CN110553475B

CN110553475B - Drying oven and heat flow circulation control method

Info

Publication number: CN110553475B
Application number: CN201910818714.6A
Authority: CN
Inventors: 喻季红; 龚伟业; 谢品德; 张仲焘
Original assignee: Hunan Sundy Science and Technology Co Ltd
Current assignee: Hunan Sundy Science and Technology Co Ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2024-02-02
Anticipated expiration: 2039-08-30
Also published as: CN110553475A

Abstract

The invention discloses a drying oven and a heat flow circulation control method, which belong to the technical field of sample total moisture measurement and are used for solving the technical problem of low drying efficiency of the existing drying oven, and the adopted technical scheme is as follows: the heating device comprises a box body, and an air return channel is arranged at two sides of a main cavity formed by encircling the box body and a heating cavity main cavity, and the main cavity, the heating cavity and the two air return channels are sequentially communicated to form an internal circulation air channel; the heating cavity is provided with an exhaust port at the air inlet of each return air channel, and a telescopic folding door switched between a folding state and a stretching state is arranged at the exhaust port; when the telescopic folding door is in a folding state, the exhaust port is blocked by the telescopic folding door in the folding state, and the air inlets of the air return channels are opened to perform an internal circulation mode; when the telescopic folding door is in the stretching state, the air inlets of the air return channels are blocked by the telescopic folding door in the stretching state, and the air outlets are opened to perform an external circulation mode. The technical scheme has the advantages of high drying efficiency, strong applicability and the like.

Description

Drying oven and heat flow circulation control method

Technical Field

The invention mainly relates to the technical field of full moisture measurement of samples, in particular to a drying oven and a heat flow circulation control method.

Background

For the determination of the total moisture of the coal sample, the drying of the sample and the verification of the weight of the sample are the most important two links, particularly the advantages and disadvantages of a drying box directly affect the drying efficiency and the compliance of the drying environment, particularly the latest line standard requirements put forward higher requirements on the drying box, and the forced nitrogen passing requirements are further put forward on the lignite line standard.

The traditional drying box adopts the mode of light wave heating or light wave and blast air heating combination, does not accord with national standard and surveys the drying mode requirement of full water to the coal sample, and traditional drying box is very big simultaneously, and under the circumstances of last standard to the forced nitrogen-introducing drying of brown coal, very big to nitrogen consumption, simultaneously also be difficult to guarantee that the nitrogen concentration reaches 99.9% in the drying box requirement, simultaneously the temperature in the big drying box is difficult to guarantee the cavity in qualified value range, and moreover traditional drying box is because gas exchange speed is insufficient, and the vapor stream is difficult to be discharged fast, leads to drying efficiency lower.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the technical problems existing in the prior art, the invention provides a drying oven with high drying efficiency and a heat flow circulation control method.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the utility model provides a drying cabinet, includes the box and encloses the main cavity that closes the formation by the box, the one end of box is equipped with the introduction door, the opposite one end of introduction door is provided with the heating chamber with main cavity intercommunication, be provided with blast heating element in the heating chamber, the both sides of main cavity all are provided with the return air passageway, each the air inlet of return air passageway all with the heating chamber intercommunication, each the gas outlet of return air passageway is located and is close to the both sides of introduction door, and all with main cavity intercommunication, main cavity, heating chamber and two return air passageway communicate in proper order and form the inner loop wind channel; an air inlet component facing the heating cavity is arranged on one side of the sample inlet door of the main cavity; the heating cavity is provided with an exhaust port at the air inlet of each return air channel, and a telescopic folding door switched between a folding state and a stretching state is arranged at the exhaust port; when the telescopic folding door is in the folding state, the exhaust port is blocked by the telescopic folding door in the folding state, and the air inlets of all the return air channels are opened to perform an internal circulation mode; when the telescopic folding door is in the stretching state, the air inlet of each return air channel is blocked by the telescopic folding door in the stretching state, and the air outlet is opened to perform an external circulation mode.

As a further improvement of the above technical scheme:

the telescopic folding door comprises a plurality of door bodies which are hinged in sequence, wherein the door body on one side is hinged on the inner wall of the box body, the door body on the other side is connected with a driving piece, and the driving piece makes linear motion to drive the door body to switch between a folding state and a stretching state.

The driving piece comprises a rotating motor and a screw rod mechanism, and the rotating motor is connected with the door body through the screw rod mechanism.

