CN207113966U - A kind of liquid level gauge and crystallizer - Google Patents
A kind of liquid level gauge and crystallizer Download PDFInfo
- Publication number
- CN207113966U CN207113966U CN201721110982.5U CN201721110982U CN207113966U CN 207113966 U CN207113966 U CN 207113966U CN 201721110982 U CN201721110982 U CN 201721110982U CN 207113966 U CN207113966 U CN 207113966U
- Authority
- CN
- China
- Prior art keywords
- bypass pipe
- liquid level
- crystallizer
- level gauge
- dilution tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Control Of Non-Electrical Variables (AREA)
Abstract
A kind of liquid level gauge and crystallizer provided by the utility model, it is related to crystallizer technology field, including bypass pipe, dilution tube and diaphragm type level-sensing device；The upper and lower part of bypass pipe is separately provided for high-order connector and the low level connector connected with crystallizer；Dilution tube connects with the bottom of bypass pipe, for injecting dilution into bypass pipe；The bottom of bypass pipe is arranged on the top of decanting zone formed with decanting zone, diaphragm type level-sensing device.In the above-mentioned technical solutions, by the way that there is provided dilution tube, can utilizes dilution tube diluting high-concentration saline solution, high concentration saline solution in bypass pipe will be deposited in bypass bottom of the tube tubule, the decanting zone of saline solution is formed in this place, so that maintain low concentration feed liquid above decanting zone, it membrane surface formation will not thus crystallize again, nor affect on the accuracy of detection of diaphragm type feed liquid instrument.
Description
Technical field
Crystallizer technology field is the utility model is related to, more particularly, to a kind of liquid level gauge and crystallizer.
Background technology
Crystallizer is the equipment for crystallization operation, and crystallizer type of the prior art is a lot, such as is obtained according to solution
Crystallizing evaporator and cooler crystallizer can be divided by obtaining the method for hypersaturated state, or can decomposition mother solution circulation crystallization according to the type of flow
Device and magma (i.e. the mixture of mother liquor and crystal) circulation crystallization device, in another example according to mode of operation can divide continuous crystalizer and
Have a rest crystallizer.
Illustrate by crystallizing evaporator, among the evaporation and crystal process of crystallizing evaporator, can typically be obtained using liquid level gauge
Know the height of saline solution liquid level in crystallizer, and then the process of evaporative crystallization is controlled.
But the problem of precision reduces is occurring in existing liquid level gauge after by much time using, that is when
Larger deviation occurs when saline solution liquid level is measured using rear existing liquid level gauge for a long time, can thus have a strong impact on
Vapo(u)rization system technique.
Utility model content
The purpose of this utility model is to provide a kind of liquid level gauge and crystallizer, to solve liquid present in prior art
Position meter precision reduces, and the technical problem of relatively large deviation occurs when being measured to the saline solution liquid level in crystallizer.
For the technical problem of above-mentioned generation, after research, iting is found that precision occurs for liquid level gauge of the prior art
The problem of reduction, is primarily due to during evaporative crystallization, crystallization is easily produced on the diaphragm of liquid level gauge, so will be right
The sensitivity of the induction pressure of diaphragm impacts, and then the precision that also will result in liquid level gauge reduces.
It is by for perceiving the diaphragm arrangement of saline solution specifically, because liquid level gauge of the prior art is when design
In the bottom position of liquid level gauge, and liquid level gauge of the prior art is when in use, and the bottom position of liquid level gauge is usually
Position below normal saline solution liquid level is connected to by flange, that is to say, that the diaphragm for being arranged on liquid level gauge bottom is also to pass through method
Orchid is connected to position below normal saline solution liquid level, and the top of liquid level gauge is the upper steam for being connected to normal saline solution liquid level
On shell side, after liquid level gauge is assembled into setting in this manner, the diaphragm can of liquid level gauge is perceived in crystallizer
Dense saline solution to diaphragm caused pressure in itself, and the change of the liquid level of saline solution also changes to pressure caused by diaphragm with liquid level
Become, so by diaphragm to the pressure change of dense saline solution, it becomes possible to speculate and simulate saline solution liquid level position.
