CN111300865A

CN111300865A - Screw extrusion dehydrator and application

Info

Publication number: CN111300865A
Application number: CN202010250281.1A
Authority: CN
Inventors: 翟海波; 岳建文; 贾春平; 张博; 王伟
Original assignee: Shandong Xinhua Pharmaceutical Co Ltd
Current assignee: Shandong Xinhua Pharmaceutical Co Ltd
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2020-06-19

Abstract

The invention provides a screw extrusion dehydrator which comprises a motor, a speed reducer, a gearbox, a feeding box, a shell, a water filtering net, a constant pressure mechanism, a rack, a screw shaft, a screw blade, a discharge hole and a water outlet, wherein the motor is connected with the speed reducer; the invention also provides the application of the screw extrusion dehydrator in the production of calcium polycarbophil, wherein the materials are discharged from the reaction kettle, enter the screw extrusion dehydrator, are extruded and dehydrated through the screw extrusion dehydrator, are conveyed to a skip car through material conveying equipment, and are subsequently conveyed to a drying process; the invention can realize stable, continuous, reliable and mass production mechanical dehydration, can reduce the water content of materials with 80-90 percent to below 50 percent, and has the dehydration rate of more than 80 percent.

Description

Screw extrusion dehydrator and application

Technical Field

The invention belongs to the field of machine manufacturing, and particularly relates to a spiral extrusion dehydrator and application thereof in dehydration in calcium polycarbophil production.

Background

Calcium Polycarbophil, abbreviated as CPC, is hydrophilic polyacrylic resin, has hydrophilicity, has obvious binding capacity to water, can absorb water which is 60 times of the weight of the Calcium Polycarbophil, expands after absorbing water, has 80-90 percent of water content (the water-material ratio is 5:1), is colloidal and high in viscosity, and influences dehydration and drying in the production process.

At present, the drying procedure in the CPC production process is to adopt the manual work to catch the material and then to stand for dehydration, and then to adopt the hot air circulation oven drying mode to dry the product after standing. The following problems exist in the process:

firstly, the heating is completely dependent on electric energy, the heat efficiency of the electric energy is about 30 percent, and the energy consumption is as high as 1.8 yuan/kg;

secondly, the drying time is very long due to low heat transfer efficiency, and the product is easy to carbonize and has large potential safety hazard after being dried in an oven for a long time at high temperature;

thirdly, the drying efficiency of the oven is not high, the drying time of the oven needs 20 hours, the polymerization reaction time is only about 10 hours, and the drying becomes the bottleneck restricting the productivity.

The industry always hopes that CPC products are produced by mechanical dehydration to reduce water content and then dried so as to reduce energy consumption and improve drying efficiency, but at present, no stable, continuous, reliable and mass production mechanical dehydration method exists.

Disclosure of Invention

The invention provides a screw extrusion dehydrator which comprises a motor, a speed reducer, a gearbox, a feeding box, a shell, a water filtering net, a constant pressure mechanism, a rack, a screw shaft, a screw blade, a discharge hole and a water outlet, wherein the motor is connected with the speed reducer;

the gear box, the feeding box, the shell, the constant pressure mechanism and the speed reducer are respectively fixed on the rack through bolts; the discharge port and the water outlet are welded on the frame; the motor is connected to the speed reducer through a coupler, and the gearbox is connected with the speed reducer through a coupler; two ends of the spiral shaft are fixed on the gearbox and the rack through a coupler and a bearing respectively, and two ends of the water filter screen are fixed on the shell of the feed box and the rack through a clamping groove and a bolt respectively; the spiral blade is fixed on the spiral shaft, the peripheral connecting line is cylindrical, the shell is cylindrical, and the cylindrical body is coaxial with the spiral shaft; the constant pressure mechanism is a pneumatic device, and the pressure of the discharge hole is adjusted by adjusting air pressure.

After the equipment operation, the material is evenly added from the feeding box, the material after advancing advances along the axial under the promotion of helical rotating blade, and the in-process material that advances receives the pitch that changes and the effect of water strainer, forms huge extrusion force, makes the material carry out mechanical dehydration under the exogenic action, and moisture content is discharged at the delivery port department through the screen cloth, and the material after the dehydration is discharged at the delivery port department. The equipment can control the water content of the discharged material by adjusting the pressure of the constant pressure mechanism.

The technical scheme has the advantages of simple structure, reasonable design and strong dehydration capability.

The invention also provides an application of the screw extrusion dehydrator, in particular to an application of the screw extrusion dehydrator in the dehydration of calcium polycarbophil production, and the system comprises a reaction kettle, the screw extrusion dehydrator, material conveying equipment and a skip car; the materials are discharged from the reaction kettle, enter the screw extrusion dehydrator, are extruded and dehydrated through the screw extrusion dehydrator, are conveyed to the skip car through the material conveying equipment, and are subsequently conveyed to the drying process.

Through repeated research on the characteristics of CPC products and various mechanical dehydration methods, a mechanical dehydration method capable of realizing stable, continuous, reliable and large-scale production is found, 80-90% of materials containing water can be reduced to below 50% of water (dehydration rate is 80%), and the dehydration method is spiral extrusion dehydration.

The spiral extrusion dehydration equipment is mainly equipment for extruding and dehydrating high-water-content and fibrous substances at present, is mainly applied to the food and biological industries, is rarely applied to the chemical industry, and has no application to mechanical dehydration in the production of CPC products.