The air inlet assembly comprises a nitrogen air inlet unit, an air inlet unit and a strip gas distributor, and the gas distributor is arranged along the arrangement direction of the sample inlet door; the nitrogen gas inlet unit and the air inlet unit are respectively connected with the gas distributor, and the nitrogen gas inlet unit and the air inlet unit are interlocked.

The nitrogen inlet unit comprises a nitrogen source, a pressure reducing valve, a nitrogen electric control switch and a drying module which are sequentially connected, and the drying module is connected with one end of the gas distributor; the air inlet unit comprises an air electric control switch which is connected with the other end of the air distributor; the nitrogen gas electric control switch is electrically or mechanically interlocked with the air electric control switch.

The sample injection door comprises a door plate, a rotating rod and a driving assembly, one end of the door plate is rotatably mounted on the box body through a rotating shaft, one end of the rotating rod is connected with the door plate, the other end of the rotating rod is connected with the driving assembly, and the driving assembly is used for driving the rotating rod to rotate so as to realize door plate opening and closing and provides certain self-closing force when the door plate is closed.

The sample introduction door comprises a door plate, wherein the upper end of the door plate is arranged on the box body through a hinge piece so that the door plate can be turned over and opened in the box body under the pushing of external force or can be closed by falling back under the action of gravity.

The lower end edge of the door plate is in an arc transition shape.

The blast heating assembly comprises a blast assembly and a heating assembly; the air blast assembly comprises a centrifugal fan and centrifugal fan blades; the centrifugal fan is arranged on the outer side of the box body, and the centrifugal fan blades are arranged in the heating cavity and connected with the centrifugal fan; and the main chamber is provided with an air inlet of the heating cavity at the inner circle of the centrifugal fan blade.

The heating component is positioned at one side or two sides of the air blowing component in the heating cavity and is used for heating the air.

The heating component is a PTC heating plate.

The shape of the PTC heating piece is matched with that of the heating cavity, and a wind shield is arranged at a connecting terminal of the PTC heating piece in the heating cavity.

The air blast component and the heating component are both positioned on the mounting plate at one side of the box body.

And the inner side of the mounting plate is paved with a heat insulation plate.

A temperature detection piece is arranged in the box body and used for detecting the temperature of the gas in the main cavity; the heating component is connected with the temperature detection piece and is used for receiving the detected gas temperature value to carry out heating adjustment so as to maintain the gas temperature in the main cavity within a constant range.

The temperature detection part comprises a fixing seat and a temperature measurement probe, wherein the fixing seat is detachably connected to the side wall of the return air channel, and the temperature measurement probe is installed in the fixing seat.

The air outlet of each return air channel comprises a plurality of vertical strip-shaped holes, and the length of each strip-shaped hole is sequentially shortened along the air conveying direction.

And a mixed flow plate is arranged at the air outlet of each return air channel.

And a heat insulation layer is paved on the outer layer of the box body.

The section of the main cavity close to the heating cavity gradually contracts towards the heating cavity.

And a concentration detection piece is arranged in the main cavity and used for detecting the concentration of water vapor so as to control the telescopic folding door to switch between a folding state and a stretching state.

The invention also discloses a heat flow circulation control method based on the drying oven, which comprises the following steps:

s01, detecting the concentration of water vapor in a main chamber in the box body;

s02, when the detected water vapor concentration does not reach the preset water vapor concentration, controlling the telescopic folding door to be switched to a folding state, plugging the exhaust port, and opening the air inlet of each return air channel to dry the sample in an internal circulation mode; when the detected water vapor concentration reaches the preset water vapor concentration, the telescopic folding door is controlled to be switched to a stretching state, the air inlets of the air return channels are blocked, and the air outlets are opened to enter an external circulation mode for discharging water vapor.

As a further improvement of the above technical scheme:

in step S01, the water vapor concentration of the main chamber in the tank is obtained by the water vapor concentration detecting member or according to the internal circulation pattern on time in the tank.

In step S02, when the external circulation mode is entered, the internal circulation mode is switched to after a predetermined time.

Compared with the prior art, the invention has the advantages that:

according to the drying box, through the air blowing effect of the air blowing heating component, the internal air circulation speed in the circulating air duct can be increased, the circulation period is short, and the drying effect is improved; furthermore, the air is circularly heated by matching with the blast heating component, so that the temperature rise of the gas is accelerated, the temperature rise time is shortened, the evaporation of water inside and outside a sample is accelerated to form water vapor, the consumption of nitrogen in a main cavity is greatly reduced, and meanwhile, the power of a cavity heating plate can be greatly reduced by an internal circulation mode, and the aim of saving energy can be achieved; when the concentration of the water vapor in the main cavity reaches or is close to the saturated vapor pressure, the switching between the folding state and the stretching state is realized through the telescopic folding door, the switching from the internal circulation mode to the external circulation mode is realized, the discharge of the water vapor is accelerated through the exhaust port, and the drying efficiency of the subsequent samples is further improved; in addition, the structure of the telescopic folding door is simple and ingenious, and the switching is simple, quick, convenient and effective.