But the assembly method of this liquid level gauge of the prior art will produce one it is important the problem of because crystallization
Inside device during crystallization is evaporated, using the dense saline solution of high saturation, therefore the meeting on the liquid level gauge diaphragm of detection
It is easy to produce crystallization because of the temperature difference, once foring crystallization on diaphragm, the crystallization positioned at diaphragm top layer will influence saline solution
Liquid is to the induction pressure of diaphragm, and so as to influence the judgement precision to saline solution liquid level, the reduction of this precision can cause pair
The measurement of saline solution actual liquid level inside crystallizer produces relatively large deviation, can have a strong impact on vapo(u)rization system technique.
So in order to solve above-mentioned caused technical problem, this application provides following technical scheme：
A kind of liquid level gauge provided by the utility model, including bypass pipe, dilution tube and diaphragm type level-sensing device；
The high-order connector and low level that the upper and lower part of the bypass pipe is separately provided for connecting with crystallizer connect
Interface；
The dilution tube connects with the bottom of the bypass pipe, for injecting dilution into the bypass pipe；
The bottom of the bypass pipe is arranged on the top of the decanting zone formed with decanting zone, the diaphragm type level-sensing device.
In the above-mentioned technical solutions, bypass pipe connects with the inner chamber of crystallizer under normal circumstances, so the height in crystallizer
Concentration saline solution can enter in bypass pipe, and by the way that there is provided dilution tube, it is possible to using the dilution tube into the bypass pipe
Quantitative low concentration feed liquid is poured in timing, is replaced the high concentration saline solution in bypass pipe using low concentration feed liquid, dilution
High concentration saline solution, and make the low concentration liquid level in bypass pipe and the liquid level guarantor of high concentration saline solution (saturated concentration saline solution) in crystallizer
Hold consistent.
So the high concentration saline solution constantly invaded from crystallizer in production run in bypass pipe will be deposited on bypass
In bottom of the tube tubule, the decanting zone of saline solution is formed in this place, so that maintain low concentration feed liquid above decanting zone, thus
It membrane surface formation will not crystallize again, nor affect on the accuracy of detection of diaphragm type feed liquid instrument.
Further, in embodiment of the present utility model, the dilution tube is U-shaped；
One end of the dilution tube connects with the bypass pipe, and the other end of the dilution tube is hanging.
Further, in embodiment of the present utility model, magnetic turnover plate type level-sensing device is additionally provided with the bypass pipe；
The magnetic turnover plate type level-sensing device is correspondingly arranged with the diaphragm type level-sensing device.
Further, in embodiment of the present utility model, multiple peep holes are additionally provided with the bypass pipe；
Axial direction of multiple peep holes along the bypass pipe is uniformly arranged, for observing the liquid level in bypass pipe.
Further, in embodiment of the present utility model, the diameter on the bypass pipe top is more than the diameter of bottom.
Further, in embodiment of the present utility model, the upper diameter of the bypass pipe is 80mm, the bypass pipe
Lower diameter be 60mm.
Further, in embodiment of the present utility model, the junction of the dilution tube and the bypass pipe is provided with
First control valve；
The bypass pipe is connected or closed with the inner chamber of crystallizer by first control valve.
Further, in embodiment of the present utility model, the second control valve is provided with the dilution tube；
The dilution tube is connected or closed with the source of dilution by second control valve.
Present invention also provides a kind of crystallizer, including the liquid level gauge.
In the above-mentioned technical solutions, the crystallizer is provided with the liquid level gauge, by dilution tube on liquid level gauge to bypass
After high concentration saline solution in pipe is diluted, the high salt concentration in bypass pipe is constantly invaded from crystallizer in production run
Liquid will be deposited in bypass bottom of the tube tubule, the decanting zone of saline solution is formed in this place, so that maintain above decanting zone
Low concentration feed liquid, it membrane surface formation will not thus crystallize again, nor affect on the accuracy of detection of diaphragm type feed liquid instrument.