Compared with the prior art, the invention has the beneficial effects that:

after the spiral extrusion dewatering equipment is applied to the production process of the CPC product, the water content is greatly reduced. At present, four production lines are provided for producing polycarbophil calcium in our company, the yield of each batch is 180kg, 4 batches are produced in one day, the water content of CPC is reduced from 80-90% to below 50% after the equipment is applied compared with that before the equipment is applied, and the water content of materials is reduced by more than 80% compared with that before extrusion. After the material is mechanically pre-dehydrated and the moisture is greatly reduced, the method is very beneficial to the following drying:

firstly, the drying efficiency is greatly improved, the drying time is shortened from 20h to 8h, and the drying efficiency and the productivity are improved by more than 1 time;

secondly, the drying power consumption is reduced from 1.8 yuan/kg to 0.8 yuan/kg, and is reduced by 73 percent;

and thirdly, the process is automated, the labor intensity of workers is reduced, and the field sanitary conditions are improved.

Drawings

FIG. 1 is a schematic view of a screw extruder-dehydrator according to the present invention;

in the figure: 1. the device comprises a motor, 2, a gearbox, 3, a feeding box, 4, a shell, 5, a water filter screen, 6, a constant pressure mechanism, 7, a rack, 8, a spiral shaft, 9, a spiral blade, 10, a speed reducer, 11, a discharge hole, 12 and a water outlet.

FIG. 2 is a schematic diagram of the apparatus for dehydration in calcium polycarbophil production according to the present invention;

in the figure: 13. a reaction kettle, 14, a screw extrusion dehydrator, 15, material conveying equipment, 16 and a skip car.

Detailed Description

The specific operation process comprises the following steps:

equipment: 12 cubic reaction kettles 13, 1 screw extrusion dehydrator 14 with the processing capacity of 2 cubic/hour, and 1 chain plate type material conveying device 15 with the processing capacity of 2 cubic/hour;

materials: discharging 1680 kg of CPC wet material from the reaction kettle 13, putting the CPC wet material into a feeding box 3 of a screw extrusion dehydrator 14, turning on a power supply of the screw extrusion dehydrator 14, and then adjusting a constant pressure mechanism 6 of the screw extrusion dehydrator 14 to 0.4 Mpa; the input materials are extruded and dehydrated under the driving of a screw, after the extrusion, the water is extruded out by the water filter screen 5 and then is discharged by the water outlet 12, and the dehydrated materials are discharged by the discharge port 11. The water content of the material is 45%, and the whole process takes about 10 minutes; then the materials are automatically conveyed to a skip 16 through a material conveying device 15 and then are conveyed to an oven of a drying chamber for drying.

Attached: test data

The test is mainly a comparison of production data before and after project reconstruction. The test equipment comprises a single 2-cubic reaction kettle 13, a screw extrusion dehydrator 14 with the handling capacity of 2 cubic meters per hour, a single batch of 180kg of materials produced in a standard mode, and 1500 kg of water.

The production flow before modification is as follows: discharging the reaction kettle 13, placing in a container, manually draining and fishing the materials, and drying by a skip car 16;

the modified production flow comprises the following steps: discharging the materials in the reaction kettle 13, spirally extruding and dewatering 14, automatically conveying the materials 15, and drying by a skip car 16.

Item	Before transformation	After transformation	After transformation
				Test time	2017.08.07	2018.03.06	2018.04.08
Dehydration mode	Manual draining	Automatic squeezing and dewatering	Automatic squeezing and dewatering
				From discharge to skip	1h52min	11min	9min
State of material	Colloidal, high viscosity	Cotton-like and non-viscous	Cotton-like and non-viscous
				Water content of material	83.3％	43.9％	45.2％
Drying requirements	Vitrification	Vitrification	Vitrification
				Length of drying	20h6min	7h30min	7h53min
Consumption of dry electricity	498kwh	202kwh	223kwh
				Specific power consumption	2.77kwh/kg	1.12kwh/kg	1.20kwh/kg

Claims

1. A screw extrusion dewaterer is characterized in that: comprises a motor (1), a speed reducer (10), a gear box (2), a feeding box (3), a shell (4), a water filter screen (5), a constant pressure mechanism (6), a frame (7), a spiral shaft (8), a spiral blade (9), a discharge hole (11) and a water outlet (12);

the gearbox (2), the feeding box (3), the shell (4), the constant pressure mechanism (6) and the speed reducer (10) are respectively fixed on the rack (7) through bolts; the discharge port (11) and the water outlet (12) are welded on the frame (7); the motor (1) is connected to the speed reducer (10) through a coupler, and the gearbox (2) is connected with the speed reducer (10) through a coupler; two ends of the spiral shaft (8) are respectively fixed on the gearbox (2) and the rack (7) through a coupler and a bearing, and two ends of the water filter screen (5) are respectively fixed on the shell of the feeding box (3) and the rack (7) through clamping groove positioning and bolts; the spiral blade (9) is fixed on the spiral shaft (8), the peripheral connecting line is cylindrical, the shell is cylindrical, and the cylinder is coaxial with the spiral shaft (8); the constant pressure mechanism (6) is a pneumatic device, and the pressure of the discharge hole (11) is adjusted by adjusting air pressure.

2. The application of the screw extrusion dehydrator is characterized in that: comprises a reaction kettle (11), a screw extrusion dehydrator (12), material conveying equipment (13) and a skip car (14); the material gets into screw extrusion hydroextractor (12) after discharging from reation kettle, and through screw extrusion hydroextractor (12) extrusion dehydration, the material after the dehydration is carried skip (14) through material conveying equipment (13) again, and the follow-up stoving process that sends to.