According to the drying box, the temperature detection piece is arranged in the box body and used for detecting the gas temperature in the main cavity so as to heat and regulate the heating component, so that the gas temperature in the main cavity is maintained in a constant range.

According to the drying box disclosed by the invention, the air outlet of each air return channel comprises a plurality of vertical strip-shaped holes, and the lengths of the strip-shaped holes are sequentially shortened along the air conveying direction, so that the whole air outlet is V-shaped, hot air flows in the air return channels can be uniformly mixed, and the temperature difference of the air outlets is reduced; further, the air outlets of the air return channels are provided with mixed flow plates for uniformly mixing the hot air again, so that the temperature difference of the air at each position is further reduced, and the temperature in the whole main cavity is ensured to be within a reasonable range.

The drying box provided by the invention has the advantages that the shape of the box body is compatible with the drying operation in the full-moisture measurement of the coal samples with the size of 6mm and 13mm, and the drying box can be flexibly configured according to the requirements of customers. In addition, the whole flat form that is of box, and the one section that the main cavity is close to the heating chamber contracts to the heating chamber gradually, not only is convenient for the circulation of gas in the main cavity, can guarantee simultaneously that the shape and the inner space of box are minimum, reduces the consumption of nitrogen gas under the circumstances of guaranteeing drying efficiency, has practiced thrift the required consumptive material cost of dry operation.

According to the heat flow circulation control method, the internal circulation accelerates the evaporation of water inside and outside the sample to form water vapor, so that the consumption of nitrogen in the main cavity is greatly reduced, and meanwhile, the internal circulation mode can greatly reduce the power of the cavity heating plate and can achieve the purpose of energy conservation; when the concentration of the water vapor in the main cavity reaches or is close to the saturated vapor pressure, the folding state is switched to the stretching state through the telescopic folding door, so that the switching from the internal circulation mode to the external circulation mode is realized, the discharge of the water vapor is accelerated through the exhaust port, and the drying efficiency of the subsequent samples is further improved; through the cooperation of the internal and external circulation modes, the rapid drying of the sample is realized.

Drawings

Fig. 1 is a diagram showing the construction of the inside of a case according to an embodiment of the present invention.

Fig. 2 is a diagram of an internal circulation pattern in an embodiment of the present invention.

Fig. 3 is a diagram of an outer loop pattern in an embodiment of the invention.

Fig. 4 is a structural view (in a stretched state) of the telescopic folding door in the embodiment of the present invention.

Fig. 5 is a structural view (in a folded state) of the telescopic folding door in an embodiment of the present invention.

Fig. 6 is a block diagram of an air intake assembly in an embodiment of the invention.

FIG. 7 is a block diagram of a sample gate in an embodiment of the invention.

Fig. 8 is a structural view of a blast heating assembly in an embodiment of the present invention.

Fig. 9 is a structural view of the air outlet of the return air duct in the embodiment of the present invention.

Fig. 10 is a structural view of a temperature sensing member in an embodiment of the present invention.

The reference numerals in the figures denote: 1. a blast heating assembly; 101. a centrifugal fan; 102. centrifugal fan blades; 103. a heat insulating plate; 104. a mounting plate; 105. a wind deflector; 106. a heating assembly; 2. an internal circulation air duct; 201. a heating chamber; 202. a return air channel; 203. a bar-shaped hole; 204. a mixed flow plate; 205. a main chamber; 3. a sample inlet door; 301. a door panel; 302. sealing cotton; 303. a drive assembly; 304. a rotating rod; 4. a temperature detecting member; 401. a temperature measurement probe; 402. a fixing seat; 5. an air intake assembly; 501. a gas distributor; 502. a nitrogen gas inlet unit; 5021. a nitrogen source; 5022. a pressure reducing valve; 5023. a nitrogen electric control switch; 5024. a drying module; 503. an air intake unit; 5031. an air electric control switch; 6. a case; 601. a heat insulation layer; 7. an exhaust port; 8. a retractable folding door; 801. a door body; 802. a driving member.

Detailed Description

The invention is further described below with reference to the drawings and specific examples.

