JPS6221607B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new and improved sealing device for rotary processing equipment, and more particularly to a sealing device for processing viscous or particulate plastic or polymeric materials.

In the prior art of such processing devices, individual annular processing channels basically consist of a rotatable element comprising at least one annular processing channel and a stationary element providing a coaxial surface cooperating with said channel. There is a device whose main component is formed of a closed processing passage. In the prior art, a stationary element includes an inlet for feeding material into a processing passageway and a stationary element spaced from said inlet by a distance approximately approximating the entire circumference around the processing passageway for discharging treated material from said passageway. and an outlet. A member providing an end wall surface for collecting liquid material is disposed on the stationary element and disposed in the passageway near the outlet to limit movement of the material fed into the passageway and cooperate with the rotating channel wall. The material is rotated in the direction of the outlet so as to cause relative movement between the inner surface of the channel wall and the inner surface of the channel wall. This special interaction allows only the liquid that is in contact with the inner surface of the rotating channel to be drawn forward towards the liquid collection end wall to control the processing and/or evacuation of the material.

The basic elements of this processing device are arranged in such a way that the element with a rotatable channel can be moved in rotation within a stationary housing or chamber (stationary element). The processing channels (preferably a plurality of processing channels) are formed within the cylindrical surface of the rotor, each channel having opposing sidewalls extending inwardly from the rotor surface. The stationary housing or chamber has an internal cylindrical surface that provides cooperating coaxial surfaces that together with the annular processing channel form a closed processing passage.

These devices are used to transfer solids or to melt or plasticize plastic or polymeric materials; to transfer, pump, or pressurize viscous liquids; to mix, blend, and formulate materials; for homogenization: as well as for degassing or by chemical reactions such as polymerization.
It is useful for bringing about micro or macro structural changes.

Because of the flexibility and adaptability of each of the basic processing passages as described above, it is common to employ one or two processing passages to accomplish different operations or functions. The processing device is equipped with the above passages. For example, one or more passages may be used to receive and transfer materials from one passage to another, or one or more passages may be used to transport polymeric or plastic materials. The effect of melting, mixing, volatilizing or releasing can be given. The particular action applied to an individual passageway typically determines the pressure characteristics of that passageway. For example, when effects such as melting or discharging are applied, the generation of very high pressure is of course a prerequisite. Other effects, such as volatilization, involve the generation of low pressures, while mixing effects involve moderate pressures. Furthermore, the pressure distribution along the circumference of each passageway varies depending on the action or actuation applied to the passageway.
The pressure may increase linearly along the entire circumference or along a portion of the circumference, or there may be one or more pressure increases along the circumference. There are also cases where the action provides a pressure profile in which there are one or more rapid drops. Furthermore, basic processing channels with particular pressure characteristics (eg, high pressure) have often been placed alongside or between devices with completely disparate pressure characteristics (eg, low pressure).

In most cases, it is desirable to provide an effective seal to all or some of the individual elementary passages in a multi-passage processing apparatus to prevent the leakage of undesired materials from at least some portion of the passages. Unwanted leakage is, for example, external leakage from one or both ends of the passages of a multi-passage processing device. Furthermore, undesirable leakage can also occur internally between adjacent individual processing channels. In all cases, however, the leakage of particular interest is the required clearance between the peripheral or top surface of the rotatable cylindrical channel wall and the stationary internal coaxial annular surface, especially where high pressures occur. Occurs in passageways.

The problem of external and internal leakage is particularly complex in multi-unit rotary processing equipment because radial pressure differences typically occur along the perimeter of the passageways.
For example, the pressure at the entrance to the passageway is typically low, but the pressure at the material collection end wall can be extremely high. In fact, the pressure difference in radial pressure is large enough to cause deflection of the rotor or shaft, thereby exploiting the required clearance between the top surface of the rotatable cylindrical channel wall and the stationary internal coaxial annular surface. place undesirable limits on what is possible.

Thus, the present invention relates to leakage problems in rotary processing equipment and effectively minimizes or prevents leakage under high or low pressures that exist between substantially coaxial surfaces moving relative to each other. A new and improved rotary processing apparatus is provided having a sealing device that can be rotated.

TECHNICAL FIELD This invention relates to a novel low friction seal that controls leakage of material between complementary surfaces that move relative to each other. The novel sealing arrangement of the present invention is particularly suitable for controlling liquid leakage between a relatively narrow circumferential portion of a rotor adjacent a rotatable channel and a stationary coaxial annular surface proximate to the channel; The gap between them is designed so that only a thin film of liquid can be inserted. a seal is provided, the seal being capable of effectively minimizing or preventing leakage of a thin film of liquid between the two surfaces at or near the gap;
Furthermore, they can be moved relative to each other. Basically, the seal consists of a number of seal channels (preferably parallel,
(spiral or oblique) so that liquid that has entered the gap during relative movement can penetrate into the sealing channel.
The effective width of the surface with helical channels, the number and angle of the helical channels on the surface, and the size or shape of the helical channels are appropriately chosen to reduce the distance between the surface with helical channels and the other surface. The relative motion provides an effective pumping action that inhibits and resists the flow of liquid through the gap to control the length of liquid penetration into the channel.

