperature unevenness can be reduced.

[0032] 2. In the present application, after the heating disc is heated for a certain period of time, the closed box can be taken out by rotating to stir and move the sand particles in the heating space, so that the low-temperature sand particles at the edge and the high-temperature sand particles at the center are fully mixed, the temperature unevenness is avoided, and the data detection accuracy is improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0034] Figure 1 is a schematic view of the three-dimensional structure of the present application;

[0035] Figure 2 is a sectional view of the present application;

[0036] Figure 3 is a schematic view of the structure of the heating box in the present application;

[0037] Figure 4 is a schematic view of the structure of the heat preservation cover in the present application Figure 1 ;

[0038] Figure 5 is a schematic view of the structure of the heat preservation cover in the present application Figure 2 ;

[0039] Figure 6 is a schematic view of the structure of the closed box in the present application.

[0040] Markings in the drawings and corresponding names of parts:

[0041] 1, heating disc; 11, base; 2, closed box; 21, turnover rib; 22, through slot; 23, cover; 24, sleeve; 3, heat preservation cover; 31, partition; 32, module; 33, groove; 34, baffle. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the present application will be further described in detail below in combination with embodiments and drawings, the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and do not limit the present application. It should be noted that the present application has been in the actual research and development stage.

[0043] Example 1:

[0044] As shown in the figure, the present embodiment provides a multi-zone heating soil organic matter sand bath device, which comprises: Figures 1 to 6 A heating pot is provided with a heating disc 1 on the top surface, and a plurality of detection zones with equal areas and sequentially adjacent are formed on the heating disc 1, and a base 11 is fixedly connected to the center of each detection zone;

[0045]

[0046] ​A plurality of closed boxes 2 are detachably connected to the base 11, and the closed boxes 2 in the same detection area are arranged around the base 11 to form a heating unit, and there is a gap between adjacent heating units and the inner side wall of the heating disc 1 to form a heating space, and a containing cavity is formed in the closed box 2.

[0047] A heat preservation cover 3 is detachably connected to the top of the heating disc 1.

[0048] The containing cavity and the heating space are filled with sand particles, the heating unit can rotate along the base 11, the base 11 is used to place the digestion tube, and the heating unit is used to wrap the digestion tube.

[0049] As shown in Figure 6 , the top of the closed box 2 is provided with a cover 23, one side of the closed box 2 in the width direction is connected with a convex strip, and the other side of the closed box 2 in the width direction is provided with a clamping groove for clamping the convex strip.

[0050] As shown in Figure 1 and Figure 2 , and Figure 6 , the cross section of the closed box 2 is a fan-shaped structure, and the closed boxes 2 in the same detection area are arranged in a circular ring structure around the base 11.

[0051] Specifically, a temperature sensor and an electric control device are arranged on the heating pot, so that the heating disc 1 can be controlled to heat, the heating disc 1 is equally divided into a plurality of detection areas, the center of each detection area is fixedly connected with a base 11, the heating disc 1 can be connected to a power supply to generate heat, and the size of each detection area is equal, and preferably, the detection area is a square.

[0052] When heating for experiment, the closed box 2 is first loaded into the base 11, in this embodiment, there are four closed boxes 2 connected with each other in one detection area, the adjacent closed boxes 2 are clamped with each other by the convex strip and the clamping groove to form a circular ring-shaped heating unit, then the digestion tube is inserted into the center of the heating unit above the base 11, after the digestion tube is placed, the sand particles are filled into the heating space and the containing cavity, the sand particles on the top layer are smoothed by a tool, and finally the heat preservation cover 3 is placed, the heat preservation cover 3 is consistent with the opening area of the heating disc 1, can shield the sand particles on the heating disc 1, avoid heat loss, and can press downward the heat preservation cover 3 to make the sand particles as much as possible to be pressed, reduce the gap between the adjacent sand particles, and further improve the heat conduction efficiency between the sand particles.

