Automatic pressure control apparatus for an end-face seal plate in seal mechanism of high pressure steamer

An automatic pressure control apparatus for an end-face seal plate in a seal mechanism of a high pressure steamer for wet-heat treatment of a textile product comprising; a seal mechanism having a pair of seal rubber rolls located above a hole in the high pressure steamer body, through which the cloth is passed for the purpose of sealing said hole, a seal block for supporting the seal rubber rolls which are freely rotatable, an end-face seal plate supported by the seal block, in pressure contact with the seal rubber rolls and the end face of the seal block so as to be freely slidable in the axial direction of the seal rubber rolls, an end-face seal plate support fitting for support of the end-face seal plate, a pressure control screw supported by means of a support fitting fixed to the seal block so as to be freely slidable in the axial direction of the seal rubber rolls, and a press-down plate movable in the axial direction of the seal rubber rolls by means of the pressure control screw, a pressure detector provided between the press-down plate and the end face of the seal rubber rolls for detecting the contact pressure between the end faces of the seal rubber rolls and the end-face seal plate, and an operation mechanism driven by means of a pressurized fluid to move said pressure control screw back and forth, thus allowing the end faces of the seal rubber rolls to make contact with the end-face seal plate under an appropriate amount of pressure, and a modification thereof.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an automatic pressure control for an 
end-face seal plate in seal mechanism of a high pressure steamer for 
wet-heat treatment of a textile product, in which the end-face seal plate 
is controlled automatically in accordance with the thermal expansion of 
seal rolls, incorporated in the seal mechanism, in order to create a 
constant sealing effect with a prescribed amount of pressure. 
2. Description of the Prior Arts 
A known seal mechanism for a high pressure steamer comprises an end-face 
seal plate for sealing the openings formed by a pair of seal rolls, their 
end-faces and the end face of a seal frame. For the purpose of making a 
close contact of said end-face seal plate with the end faces of the seal 
roll and the seal frame effectively, the present invention offers an 
automatic pressure control apparatus for the end-face seal plate. This 
apparatus enables the end-face seal plate and the end faces of the seal 
rolls and the seal frame to have close contact to each other automatically 
and effectively in accordance with the thermal expansion of the seal rolls 
incorporated in the seal mechanism. These seal rolls and the seal frame 
attached to the seal mechanism are heated to a tolerable degree in service 
so as to cause thermal expansion of the seal rolls and the seal frame. If 
the end-face seal plate is arranged closely in contact with the end faces 
of the seal rolls and the seal frame before putting in service, the 
operation becomes impossible due to an abnormal friction force caused by 
thermal expansion during the operation, but if a gap is provided 
previously between these fittings in anticipation of expansion, the 
pressure in the interior of the steamer body can hardly be raised to a 
prescribed value and needs a long period of time before it can reach a 
normal operation state. 
To solve such drawbacks as the above-mentioned, the present inventors have 
recently proposed a seal mechanism comprising a pair of seal rubber rolls 
arranged above a hole of the high pressure steamer body through which the 
cloth is passed for the purpose of sealing the hole, seal frames for 
supporting these rolls to be freely rotatable, and an end-face seal plate 
pressedly in contact with the end faces of the seal rubber rolls and the 
seal frame; an automatic pressure control apparatus for the end-face seal 
plate comprising a press-down rod for causing the pressed contact of said 
end-face seal plate with the end-faces of the seal rubber rolls and the 
seal frame, a pressure responsive mechanism to push the press-down rod in 
the direction forward the end faces of the seal rubber rolls and the seal 
frame in cooperation with the inner pressure of the high pressure steamer 
body, and a plurality of springs for pressing down the end-face seal plate 
to the end faces of the seal rubber rolls and the seal frame with an 
appropriate pressure in case the pressure responsive mechanism is 
non-operative. In this apparatus, since the end-face seal plate is moved 
due to the inner pressure of the steamer body, the contact pressure 
between the seal rubber rolls and the end-face seal plate is elevated, as 
the inner pressure of the steamer body increases. On the other hand, the 
immediate reason for the change in the contact pressure between the seal 
rubber rolls and the seal end-face plate in the course of operation of a 
high pressure steamer is the thermal expansion of the seal rubber roll and 
the end-face seal plate. Accordingly, even when the pressure of the 
steamer body is increased, the contact pressure between the seal rubber 
rolls and the seal end-face plate becomes insufficient in a case where the 
degree of thermal expansion of the seal rubber rolls and the end-face seal 
plate is small, thus causing the problem of pressure leakage. 