Further, in accordance with the present invention (particularly preferred embodiments thereof), power losses in seals between relatively moving surfaces are minimized or reduced, and external removal of material from end passages of rotary processing equipment is achieved. A novel seal is provided that can effectively minimize or prevent leakage or internal leakage of material from one passageway of a processing device to another.

The invention has been described for use in a multi-pass rotary processing apparatus. However, it should be appreciated that the dynamic seals described herein are also useful in other applications where a seal is required between surfaces that rotate relative to each other.

The rotary processing device (see Fig. 1) has a cylindrical inner surface 14.
The rotatable element comprises a rotor 10 mounted for rotational movement within a housing 12 having a rotor 10 supported by a drive shaft 16 journalled in an end wall 18 of the housing 12. The rotor 10 has a number of channels 20, each channel having side walls 24 facing each other in fixed relationship;
Housing 12 located on the side of channel 20
having a top surface portion 26 coaxial with and closely spaced from the stationary inner surface 14 of. The rotatable channel 20 and the stationary inner surface 14 of the housing 12 form the basic processing passageway into which material is introduced for processing through the inlet 28. Movement of the channel draws material in contact with the channel walls 24 toward the members forming the material collection end walls (not shown). The collected and processed material is discharged from the outlet 29 of the housing 12.
Pressure is created by drawing the material on the channel wall 24 in the direction of the material collection end wall, resulting in the channel becoming an area of high pressure that increases in the direction of rotation.

As shown in FIG. 1, there is a narrow gap 50 between the stationary inner surface 14 and the top surface 26 of the housing 12. Ideally, the clearance 50 should be about 10 mils (2.5
mm) or less, preferably about 3 to 5 mils (0.77 to 1.5 mm). Generally, the gap 50 is substantially constant around the perimeter of the passageway. However, maintenance within such a narrow constant gap is
This is complicated by the presence of radially different pressures along the periphery of the channel. This radial pressure imbalance can be large enough to cause deflection of the shaft or rotor from the high pressure region to the low pressure region. It is clear that any deflection will affect the maintenance of the desired narrow constant gap, since additional gaps have to be provided to compensate for that degree of deflection, if the flow directing device is not radially They may also be arranged in opposing relationship so that radial pressures occurring in one part of the process passage or group of process passages are balanced by radial pressures occurring in another part. Although leakage can be reduced by controlling shaft deflection, it is often preferable to provide auxiliary or additional sealing devices to minimize leakage. The present invention
A novel sealing device is provided that controls leakage between surfaces that move relative to each other at or near a gap 50.

An embodiment of the dynamic seal of the present invention is shown in FIGS. 2 and 3.
4, a number of inclined, preferably parallel, narrow sealing channels 27 are formed in the surface 26 between the channel sidewalls 24 and/or
or supported by surface 26, housing 1
2 provides a dynamic seal between the stationary coaxial surface 14 and the surface 26. As shown, the diagonal seal channel 27 is preferably formed in the surface 26 and moves relative to the smooth surface 14 of the housing 12. The most important relationship between the various design parameters of the dynamic seal of the present invention is the third
4 and 4, which figures are shown in connection with the following description of the dynamic seal of the present invention.

As mentioned above, the above dynamic seal is basically:
This is achieved by providing one of the two relative movement surfaces at or near the gap 50 with a number of inclined, preferably parallel, sealing channels.
Consequently, each sloped seal channel is
It acts as part of an extrusion rotor (screw flight) with a stationary coaxial surface 14 acting as a barrel for multiple seal channels (or multiple extrusion rotor sections). Therefore, the surface 26
The net flow rate q of liquid across the width τ is determined by using the same analysis applied to screw extruders. Therefore, the net flow rate is the difference between the draw flow rate in one direction and the pressure flow rate in the opposite direction, ie, q = q _D - q _P (Equation A).

In this case, q _D is the theoretical drawing flow rate and q _P is the theoretical pressure flow rate.