Further, in embodiment of the present utility model, including crystallizer cylinder, the crystallizer cylinder include crystallization
Cylinder and extension cylinder；
The high-order connector of the bypass pipe of the liquid level gauge connects with the extension cylinder, the bypass pipe of the liquid level gauge
Low level connector connects with the crystallization cylinder.
Brief description of the drawings
, below will be right in order to illustrate more clearly of the utility model embodiment or technical scheme of the prior art
The required accompanying drawing used is briefly described in embodiment or description of the prior art, it should be apparent that, describe below
In accompanying drawing be some embodiments of the present utility model, for those of ordinary skill in the art, do not paying creativeness
On the premise of work, other accompanying drawings can also be obtained according to these accompanying drawings.
Fig. 1 is the first structure schematic diagram for the liquid level gauge that the utility model one embodiment provides；
Fig. 2 is the close-up schematic view of the liquid level gauge shown in Fig. 1；
Fig. 3 is the second structural representation of the liquid level gauge that the utility model one embodiment provides；
Fig. 4 is the structural representation for the crystallizer that the utility model one embodiment provides.
Reference：
1- bypass pipes；2- dilution tubes；3- diaphragm type level-sensing devices；4- magnetic turnover plate type level-sensing devices；
11- high position connectors；12- low level connectors；13- decanting zones；14- peep holes；The control valves of 15- first；
51- crystallizes cylinder；52- extends cylinder.
Embodiment
The technical solution of the utility model is clearly and completely described below in conjunction with accompanying drawing, it is clear that described
Embodiment is the utility model part of the embodiment, rather than whole embodiments.Based on the embodiment in the utility model, sheet
The every other embodiment that field those of ordinary skill is obtained under the premise of creative work is not made, belongs to this practicality
Novel protected scope.
, it is necessary to explanation in description of the present utility model, term " " center ", " on ", " under ", it is "left", "right", " perpendicular
Directly ", the orientation of the instruction such as " level ", " interior ", " outer " or position relationship are based on orientation shown in the drawings or position relationship, are only
Described for the ease of description the utility model and simplifying, rather than instruction or imply signified device or element must have it is specific
Orientation, with specific azimuth configuration and operation, therefore it is not intended that to limitation of the present utility model.In addition, term " the
One ", " second ", " the 3rd " are only used for describing purpose, and it is not intended that instruction or hint relative importance.
, it is necessary to which explanation, unless otherwise clearly defined and limited, term " are pacified in description of the present utility model
Dress ", " connected ", " connection " should be interpreted broadly, for example, it may be fixedly connected or be detachably connected, or integratedly
Connection；Can be mechanical connection or electrical connection；Can be joined directly together, can also be indirectly connected by intermediary,
It can be the connection of two element internals.For the ordinary skill in the art, above-mentioned art can be understood with concrete condition
Concrete meaning of the language in the utility model.
Fig. 1 is the first structure schematic diagram for the liquid level gauge that the utility model one embodiment provides；
Fig. 2 is the close-up schematic view of the liquid level gauge shown in Fig. 1.
As depicted in figs. 1 and 2, a kind of liquid level gauge that the present embodiment provides, including bypass pipe 1, dilution tube 2 and diaphragm type material
Position instrument 3.
Normally, the upper and lower part of the bypass pipe 1 is separately provided for the high-order connector connected with crystallizer
11 and low level connector 12, the general low level connector 12 is exactly the high concentration saline solution required connect in crystallizer internal cavity
Once, then the high-order connector 11 is to need to be connected to the steam shell side part in crystallizer internal cavity to liquid level.
Importantly, influence diaphragm type level-sensing device 3 in order to solve the easy crystallization of membrane surface mentioned above and examine
The insensitive problem of precision is surveyed, so dilution tube 2 is added on bypass pipe 1, by the dilution tube 2 and the bypass pipe 1
Bottom connects, and the dilution tube 2 is for injecting dilution into the bypass pipe 1.
