Temperature-controllable electric heating plate

Abstract

The utility model discloses a temperature control electric heating plate can adjust, relate to laboratory heating equipment technical field. Including heating device ontology, the aluminium heating plate is provided with on heating device ontology top, the graphite board is provided with at aluminium heating plate top, the surface of graphite board has the teflon coating that sprays, teflon has the effect of high temperature resistance, anticorrosion, and the control instrument is provided with on heating device ontology, and the control instrument can control semiconductor to the aluminium heating plate on -off control, and then realizes temperature control. The utility model graphite board heat conduction is fast and even, and the double -deck heat preservation structure that cooperation aluminium heating plate outer wall is established first heat preservation layer and second heat preservation layer has improved the thermal efficiency, adopts the combination of teflon coating and metal support, has improved the corrosion resistance of device, has prolonged the service life of equipment, has solved the long processing time of traditional soil test technology, the individual element of sample is not sufficient, and the low analysis efficiency, the uneven heating, the problem such as high cost of temperature control, etc.

Description

Technical Field

[0001] This utility model relates to the technical field of laboratory heating equipment, specifically to an adjustable temperature control electric heating plate. Background Technology

[0002] Laboratory hot plates and graphite digestion apparatus are commonly used experimental devices, playing an important role in the study of various available forms and single elements in chemistry, biology, environment, soil, and other fields.

[0003] Traditional electric heating plates are mainly made by firing loess at high temperatures and inserting resistance wires. Their main drawbacks are slow heat conduction, long power-on time, and long heating time. They need to be powered on more than an hour in advance. Because the resistance wires are exposed at the heating plate's ports, they are susceptible to corrosion from acids and alkalis, frequently leading to open circuit failures.

[0004] To address the problems of long processing time, low analysis efficiency, uneven heating, and inability to control temperature in traditional soil testing techniques, this paper proposes a more efficient and accurate soil testing solution based on a graphite digester and electric heating plate, through technical optimization and equipment improvement, to enhance testing efficiency and data quality. Utility Model Content

[0005] The purpose of this invention is to provide an adjustable temperature control electric heating plate to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: an adjustable temperature control electric heating plate, comprising: a heating device body,

[0007] An aluminum heating plate is installed above the main body of the heating device, and a graphite plate is installed on top of the aluminum heating plate. The surface of the graphite plate is coated with Teflon, which has the functions of high temperature resistance and corrosion resistance.

[0008] The heating device is equipped with a control instrument that controls the semiconductor to turn the aluminum heating plate on and off, thereby achieving temperature control.

[0009] Furthermore, the top of the heating device body is provided with a metal bracket, and the inner wall of the metal bracket is covered with two layers of insulation material, namely the first insulation layer and the second insulation layer.

[0010] Furthermore, the first insulation layer is a ceramic fiber board, and the second insulation layer is aluminum silicate fiber cotton.

[0011] Furthermore, the aluminum heating plate is enclosed by a closed insulation layer formed by the first insulation layer and the second insulation layer, so that the heat of the aluminum heating plate can only be conducted upward to the graphite plate.

[0012] Furthermore, the graphite plate has several round holes on its upper surface. Under the action of the round holes, the graphite plate is transformed into a perforated graphite plate, and the round holes are adapted to the crucible.

[0013] Furthermore, a temperature sensor is mounted on the graphite plate to detect the temperature of the graphite plate and transmit the signal to the control instrument.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] This adjustable temperature-controlled heating plate features a graphite plate that conducts heat quickly and evenly. Combined with the double-layer insulation structure of the first and second insulation layers on the outer wall of the aluminum heating plate, it improves thermal efficiency. The combination of Teflon coating and metal support enhances the device's corrosion resistance and extends its service life. It solves the problems of long processing time, incomplete dissolution of individual elements in samples, low analysis efficiency, uneven heating, inability to control temperature, and high cost that exist in traditional soil testing techniques. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0017] Figure 2 This is a partial cross-sectional schematic diagram of the present invention;

[0018] Figure 3 This is a flowchart of the temperature control circuit of this utility model;

[0019] Figure 4 This is a schematic diagram of the working principle of the temperature control circuit of this utility model.

[0020] In the diagram: 1. Heating equipment body; 2. Control instrument; 3. Metal bracket; 4. Temperature sensor; 5. Graphite plate; 6. Round hole; 7. Crucible; 8. First insulation layer; 9. Second insulation layer; 10. Aluminum heating plate. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," etc., are used only for descriptive distinction and should not be construed as indicating or implying relative importance. All electrical components mentioned in this document are electrically connected to an external main controller and 220V AC mains power, and the main controller can be a conventionally known device such as a computer that provides control.