As shown in fig. 1 to 10, the drying oven of the present embodiment is used for drying operation in sample moisture measurement, and includes a box 6 and a main chamber 205 surrounded by the box 6, wherein one end of the box 6 is provided with a sample inlet door 3, the opposite end of the sample inlet door 3 is provided with a heating cavity 201 communicated with the main chamber 205, a blast heating assembly 1 is provided in the heating cavity 201, both sides of the main chamber 205 are provided with air return channels 202, air inlets of the air return channels 202 are all communicated with the heating cavity 201, air outlets of the air return channels 202 are located at both sides close to the sample inlet door 3 and are all communicated with the main chamber 205, and the main chamber 205, the heating cavity 201 and the two air return channels 202 are sequentially communicated to form an internal circulation air channel 2; the main chamber 205 is provided with an air inlet component 5 facing the heating cavity 201 at one side of the sample inlet door 3; the heating cavity 201 is provided with an exhaust port 7 at the air inlet of each return air channel 202, and a telescopic folding door 8 switched between a folding state and a stretching state is arranged at the exhaust port 7; when the telescopic folding door 8 is in the folded state, the exhaust port 7 is blocked by the telescopic folding door 8 in the folded state, and the air inlets of the air return channels 202 are opened to perform an internal circulation mode; when the telescopic folding door 8 is in the stretched state, the air inlet of each return air channel 202 is blocked by the telescopic folding door 8 in the stretched state and the air outlet 7 is opened for the external circulation mode.

According to the drying box disclosed by the invention, the internal circulation speed of air in the circulating air duct can be increased through the air blowing action of the air blowing heating component 1, and the circulation period is short, so that the drying effect is improved; further, the air is circularly heated by matching with the blast heating component 1, so that the temperature rise of the air is accelerated, the temperature rise time is shortened, the evaporation of water inside and outside the sample is accelerated to form water vapor, the consumption of nitrogen in the main chamber 205 is greatly reduced, and meanwhile, the heating power can be greatly reduced by an internal circulation mode, and the aim of saving energy can be achieved; when the concentration of the water vapor in the main chamber 205 reaches or approaches to the saturated vapor pressure, the telescopic folding door 8 is switched between a folding state and a stretching state, so that the switching from an inner circulation mode to an outer circulation mode is realized, the discharge of the water vapor is accelerated through the exhaust port 7, and the drying efficiency of the subsequent samples is further improved; in addition, the telescopic folding door 8 is simple and ingenious in structure, and is simple, quick, convenient and effective in switching.

As shown in fig. 4 and 5, in this embodiment, the retractable folding door 8 includes a plurality of door bodies 801 hinged in sequence, wherein one door body 801 is hinged to the inner wall of the box 6, and the other door body 801 is connected with a driving member 802, and the driving member 802 moves linearly to drive the door body 801 to switch between a folded state and a stretched state. The driving member 802 includes a rotary motor and a screw mechanism, the rotary motor is connected to the door body 801 through the screw mechanism, and a rotational motion of the rotary motor is converted into a linear motion through the screw mechanism, thereby driving the door body 801 to switch between a folded state and a stretched state. As shown in fig. 5, when the telescopic folding door 8 is in the folded state, the air outlet 7 is blocked by the telescopic folding in the folded state, and at this time, the air inlets of the air return channels 202 are opened to perform the internal circulation mode, as shown in fig. 2; when the expansion and contraction folding door 8 is in the stretched state, as shown in fig. 4, the air inlet of each return air channel 202 is blocked by the expansion and contraction folding door 8 in the stretched state, and the air outlet 7 is opened to perform the external circulation mode, as shown in fig. 3. Of course, in other embodiments, the screw mechanism may also use other conversion mechanisms such as a rack and pinion, or directly use a telescopic cylinder or a telescopic cylinder to realize the state switching of the door 801.