[0053] It should be noted that the sand bath heating is inevitable, that is, the center sand particle temperature is high, and the edge sand particle temperature is low; in the present application, after the above arrangement work is completed and the heating disc 1 is heated for a certain time, the above temperature unevenness will also occur; at this time, any one closed box 2 in the detection area can be rotated, and other adjacent closed boxes 2 will also rotate to realize that the closed box 2 deviated to one side of the center is rotated to the edge of the heating disc 1, and the closed box 2 at the edge is rotated to the center; preferably, the closed box 2 can be higher than the heat preservation cover 3, so as to facilitate rotation, and during the operation process, the digestion tube can be fixed by hand, and the other hand rotates the closed box 2 to realize the exchange of high and low temperature zones.

[0054] Example 2:

[0055] As shown in Figure 2 and Figure 6 , the outer peripheral surface of the closed box 2 is fixedly connected with a material overturning convex rib 21, the material overturning convex rib 21 is of an arc structure, and the center of the material overturning convex rib 21 is concentrically arranged with the center of the closed box 2.

[0056] As shown in Figure 2 and Figure 6 , a plurality of material overturning convex ribs 21 are arranged in parallel along the height direction of the closed box 2, and the lengths of the material overturning convex ribs 21 on the closed box 2 gradually decrease towards the bottom.

[0057] As shown in Figure 2 and Figure 6 , one end of the material overturning convex rib 21 away from the closed box 2 is an arc surface, and the end face of the material overturning convex rib 21 along the length direction is an inclined surface, and the inclined surface faces the closed box 2.

[0058] As shown in Figure 4 and Figure 5 , the bottom surface of the heat preservation cover 3 is provided with a partition plate 31, the partition plate 31 is used to divide the bottom surface of the heat preservation cover 3 to form a plurality of heating zones, the heating zones correspond to the detection zones one by one, the bottom surface of the heat preservation cover 3 is provided with a plurality of modules 32, the height of the module 32 is equal to the depth of the heating disc 1, four modules 32 are arranged corresponding to each heating zone, and the modules 32 in each heating zone are arranged at four corners respectively.

[0059] As shown in Figures 2 to 5 , the face of the module 32 along the height direction includes two mutually perpendicular planes and an arc-shaped concave surface, and the rotation path of the material overturning convex rib 21 passes through the concave surface of the module 32.

[0060] As shown in Figure 4 and Figure 5 , the side wall of the partition plate 31 and the concave surface of the module 32 in the same heating zone are located on the same circular arc, and the heating zone is a circular area.

[0061] Specifically, in the process of rotating the closed box 2 as in Embodiment 1, the material-turning protrusions 21 on the outer circumferential surface of the closed box 2 also move, the material-turning protrusions 21 can stir the sand particles in the heating space, and the multiple closed boxes 2 in the same detection area simultaneously drive the material-turning protrusions 21 to rotate, which can achieve the effect of mixing and stirring, and can mix the sand particles with high temperature and the sand particles with low temperature in the heating space to realize heat exchange and minimize the situation that the center temperature is high and the edge temperature is low.

[0062] More preferably, the heat preservation cover 3 is detachably connected with a partition plate 31 below, the partition plate 31 is in a grid structure intersecting longitudinally and transversely, and the partition plate 31 can be detached from the heat preservation cover 3 and assembled to the heating disc 1 before filling the sand particles, for separating the detection area, and more preferably, the heat preservation cover 3 is also provided with a breathable hole corresponding to each heating area.

[0063] In this embodiment, after the closed box 2 is installed, the heat preservation cover 3 is directly installed, then the sand particles are injected into the heating space through the breathable holes, and the sand particles are injected into the containing cavity of the closed box 2 by opening the cover 23, and after filling, the heating disc 1 is shaken to keep the sand particles flat; when the closed box 2 is subsequently rotated, the material-turning protrusions 21 pass through the partition plate 31 and the module 32, the concave surfaces of the partition plate 31 and the module 32 together form a heating area, which is a circular area and can be in contact with the material-turning protrusions 21, so as to avoid the dead angle of the material-turning protrusions 21 at the right-angled corners of the heating disc 1, the setting of the heating area not only further reduces the space of the detection area, but also makes the heat transfer faster, and the material-turning protrusions 21 can pass through any place, so that the sand particles with different temperatures in the heating space are fully mixed.

