Energy-saving dryer and its heating, dehumidification and fresh air valve operation process

Abstract

The present invention discloses an energy-saving dryer and its heating, dehumidification and fresh air valve operation process, which comprises a drying room, a heating system and a return air system of an air source heat pump including an evaporator, a compressor, a condenser and a throttling device, two or more condensers are installed on a side of the drying room, two or more fans for pumping hot air and returning air are installed on the upper part of the condenser, and the entire top surface of the drying room has a hot air and return air mixing duct. A fresh air valve is installed on the upper part of the side of the drying room opposite to the fan for pumping hot air and returning air. An evaporator in the drying room is installed at the lower part of the condenser, the inlet of the evaporator in the drying room and the inlet of the evaporator outside the drying room are respectively connected to the throttling device through an electromagnetic valve, and the outlet of the evaporator in the drying room and the outlet of the evaporator outside the drying room are connected to the compressor. The machine performs different heating, dehumidification and fresh air valve operations according to different drying stages. The advantages of the present invention are that the material drying speed is consistent, the drying time is reduced, and energy is saved.

Description

Technical Field

[0001] The invention relates to drying equipment, in particular to an energy-saving drying machine and a heating, dehumidification and fresh air valve operation process thereof. Background Art

[0002] There are several problems with current dryers. First, the heating device is installed outside the drying room and sent into the drying room through the hot air duct. This not only causes heat loss, but also the hot air is unevenly distributed in the drying room, resulting in different drying speeds for the dried materials in different places, which prolongs the drying time. Even if a single heating device is installed in the drying room, the ratio of the heating area of ​​the heating device and the cross-sectional area of ​​the hot air duct to the cross-sectional area of ​​the hot air delivery direction in the drying room is very small, resulting in different drying speeds for the dried materials in different places, which prolongs the drying time. Secondly, the heating system heats the fresh air outside the drying room through the fan and sends it into the drying room to dry the materials. The return air system extracts the air in the drying room that has both residual heat and water vapor that has undergone heat exchange with the materials, removes some of the water vapor and sends it back to the drying room. However, after multiple cycles, the air in the drying room has more and more water vapor, resulting in a long drying time and poor drying effect. Third, for dehumidification in the drying room, either a simple fan dehumidification is used, which has a poor dehumidification effect, or a special dehumidifier is installed outside the drying room, which increases equipment costs and production energy consumption. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present invention provides an energy-saving dryer and a heating, dehumidification and fresh air damper operation process thereof.

[0004] The present invention adopts the following technical scheme.

[0005] An energy-saving dryer comprises a drying room, a heating system of an air source heat pump including an evaporator, a compressor, a condenser and a throttling device, and a return air system. Two or more condensers are installed on a side of the drying room, two or more fans for pumping hot air and returning air are installed on the upper part of the condensers, and the entire top surface of the drying room has a hot air and return air mixing duct.

[0006] A fresh air valve is installed on the upper part of the side of the drying room opposite to the fan for extracting hot air and returning air.

[0007] The lower part of the condenser is provided with an evaporator in the drying room. The inlet of the evaporator in the drying room and the inlet of the evaporator outside the drying room are respectively connected to the throttling device through a solenoid valve. The outlet of the evaporator in the drying room and the outlet of the evaporator outside the drying room are connected to the compressor.

[0008] A heating and dehumidification operation process of an energy-saving dryer comprises the following steps:

[0009] 1) The drying room enters the simple heating stage, the evaporator inside the drying room does not work, and the evaporator outside the drying room works. When the temperature reaches the set value, it enters the heating and intermittent dehumidification stage;

[0010] 2) The drying room enters the heating and intermittent dehumidification stage. During dehumidification, the evaporator in the drying room works, and the evaporator outside the drying room does not work. During heating, the evaporator in the drying room does not work, and the evaporator outside the drying room works until the temperature and humidity of the drying room reach the set value, and then enter the insulation and dehumidification stage;

[0011] 3) The drying room enters the heat preservation and dehumidification stage. When the drying room temperature is greater than or equal to the set dehumidification temperature, the evaporator in the drying room works, and the evaporator outside the drying room does not work. If the drying room temperature is lower than the set dehumidification temperature, the dehumidification stops. At this time, heating must be performed. The evaporator in the drying room does not work, and the evaporator outside the drying room works. When the drying room temperature is greater than or equal to the set dehumidification temperature, the dehumidification restarts, the evaporator in the drying room works, and the evaporator outside the drying room does not work. This stage is controlled by the minimum drying room humidity. When the drying room humidity reaches the set value, it enters the cooling stage;

[0012] 4) The drying room enters the cooling stage, heating and dehumidification all stop working, the evaporator in the drying room does not work, and the evaporator outside the drying room does not work. During the set natural cooling time, the drying room door is not opened, and the residual heat is used to continue drying the material.