As shown in fig. 6, in the present embodiment, the air intake assembly 5 includes a nitrogen air intake unit 502, an air intake unit 503, and an elongated gas distributor 501, the gas distributor 501 being disposed along the arrangement direction of the sample gate 3; the nitrogen inlet unit 502 and the air inlet unit 503 are respectively connected with the gas distributor 501, and the nitrogen inlet unit 502 and the air inlet unit 503 are interlocked; specifically, the nitrogen gas inlet unit 502 includes a nitrogen gas source 5021, a pressure reducing valve 5022, a nitrogen gas electric control switch 5023 and a drying module 5024 (such as a drying agent) which are sequentially connected, and the drying module 5024 is connected with one end of the gas distributor 501; the air inlet unit 503 comprises an air electric control switch 5031, and the air electric control switch 5031 is connected with the other end of the air distributor 501; the nitrogen electrical switch 5023 is electrically or mechanically interlocked with the air electrical switch 5031. In actual work, different air inlet units can be switched according to the properties of the coal sample, such as an air drying method is carried out on anthracite and bituminous coal with dry ashless base volatile components less than 20%, and a nitrogen drying method is carried out on anthracite, bituminous coal and lignite. In addition, the gas distributor 501 is disposed along the arrangement direction of the sample gate 3, the gas distributor 501 is a long gas pipe, and a plurality of gas outlet holes (circular or long, etc.) are disposed on the long gas pipe, and since the gas is introduced at two ends of the long gas pipe, in order to ensure that parallel nitrogen gas flows are formed, and ensure that the nitrogen gas pressure and flow at each gas outlet hole are consistent, the space between the gas outlet holes is gradually shortened along the direction from the gas inlet end to the middle, and the size of the gas outlet hole is also gradually increased; meanwhile, the gas distributor 501 is arranged at the hot gas flow reversing position of the main chamber 205, so that not only can hot gas flow at two ends rapidly heat nitrogen, but also a relatively low-pressure area is formed at the two hot gas flow reversing positions, so that the nitrogen can flow in an accelerating manner, and the nitrogen concentration in the main chamber 205 can reach the required standard concentration more rapidly.

As shown in fig. 7, in this embodiment, the sample door 3 includes a door plate 301, a rotating rod 304 and a driving component 303, where a high-temperature sealing cotton 302 is embedded in the door plate 301, one end of the door plate 301 is rotatably installed on the box 6 through a rotating shaft, one end of the rotating rod 304 is hinged with the door plate 301, the other end is connected with the driving component 303 (such as a rotating motor), the driving component 303 is installed on the box 6, and drives the rotating rod 304 to rotate when rotating, so as to realize the switching function of the door plate 301; in addition, when the door 301 is in the closed state, the driving component 303 applies a certain self-closing force to the door 301, so that the tightness of the door 301 can be further ensured, and the reliability of drying can be improved. By adopting the rotary sealing door plate 301, the sealing performance of the main chamber 205 is ensured, so that the air in the main chamber 205 can be discharged as soon as possible when nitrogen-introducing drying is performed, and the nitrogen concentration in the main chamber 205 reaches the standard value. The door plate 301 is preferably made of stainless steel, and the lower edge of the door plate 301 is curled (for example, in a circular arc transition shape), so that the door plate 301 can smoothly transition on the crucible tray; the inner side of the door plate 301 is provided with a heat insulation layer, so that the outward emission of heat in the main chamber 205 is reduced, and meanwhile, the balance weight of the door plate 301 is increased, so that the sealing effect of the sample inlet door 3 is better ensured; of course, in other embodiments, the upper end of the door 301 may be mounted to the case 6 by a hinge (e.g., a hinge) to allow the door 301 to be turned open toward the inside of the case 6 by external force or to be closed by falling back under gravity. The hinge is used to connect the door plate 301 and the box 6, the hinge needs to ensure flexible movement, and the door plate 301 can smoothly rotate under the action of gravity. Naturally, a return spring may be provided at the hinge, so that the door panel 301 forms a certain self-closing force with the sealing material when the door panel 301 falls back and closes, and the sealing effect is further ensured.

As shown in fig. 8, in the present embodiment, the blast heating assembly 1 includes a blast assembly and a heating assembly 106; the blast assembly is used for accelerating gas circulation and improving drying efficiency. Specifically, the blower assembly includes a centrifugal blower 101 and a centrifugal blower blade 102; the centrifugal fan 101 is arranged on the outer side of the box body 6, and the centrifugal fan blades 102 are arranged in the heating cavity 201 and are connected with the centrifugal fan 101; the inner circle of the centrifugal fan blades 102 forms an air inlet of the heating chamber 201 to communicate with the main chamber 205. The centrifugal fan 101 is a high-temperature-resistant centrifugal fan 101, and is required to work at a high temperature under the premise of ensuring that the air quantity and the air pressure meet the ventilation times, so as to provide power for the centrifugal fan blades 102; the centrifugal fan blades 102 can accelerate the circulation of gas when rotating at high speed, and meanwhile, the circular ring of the air outlet 7 in the center of the heating cavity 201 is just inserted into the inner circle of the centrifugal fan blades 102, so that the air flow exchange effect is better ensured. Of course, in other embodiments, axial flow fan blades may be used in place of the centrifugal fan blades 102.