[0064] Embodiment 3:

[0065] The inner circumferential surface of the closed box 2 is provided with a thread line, the thread lines of the multiple closed boxes 2 in the same heating unit form a continuous internal thread line, the sleeve 24 is sleeved on the wall of the base 11, the outer circumferential wall of the sleeve 24 is connected with an external thread for thread connection with the internal thread line, the top thread termination line of the external thread is lower than half the height of the sleeve 24, the heat preservation cover 3 is provided with a through hole, and the bottom surface of the closed box 2 is provided with a through slot 22.

[0066] The top surface of the base 11 is provided with a type slot, and the bottom of the sleeve 24 is connected with a limiting block for clamping with the type slot.

[0067] Specifically, when the closed box 2 is rotated to mix the sand particles in the heating space, the closed box 2 has a threaded line. The four closed boxes 2 of the same heating unit form a complete internal thread. The base 11 is also fitted with a sleeve 24. When the closed box 2 is rotated, the closed box 2 is rotated and rises vertically at the same time through the cooperation of the internal thread and the external thread on the sleeve 24. The material turning ridge 21 also rotates and rises with it. Multiple material turning ridges 21 can gradually stir and mix the sand particles from the bottom of the heating space upwards, which can make the sand particles more uniformly mixed.

[0068] When the closed box 2 rises to the end line of the external thread of the sleeve 24, it can no longer rotate. At this time, the closed box 2 can be pulled up. The limiting block that is engaged with the base 11 of the sleeve 24 disengages from the groove and rises vertically. During the initial rotation and subsequent vertical rise, the heated sand particles in the closed box 2 gradually leak into the heating space along the through groove 22. During this period, the material turning protrusion 21 will also mix with the leaked sand particles during rotation. During the subsequent vertical rise, the multiple material turning protrusions 21 set along the height direction can also push the leaked sand particles while rising, achieving a certain degree of mixing.

[0069] After the enclosed box 2 rises to a certain height, it stops rising, allowing a certain amount of space at the bottom to remain within the heating space. (This is in conjunction with the attached...) Figure 2 It can be seen that after the sealed box 2 rises: firstly, the sealed box 2 and the sleeve 24 block the through hole to prevent heat loss from the heating box; secondly, it can limit the digestion tube to prevent the digestion tube from tilting or deviating during subsequent experiments, thus affecting the experimental results; thirdly, in traditional experiments, the experimental sample usually falls to the bottom of the digestion tube and is heated by the sand bath, rather than filling the digestion tube. After the sealed box 2 and the sleeve 24 rise, they leave the bottom of the digestion tube, thereby allowing the sand particles to wrap around the bottom of the digestion tube, achieving sand bath heating.

[0070] Example 4:

[0071] like Figure 1 and Figure 2 As shown, the top surface of the heat insulation cover 3 is provided with several grooves 33 around the through hole, and a baffle 34 is rotatably connected in the grooves 33.

[0072] Specifically, after the sealed box 2 rises as in Example 3, the baffle 34 above the heat insulation cover 3 can be moved to the underside of the turning protrusion 21 to restrict the sealed box 2 from falling.

[0073] In this invention, a complete and large heating plate 1 is divided into several detection zones. Within each detection zone, the partition 31 and module 32 of the heat insulation cover 3 further limit the movement of the heating zone, forming a circular and smaller heating zone. It should be noted that the temperature of the heating plate 1 itself is uniform. It is only in traditional sand bath heating that the sand particles are too numerous, have gaps between them, and are in contact with the outside environment, which causes the temperature of the center of the sand particles to be too high and the temperature of the edges to be low. This is not the reason of the heating plate 1.

[0074] In the present embodiment, after the heating disc 1 is heated, the temperature is uniformly transmitted to each heating area. The heat in each heating area is further transmitted to the sand particles in the area, achieving sand bath heating. The heating efficiency of the heating disc 1 remains unchanged, but the number of sand particles in each heating area of the relatively complete heating disc 1 is significantly reduced. It can be understood that the heating efficiency and area of the original heating disc 1 remain unchanged, but multiple small areas can be simultaneously heated. The sand particles in each heating area are relatively small in space and are not in contact with the outside world due to being enclosed by the heat preservation cover 3 and the closed box. Therefore, heat conduction can be better, and temperature unevenness can be avoided. The metal partition plate 31 and the module 32, as well as the closed box 2 after rising, can provide a certain heat preservation effect for the sand particles in the heating area, avoid heat dissipation, and further improve the heating effect.

