Add:No.352, Huashan North Road, Deyang City, Sichuan Province, China
Post Code::
E-mail:SCDYLIUHONG@163.COM
Detail Information
Catalogue
1. General Description
2. Composition
3. Materials for Extrusion
4. Extruding Capacity
5. Technological Features
6. Description to Individual Units
7. Consumption of Water and Electricity
8. Attached drawings:
Technological Layout Drawing No.1
Technological Layout Drawing No. 2
Foundation Drawing
1. General Description
For meeting the developing demand for cable industry & rubber hose industry in our country, this continuous lead extruder is designed basing on the equipment made by Sweden Sandelin Company. It is used to sheathe lead layer over cable and to vulcanize rubber pipe after extruding.
The outer diameter of lead layer is from 30mm to 110mm, to be achieved from two die-stocks. one for outer diameter between 30mm and 100mm, one for outer diameter between 40mm and 100mm. The user can adopt either of them according to his technical demand.
The machine performs continuous extrusion of lead with the rotation of a screw, which is able to ensure even thickness of lead on the longitudinal line of the lead pipe. Due to the strict control of temperature on each position, the extruding pressure and temperature can remain constant so that it is possible to keep the difference in lead thickness within a minimum, thus saving some 10% of lead consumption as compared with intermittent lead press.
As the melting furnace, the purifying & holding furnace and the lead conveyor are enclosed, vaporization from lead can be greatly reduced. Therefore this extruder basically does not cause pollution to the environment.
This extruder is light in weight, and involves low labor intensity in operation, and takes a comparatively small area.
The following individual units are available for separate order from customers according to their demand of production:
1) Lead ingot roll gang
2) Lead flake conveyer
3) Vertical lead stripper
4) Mobile pay-off stand (which is to be provided by the user)
5) Mobile traversing take-up stand (which is to be provided by the user)
2. Composition
Either for lead sheathing or for vulcanization of rubber, the following main equipments are needed:
1) The host machine of lead extruder,
2) 18-ton Lead Melting furnace
3) 10-ton purifying & holding furnace
4) Lead flake conveyer ( for rubber industry)
5) Vertical lead stripper (for rubber industry)
Additonally, the user can also choose the following items:
6) Lead ingot roll gang
7) Pay-off stand and take-up stand as per different size of bobbins
3. Materials for Extrusion
The extruder extrudes pure lead or alloy lead, and the ideal composition of
alloy lead is as follows :
3.1.Lead-antimony alloy: antimony content at 0.5%~0.6%
3.2.Lead-stannum-antimony alloy: stannum content at 0.4%, antimony content at 0.2%
3.3 Lead-tellurium-copper alloy: tellurium content at 0.04%, copper content at 0.04%
3.4.Lead-stannum-cadmium alloy: stannum content at 0.2%, cadmium content at 0.075%
The product produced by this equipment is that covers a lead-alloy sheath over tubes through a way of extrusion and the alloy element in lead layer is distributed evenly, so the quality of lead sheathing is very higher and it is not necessary to increase the antimony content in lead alloy. Additionally, owing to the limit of structure and use technology of the equipment, the process of lead press is quite different with intermittent lead press. Thus, it is not allowable for alloy lead with antimony content above 60%.
4. Extruding Capability
Lead composition Screw speed (rpm) Extruded output(kg/min)
Pure lead 13~15 30~35
Soft alloy lead 11~12 20~22
Hard alloy lead 9~10 15~16
5. Technological Features
5.1.Constant temperature:
The more the difference in the temperature of the molten lead, the more difference in the thickness of the lead pipe. Normally when there is a difference of 10℃,in the temperature, there will be a difference of 0.10mm in the thickness. Throughout the process when molten lead flows from the furnace into the barrel and into the die stock, and then is pressed into lead pipe, it is possible to keep the temperature constant at a preset value, with variation within ≤±3℃。
5.2.Constant pressure:
As the rotation speed of screw is constant, and the temperature is constant, the pressure during the extrusion process is also constant, whereby even thickness of lead layer can be ensured.
5.3.Constant speed:
As the rotation speed of screw is constant, the machine can works under a condition of constant temperature, constant pressure, and constant speed, not only even thickness of lead layer can be produced, but also produced in its minimal thickness, thus greatly reducing the consumption of lead.
6. Description to Individual Units
6.1. 18-ton Melting Furnace
The body of the furnace is made from welded steel, and inside it is partitioned into three chambers by vertical steel plate respectively for melting, mixing, purifying and holding. In the melting chamber molten lead flows through a purifying pipe vertically into the mixing chamber, and from the mixing chamber it flows into the purifying and holding chamber through an overflow pipe. In order to achieve even distribution of alloy elements, a mixer is fitted in the mixing chamber. On top of the furnace, three covers are fitted, which can be open and closed easily to make it possible to check molten lead and remove dross. Also on top an indicator to indicate the level of molten lead, a signal device, a temperature finder, transfer valves, discharge valve, charging opening, and roll gang are set, including air vent, etc.
The lead melting furnace is heated by adopting tubular electrical heater, with total heating power at 140kw, and working temperature at 400℃.
6.2. 10-ton Purifying & Holding Furnace
With the same function as that of the melting furnace, according to different requirements of use, it can be also used as a lead melting furnace. Generally speaking, the lead extruder is equipped with one 18-ton lead melting furnace and one 10-purifying & holding furnace. The two furnaces are connected through a lead conveying pipe. The 10-ton purifying & holding furnace, which is linked with the host machine, partitioned into two chambers by steel plate.
The purifying & holding furnace is also heated by adopting electricity, with total heating power at 100kw, and working temperature at 400℃.
6.3.The host machine of the lead extruder (to see a detailed description in operation instructoin of the host machine)
The working principle: after entering into the host machine, the molten lead is conveyed into the die stock through the rotation of a specially-structured screw installed vertically and then the lead pipe is extruded out from the exit of die-stock.
Machine body:
Consisting of bi-metallic inner barrel and outer barrel. Heating and cooling facilities are set over the outer barrel. Heating is for tubular electrical heater and circulation of cooling water adopts plate type heater. The wearable bearing insert is set bwetween the screw and the bareel. There is a water reserving tank with a capacity of 1000 liters at the base of the host machine. No heat exchangers and water pumps are fixed, which ensures constant temperatures of cooling water and lubrication oil. The whole oil & water systems are placed on the pedestal of the host machine.
6.4.Other auxiliary equipments
Lead stripper, lead flake conveyer (to see a detailed instruction of the machine),this machine is specially designed for rubber industry.
Lead ingot hoisting device and leat ingot roll gang are ordered basing on the demand of the user.
6.5 It is very easy to operate the machine with a low technical requirement and generally two workers can operate the whole equipment. Adjustment of the die can be done with the help of hydraulic system, the labour intensity is not high.
7. Consumption of water and electricity
7. 1Consumption of water at 6.80t/h
Consumed at the die, the outlet of die stock, cooling of lead pipe, and chillers for oil or water.
7.2. Installed capacity:
Extruder and heating: 145kw
18-ton lead melting furnace: 141.1kw
10-ton purifying & holding furnace: 101.1kw
Lead stripper 15kw
Lead flake conveyer 1.5kw