The structure of dilution tube 2 based on setting, in use, the bottom of the bypass pipe 1 can formed with decanting zone 13,
This decanting zone 13 is for carrying out the depositional of high concentration saline solution, and the diaphragm type level-sensing device 3 needs to be arranged on institute
State the top of decanting zone 13.
In order to preferably understand the functional effect of the liquid level gauge, so below from overall angle to institute
The service condition for stating liquid level gauge is illustrated：
Bypass pipe 1 connects with the inner chamber of crystallizer under normal circumstances, so the high concentration saline solution in crystallizer can enter side
In siphunculus 1, at this moment if having connected dilution tube 2 in the bottom of bypass pipe 1, it is possible to utilize the dilution tube 2 to the bypass
Quantitative low concentration feed liquid is poured in timing in pipe 1, using low concentration feed liquid is put the high concentration saline solution in bypass pipe 1
Change, diluting high-concentration saline solution, and make the low concentration liquid level in bypass pipe 1 and high concentration saline solution (saturated concentration saline solution) in crystallizer
Liquid level be consistent.
So the high concentration saline solution constantly invaded from crystallizer in production run in bypass pipe 1 will be deposited on side
In the bottom tubule of siphunculus 1, that is, the position of the decanting zone 13, like this, the salt crystalline substance of high concentration has all been deposited to described
After decanting zone 13, the top of decanting zone 13 will be made to maintain low concentration feed liquid.
Now, diaphragm arrangement is only in contact with the liquid of low concentration in the top of decanting zone 13, would not be in membrane surface
Formation crystallizes, and the influence without crystallization would not also influence the accuracy of detection of diaphragm type feed liquid instrument.
In addition, caused steam can be also condensed out on a small quantity to the cold in the upper end of bypass pipe 1 during crystallizer evaporative crystallization
Distilled water, this distilled water condensed can constantly replenish the top position of decanting zone 13, may proceed to make this position
In the range of crystallizer regular burden(ing) hydraulic control system.
Wherein, the low-concentration liquid can use clear water or other there is the liquid of diluting effect, do not do have herein
Body limits.
With continued reference to Fig. 1, in embodiment of the present utility model, the dilution tube 2 is U-shaped, and the dilution tube 2
One end connects with the bypass pipe 1, and the other end of the dilution tube 2 is hanging, and like this U-shaped structure can also make sedimentation
The enough stable bottom for being deposited in dilution tube 2 of high salt concentration liquid energy, the strength of fluid without influenceing the top of decanting zone 13.
Fig. 3 is the second structural representation of the liquid level gauge that the utility model one embodiment provides.
As shown in figure 3, in embodiment of the present utility model, magnetic turnover plate type level-sensing device is additionally provided with the bypass pipe 1
4, and the magnetic turnover plate type level-sensing device 4 is correspondingly arranged with the diaphragm type level-sensing device 3, meanwhile, also set up on the bypass pipe 1
There are multiple peep holes 14, axial direction of multiple peep holes 14 along the bypass pipe 1 is uniformly arranged, for observing in bypass pipe 1
Liquid level.
Thus, due in the same position of the diaphragm type level-sensing device 3 of bypass pipe 1, also setting up and being provided with magnetic turnover plate type
Level-sensing device 4, and be provided with the peep hole 14 of different material positions, thus can be carrying out intuitively to diaphragm type level-sensing device 3
Check and correction, it is ensured that the accuracy of material position in production.
Further, in embodiment of the present utility model, the diameter on the top of bypass pipe 1 is more than the diameter of bottom,
By this structure the bypass pipe 1 can be made to form a kind of structure of back taper from top to bottom, so, the decanting zone 13 of bottom
Cavity volume will be less than top and be used to holding the cavity volume of low concentration solution, such design is to allow the height of bottom
The solution of concentration sedimentation is few, and makes the low concentration solution on top more, because highly concentrated solution is few, and majority is all
Low concentration solution, thus can further it reduce because membrane surface crystallisation problems described above are to diaphragm type level-sensing device
The influence of 3 normal works.