In this embodiment, the heating component 106 is used to heat the gas; the heating assembly 106 is located in the heating chamber 201 on one or both sides of the blower assembly. Specifically, the heating component 106 is a PTC heating plate (PTC is abbreviated as Positive Temperature Coefficient), and the shape of the PTC heating plate matches that of the heating cavity 201, so as to occupy the entire cross section of the heating cavity 201. In addition, since one end of the PTC heating plate is provided with the connection terminal, the wind deflector 105 is disposed at the connection terminal of the heating chamber 201 and the PTC heating plate, so that the gas in the heating chamber 201 is ensured to completely pass through the heating plate, and the temperature rising speed is increased. Of course, in other embodiments, other forms of heat patch are also employed, as the case may be.

In this embodiment, the centrifugal fan 101, the centrifugal fan blade 102, the PCT heating sheet and the wind shield 105 are all mounted on the mounting plate 104 on one side of the box 6, so as to form a component that can be integrally detached from the box 6, and the component is convenient to assemble and disassemble, and convenient for subsequent maintenance. In addition, the heat insulation plate 103 is paved on the inner side of the mounting plate 104, so that on one hand, the heat insulation effect is achieved, and meanwhile, the influence of heat in the heating cavity 201 on the centrifugal fan 101 can be avoided, and the normal work and the service life of the centrifugal fan are ensured.

As shown in fig. 10, in the present embodiment, a temperature detecting member 4 is provided in the case 6 for detecting the temperature of the gas in the main chamber 205; the heating assembly 106 is connected to the temperature sensing member 4 for receiving the sensed gas temperature value for heating adjustment to maintain the gas temperature in the main chamber 205 within a constant range (e.g., 105 c-110 c). Specifically, a normally closed contact of a temperature relay is connected in series in a power supply loop of the heating component 106, when the temperature detection piece 4 detects that the temperature is greater than a preset value, the action of the temperature relay is controlled (or the temperature detection piece 4 sends a temperature signal to a control unit, and the control unit sends a corresponding control instruction after temperature judgment), and the normally closed contact is disconnected, namely the heating is disconnected; of course, the heating power of the heating assembly 106 may also be adjusted. In addition, in other embodiments, the rotation speed of the centrifugal fan 101 may be adjusted according to the temperature value, so as to accelerate circulation and further improve drying efficiency. Specifically, as shown in fig. 9, the temperature detecting element 4 includes a fixing base 402 and a temperature measuring probe 401, the temperature measuring probe 401 is installed in the fixing base 402, the fixing base 402 is detachably connected (e.g. screwed) to the side wall of the air return channel 202, and the dismounting is convenient and the maintenance is convenient.

As shown in fig. 9, in this embodiment, the air outlet of each air return channel 202 includes a plurality of vertical strip-shaped holes 203, and the lengths of the strip-shaped holes 203 are sequentially shortened along the air conveying direction, so that the overall air outlet is V-shaped, and hot air flows in the air return channels 202 can be uniformly mixed, and the temperature difference of the air outlets is reduced; further, the air outlet of each return air channel 202 is provided with a mixing plate 204 for uniformly mixing the hot air again, so as to further reduce the temperature difference of the air at each position and ensure that the temperature in the whole main chamber 205 is within a reasonable range.

In this embodiment, the outer layer of the box body 6 is laid with a heat insulation layer 601 for heat insulation and heat preservation, so as to reduce the influence of temperature channeling between the box bodies 6 arranged side by side.

In this embodiment, the shape of the case 6 can be compatible with the drying operation of the full moisture measurement of the 6mm and 13mm coal samples, and flexibly configured according to the needs of customers. In addition, the whole box 6 is flat, and the section of the main chamber 205, which is close to the heating chamber 201, gradually contracts towards the heating chamber 201, so that the circulation of gas in the main chamber 205 is not only facilitated, but also the shape and the minimum internal space of the box 6 can be ensured, the consumption of nitrogen is reduced under the condition of ensuring the drying efficiency, and the consumable cost required by the drying operation in the full-moisture measurement is saved.

s01, detecting the water vapor concentration of the main chamber 205 in the box 6;

s02, when the detected water vapor concentration does not reach the preset water vapor concentration, controlling the telescopic folding door 8 to switch to a folding state, blocking the air outlet 7, and opening the air inlet of each air return channel 202 to dry the sample in an internal circulation mode, as shown in FIG. 2; when the detected water vapor concentration reaches the preset water vapor concentration, the telescopic folding door 8 is controlled to switch to a stretched state, the air inlet of each return air channel 202 is blocked, and the air outlet 7 is opened to enter an external circulation mode for discharging water vapor, as shown in fig. 3.