For illustrative purposes, it is shown graphically in FIG. 4 that the dynamic seals of FIGS _. q _P ) is equal to 0. Draw-in flow rate q _D
is a function of seal channel shape and actuation speed. However, the pressure flow rate q _P for a given pressure is inversely proportional to the penetration length of the liquid in the channel (ie, the length of the channel filled with liquid). As shown in Figures 3 and 4, under these conditions, the liquid has a pressure flow rate (the flow rate that moves the liquid into the channel) equal to the drawing flow rate.
The equilibrium condition is reached as soon as the seal channel is penetrated to a length that reduces . If the axially measured penetration length is less than the length of the seal channel 27, no liquid will leak across the width of the helical seal channel support surface 26.

However, the dynamic seal of the present invention does not operate under constant pressure conditions, as described in connection with FIG. Instead, FIG. 5 shows a typical pressure profile that occurs along the circumference of a rotary processing path. After a period of relatively low pressure, the pressure in the passage increases gradually, reaching a maximum value at the end of the passage, and then drops sharply across an obstacle such as a channel block to its original low pressure. Return to level.
Therefore, the dynamic seal of the present invention typically operates against variable pressures that repeat periodically during each rotation of the channel wall 24. The length of liquid penetration into the helical sealing channel 27 for the pressure profile shown in FIG. 5 was calculated by means of a suitable dynamic model and is shown for the pressure profile in FIG. It can be seen that once the pressure drops suddenly, the penetration length of the liquid in the seal channel gradually decreases to a point approximately opposite the onset of the pressure increase. Then the penetration length of the liquid in the seal channel increases again. In general, the net flow rate q (Equation A) will not reach equilibrium during any one revolution. The length of liquid penetration in the seal channel is determined by the time required to empty the seal channel of liquid when the pressure is lowest or to refill the seal channel with liquid when the pressure is highest. It lags or precedes the pressure profile. For example, after the rapid drop in pressure shown in FIG. 5, there is a gradual decrease in the length of liquid penetration within the seal channel. However, by making the length of each seal channel long enough so that the liquid penetration length exceeds the length of the helical seal channel, undesirable leakage can be avoided by making the length of the helical seal channel large enough. cannot traverse the width τ of the surface.

A preferred dynamic seal of the present invention is a dynamic seal having multiple (preferably parallel) helical seal channels with multiple flights and with relatively small helical angles θ. small helix angle θ
It is preferred to have a small width τ to provide a seal channel with a minimum penetration length for the seal channel bearing surface with a relatively narrow width τ. Helix angles θ of about 20° or less are particularly suitable for the dynamic seals of the present invention.

The number of seal channels used to provide the dynamic seal system of the present invention is important.
The channel wall 24 has a relatively large outer diameter O.
D. A multi-flighted seal channel supporting surface 26 is particularly preferred. This is because the lead L of the helical sealing channel 27 is larger than the width τ of the sealing surface 26. Thus, multiple (preferably parallel) helical seal channels are formed to provide an effective dynamic seal. There is another reason to use multiple helical seal channels. For the net flow rate q to be equal to zero, the pressure flow rate, the drawing flow rate must be equal. However, the seal channel width H (third
Since the ratio of seal chamber width W (FIG. 4) to seal chamber width W (FIG. 4) increases as channel width W decreases, the pressure flow value in Equation A decreases faster than the retraction flow value.
Referring to equation A above, under these conditions,
That is, it turns out that sealing is more efficient for reducing the channel width W, which means that
A low liquid penetration length of the seal channel means that zero net flow is obtained. Furthermore, it is clear from the equation for channel width W (FIG. 4) that an increasing number of channels results in a decreasing channel width. A narrow seal channel width W is particularly preferred for the practice of the invention due to the different radial pressures encountered around the circumference of the passage. By using a large number of parallel helical seal channels with narrow widths W, the pressure variation acting on each individual seal channel at any time is kept to a small value and each channel is used independently. .

Referring again to FIG. 6, the illustrated liquid infiltration boundary indicates the area that the seal channel 27 fills during complete rotational movement of the helical seal channel support surface 26. This area also corresponds to the area of the stationary coaxial inner annular surface 14 in contact with the liquid. Helical seal channel support surface 26 and coaxial inner annular surface 1
4 and the liquid creates a shearing action that provides a favorable draw flow rate that limits the extent of liquid infiltration of the seal channel. However, this shearing action is accompanied by undesirable power losses at the seal due to the conversion of energy into heat.