[0013] A new air valve operation process for an energy-saving dryer comprises the following steps:

[0014] 1) The drying room enters the simple heating stage. When the drying room temperature is 30 degrees, the fresh air valve is opened for 1-4 minutes, closed for 7-14 minutes, opened for 1-4 minutes, closed for 7-14 minutes, and repeated in this way. When the temperature reaches the set value, it enters the heating and intermittent dehumidification stage;

[0015] 2) The drying room enters the heating and intermittent dehumidification stage. The fresh air valve is opened for 2-5 minutes, closed for 7-18 minutes, opened for 2-5 minutes, closed for 7-18 minutes, and repeated until the temperature and humidity of the drying room reach the set value and then enter the heat preservation and dehumidification stage;

[0016] 3) The drying room enters the insulation and dehumidification stage. The fresh air valve is opened for 2-5 minutes, closed for 7-21 minutes, opened for 2-5 minutes, closed for 7-21 minutes, and repeated in this way. When the humidity in the drying room reaches the set value, it enters the cooling stage.

[0017] 4) The drying room enters the cooling stage, the fresh air valve is kept closed, and the residual heat is used to continue drying the material.

[0018] Compared with the prior art, the advantage of the present invention is that multiple condensers are directly installed on one side of the drying room, which reduces the heat transfer loss compared to the condenser installed outside the drying room, and multiple condensers are arranged together for heating, so that the temperature in the drying room is uniform, and the drying time is reduced. Multiple fans for pumping hot air and return air are installed on the upper part of the evaporator, and the entire top surface of the drying room has a hot air and return air mixing duct, so that the drying speed of the dried materials is consistent, the drying time is reduced, and energy is saved. According to the situation of each drying stage of the material, different heating and dehumidification are performed, the new air valve is intermittently opened and closed, and the return air with water vapor is discharged in small quantities and multiple times, and the introduction of new air is increased, thereby speeding up the drying time. Just adding an evaporator in the drying room can replace the dedicated dehumidifier, reducing equipment costs and production energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0020] Figure 2 This is a top view of the installation of the condenser in the drying room.

[0021] Figure 3 This is a connection diagram of the evaporator inside the drying room and the evaporator outside the drying room. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0023] like Figure 1-3 As shown, an energy-saving drying machine has a drying room 1, a heating system and a return air system of an air source heat pump including a condenser 3, an evaporator 6 in the drying room, an evaporator 11 outside the drying room, a compressor 12 and a throttling device 8. The four condensers are all installed on a side of the drying room, and the four fans 4 for pumping hot air and returning air are installed on the upper part of the condenser 3. The entire top surface of the drying room 1 has a top air duct 2 and a side air duct 7 for mixing hot air and returning air. A new air valve 5 is installed on the upper part of the side of the drying room opposite to the fan 4 for pumping hot air and returning air. After the new air valve 5 is opened, fresh air outside the drying room can enter the drying room. The evaporator 6 in the drying room is installed at the lower part of the condenser 3. The inlet of the evaporator 6 in the drying room is connected to the throttling device 8 through the electromagnetic valve A 10, and the outlet of the evaporator 6 in the drying room is connected to the compressor 12. The inlet of the evaporator 11 outside the drying room is connected to the throttling device 8 through the electromagnetic valve B 9, and the outlet of the evaporator 11 outside the drying room is connected to the compressor 12. There is a PTC electric heater (not shown) next to the condenser 3, which is turned on when the ambient temperature is low. Figure 1 The arrows in the figure indicate the flow direction of the hot air.

[0024] The heating and dehumidification operation process of this machine includes the following steps:

[0025] 1) The drying room enters the simple heating stage, the evaporator 6 in the drying room does not work, and the evaporator 11 outside the drying room works. When the temperature reaches the set value of 50 degrees, it enters the heating and intermittent dehumidification stage;

[0026] 2) The drying room enters the heating and intermittent dehumidification stage. During dehumidification, the evaporator 6 in the drying room works, and the evaporator 11 outside the drying room does not work. During heating, the evaporator 6 in the drying room does not work, and the evaporator 11 outside the drying room works, until the drying room temperature reaches the set value of 65 degrees and the humidity reaches the set value of 15%, and then enters the insulation and dehumidification stage;

[0027] 3) The drying room enters the heat preservation and dehumidification stage. When the drying room temperature is greater than or equal to the set dehumidification temperature of 65 degrees, the evaporator 6 in the drying room works, and the evaporator 11 outside the drying room does not work. If the drying room temperature is lower than the set dehumidification temperature of 65 degrees, the dehumidification stops. At this time, heating must be performed. The evaporator 6 in the drying room does not work, and the evaporator 11 outside the drying room works. When the drying room temperature is greater than or equal to the set dehumidification temperature of 65 degrees, the dehumidification restarts, the evaporator 6 in the drying room works, and the evaporator 11 outside the drying room does not work. This stage is controlled by the minimum drying room humidity. When the drying room humidity reaches the set value of 8%, it enters the cooling stage;

[0028] 4) The drying room enters the cooling stage, heating and dehumidification all stop working, the evaporator 6 in the drying room does not work, and the evaporator 11 outside the drying room does not work. Within the set natural cooling time of 2 hours, the drying room door is not opened, and the residual heat is used to continue drying the material.

