Preheating structure of drying system before first production

Abstract

The utility model relates to the technical field of drying equipment, in particular to a preheating structure of a drying system before first production, which comprises a drying hopper, a drying hopper cone, a main air return pipe, a pneumatic switch blade and a preheating structure, the main air return pipe is arranged above the drying hopper, the drying hopper cone is arranged below the drying hopper, and the pneumatic switch blade is arranged below the drying hopper cone. The lower portion of the drying hopper cone is connected with the preheating structure, the lower portion of the preheating structure is connected with the pneumatic knife switch, the preheating structure comprises a heat preservation unit, a preheating pipeline, a pneumatic shut-off valve, a manual shut-off valve and a preheating cavity, and the preheating cavity is formed in the heat preservation unit. In the preheating stage, a pneumatic knife switch below a drying hopper is closed, a valve above a preheating structure is opened, during continuous production, a pneumatic closing valve above the preheating structure is closed, and high-temperature air of a drying part flows through an injection molding opening along with PET particles to complete production.

Description

Technical Field

[0001] The utility model relates to the technical field of drying equipment, in particular to a preheating structure of a drying system before initial production. Background Art

[0002] Normally, when producing preforms in an injection molding machine, the PET pellets need to be dried first. However, after the injection molding machine has not been used for a long time, bubbles will appear in the first batch of preforms produced each time it is restarted. This is because the PET pellets in the drying hopper need to be dried for 8 hours before the injection molding machine is started. When the air is heated, its volume expands, its density decreases, and its weight becomes lighter. The hot air will flow upward. At this time, the pneumatic knife at the bottom of the hopper is closed, and air will only circulate upward. The temperature of the PET pellets in the cone part of the drying hopper is always low. The inconsistent temperature causes bubbles to appear in the first batch of preforms, resulting in waste of raw materials. Summary of the Invention

[0003] In order to overcome the deficiencies of the prior art, the utility model provides a preheating structure for a drying system before the first production. The preheating structure is provided with a manual shut-off valve and a pneumatic shut-off valve. Before the first start-up, the preheating structure and the dryer can be connected to form an additional ventilation duct to fully heat the drying hopper cone, so that bubbles will not be generated in the first batch of bottle blanks.

[0004] To achieve the above-mentioned purpose, a preheating structure of the first pre-production drying system is designed, comprising a drying hopper, a drying hopper cone, a main return air duct, a pneumatic knife gate, and a preheating structure. The main return air duct is provided above the drying hopper, and a drying hopper cone is provided below the drying hopper. The preheating structure is connected below the drying hopper cone, and the pneumatic knife gate is connected below the preheating structure. The preheating structure comprises an insulation unit, a preheating pipe, a pneumatic shut-off valve, a manual shut-off valve, and a preheating chamber. A preheating chamber is provided inside the insulation unit, and a preheating pipe is provided on one side of the preheating chamber. A manual shut-off valve is provided on the preheating pipe, and one end of the preheating pipe is connected to the pneumatic shut-off valve, which is connected to the main return air duct through the return air duct.

[0005] The drying hopper is provided with PET particle raw materials.

[0006] One side of the drying hopper is connected to the air inlet of the dryer.

[0007] The preheating chamber structure is a rhombus, and the upper half of the rhombus of the preheating chamber is a mesh structure.

[0008] The drying hopper is a barrel-shaped structure, and drying hopper fixing brackets are provided on both sides of the top of the drying hopper.

[0009] A feeding port is connected below the pneumatic knife gate.

[0010] Compared with the prior art, the utility model can be operated manually or controlled by a program. In the preheating stage, the pneumatic knife gate below the drying hopper is closed and the valve above the preheating structure is opened. In continuous production, the pneumatic closing valve above the preheating structure is closed, and the high-temperature air of the drying part flows through the injection port along with the PET particles to complete the production. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural diagram of the present utility model.

[0012] Figure 2 This is a partial enlarged view of the preheating structure.

[0013] Figure 3 This is a cross-sectional view of the preheating structure.

[0014] Figure 4 It is a schematic diagram of the preheating structure.