According to a particularly preferred embodiment of the invention, the power loss in the novel dynamic seal is such that liquid contact between the surfaces forming the dynamic seal during a portion of each rotational movement of one surface provides the dynamic seal. substantially reduced by destroying the This embodiment is shown in FIGS. 7, 7a, 7b, 8, and 8.
It is shown in Figures a, 8b, 9 and 10. As shown in FIGS. 7, 7a and 7b, a scraper 30 is positioned at the inlet of the channel block 19 (FIG. 7a) to scrape liquid at the helical seal channel bearing surface 26; The bearing surface provides a dynamic seal configured to prevent unwanted external leakage from the end passages of the rotary processing equipment. The scraper gap between the scraper 30 and the peripheral portion 26 of the helical seal 27 must be tight. Preferably, the scraper gap should be tight enough to scrape off most of the oil that contacts the helical seal channel surface 26 and the stationary inner coaxial annular surface 14. Therefore, after the scraping action, the surface 2 supporting the helical sealing channel 27
The liquid contact between 6 and surface 14 is broken and the sealing channels 27 are filled with liquid to the extent that they are filled before the scraping action. The power loss due to the dissipation of energy in the dynamic seal is therefore reduced after the scraper action and does not increase again, since enough liquid can re-establish liquid contact between the coaxial annular surfaces of the dynamic seal. is pumped into a spiral seal channel. The liquid material scraped off the helical seal channel support surface is discharged at low pressure into the inlet.

8, 8a and 8b show a scraper 31 in cooperation with another embodiment of the dynamic seal of the present invention formed between a surface forming gap 50. FIGS. As shown, two sets of intersecting helical seal channels 27 and 27a are disposed on the peripheral surface 26 between the helical adjacent process passage channel walls 24 of each set of seal channels facing each other. . The scraper 31 is connected to the channel block 1.
9 (FIG. 8a) and with respect to a helical seal channel bearing surface 26 for breaking liquid contact between the dynamic seal-providing surfaces and for discharging material scraped by the scraper into the inlet. Maintained in close scraper condition.

The effect of breaking liquid contact between the surfaces of the dynamic seal of the present invention is illustrated in FIGS. 9 and 10. FIG. 9 (also FIG. 5) shows a typical pressure profile that occurs along the circumference of a rotary processing channel. The calculated length of liquid penetration into the helical seal channel for the pressure profile of FIG. 9 but with the scraper cooperating with the helical seal channel support surface as shown and described is shown in FIG. It is shown. As shown, the scraping action is performed at or near the inlet or low pressure side of the passageway. This scraping action breaks the liquid contact between the surfaces of the dynamic seal, but leaves the helical seal channel filled to a certain level with liquid. Since the layer providing liquid contact between the surfaces of the dynamic seal has been removed, very little of the liquid on the surface extending from the back side of the scraper 30 or 31 to number 10 on the scale of FIG. Minor ingress and power losses are reduced. However, once the pressure begins to increase, the length of liquid ingress immediately and very closely follows the pressure profile with maximum ingress occurring rather close to the maximum pressure. A comparison of FIG. 10 and FIG. 5 shows that the area of maximum liquid penetration in FIG. 10 is considerably smaller than the area of maximum liquid penetration in FIG. As a result, the scraper
Reduce dynamic losses without compromising dynamic seal efficiency.

In the embodiment of the invention described above, a dynamic seal is formed between the surface forming gaps (FIGS. 2 and 3). However, dynamic seals within the scope of the present invention are formed less at the gap 50 than at other surfaces disposed in its vicinity. 11th
11a, 11b, 12, 12
Figures a and 12b show another embodiment of the invention. FIG. 11 illustrates a dynamic seal in which a portion of the outer surface 32 of the rotor 10 has a number of diagonal seal channels 35 extending along the outer surface 32. The portion of the outer surface 32 that supports a number of seal channels 35 is shown as having a width τ (FIGS. 11 and 11a). The seal channel supporting surface or outer surface 32 has a gap 50
a static spaced apart from the seal channel support surface by a tight gap 51 that is equal to or greater than or less than, but typically about 10 mils (2.5 mm) or less. surface 3
Rotating motion about 3. The stationary surface 33 is formed by a stationary annular element 34 secured to the stationary inner surface 14 of the housing 12. Figure 11a shows the outer surface 3.
2 is a drawing of the outer surface 32 of the rotor 10 showing a number of spiral seal channels 35 provided with a width τ extending around a circumferential area of 2; FIG. Although the grooves are shown in FIG. 11a in a curved spiral configuration, the grooves can be obliquely disposed and straight without departing from the scope of the invention. FIG. 11b shows surfaces 32 and 3 forming the dynamic seal of FIG.
3 is a top view showing the relationship between the scraper 36 and the scraper 36. FIG. As shown, a scraper 36 is secured to the stationary annular member 34 and is attached to the surface 33 to break liquid contact between the surfaces 33 and 32.
Extend outward from. The scraper 36 extends across at least the width τ and is located at or near the entrance to the passageway (not shown).