Preferably, in embodiment of the present utility model, the upper diameter of the bypass pipe 1 is 80mm, the bypass pipe 1
Lower diameter be 60mm, so bypass pipe 1 is from top to bottom from 80mm diameter to 60mm Diameter Gradual Change.
Further, in embodiment of the present utility model, the junction of the dilution tube 2 and the bypass pipe 1 is set
There is the first control valve 15, using first control valve 15, the can of bypass pipe 1 passes through first control valve
15 connect or close with the inner chamber of crystallizer, control high concentration liquid in crystallizer to enter bypass pipe 1.
Further, in embodiment of the present utility model, the second control valve is provided with the dilution tube 2, is utilized
Second control valve, the can of dilution tube 2 are connected or closed with the source of dilution by second control valve
Close, control the entrance of low-concentration liquid.
Present invention also provides a kind of crystallizer, including the liquid level gauge.
Because the concrete structure of the liquid level gauge, the principle of work and power and technique effect are in detailed hereinbefore, herein just not
Repeat again.
So any technology contents for being related to the liquid level gauge, also refer to record above.
From the foregoing, it will be observed that the crystallizer is provided with the liquid level gauge, by dilution tube on liquid level gauge 2 in bypass pipe 1
After high concentration saline solution is diluted, high concentration saline solution in bypass pipe 1 is constantly invaded from crystallizer in production run just
It can be deposited in the bottom tubule of bypass pipe 1, the decanting zone 13 of saline solution be formed in this place, so that the top of decanting zone 13 maintains
Low concentration feed liquid, it membrane surface formation will not thus crystallize again, nor affect on the accuracy of detection of diaphragm type feed liquid instrument.
Further, in embodiment of the present utility model, including crystallizer cylinder, the crystallizer cylinder include crystallization
Cylinder 51 and extension cylinder 52；
The high-order connector 11 of the bypass pipe 1 of the liquid level gauge connects with the extension cylinder 52, the side of the liquid level gauge
The low level connector 12 of siphunculus 1 connects with the crystallization cylinder 51.
Finally it should be noted that：Various embodiments above is only to illustrate the technical solution of the utility model, rather than it is limited
System；Although the utility model is described in detail with reference to foregoing embodiments, one of ordinary skill in the art should
Understand：It can still modify to the technical scheme described in foregoing embodiments, either to which part or whole
Technical characteristic carries out equivalent substitution；And these modifications or replacement, the essence of appropriate technical solution is departed from this practicality newly
The scope of each embodiment technical scheme of type.
Claims (10)
1. a kind of liquid level gauge, it is characterised in that including bypass pipe (1), dilution tube (2) and diaphragm type level-sensing device (3)；
The upper and lower part of the bypass pipe (1) is separately provided for the high-order connector (11) connected with crystallizer and low level
Connector (12)；
The dilution tube (2) connects with the bottom of the bypass pipe (1), for the injection dilution into the bypass pipe (1)；
The bottom of the bypass pipe (1) is arranged on the decanting zone formed with decanting zone (13), the diaphragm type level-sensing device (3)
(13) top.
2. liquid level gauge according to claim 1, it is characterised in that the dilution tube (2) is U-shaped；
One end of the dilution tube (2) connects with the bypass pipe (1), and the other end of the dilution tube (2) is hanging.
3. liquid level gauge according to claim 1, it is characterised in that be additionally provided with magnetic turnover plate type material on the bypass pipe (1)
Position instrument (4)；
The magnetic turnover plate type level-sensing device (4) is correspondingly arranged with the diaphragm type level-sensing device (3).
4. liquid level gauge according to claim 1, it is characterised in that be additionally provided with multiple peep holes on the bypass pipe (1)
(14)；
Axial direction of multiple peep holes (14) along the bypass pipe (1) is uniformly arranged, for observing the liquid in bypass pipe (1)
Position.
5. liquid level gauge according to claim 1, it is characterised in that the diameter on bypass pipe (1) top is more than bottom
Diameter.
6. liquid level gauge according to claim 5, it is characterised in that the upper diameter of the bypass pipe (1) is 80mm, described
The lower diameter of bypass pipe (1) is 60mm.