SUMMARY OF THE INVENTION 
To resolve the above-mentioned problems, the object of the present 
invention is to offer an improved apparatus for automatic pressure control 
of the end-face seal plate in the seal mechanism of a high pressure 
steamer for the wet-heat treatment process of a textile product. 
The essential point of the inventive apparatus comprises: a seal mechanism 
having a pair of seal rubber rolls located above the hole, through which 
the cloth is passed, of a high pressure steamer body, for the purpose of 
sealing the hole, a seal block for supporting the seal rubber rolls which 
are freely rotatable, an end-face seal plate supported by the seal block 
and in contact pressure with the seal rubber rolls and the end face of the 
seal block so as to be freely slidable in the axial direction of the seal 
rubber rolls, an end-face seal plate support fitting for support of the 
end-face seal plate, a pressure control screw supported by means of a 
support fitting fixed to the seal block so as to be freely slidable in the 
axial direction of the seal rubber rolls, and a press-down plate movable 
in the axial direction of the seal rubber rolls by means of the pressure 
control screw, a pressure detector provided between the press-down plate 
and the end faces of the seal rubber rolls for detecting the contact 
pressure between the end face of the seal rubber rolls and the end-face 
seal plate, and an operation mechanism driven by means of a pressurized 
fluid so that the pressure control screw can be moved back and forth thus 
allowing contacting the end faces of the seal rubber rolls to make contact 
with the end-face seal plate under an appropriate amount of pressure; and 
a modification thereof.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention will be explained in detail in the following 
paragraphs with reference to the drawings which show examples of the 
inventive apparatus. 
An example of the apparatus shown in FIGS. 1 to 3, 1 is a seal block 
provided on a high pressure steamer 2, and a hole 3, for the purpose of 
passing a cloth therethrough, is provided through the seal block 1. Above 
the hole 3, a pair of seal rubber rolls 4 and 4', being in contact 
pressure with each other, are provided in a freely rotatable manner. To 
seal the gap formed between the pair of seal rubber rolls 4, 4' and the 
edge of the upper opening of the hole 3 through which the cloth is passed, 
a pair of seal plates 5, 5', being a hemicycle shape in section, are fixed 
to the seal block 1. 6 is an end-face seal plate for sealing a 
mountain-shaped gap formed between the end faces of said pair of seal 
rubber rolls 4, 4' and the seal block 1, and 7 is a support fitting for 
the end-face seal plate 6. This support fitting 7 is supported by a guide 
fitting 8 attached to the seal block 1 and is freely slidable in the 
direction parallel to the axes of the seal rubber rolls 4, 4'. 
9 is a press-down plate used to press down the end-face seal plate support 
fitting 7 by putting three gap control bars 10 and a pressure detector 11. 
The front end of a pressure control screw 12 is screwed into the backside 
of the press-down plate 9. 13 is a support fitting fixed to the side face 
of the seal block 1, in order to support the pressure control screw 12. 14 
is a stop ring which is stoppable in the axial direction of the pressure 
control screw but is not stoppable in the rotation direction thereof. 16 
is a support shaft supported by a support fitting 15 integrated with the 
seal block 1, and the stop ring 14 is pivotably supported by one end of an 
arm 17 swingably supported by the support shaft 16. The other end of the 
arm 17 is connected to the front end of a rod 18. 19 is an air-tight 
chamber situated between the tail end of the rod 18 and the seal block 1 
thus enabling the rod 18 to move back and forth in accordance with the 
pressure in the air-tight chamber 19. This air-tight chamber 19 may be one 
such as an air cylinder or a diaphragm. 20 is a handle attached to the 
pressure control screw 12 en bloc, and 21 is an electromagnetic valve for 
supplying air to the air-tight chamber 19 in accordance with the pressure 
in the pressure detector 11. 
The function of this example will be described hereinbelow. 