Figures 12, 12a and 12b show the gap 5.
2 shows another example of a dynamic seal formed between surfaces nearer than at zero. In the illustrated embodiment, a number of helical or angled seal channels 37 are provided on the stationary surface of an annular element 39 secured to the stationary interior surface 14 of the housing 12.
The width τ of the stationary channel support surface 38 is spaced from a portion of the outer surface of the rotor 10 by a gap 51. FIG. 12a shows an annular element 39 showing a number of sealing channels 37 provided in the width τ of the surface 38.
FIG. FIG. 12b is a top view showing the relationship between the surfaces forming the dynamic seal of FIG. 12 and the scraper 41. FIG. A scraper 41 is fixedly disposed and retained on stationary annular member 39 and extends outwardly from surface 38 to break liquid contact between surfaces 38 and 40. 12th
As shown in FIG. It is located in

The dynamic seal shown in Figures 12, 12a and 12b differs somewhat from the previous dynamic seals in that multiple seal channels are supported by rotating surfaces. Figure 12, 12
In the dynamic seal of Figures a and 12b, multiple seal channels are formed in a stationary surface. As previously discussed, the length of liquid penetration into each seal channel supported by a rotating cylindrical surface is determined by
As shown graphically in Figure 0, the differential pressure encountered along the circumference of the passage changes gradually during each rotational movement. Changes in the length of liquid entry into each helical seal chamber are not encountered during each rotational movement in a dynamic seal with a static helical seal channel support surface. Instead, since each seal channel is always in place around the passageway, each helical seal channel can always observe the same head pressure during each rotational movement of the channel wall 24 of the rotor 10. Therefore, the length of liquid penetration into each stationary seal channel is different, but the maximum penetration length into any given channel is such that a constant pressure is applied to the seal channel during each rotational movement of rotor 10. remains virtually constant as long as Additionally, however, as long as the length of liquid penetration into any helical seal channel on a stationary surface does not exceed any seal channel length, undesirable leakage between surfaces will not occur.

FIG. 13 shows another dynamic seal of the present invention formed between a cylindrical surface-forming gap 50, which dynamic seal is similar to the dynamic seal of FIGS. 12, 12a and 12b. It works in the same way as described. As shown in FIG. 13, a helical sealing channel 42 is formed in the stationary inner surface 14 of the housing 12 spaced from and coaxial with the top portion 26 of the rotor 10 by a gap 50. Accordingly, the length of liquid penetration into each helical seal channel 42 supported by the stationary inner surface 14 varies. However, Fig. 12, 12a
As in the dynamic seal of Figs. and 12b,
The maximum length of liquid penetration into a given helical channel 42 at a given pressure location along the rotating channel wall is substantially always constant as long as a constant pressure is applied at that location. Therefore, no leakage of liquid will occur across the dynamic seal formed between the surfaces in the gap 50 unless the length of liquid penetration into the static helical seal channel 42 exceeds the length of the channel.

In the above description of the invention, leakage of liquid in a gap formed by two coaxial surfaces is controlled by a number of helical or diagonal seal channels supported by one of the surfaces. . The number, shape, size and angle of the seal channels are selected such that the length of liquid penetration into each seal channel does not exceed the length of the penetrated seal channel. However, it is understood that the best function of the dynamic seal of the present invention is to reduce the extent of liquid ingress within the channel by controlling the amount of liquid leakage in the gap. For example, even if the length of leakage fluid into the channel exceeds the length of the channel into which it enters, the degree of control is achieved. Under these circumstances, some liquid leakage occurs in the gap, but the helical seal channel provides control over a certain amount of leakage, which is less than the leakage that would occur without the seal channel.

Figures 14, 14a, 15 and 15a
The figure shows an embodiment of the invention in which effective control of liquid leakage in the gap is achieved even if the penetration of liquid leakage exceeds the length of the seal channel. The embodiment shown in FIGS. 14 and 14a has multiple helical seal channels 27 supported on the peripheral surface 26 of the channel wall 24. The embodiment shown in FIGS. As shown here, the width τ of the seal channel support surface does not extend across the entire width of surface 26, allowing liquid ingress into channel 27 to exceed the length of channel 27. However, a liquid inlet collection channel 57 is provided to collect the liquid inlet channel 27 and retain the collected liquid, which liquid is discharged through the channel 27 in a low pressure region of the passageway. Liquid infiltration collection channel 57 is channel 2
7 (FIG. 4).

Figure 15 and Figure 15a are Figures 14 and 14.
Figure a shows another embodiment of the embodiment shown in Figure a; The width τ of the seal channel support surface occupies only a portion of the total width of surface 26. Instead, the concave portion 5
9, the seal channel support surface τ and the width of the liquid infiltration collection channel 57 are disposed across the entire width of the surface 26 of the channel wall 24. The depth of the liquid infiltration collection channel is the depth H of channel 27.
(FIG. 4) is preferably the same. The depth of the recessed portion 59 may be the same as or different from the depth of the channel 27, and the recessed portion 59 tapers downward (not shown) from the surface 26.