[0023] In the description of the embodiments of this utility model, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] like Figures 1-4 As shown, this utility model provides a technical solution: an adjustable temperature control electric heating plate, including a heating device body, an aluminum heating plate 10 is arranged above the heating device body, a graphite plate 5 is arranged on the top of the aluminum heating plate 10, the surface of the graphite plate 5 is coated with a Teflon coating, Teflon has the functions of high temperature resistance and corrosion resistance, and a control instrument 2 is arranged on the heating device body. The control instrument 2 can control the semiconductor to control the conduction and disconnection of the aluminum heating plate 10, thereby realizing temperature control.

[0025] like Figure 1-4 As shown in the embodiment of this application, a metal support 3 is provided on the top of the heating device body. The inner wall of the metal support 3 is covered with two layers of insulation material, namely a first insulation layer 8 and a second insulation layer 9. The first insulation layer 8 is a ceramic fiber board, and the second insulation layer 9 is aluminum silicate fiber cotton. The aluminum heating plate 10 is wrapped by the closed insulation layer formed by the first insulation layer 8 and the second insulation layer 9, so that the heat of the aluminum heating plate 10 can only be conducted upward to the graphite plate 5. Specifically, the metal support 3 is made of 304 stainless steel, which is corrosion resistant. The first insulation layer 8 is made of ceramic fiber board, which has the characteristics of high temperature resistance and can block the heat generated by the aluminum heating plate 10 from diffusing to the side. The second insulation layer 9 is made of aluminum carbonate fiber cotton, which is soft and heat-insulating and can fill the space between the ceramic fiber board and the aluminum heating plate 10 to reduce the heat loss rate. When the aluminum heating plate 10 is wrapped by the double insulation layer, only the upper surface is in contact with the graphite plate 5, thereby ensuring unidirectional heat conduction.

[0026] like Figure 1-4As shown in the embodiment of this application, several circular holes 6 are formed on the upper surface of the graphite plate 5. Under the action of the circular holes 6, the graphite plate 5 is transformed into a perforated graphite plate 5. The circular holes 6 are adapted to the crucible 7. A temperature sensor 4 is mounted on the graphite plate 5. The temperature sensor 4 is used to detect the temperature of the graphite plate 5 and transmit the signal to the control instrument 2. Specifically, the surface of the graphite plate 5 is uniformly coated with a Teflon coating, which can withstand pH 0-14 chemical corrosion and a high temperature of 280°C. Circular holes 6 are arrayed on the upper surface of the graphite plate 5 to adapt to the crucible 7. The crucible 7 here is a polytetrafluoroethylene crucible 7, thereby ensuring that the sample heating area is consistent. The graphite plate 5 is equipped with a temperature sensor 4 to monitor the temperature of the graphite plate 5 in real time and transmit the data to the control instrument 2.

[0027] like Figure 1-4 As shown in the embodiments of this application, in accordance with GB / T 14506.30-2010, this temperature-controlled heating plate is suitable for the preliminary preparation of solutions for the determination of the amounts of 44 elements, including lithium, beryllium, scandium, titanium, vanadium, manganese, cobalt, nickel, copper, zinc, gallium, arsenic, rubidium, strontium, yttrium, zirconium, niobium, molybdenum, cadmium, indium, cesium, barium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, zirconium, hafnium, tantalum, tungsten, thallium, lead, bismuth, thorium, and uranium, in silicate rocks. It is also suitable for the preliminary preparation of solutions for the determination of the amounts of the above elements in soil and sediment samples.

[0028] According to GB / T 14506.32-2019, this temperature-controlled electric heating plate is suitable for the preliminary preparation of solutions for the determination of calcium, magnesium, potassium, sodium, aluminum, iron, titanium, manganese, copper, lead, zinc and phosphorus in silicate rocks.

[0029] like Figure 1-4 As shown in the embodiments of this application, a comparison is made between a common non-porous, non-temperature-controlled electric heating plate and a self-made temperature-controlled electric heating plate in terms of chromium, nickel, and lead element analysis.

[0030] Chromium, nickel, and lead were analyzed by ICP-MS using an acid-soluble pretreatment method, according to GB / T14506.30-2010. The pretreatment involved changing the hot plate, and the results were compared. The experimental results are as follows:

[0031]

[0032] Table 1 Comparison between homemade temperature-controlled electric heating plate and ordinary non-perforated, temperature-controlled electric heating plate

[0033]

[0034] Table 2 Experimental data for traditional electric heating plates

[0035]

[0036] Table 3 Experimental data of self-made temperature-controlled electric heating plate

[0037] like Figure 1-4 As shown in the embodiments of this application, a comparison is made between a microwave digester and a self-made temperature-controlled heating plate in the analysis of chromium, nickel, and lead elements.

[0038] Chromium, nickel, and lead were analyzed by ICP-MS using acid dissolution and microwave digestion methods. For pretreatment, acid dissolution with a hot plate and microwave digestion were used, and the results were compared. Data from the acid dissolution method are shown in Table 2. The experimental results are as follows:

[0039]

[0040] Table 4 compares the results with those of a microwave digester.