[0029] The operation process of the fresh air damper 5 of this machine includes the following steps:

[0030] 1) The drying room enters the simple heating stage. When the drying room temperature is 30 degrees, the fresh air valve 5 is opened for 2 minutes, closed for 10 minutes, opened for 2 minutes, closed for 10 minutes, and repeated in this way. When the temperature reaches the set value of 50 degrees, it enters the heating and intermittent dehumidification stage;

[0031] 2) The drying room enters the heating and intermittent dehumidification stage, the fresh air valve 5 is opened for 3 minutes, closed for 15 minutes, opened for 3 minutes, closed for 15 minutes, and repeated until the drying room temperature reaches the set value of 65 degrees and the humidity reaches the set value of 15%, and then enters the insulation and dehumidification stage;

[0032] 3) The drying room enters the heat preservation and dehumidification stage, the fresh air valve 5 is opened for 3 minutes, closed for 18 minutes, opened for 3 minutes, closed for 18 minutes, and repeated in this way. When the humidity in the drying room reaches the set value of 8%, it enters the cooling stage;

[0033] 4) The drying room enters the cooling stage, the fresh air valve 5 is closed all the time, and the residual heat is used to continue drying the material.

[0034] Comparative experiment:

[0035] In comparative experiment 1, paper tubes with an inner diameter of 30 mm, an outer diameter of 36 mm, and a length of 300 mm were dried. The initial moisture content of the paper tubes was 20.2%, and the number of paper tubes was 112,000.

[0036] 1) Using this energy-saving dryer and its heating, dehumidification and fresh air valve operation process, the drying time is 11.25 hours, the moisture content of the package is 7.2%, and the power consumption is 577 degrees.

[0037] 2) Using an ordinary heat pump dryer, the drying time is 13.25 hours, the moisture content of the bobbin is 7.5%, and the power consumption is 897 degrees.

[0038] In comparative experiment 2, paper tubes with an inner diameter of 30 mm, an outer diameter of 36 mm, and a length of 300 mm were dried. The initial moisture content of the paper tubes was 20.2%, and the number of paper tubes was 112,000.

[0039] 1) Using this energy-saving dryer and its heating, dehumidification and fresh air valve operation process, the drying time is 11.3 hours, the moisture content of the package is 7.1%, and the power consumption is 580 degrees.

[0040] 2) Using ordinary heat pump dryer, the drying time is 13.4 hours, the moisture content of the package is 7.3%, and the power consumption is 910 degrees.

[0041] In comparative experiment 3, paper tubes with an inner diameter of 30 mm, an outer diameter of 36 mm, and a length of 300 mm were dried. The initial moisture content of the paper tubes was 20.2%, and the number of paper tubes was 112,000.

[0042] 1) Using this energy-saving dryer and its heating, dehumidification and fresh air valve operation process, the drying time is 11.2 hours, the moisture content of the package is 7.2%, and the power consumption is 570 degrees.

[0043] 2) Using a common heat pump dryer, the drying time is 13.1 hours, the moisture content of the bobbin is 7.6%, and the power consumption is 910 degrees.

Claims

1. A new air valve operation process for an energy-saving dryer, wherein the energy-saving dryer comprises a drying room, a heating system and a return air system of an air source heat pump including an evaporator, a compressor, a condenser and a throttling device, two or more condensers are installed on a side surface in the drying room, two or more fans for pumping hot air and returning air are installed on the upper part of the condenser, a hot air and return air mixing air duct is arranged on the entire top surface of the drying room, a new air valve is installed on the upper part of the side surface of the drying room opposite to the fan for pumping hot air and returning air, an evaporator in the drying room is installed on the lower part of the condenser, an inlet of the evaporator in the drying room and an inlet of the evaporator outside the drying room are respectively connected to the throttling device through an electromagnetic valve, and an outlet of the evaporator in the drying room and an outlet of the evaporator outside the drying room are connected to the compressor, characterized in that The following steps are involved: 1) The drying room enters the simple heating stage. When the drying room temperature is 30 degrees, the fresh air valve is opened for 1-4 minutes, closed for 7-14 minutes, opened for 1-4 minutes, closed for 7-14 minutes, and repeated in this way. When the temperature reaches the set value, it enters the heating and intermittent dehumidification stage; 2) The drying room enters the heating and intermittent dehumidification stage. The fresh air valve is opened for 2-5 minutes, closed for 7-18 minutes, opened for 2-5 minutes, closed for 7-18 minutes, and repeated until the temperature and humidity of the drying room reach the set value and then enter the heat preservation and dehumidification stage; 3) The drying room enters the insulation and dehumidification stage. The fresh air valve is opened for 2-5 minutes, closed for 7-21 minutes, opened for 2-5 minutes, closed for 7-21 minutes, and repeated in this way. When the humidity in the drying room reaches the set value, it enters the cooling stage. 4) The drying room enters the cooling stage, the fresh air valve is kept closed, and the residual heat is used to continue drying the materials.

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