Various alternative configurations of dynamic seals may be used to prevent external leakage of unwanted liquids from one or more end devices of a process device or from one or more channels to another. To prevent undesirable internal leakage of liquid up to the channel,
The present invention is described with reference to a multi-pass rotary process device comprising at least one, but preferably a plurality of dynamic seals. Therefore, it is preferred that the dynamic seal of the present invention be integral to a multipass rotary processing device. Basically, a multi-unit processing device is one in which a rotor supporting the processing channels has a cylindrical section between the processing channels in close relation to the housing of the rotor.

In a preferred embodiment of such a processor, the transfer passageway between the channels is carried by the processor housing and includes a movable flow director device having a surface portion forming part of the annular housing surface. thus provided, the transfer channels being formed in these surface portions of the flow director device. Additionally, the flow director device supports a lock at the channel end extending into the process channel of the rotor. In yet another embodiment, the transfer passageway and end block are circumferential and/or circumferential to reduce bearing loads to generate opposing radial forces in the processing channel.
or axially arranged. For example, the annular passages, blocking members and transfer passages may be arranged in at least one annular passageway to counter radial forces generated in at least one other annular passageway to provide substantially axial balance of radial forces. It is arranged to generate a radial force in the passageway. Axial balance of radial forces minimizes shaft or rotor deflection, thereby providing closer proximity and better control across the gap between surfaces providing the dynamic seal of the present invention. It is preferable because it can be done.

The dynamic seal of the present invention is commonly used to provide a seal between surfaces separated from each other by gaps of up to about 10 mils (2.5 mm). However, the dynamic seal of the present invention is particularly effective if the surfaces providing the seal are spaced apart from each other by a gap of about 5 mils (1.2 mm) or less. Therefore, the degree of shaft or rotor deflection is a factor that must be considered in selecting the particular dynamic seal of the present invention for use in rotary processing equipment.

Yet another advantage is that the relatively rotatable member has an inner edge of the member providing a surface adjacent to the flow resistance with respect to one rotating surface and an outer edge of the member providing a surface adjacent to the flow resistance with respect to the other coaxial surface. This is achieved by using a seal having nested frusto-conical members of hard resistive material disposed between coaxial surfaces. Edges on either the interior or exterior of the member are maintained such that pressure on the member can force the outer or inner edges, respectively, into an improved seal with respect to adjacent surfaces.

16 and 17 illustrate the dynamic sealing device of the present invention. As shown in FIGS. 16 and 17, the frusto-conical member 44 includes a surface 43 of the member 44.
are supported by the rotor 10 in such an arrangement that they are inclined in the direction of the channel 20, ie in the direction of the high pressure region. Member 4 furthest from channel 20
The inner edge 45 of 4 is held against axial movement and is provided with a retaining member such as a ring 47 and a shoulder 46.
The rotor is held in a sealed condition with respect to the rotor. Retaining member 47 acts on member 44 furthest from the channel to hold member 44 nested against shoulder 46 . Outer free edge 48 of the member closest to channel 20
is a surface 49 that is sealed with respect to the inner cylindrical surface 14 such that the member 44 seals the space between the surface 49 and the inner surface 14 of the housing 12.
I will provide a. According to the embodiment of the invention shown in FIG. 16, surface 49 has a number of helical sealing channels 52 to improve the seal between surface 49 and surface 14. The embodiment of the invention shown in FIG. 16 is particularly preferred if shaft deflection requires more than about 0.005 inches (0.127 mm) of clearance to be maintained between surfaces 49 and 14. . FIG. 17 shows an alternative arrangement of the dynamic seal element of FIG. 16. As shown in FIG. 17, a number of helical seal channels are provided on interior surface 14 to provide a dynamic seal between helical seal channel support surface 14 and surface 49. As shown in FIG.

Further details regarding the present invention are shown in FIG.
This is explained with reference to FIGS. 9 and 20. These drawings show the rotational speed for several values of maximum liquid penetration length into each seal channel versus width τ.
The calculated values are shown in the graph for RPM. The width τ of the seal channel bearing surface, the number and shape of the seal channels, and other operating conditions are shown in the respective drawings. These drawings include approximately 10 or more channels of limited shape with an axial length of approximately 0.5 inches (12.5 mm), especially if the width is low, e.g., 15° or less. We show that the leakage of liquid across τ can be controlled. It has been shown that a maximum pressure of 1000 psl is preferred, or above the pressure normally expected to occur in the passageways of rotary process equipment. However, the maximum pressure was selected to determine the maximum axial penetration length of liquid into the seal channel of the indicated construction or dimensions under extreme operating conditions.

