DESCRIPTION
FOR
PUSH – OUT- SYSTEM
DBP Patent Smitka Nr. 2919 705
1.
Description
The manual renewal of a crucible lining is a time consuming, difficult and dangerous
procedure. There is always the possibility of damaging the crucible coil whilst
breaking out the curcible with a jackhammer.
For this reason a method was sought to save time and to protect the coil from being
damaged. This has been achieved with the crucible push out system that can be
adopted to fit any crucible furnace.
The system consists of two major components, namely:
• Pivot
• Hydraulic system (on a transportable frame)
The hydraulic system, cylinder, connection hoses, together with the quick release
couplings are mounted on to the transportable frame.
To push out the crucible from a furnace, the transportable frame with the hydraulic
sysem will be placed behind the tilted furnace, hydraulic cylinder hooked into the
pivot and the crucible can then be pushed out within a very short time.
Measures to be taken for the operation of the Push-Out System
Additional steps to be taken before the first time use of a push-out system:
• A smooth conical refractory finish must be applied to the coil
• Installation of ceramic and mica slide insulating material to the conical refractory
before the casting of the crucible.
• Lower and centre a former into the furnace, conical plug must be fitted, fill with dry
lining material, pull out former and sinter the furnace
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2.
Hydraulic
2.1
Hydraulic-Unit
The hydraulic unit consists of a welded steel oil-container, three-phase motor with
emergency "OFF" switch, high-pressure pump, return-flow filter, manometer with
stoppage-valve and a manual way-valve.
2.2
Hydraulic-Cylinder
The hydraulic cylinder is supplied as a differential cylinder. The diameter and stroke
depend on the individual crucible furnace.
3.
Operation of the Plant
To push-out a crucible, the following steps must be taken:
Hydraulic cylinder to be inserted at head and support the cylinder.
Hydraulic unit to be linked to the cylinder by means of both hydraulic hoses.
Motor pump to be switched on and vent cylinder by means of the manual valve, drive
in and out without load.
As the manual valve exhibits a proportional-characteristic, the extent of the control
over the drive-out speed of the cylinder can therefore be adjusted.
The adjustable choke-reversion valve has the same function, however, has a setting
which remains. The tightened threaded plug next to the operating handle serves the
purpose of setting the operating pressure. If the plug is screwed in, the pressure is
increased, if the plug is unscrewed, the pressure is decreased.
Under normal conditions it is not necessary to adjust the pressure of 160 bar as set by
the manufacturer. Every three to four months the impurity filter indicator should be
checked, and if necessary the filter cartridge should be changed.
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Attention
Before the plant is operated for the first time, the hydraulic unit must be filled with
hydraulic oil up to the maximum oil level. (Recommendation:type of oil V G 46)
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