Pressure screw feeder

Abstract

The utility model belongs to the technical field of spiral conveying equipment, and provides a pressure spiral feeder. Comprising a spiral shaft tube, a spiral shaft and a driving motor, the spiral shaft is divided into a conveying section, a compression section, a material plug section and a reverse pushing section, spiral blades are arranged on the conveying section and the compression section, no spiral blade is arranged on the material plug section, reverse compression spiral blades are arranged on the reverse pushing section, the screw pitch between the spiral blades on the compression section is gradually decreased, and the screw pitch between the spiral blades on the compression section is gradually decreased. A plurality of cutting tool grooves are formed in the reverse compression spiral blade on the reverse thrust section. According to the feeder, due to the fact that the formed material plug is compact enough, tests show that the feeder can dynamically and continuously feed materials into a high-pressure cooking container from normal pressure under the high-temperature and high-pressure working conditions of 1.6 MPa saturated steam, so that biomass raw materials can be rapidly decomposed, separated, extracted, cured and the like under the high-temperature and high-pressure conditions, and the biomass raw materials can be continuously fed into the high-pressure cooking container from the normal pressure under the high-temperature and high-pressure working conditions. The device is suitable for being widely popularized and used in papermaking, cellulosic ethanol and traditional Chinese medicine industries.

Description

Technical Field

[0001] The utility model belongs to the technical field of screw conveying equipment, in particular to a pressure screw feeder. Background Art

[0002] As a commonly used material conveying device, screw conveying equipment is widely used in various working occasions.

[0003] For example, in the process of crushing, cooking, ripening, extracting and extracting wood chips, crop straw, bark or wood chips, Chinese herbal medicine and other woody plants as raw materials, the crushed raw materials need to be conveyed to a cooking container by a screw feeder for heating and pressurized cooking to soften the materials, and complete the cooking, ripening, extraction and other process requirements under high temperature and high pressure conditions, while degrading the hemicellulose connecting cellulose and lignin into xylose or xylose oligomers.

[0004] For example, in the horizontal tube continuous steaming process of the pulp and paper industry, it is also necessary to pressurize and steam woody materials such as rice straw, wheat straw, reed, wood chips, and bamboo chips. Among them, when the fibrous material is transported from the external normal pressure state to a steaming container in a pressurized state, a feeder that can seal the pressure in the container is required. The screw feeder commonly used in the horizontal tube continuous steaming process of the pulp and paper industry at present has the following structural characteristics and working principles: the feeder mainly includes a driving motor, a spiral shaft tube, and a spiral shaft consisting of a conveying section, a conical compression section, and an outlet plug section. The driving motor is connected to the spiral shaft in a transmission manner. Among them, the function of the conveying section is to receive the raw materials and transport the raw materials forward to the compression section. The spiral shaft of the compression section is generally conical, and the volume of the spiral cavity surrounded by two adjacent spiral blades inside it is constantly reduced. Therefore, while the material is transported forward in this section, the volume is constantly compressed. In the plug section, the spiral shaft is a bare shaft without spiral blades, and the spiral shaft tube is a circular cylinder. The gas medium pressure in the cooking vessel acts on the material in the plug section to squeeze it tightly, thereby preventing gas from leaking from the feeder and spraying back from the feeder inlet with the material. The material in the plug section is pushed forward by the material at the rear, so that the material is continuously fed into the digester. However, this feeder can only withstand a pressure of less than 0.8Mpa because the plug formed is not dense enough. There is no dedicated high-density plug section. Under the condition of high temperature and high pressure dynamic feeding, the steam cannot be sealed and is easy to spray back. In order to fully crush and allow steam to penetrate the cell wall of biomass raw materials faster for rapid cooking and maturation, the pressure of the cooking container in the industry is gradually increasing, and traditional feeders can no longer meet the needs of the industry. Summary of the invention

[0005] The purpose of the invention is to provide a pressure screw feeder which can solve the problem of insufficient pressure resistance in the prior art on the basis of stably and continuously conveying materials.

[0006] To achieve the above-mentioned purpose, the present invention designs a pressure screw feeder, comprising a screw shaft tube, a screw shaft and a driving motor, wherein the screw shaft is divided into a conveying section, a compression section, a plug section and a reverse thrust section, the conveying section and the compression section are provided with spiral blades, the plug section has no spiral blades, the reverse thrust section is provided with reverse compression spiral blades, the pitch between the spiral blades on the compression section gradually becomes smaller, and the reverse compression spiral blades on the reverse thrust section are provided with a plurality of cutting grooves.

[0007] Furthermore, the cutting groove forms an angle with the axis of the screw shaft.

[0008] Furthermore, the cutting groove has a cutting edge, and the cutting edge is made of cemented carbide material.