From the foregoing, it is apparent that the present invention provides a novel sealing arrangement for controlling liquid leakage between two relatively rotatable coaxial closely spaced surfaces. The sealing device of the present invention combines liquid and/or solid polymers in a highly efficient manner that provides a low friction positive seal to control external or internal leakage of liquid with minimal power loss in the sealed condition. It is particularly applicable to rotary processing equipment for processing materials. Accordingly, the present invention provides a new and useful device with particularly favorable and unexpectedly improved performance characteristics.

[Brief explanation of the drawing]

FIG. 1 is a partially cut-away side view showing the rotor, channel and annular coaxial surfaces with the individual elementary processing units of a multi-unit rotary processing equipment; FIG. 2 shows the dynamic seal of the present invention; FIG. 3 is an enlarged cross-sectional view of FIG. 1 showing the relationship between two surfaces that provide the dynamic seal of the present invention; FIG. , FIG. 4 shows a second seal having multiple helical seal channels.
An exploded view of the cylindrical peripheral portion of one surface shown in FIGS. Graphs for the developed pressure profile; FIG. 6 is a graph showing calculated numerical values for the length of liquid penetration into the helical seal channel obtained for the pressure profile of FIG. 5; FIG. 7 is a graph for a number of helical seals. FIG. 7a is a partial cross-sectional side view of an end channel wall of a multi-pass rotary processing apparatus showing the relationship between the rotating surface supporting the channel and the stationary scraper; FIG. The top view of FIG. 7b is taken from line 7b-7 of FIG. 7a.
FIG. 8 is a cross-sectional view of the scraper and end channel wall in FIG. FIG. 8a is a partial cross-sectional side view of FIG.
Top view of the scraper and channel wall in Figure 8b.
8a is a cross-sectional view of the scraper and channel wall of FIG. 8 taken along line 8b--8b of FIG. 8a; FIG.
FIG. 1 is a graph of the pressure profile developed around a typical basic process path of a multi-unit rotary processing apparatus; FIG. 10 is a graph of the spiral obtained for the pressure profile of FIG. 9; Figure 3 shows calculated values for the length of liquid penetration into a shaped seal channel and results for the length of liquid penetration by periodically scraping liquid from the surface providing the dynamic seal of the present invention. graph,
FIG. 11 is a cross-sectional view of a channel showing another embodiment of the invention; FIG. 11a is an end view of a surface providing a dynamic seal of the alternative embodiment shown in FIG. 11; FIG. 11b 11 is a partial cross-sectional top view of the dynamic seal of FIG. 11 showing the relationship between the rotating surfaces supporting multiple helical seal channels and the stationary scraper; FIG. 12 shows another embodiment of the invention; 1st to show
12a is an end view of one surface providing a dynamic seal of the alternative embodiment shown in FIG. 12; FIG. 12b is a cross-sectional view similar to FIG. a top view of the portion shown in FIG. 12 showing the relationship between the supporting stationary surface and the scraper;
FIG. 13 is an enlarged fragmentary cross-sectional view showing another embodiment of the invention; FIGS. 14 and 14a; FIG.
15 and 15a are similar drawings to FIGS. 3 and 4, respectively showing another embodiment of the invention; FIGS. 15 and 15a are drawings similar to FIGS. FIGS. 16 and 17, similar to FIGS. Figures 1 and 20 are graphs of the length of liquid penetration into a number of helical seal channels as a function of different conditions such as the number and angle of the helical seal channels and the rotational speed of the seal channel support surface. . DESCRIPTION OF SYMBOLS 10... Rotor, 12... Housing, 14... Inner surface, 18... End wall, 20... Channel, 24... Channel side wall, 26... Top surface portion, 28... Inlet, 27, 27a... Channel, 29... Outlet, 3
0, 31...Scraper, 33...Stationary surface, 34...
Stationary annular element, 32...Outer surface, 35...Seal channel, 36...Scraper, 37...Seal channel, 38...Stationary surface, 39...Annular element, 40...Outer surface, 41...Scraper, 43...Surface, 42...Seal channel , 44... frustoconical member, 45... inner edge, 46... shoulder, 47... ring, 48... edge, 4
9...Surface, 51...Gap, 57...Channel, 59
...concavity.