According to the heat flow circulation control method based on the drying box, the internal circulation heating mode is used for accelerating the evaporation of water inside and outside the sample to form water vapor, so that the consumption of nitrogen in the main chamber 205 is greatly reduced, meanwhile, the internal circulation mode can be used for greatly reducing the power of the heating plate, and the aim of saving energy can be achieved; when the concentration of the water vapor in the main chamber 205 reaches or approaches to the saturated vapor pressure, the folding state is switched to the stretching state through the telescopic folding door 8, so that the switching from the inner circulation mode to the outer circulation mode is realized, the discharge of the water vapor is accelerated through the exhaust port 7, and the drying efficiency of the subsequent samples is further improved; through the cooperation of the internal and external circulation modes, the rapid drying of the sample is realized.

In the present embodiment, in step S01, the water vapor concentration of the main chamber 205 in the tank 6 is obtained by a water vapor concentration detecting member (not shown) or according to the internal circulation mode on time in the tank 6. In step S02, after entering the outer circulation mode, the process is switched to the inner circulation mode after a predetermined time, and then the process is repeated until the drying is completed.

While the invention has been described with reference to preferred embodiments, it is not intended to be limiting. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art, or equivalent embodiments with equivalent variations can be made, without departing from the scope of the invention. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. The utility model provides a drying cabinet, its characterized in that includes box (6) and encloses main cavity (205) that form by box (6), the one end of box (6) is equipped with advances kind door (3), advance kind door (3) relative one end be provided with main cavity (205) the heating chamber (201) of intercommunication, be provided with blast heating subassembly (1) in heating chamber (201), the both sides of main cavity (205) all are provided with return air passageway (202), the air inlet of each return air passageway (202) all with heating chamber (201) intercommunication, the gas outlet of each return air passageway (202) is located the both sides that are close to advance kind door (3), and all with main cavity (205) intercommunication, main cavity (205), heating chamber (201) and two return air passageway (202) communicate in proper order and form inner loop wind channel (106); an air inlet component (5) facing the heating cavity (201) is arranged on one side of the sample inlet door (3) of the main cavity (205); an air outlet (7) is arranged at the air inlet of each air return channel (202) of the heating cavity (201), and a telescopic folding door (8) which is switched between a folding state and a stretching state is arranged at the air outlet (7); when the telescopic folding door (8) is in the folded state, the exhaust port (7) is blocked by the telescopic folding door (8) in the folded state, and the air inlets of the air return channels (202) are opened to perform an internal circulation mode; when the telescopic folding door (8) is in the stretching state, the air inlet of each return air channel (202) is blocked by the telescopic folding door (8) in the stretching state, and the air outlet (7) is opened to perform an external circulation mode;

the air inlet assembly (5) comprises a nitrogen air inlet unit (502), an air inlet unit (503) and a strip gas distributor (501), wherein the gas distributor (501) is arranged along the arrangement direction of the sample inlet door (3) and is arranged at the hot air flow reversing position of the main chamber (205); the nitrogen gas inlet unit (502) and the air inlet unit (503) are respectively connected with the gas distributor (501), and the nitrogen gas inlet unit (502) and the air inlet unit (503) are interlocked;

the sample injection door (3) comprises a door plate (301), wherein the upper end of the door plate (301) is arranged on the box body (6) through a hinge piece, so that the door plate (301) is turned over and opened towards the inside of the box body (6) under the pushing of external force or falls back and is closed under the action of gravity.

2. The drying cabinet according to claim 1, wherein the retractable folding door (8) comprises a plurality of door bodies (801) hinged in sequence, wherein one door body (801) is hinged on the inner wall of the cabinet (6), the other door body (801) is connected with a driving member (802), and the driving member (802) makes linear motion to drive the door body (801) to switch between a folded state and a stretched state.

3. A drying oven according to claim 2, wherein the driving member (802) comprises a rotating motor and a screw mechanism, the rotating motor being connected to the door body (801) via the screw mechanism.

4. A drying oven according to claim 3, wherein the nitrogen inlet unit (502) comprises a nitrogen source (5021), a pressure reducing valve (5022), a nitrogen electric control switch (5023) and a drying module (5024) which are sequentially connected, and the drying module (5024) is connected with one end of the gas distributor (501); the air inlet unit (503) comprises an air electric control switch (5031), and the air electric control switch (5031) is connected with the other end of the air distributor (501); the nitrogen gas electric control switch (5023) is electrically or mechanically interlocked with the air electric control switch (5031).