[0009] Furthermore, the spiral shaft tube is provided with a feed port, which is connected to the stirring feeder.

[0010] Furthermore, the conveying section, compression section, plug section and reverse thrust section are arranged in sequence.

[0011] Furthermore, the inner wall of the spiral shaft tube is provided with an anti-slip strip to prevent the material from rotating.

[0012] Furthermore, drainage holes are provided on the spiral shaft tube at positions corresponding to the compression section and the plug section.

[0013] Furthermore, the plurality of cutting grooves are evenly distributed along the spiral direction of the reverse compression spiral blade.

[0014] The pressure screw feeder of the utility model is provided with a reverse thrust section at the front end of the screw shaft of the feeder. The reverse compression spiral blades on the reverse thrust section can extrude the material in the reverse direction, so that the material is subjected to front and rear bidirectional compression in the plug section to form a dense plug seal. With the rotation of the screw shaft and the strong push of the subsequent material, the high-density material will be cut and squeezed out from the cutting grooves of the reverse compression spiral blades and enter the cooking container, completing the dynamic feeding process of the raw material from normal pressure into the high-pressure container. After the biomass raw material is cut and crushed, the steam can quickly penetrate into the cell wall of the raw material to quickly cook, mature and separate it.

[0015] The high-temperature steam in the cooking container is blocked by the dense plug of the plug section, thereby preventing the steam from spraying back from the feeder; the material in the plug section is continuously compressed and pushed forward by the subsequent material, thereby realizing the continuous feeding of the material into the digester. Since the plug formed by the feeder is dense enough, it has been tested that under the high-temperature and high-pressure working conditions of 1.6MPa saturated steam, the feeder can dynamically feed the feeder from normal pressure to the high-pressure cooking container continuously, so that the biomass raw materials can be quickly decomposed, separated, extracted, matured and other process purposes under high-temperature and high-pressure conditions. The utility model is suitable for wide promotion and use in the papermaking, cellulosic ethanol and traditional Chinese medicine industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of the new model;

[0017] Figure 2 It is a schematic diagram of the novel spiral shaft structure;

[0018] Figure 3 This is a schematic diagram of the new thrust reverser structure. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, and its structure and advantages will become more clear.

[0020] Embodiment 1, see Figure 1-3 A pressure screw feeder comprises a screw shaft tube 1, a screw shaft 2 and a driving motor 3, wherein the screw shaft 2 is divided into a conveying section 2.1, a compression section 2.2, a plug section 2.3 and a reverse thrust section 2.4, the conveying section 2.1 and the compression section 2.2 are provided with spiral blades 2.5, the plug section 2.3 has no spiral blades 2.5, the reverse thrust section 2.4 is provided with reverse compression spiral blades 2.6, the pitch between the spiral blades 2.5 on the compression section 2.2 gradually decreases, and the reverse compression spiral blades 2.6 on the reverse thrust section 2.4 are provided with a plurality of cutting grooves 2.7.

[0021] Embodiment 2, see Figure 3 On the basis of the first embodiment, the cutting groove 2.7 forms an angle with the axis of the screw shaft 2. During specific manufacturing, the parallel line projection of the opening direction of the cutting groove 2.7 forms an angle with the projection of the axis of the screw shaft 2, preferably 30 to 60 degrees; the parallel line of the cutting groove 2.7 in the depth direction is perpendicular to the axis of the screw shaft. The purpose of this design is to form a blade 2.8 at the rear of the groove wall of the cutting groove 2.7 to achieve cutting and crushing of high-density materials in the plug section 2.3.

[0022] Embodiment 3, see Figure 3On the basis of the first embodiment, the cutting groove 2.7 has a blade 2.8 made of hard alloy material. The blade 2.8 is arranged on the groove edge that cuts into the material when the cutting groove 2.7 rotates, and the blade 2.8 is made of hard alloy material and then fixed by welding.

[0023] Embodiment 4, see Figure 1 On the basis of the first embodiment, the spiral shaft tube 1 is provided with a feed port, which is connected to the stirring feeder 4. The stirring feeder 4 is connected with the conveying section 2.1, and the stirring feeder 4 is used to feed the material, so that the material is more uniform and the material bridging is prevented.

[0024] Embodiment 5, see Figure 1 , 2 On the basis of the first embodiment, the conveying section 2.1, the compression section 2.2, the plug section 2.3 and the reverse thrust section 2.4 are arranged in sequence. The conveying section 2.1 conveys the material to the compression section 2.2, the material is initially compressed in the compression section 2.2, and the reverse compression spiral blade 2.6 on the reverse thrust section 2.4 can reversely squeeze the material, so that the material is compressed in both directions in the plug section 2.3, and the density is greatly improved compared with the traditional feeder.