Claims (1)

Claims: 1. A rotatable element having a surface comprising at least one treatment channel, the surface being spaced from and complementary to the surface of the rotatable element by a narrow gap; a stationary element co-operatively arranged with the processing channel to form a closed annular processing passageway, the inlet for feeding material into the passageway, around the passageway; an outlet spaced apart from said inlet by a distance along said channel for discharging material from said passageway; and a stationary member disposed in said channel constituting a surface for restricting movement of a body of material within said passageway. an apparatus for rotating the rotatable element from the inlet toward the material confining surface, the rotatable element and the confining surface member cooperating; a rotating device adapted to create pressure along the running length of the channel and a dynamic sealing device 27, 27 to prevent leakage of pressurized material passing through the gaps 50, 51;
a, 35, 37, 42, 52, comprising a dynamic sealing device having a number of sealing channels provided on one of said surfaces 14, 26 arranged such that said liquid material can penetrate said channels; , the gap 5 increases as the surfaces 14, 26 are rotated relative to each other to reduce the extent of outward penetration of pressurized liquid within the seal channel.
0,51 and outward penetration of the pressurized liquid into the seal channels 27,2.
7a, 35, 37, 42, 52, the number, angle and shape of the channels being selected such that the liquid in 7a, 35, 37, 42, 52 is restrained by an inward force. . 2. The part of the rotor 10 containing the liquid has an area of lowest pressure and furthermore has a scraper device 30, 31, 36 protruding into the gaps 50, 51 to remove the area from one of the surface parts 14, 26. Liquid contact is achieved by scraping sufficient liquid penetration into the rotor 1.
Claim 1, characterized in that the device is broken during rotational movement of at least a portion of the device.
Material processing equipment as described in Section. 3. According to claim 1 or 2, the liquid-containing part of the rotor has an area of pressure and a circumferentially spaced area of relatively high pressure. Material processing equipment as described. 4. The material processing apparatus according to each of the preceding claims, characterized in that during operation, the permeation range of liquid does not exceed the length of the seal channels 27, 27a, 35, 37, 42, 52. 5. The material processing apparatus according to each of the preceding claims, wherein the seal channel is spiral. 6. The material processing apparatus according to claim 5, wherein the helical angle of each seal channel is 20 degrees or less. 7. The material processing apparatus of claim 6, wherein the helical angle of each seal channel is 15 degrees or less. 8. A material processing apparatus according to the preceding claims, characterized in that the surface portions 14, 26 comprising a large number of said seal channels are stationary. 9. Material processing apparatus according to claims 1 to 7, characterized in that the surface portions (14, 26) comprising a number of the sealing channels are rotatable. 10 gap 50 between the surface portions 14, 26;
The material processing apparatus according to each of the preceding claims, wherein 51 is 2.5 mm or less. 11 Gap 50 between the surface portions 14, 26,
11. The material processing apparatus according to claim 10, wherein 51 is 1.25 mm or less. 12 Seal channel 27, 27a, 35, 3
7, 42, and 52 are arranged substantially parallel to each other, the material processing apparatus according to each of the preceding claims. 13. The sealing device is a frusto-conical member 44 of rigid resilient material having a surface 43 adjacent an outer edge 48 disposed proximate the processing channel 20 for movement under pressure. 4
4, and said member 4 so as not to move due to pressure.
retaining devices 46, 47 for holding the inner edges 45 of the housing 12 so that the outer edges 48 provide a seal with the surface portion 14 of the housing 12; 14
2. The material processing apparatus of claim 1, wherein either of said outer edges 48 has a seal channel 52 formed therein. 14 The cylindrical surface 26 of the rotor 10 constitutes a peripheral surface portion and the surface portion 1 of the housing 12
4. The material processing apparatus according to claim 1, wherein 4 is formed by a portion of the cylindrical inner surface 14 of the housing 12. 15 a peripheral surface portion of the sealing device faces inwardly of the cylindrical surface 26 and towards the processing channel 2;
an annular surface portion 32 of rotor 10 disposed opposite surface 24 to 0; 2. A material processing apparatus as claimed in claim 1, characterized in that it comprises an annular surface portion (34). 16. Claim 1, characterized in that the sealing device consists of a surface portion with a sealing channel located on one side of the processing channel 20.
15. The material processing apparatus according to item 1, item 14, or item 15. 17. The rotor 10 has a number of processing channels 20, each of which includes an annular peripheral surface portion 26, 40, 32 of the rotor 10 and an adjacent stationary surface portion 14 of the housing 12,
33, 38. A material processing apparatus according to claims 1, 14, 15, and 16, characterized in that the material processing apparatus comprises: 33, 38. 18 The scraper device 30, 31, 36 consists of an upstream surface extending across the surface portions 14, 26 which is inclined at a suitable angle to the direction of movement of said surface portions 14, 26 with respect to said scraper device 30, 31, 36. , the scraped liquid is transferred to the surface portions 14, 2
6. The material processing apparatus according to claim 2 or 3, characterized in that the material processing apparatus can be directed from 6 to the area. 19. Material processing according to claim 1, 14, 15 or 16, characterized in that the outlet from one processing channel is connected to the inlet of another processing channel 20. Device.