[0075] The above specific embodiments further illustrate the purpose, technical solutions, and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-zone sand bath apparatus for heating soil organic matter, characterized by, The utility model relates to a heating pot, the top surface of heating pot is provided with heating disc (1), form a plurality of equal area and sequentially adjacent detection area on heating disc (1), the center of each detection area is fixedly connected with pedestal (11), A plurality of closed boxes (2), each closed box (2) is detachably connected on pedestal (11), a plurality of closed boxes (2) in same detection area are arranged around pedestal (11) and form heating unit, there is gap between adjacent heating unit, heating unit and adjacent inner side wall of heating disc (1) and forms heating space, forms containing cavity in closed box (2), Heat -preserving cover (3), heat -preserving cover (3) is detachably connected at the top of heating disc (1), The containing cavity and heating space are filled with sand, the heating unit can rotate along the pedestal (11), the pedestal (11) is used to place digestion tube, the heating unit is used to wrap digestion tube, The cross section of closed box (2) is fan structure, the closed box (2) in same detection area mutually constitutes ring structure around pedestal (11), the outer peripheral surface of closed box (2) is fixedly connected with material turning convex rib (21), the material turning convex rib (21) is arc structure, the center of material turning convex rib (21) is concentric with the center of closed box (2), The inner peripheral surface of closed box (2) is provided with thread line, the thread line of a plurality of closed boxes (2) in same heating unit constitutes continuous internal thread line, the sleeve (24) is arranged on the wall of pedestal (11), the outer thread of outer thread of sleeve (24) is connected with internal thread line, the top thread termination line of outer thread is lower than half of the height of sleeve (24), the through hole is formed in heat -preserving cover (3), the bottom surface of closed box (2) is provided with through slot (22). The top of closed box (2) is provided with cover (23), one side of closed box (2) along the width direction is connected with convex strip, the other side of closed box (2) along the width direction is provided with clamping groove for clamping with convex strip.

2. A multi-zone sand bath apparatus for heating soil organic matter according to claim 1, wherein A plurality of material turning convex ribs (21) are arranged in the height direction of closed box (2), the length of material turning convex rib (21) on closed box (2) gradually shortens towards the bottom.

3. A multi-zone sand bath apparatus for heating soil organic matter according to claim 1, wherein The end of material turning convex rib (21) away from closed box (2) is arc surface, the end face of material turning convex rib (21) along the length direction is inclined surface, the inclined surface is towards closed box (2).

4. A multi-zone sand bath apparatus for heating soil organic matter according to claim 1, wherein The bottom surface of heat -preserving cover (3) is provided with baffle (31), baffle (31) is used to divide the bottom surface of heat -preserving cover (3) and form a plurality of heating areas, the heating area corresponds with detection area one by one, the bottom surface of heat -preserving cover (3) is provided with a plurality of modules (32), the height of module (32) is equal to the depth of heating disc (1), four modules (32) are arranged in each heating area, and the modules (32) in each heating area are arranged at four corners respectively.

5. A multi-zone sand bath apparatus for heating soil organic matter according to claim 1, wherein ​ 6. A multi-zone sand bath apparatus for heating soil organic matter according to claim 5, wherein The surface of the module (32) in the height direction comprises two mutually perpendicular planes and an arc-shaped concave surface, and the rotating path of the turnover convex rib (21) passes through the concave surface of the module (32).

7. A multi-zone sand bath apparatus for heating soil organic matter according to claim 6, wherein The side wall of the partition (31) and the concave surface of the module (32) in the same heating area are located on the same circular arc, and the heating area is a circular area.

8. A multi-zone sand bath apparatus for heating soil organic matter according to claim 1, wherein The top surface of the base (11) is provided with a type groove, the bottom of the sleeve (24) is connected with a limiting block for clamping the type groove, the top surface of the heat preservation cover (3) is surrounded and provided with a plurality of grooves (33) near the through hole, and the grooves (33) are rotationally connected with the baffle plates (34).

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