[0015] See also Figures 1 to 4 , 1 is the drying hopper, 2 is the PET granule raw material, 3 is the dryer air inlet, 4 is the drying hopper cone, 5 is the preheating structure, 5.1 is the insulation unit, 5.2 is the preheating pipe, 5.3 is the pneumatic shut-off valve, 5.4 is the manual shut-off valve, 5.5 is the preheating chamber, 5.6 is the mesh structure, 6 is the return air duct, 7 is the main return air duct, 8 is the pneumatic gate, 9 is the discharge port, and 10 is the drying hopper fixing bracket. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] like Figure 1 As shown, a main return air duct 7 is provided above the drying hopper 1, and one side of the drying hopper 1 is connected to the dryer air inlet 3. The high-temperature air is collected through the main return air duct 7 and circulated back to the dryer, which can realize the recycling function of the gas and play an energy-saving role. A drying hopper cone 4 is provided below the drying hopper 1, and a preheating structure 5 is connected below the drying hopper cone 4. Figures 2 to 4As shown, the preheating structure 5 is connected to a pneumatic knife gate 8 below. The opening and closing of the pneumatic knife gate 8 determines whether the PET granule raw material is discharged into the injection molding machine. The preheating structure 5 includes a heat preservation unit 5.1, a preheating pipe 5.2, a pneumatic shut-off valve 5.3, a manual shut-off valve 5.4, and a preheating chamber 5.5. The heat preservation unit 5.1 is mounted below the drying hopper cone 4. The heat preservation unit 5.1 is provided with a preheating chamber 5.5 inside. The preheating chamber 5.5 has a rhombohedral structure. The upper half of the rhombus of the preheating chamber 5.5 is a mesh structure 5.6. The mesh structure 5.6 can block the PET granules but allow gas to pass smoothly. A preheating pipe 5.2 is connected to one side of the duct 5.2. A manual shut-off valve 5.4 is installed on the preheating pipe 5.2. One end of the preheating pipe 5.2 is connected to a pneumatic shut-off valve 5.3. The pneumatic shut-off valve 5.3 is connected to the main return air duct 7 through the return air duct 6. The opening and closing of the pneumatic shut-off valve 5.3 determines the direction of gas flow. If the pneumatic shut-off valve 5.3 is closed and the pneumatic knife gate 8 is open, the high-temperature gas flows into the discharge port 9 along with the PET particles. If the pneumatic shut-off valve 5.3 is opened and the pneumatic knife gate 8 is closed, the high-temperature gas will flow into the preheating structure 5 and then circulate to the dryer through the return air duct 6. The manual shut-off valve 5.4 has the same function as the pneumatic shut-off valve 5.3.

[0018] The drying hopper 1 is provided with PET granule raw materials 2, which are the raw materials for producing bottle preforms.

[0019] The drying hopper 1 is a barrel-shaped structure. Drying hopper fixing brackets 10 are provided on both sides of the top of the drying hopper 1 . The drying hopper fixing brackets 10 play a role in supporting and fixing the drying hopper 1 .

[0020] A feeding port 9 is provided below the pneumatic knife 8. The feeding port 9 can convey the PET particles 2 downward to the injection molding machine and melt them under the action of heating and shearing, and then extrude them into the required bottle blanks through the mold.

[0021] The specific implementation process of the present invention is as follows: the automatic feeder adds the PET granule raw material 2 into the drying hopper 1, and a preheating structure 5 is installed between the drying hopper 1 and the pneumatic gate knife 8. About 8 hours before the first operation, the pneumatic gate knife 8 is closed, and the pneumatic closing valve 5.3 is opened. The drying hopper cone 4 and the return air duct 6 form a passage. At this time, the dry high-temperature air flows through the drying hopper cone 4 into the preheating structure 5, and then returns to the main return air duct 7 through the return air duct 6 for further heating and drying. This process can greatly increase the temperature of the PET granule raw material 2 in the drying hopper cone 4. After testing, it can reach 165°C, which has reached To meet the needs of normal preform production, the pneumatic shut-off valve 5.3 is closed, the pneumatic knife gate 8 is opened, and the PET granular raw material 2 is conveyed to the injection molding machine through the discharge port 9. The preforms are produced under the heating and shearing of the injection molding machine. Now it is time to start continuous production. The pneumatic shut-off valve 5.3 is kept closed and the pneumatic knife gate 8 is kept open. In addition, a manual shut-off valve 5.4 having the same function as the start-up shut-off valve 5.3 is provided in the preheating structure 5. The manual shut-off valve 5.4 can be operated manually or controlled by the dryer setting program. The utility model can avoid the situation where the first batch of preforms will be defective when the machine is first started, thereby reducing material waste.

Claims

1. A preheating structure for a drying system before initial production, comprising a drying hopper, a drying hopper cone, a main return air duct, a pneumatic knife gate, and a preheating structure, characterized in that: A main return air duct (7) is provided above the drying hopper (1), a drying hopper cone (4) is provided below the drying hopper (1), a preheating structure (5) is connected below the drying hopper cone (4), a pneumatic knife gate (8) is connected below the preheating structure (5), the preheating structure (5) comprises a heat preservation unit (5.1), a preheating pipe (5.2), a pneumatic shut-off valve (5.3), a manual shut-off valve (5.4), and a preheating chamber (5.5), a preheating chamber (5.5) is provided inside the heat preservation unit (5.1), a preheating pipe (5.2) is passed through one side of the preheating chamber (5.5), a manual shut-off valve (5.4) is provided on the preheating pipe (5.2), one end of the preheating pipe (5.2) is connected to the pneumatic shut-off valve (5.3), and the pneumatic shut-off valve (5.3) is connected to the main return air duct (7) through the return air duct (6).

2. The preheating structure of the drying system before initial production according to claim 1, characterized in that: The drying hopper (1) is provided with PET granular raw material (2).

3. The preheating structure of the drying system before initial production according to claim 1, characterized in that: One side of the drying hopper (1) is connected to the dryer air inlet (3).

4. The preheating structure of the drying system before initial production according to claim 1, characterized in that: The preheating chamber (5.5) has a rhombohedral structure, and the upper rhombus of the preheating chamber (5.5) has a mesh structure (5.6).

5. The preheating structure of the drying system before initial production according to claim 1, characterized in that: The drying hopper (1) is a barrel-shaped structure, and drying hopper fixing brackets (10) are provided on both sides of the top of the drying hopper (1).

6. The preheating structure of the drying system before initial production according to claim 1, characterized in that: A feeding port (9) is connected below the pneumatic knife gate (8).

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