[0025] Embodiment 6, see Figure 1 On the basis of the first embodiment, the inner wall of the spiral shaft tube 1 is provided with an anti-slip strip to prevent the material from rotating. The anti-slip strip enables the material to move forward better and prevents slipping.

[0026] Embodiment 7, see Figure 1 On the basis of the first embodiment, drainage holes are provided on the spiral shaft tube 1 at positions corresponding to the compression section 2.2 and the plug section 2.3, so as to facilitate the outflow of water generated by material compression.

[0027] Embodiment 8, see Figure 3 On the basis of the first embodiment, the plurality of cutting grooves 2.7 are evenly distributed along the spiral direction of the reverse compression spiral blade 2.6. The reverse compression spiral blade 2.6 on the reverse thrust section 2.4 is provided with 2-3 turns.

[0028] The cutting groove 2.7 is a groove-shaped notch arranged on the reverse compression spiral blade 2.6. The cutting surface of the notch is provided with a blade 2.8. The blade 2.8 is made of cemented carbide. The blade 2.8 can better crush high-density materials. The materials are crushed in the process of being squeezed through the cutting groove 2.7. The materials enter the cutting groove 2.7 on the front adjacent reverse compression spiral blade 2.6 from the rear cutting groove 2.7 and are crushed again. In this way, the crushed materials move forward until they enter the front end of the feeder and fall into the cooking container, completing the feeding process. The materials are fully crushed to allow steam to penetrate the cell wall of the biomass raw material faster for rapid cooking and maturation.

[0029] Furthermore, reinforcing ribs are provided on the corresponding spiral shaft tubes 1 of the compression section 2.2 and the plug section 2.3, so as to make the spiral shaft tubes 1 of this section have higher compressive strength.

[0030] The pressure screw feeder of the utility model is provided with a reverse thrust section 2.4 at the front end of the screw shaft 2 of the feeder. The reverse compression spiral blade 2.6 on the reverse thrust section 2.4 can reversely extrude the material, so that the material is subjected to front and rear bidirectional compression in the plug section 2.3. The density is greatly improved compared with the traditional feeder. With the rotation of the screw shaft 2, the high-density material will be crushed and squeezed out from the cutting groove 2.7 to complete the feeding process. The material is fully crushed so that the steam can penetrate the cell wall of the biomass raw material faster to quickly cook and mature. In addition, the gas medium pressure in the cooking container acts on the dense material in the plug section 2.3, thereby preventing the gas from the feeder. The material in the plug section 2.3 is pushed forward by the rear material, so that the material can be continuously fed into the digester. The plug formed by this feeder is dense enough to withstand a large saturated steam pressure. According to the test, it can achieve the process purpose of high-temperature cooking and maturation after continuous feeding under the working conditions of high-pressure 1.6MPa saturated steam and high temperature 207℃, which is much higher than the existing 0.8MPa working condition. It can fully soften the material and obtain higher product quality. It is suitable for promotion and use in papermaking, cellulosic ethanol and pharmaceutical industries.

Claims

1. A pressure screw feeder, comprising a screw shaft tube, a screw shaft and a drive motor, characterized in that: The spiral shaft is divided into a conveying section, a compression section, a plug section and a reverse thrust section. The conveying section and the compression section are provided with spiral blades, the plug section has no spiral blades, the reverse thrust section is provided with reverse compression spiral blades, the pitch between the spiral blades on the compression section gradually decreases, and the reverse compression spiral blades on the reverse thrust section are provided with a plurality of cutting grooves.

2. A pressure screw feeder as claimed in claim 1, characterized in that: The cutting groove forms an angle with the axis of the screw shaft.

3. A pressure screw feeder as claimed in claim 1, characterized in that: The cutting groove has a cutting edge, and the cutting edge is made of hard alloy material.

4. A pressure screw feeder as claimed in claim 1, characterized in that: The spiral shaft tube is provided with a feed port, which is connected with the stirring feeder.

5. A pressure screw feeder as claimed in claim 1, characterized in that: The conveying section, compression section, plug section and reverse thrust section are arranged in sequence.

6. A pressure screw feeder as claimed in claim 1, characterized in that: The inner wall of the spiral shaft tube is provided with an anti-slip strip to prevent the material from rotating.

7. A pressure screw feeder as claimed in claim 1, characterized in that: Drain holes are arranged on the spiral shaft tube at positions corresponding to the compression section and the plug section.

8. A pressure screw feeder as claimed in claim 1, characterized in that: The plurality of cutting grooves are evenly distributed along the spiral direction of the reverse compression spiral blade.

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