5. A drying oven according to claim 1, 2 or 3, wherein the sample inlet door (3) comprises a door plate (301), a rotating rod (304) and a driving component (303), one end of the door plate (301) is rotatably mounted on the box body (6) through a rotating shaft, one end of the rotating rod (304) is connected with the door plate (301), the other end of the rotating rod is connected with the driving component (303), and the driving component (303) is used for driving the rotating rod (304) to rotate so as to realize the opening and closing of the door plate (301) and provide a certain self-closing force when the door plate (301) is closed.

6. A drying cabinet according to claim 1, wherein the lower edge of the door panel (301) is rounded.

7. A drying oven according to claim 1 or 2 or 3, characterized in that the blast heating assembly (1) comprises a blast assembly and a heating assembly (106); the blower assembly comprises a centrifugal blower (101) and a centrifugal blower blade (102); the centrifugal fan (101) is arranged on the outer side of the box body (6), and the centrifugal fan blades (102) are arranged in the heating cavity (201) and are connected with the centrifugal fan (101); the main chamber (205) is provided with an air inlet of the heating cavity (201) at the inner circle of the centrifugal fan blade (102).

8. A drying cabinet according to claim 7, wherein the heating element (106) is located on one or both sides of the blower element in the heating chamber (201) for heating the gas.

9. A drying cabinet according to claim 7, wherein the heating assembly (106) is a PTC heating plate.

10. The drying oven according to claim 9, characterized in that the PTC heating plate is shaped to match the heating chamber (201), and that the heating chamber (201) is provided with a wind deflector (105) at the connection terminal of the PTC heating plate.

11. A drying cabinet according to claim 7, wherein the blower assembly and the heating assembly (106) are each located on a mounting plate (104) on one side of the cabinet (6).

12. A drying cabinet according to claim 11, wherein the mounting plate (104) is provided with heat insulation panels (103) on the inside.

13. A drying cabinet according to claim 7, wherein a temperature detecting member (4) is provided in the cabinet (6) for detecting the temperature of the gas in the main chamber (205); the heating component (106) is connected with the temperature detection piece (4) and is used for receiving the detected gas temperature value to perform heating adjustment so as to maintain the gas temperature in the main chamber (205) within a constant range.

14. The drying cabinet according to claim 13, wherein the temperature detecting member (4) comprises a fixing base (402) and a temperature measuring probe (401), the fixing base (402) is detachably connected to the side wall of the return air channel (202), and the temperature measuring probe (401) is installed in the fixing base (402).

15. A drying cabinet according to claim 1, 2 or 3, wherein the air outlet of each return air channel (202) comprises a plurality of vertical strip-shaped holes (203), the length of each strip-shaped hole (203) being successively shorter in the direction of air transport.

16. The drying cabinet according to claim 15, wherein a mixing plate (204) is provided at the air outlet of each return air duct (202).

17. A drying cabinet according to claim 1, 2 or 3, characterized in that the outer layer of the cabinet (6) is provided with a heat insulating layer (601).

18. A drying cabinet according to claim 1 or 2 or 3, wherein a section of the main chamber (205) adjacent to the heating chamber (201) gradually tapers towards the heating chamber (201).

19. A drying cabinet according to claim 1, 2 or 3, characterized in that a concentration detection is provided in the main chamber (205) for detecting the concentration of water vapour to control the telescopic folding door (8) to switch between a folded state and a stretched state.

20. A method of controlling the circulation of heat flow based on a drying oven according to any one of claims 1 to 19, comprising the steps of:

s01, detecting the concentration of water vapor in a main chamber (205) in the box body (6);

s02, when the detected water vapor concentration does not reach the preset water vapor concentration, controlling the telescopic folding door (8) to be switched to a folding state, blocking the exhaust port (7), and opening the air inlet of each return air channel (202) so as to dry the sample in an internal circulation mode; when the detected water vapor concentration reaches the preset water vapor concentration, the telescopic folding door (8) is controlled to be switched to a stretching state, the air inlet of each return air channel (202) is blocked, and the air outlet (7) is opened to enter an external circulation mode for discharging water vapor.

21. The heat flow cycle control method according to claim 20, wherein in step S01, the water vapor concentration of the main chamber (205) in the tank (6) is obtained by the water vapor concentration detection member or according to the internal circulation pattern on time in the tank (6).

22. The heat flux cycle control method of claim 20, wherein in step S02, after entering the outer cycle mode, the inner cycle mode is switched over after a predetermined time.