[0041]

[0042] Table 6 Microwave Digester Data

[0043] The comparison shows that, under the same conditions, the acid dissolution method using a self-made electric hot plate has advantages over traditional electric hot plates and microwave digestion apparatus in terms of time, economy, and safety. In terms of results, the acid dissolution method using a self-made electric hot plate produces better results for the samples, with better parallelism and error. Therefore, the self-made electric hot plate is more suitable for production projects.

[0044] The working principle of this utility model is as follows:

[0045] When the aluminum heating plate 10 is energized and heated, the heat is conducted to the graphite plate 5. The graphite plate 5 is equipped with a temperature sensor 4. The temperature sensor 4 transmits the detected temperature change signal to the control instrument 2. The control instrument 2 controls the semiconductor to control the on and off of the aluminum heating plate 10, realizing automatic temperature control. When the temperature reaches the critical point of the set temperature, the control instrument 2 controls the semiconductor to conduct electricity intermittently, realizing the power saving effect.

[0046] Temperature sensor 4 is a PT100 platinum resistance temperature sensor. Temperature sensor 4 is mounted 2-5mm below the surface of graphite plate 5 to ensure direct sensing of the temperature of graphite plate 5. Temperature sensor 4 is used to collect the temperature signal of graphite plate 5 in real time and convert the temperature change into an electrical signal (such as the change of resistance value). The resistance signal output by temperature sensor 4 is amplified and filtered by signal amplifier and filter, and converted into a 0-10V standard voltage signal. The voltage signal is transmitted to control instrument 2. Control instrument 2 (PD temperature controller) receives the voltage signal and compares it with the temperature set by the user. Control instrument 2 outputs the comparison result as a PWM pulse signal to solid-state relay (SSR). Solid-state relay switches the main circuit on and off according to the PWM signal to realize the adjustment of aluminum heating plate 10.

[0047] When the measured temperature is less than the set temperature - 2℃, a high-level signal is output, the semiconductor switch is turned on, and the aluminum heating plate 10 heats at full power.

[0048] When the measured temperature approaches the set temperature (-2℃≤deviation≤+3℃), a pulse signal is output, and the semiconductor switch is intermittently turned on (the on / off cycle is 10-30 seconds) to maintain temperature stability.

[0049] When the measured temperature is greater than the set temperature + 3℃, a low-level signal is output, the semiconductor switch is turned off, and heating stops.

[0050] In summary, this utility model discloses an adjustable temperature control electric heating plate, including a heating device body, an aluminum heating plate 10 disposed above the heating device body, a graphite plate 5 disposed on the top of the aluminum heating plate 10, and a Teflon coating sprayed on the surface of the graphite plate 5. Teflon has the properties of high temperature resistance and corrosion resistance. A control instrument 2 is disposed on the heating device body, which can control the semiconductor to control the conduction and disconnection of the aluminum heating plate 10, thereby realizing temperature control. The graphite plate 5 of this utility model has fast and uniform heat conduction. Combined with the double-layer insulation structure of the first insulation layer 8 and the second insulation layer 9 on the outer wall of the aluminum heating plate 10, the thermal efficiency is improved. The combination of Teflon coating and metal bracket 3 improves the corrosion resistance of the device and extends the service life of the equipment. It solves the problems of long processing time, incomplete dissolution of individual elements in the sample, low analysis efficiency, uneven heating, inability to control temperature, and high cost in traditional soil testing technology.

[0051] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended embodiments and their equivalents.

Claims

1. An adjustable temperature control electric heating plate, comprising: The heating device body is characterized by: An aluminum heating plate is installed above the main body of the heating device, and a graphite plate is installed on top of the aluminum heating plate. The surface of the graphite plate is coated with Teflon, which has the functions of high temperature resistance and corrosion resistance. The heating device is equipped with a control instrument that controls the semiconductor to turn the aluminum heating plate on and off, thereby achieving temperature control.

2. The adjustable temperature control electric heating plate according to claim 1, characterized in that: The heating device body is provided with a metal support on the top, and the inner wall of the metal support is covered with two layers of insulation material, namely the first insulation layer and the second insulation layer.

3. The adjustable temperature control electric heating plate according to claim 2, characterized in that: The first insulation layer is a ceramic fiber board, and the second insulation layer is aluminum silicate fiber cotton.

4. The adjustable temperature control electric heating plate according to claim 3, characterized in that: The aluminum heating plate is enclosed by a closed insulation layer formed by the first insulation layer and the second insulation layer, so that the heat of the aluminum heating plate can only be conducted upward to the graphite plate.

5. The adjustable temperature control electric heating plate according to claim 4, characterized in that: The graphite plate has several round holes on its upper surface. Under the action of the round holes, the graphite plate is transformed into a perforated graphite plate, and the round holes are adapted to the crucible.

6. The adjustable temperature control electric heating plate according to claim 5, characterized in that: A temperature sensor is mounted on the graphite plate to detect the temperature of the graphite plate and transmit the signal to the control instrument.

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