Firstly, at the time when the seal rubber rolls 4, 4' are not expanded, the 
pressure contact between the end faces of the seal rubber rolls 4, 4' and 
the end-face seal plate 6 is controlled by the operation of the handle 20 
so that they are just in contact with each other. When the temperature of 
the steamer body 2 is elevated during operation, upto about 150.degree. 
C., for instance, the seal rubber rolls 4, 4' are expanded due to heat, 
and accordingly the end-face seal plate 6 and the end-face seal plate 
support fitting 7 are pressed outwards in the axial direction of the seal 
rubber rolls 4, 4'. Then, the pressing force of the end-face seal plate 6 
and the end-face seal plate support fitting 7 acts on the pressure 
detector 11. An electrical output of the pressure detector 11 
corresponding to the pressure applied thereto, opens and shuts the 
electromagnetic valve 21 which is used in controlling the amount of air 
supplied into the air-tight chamber 19. That is to say, when the pressure 
acting on the pressure detector 11 becomes higher than the prescribed 
value, the pressure in the air-tight chamber 19 decreases due to the 
action of the electromagnetic valve 21, and the pressure contact between 
the end-face seal plate 6 and the seal rubber rolls 4, 4' is weakened due 
to the automatic action of the pressure control screw 12, therefore 
allowing the seal rubber rolls 4, 4' to operate smoothly by the prevention 
of an inner pressure leakage of the steamer body 2. On the other hand, 
when the pressure in the pressure detector 11 decreases below the 
prescribed value, pressurized air is supplied into the air-tight chamber 
19 by the operation of the electromagnetic valve 21, caused by the 
electrical output from the pressure detector 11, and the contact pressure 
between the end-face seal plate 6 and the seal rubber rolls 4, 4' is then 
strengthened due to the automatic effect of the pressure control valve 12 
so that the seal rubber rolls 4, 4' can also be smoothly rotated with the 
prevention of an inner pressure leakage of the steamer body 2. 
Another example of the present inventive apparatus is shown in FIG. 4. The 
constructional elements from a seal block 1 to a guide fitting 8 in this 
example are the same as in the preceding example. 9 is a press-down plate 
pressing on the end-face seal plate support fitting 7 by placing three gap 
control bars 10 therebetween, with the front end of a pressure control 
screw 12 screwed to the backside of the press-down plate 9. Supporting the 
pressure control screw 12 is a support fitting 13 which is fixed to the 
side face of the seal block 1 as in the preceding example. An air-tight 
chamber 19 is attached to the end-face seal plate 6 in this instance by 
placing a pushing body 22 therebetween, which is used to push the end-face 
seal plate 6 in a case when the inner pressure of the air-tight chamber 19 
is increased. Further, a pressure detector (not shown in the drawing) is 
attached to the air-tight chamber 19 in the direction of the end-face of 
the seal rubber rolls 4, 4'. 21 is an electromagnetic valve which acts in 
response to the signal from the pressure detector thus maintaining the 
pressure in the air-tight chamber to a prescribed value. 20 is a handle 
for rotating the pressure control screw 12 via a reduction gear 23. 
Also, in this example of the present inventive apparatus, when the 
temperature of the steamer body is elevated during operation, the seal 
rubber rolls 4, 4' expand due to heat, and the end-face seal plate 6 and 
the end-face seal plate support fitting 7 are pressed in the axial 
direction of the seal rubber rolls 4, 4'. Then, the pushing body 22 is 
pushed against the pressure of the air-tight chamber 19, and accordingly 
the pressure in the air-tight chamber 19 is elevated. The pressure 
increase in the air-tight chamber 19 is detected by means of a pressure 
detector (not shown in the drawing), the electromagnetic valve 21 is 
operated, and the pressure of air supplied into the air-tight chamber 19 
can be controlled. Therefore, the seal rubber rolls 4, 4' operate smoothly 
with the prevention of an inner pressure leakage of the steamer body 2. 
As described in the above, with the use of the present inventive apparatus, 
it is possible to control the contact pressure between the seal rubber 
rolls and the end-face seal plate in the seal mechanism of a high pressure 
steamer automatically so that the rubber seal rolls can operate smoothly 
while preventing a leakage of the inner pressure from the steamer body.