7. liquid level gauge according to claim 1, it is characterised in that the dilution tube (2) and the connection of the bypass pipe (1)
Place is provided with the first control valve (15)；
The bypass pipe (1) is connected or closed with the inner chamber of crystallizer by first control valve (15).
8. liquid level gauge according to claim 1, it is characterised in that be provided with the second control valve on the dilution tube (2)；
The dilution tube (2) is connected or closed with the source of dilution by second control valve.
9. a kind of crystallizer, it is characterised in that including the liquid level gauge as any one of claim 1-8.
10. crystallizer according to claim 9, it is characterised in that including crystallizer cylinder, the crystallizer cylinder includes
Crystallize cylinder (51) and extend cylinder (52)；
The high-order connector (11) of the bypass pipe (1) of the liquid level gauge connects with the extension cylinder (52), the liquid level gauge
The low level connector (12) of bypass pipe (1) connects with the crystallization cylinder (51).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721110982.5U CN207113966U (en) | 2017-08-31 | 2017-08-31 | A kind of liquid level gauge and crystallizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721110982.5U CN207113966U (en) | 2017-08-31 | 2017-08-31 | A kind of liquid level gauge and crystallizer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207113966U true CN207113966U (en) | 2018-03-16 |
Family
ID=61574417
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721110982.5U Active CN207113966U (en) | 2017-08-31 | 2017-08-31 | A kind of liquid level gauge and crystallizer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207113966U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110595570A (en) * | 2019-10-23 | 2019-12-20 | 云南师范大学 | Liquid level display device applying metal surface plasmons |
| CN112197835A (en) * | 2020-10-28 | 2021-01-08 | 安徽晋煤中能化工股份有限公司 | Method for preventing instrument from being blocked |
-
2017
- 2017-08-31 CN CN201721110982.5U patent/CN207113966U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110595570A (en) * | 2019-10-23 | 2019-12-20 | 云南师范大学 | Liquid level display device applying metal surface plasmons |
| CN112197835A (en) * | 2020-10-28 | 2021-01-08 | 安徽晋煤中能化工股份有限公司 | Method for preventing instrument from being blocked |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN207113966U (en) | A kind of liquid level gauge and crystallizer | |
| CN106198932B (en) | The experimental provision and method of water lithofacies interaction in a kind of simulation rock crack | |
| CN105158018B (en) | A kind of pellicle continuous sampling device for the sampling of water body passive type | |
| CN202013330U (en) | Deposition rate detection device for CaCo3 | |
| CN206063825U (en) | A kind of ethanol monitors fractionation apparatus on-line | |
| CN104391515A (en) | Methyl alcohol storage tank feed and output control device applied to medicine production | |
| CN104008290A (en) | Roadway roof fall hidden danger grading method taking bidirectional anisobaric stress fields into consideration | |
| CN204575153U (en) | A kind of high-precision ultrasonic water meter | |
| CN203274758U (en) | Quick inspection device for total station prism bar | |
| CN104502222B (en) | Method for determining metastable region of high-concentration and low-light-transmittance solution system based on microporous membrane response | |
| CN110207764A (en) | A kind of adaptive differential pressure flowmeter of angle | |
| CN204831456U (en) | Glass liquid level gauge | |
| CN107202991A (en) | Ship model water surface site monitors the optic testing system and method for experiment in real time | |
| CN103657137B (en) | Crystallizing evaporator | |
| CN203610054U (en) | Simple film yarn flux test system | |
| CN203908909U (en) | Shear viscosity measuring device for high-pressure ultralow-viscosity fluid | |
| KR200475581Y1 (en) | Water level control type soil infiltration velocity measuring apparatus | |
| CN203414126U (en) | Real-time measurement device for flow of steam-water two-phase fluid and steam dryness | |
| CN211849710U (en) | Automatic water adding device | |
| CN204924847U (en) | Cantilever beam type densimeter | |
| CN203024920U (en) | High-pressure sulphur-tolerant pressure gauge with straight-through type C-shaped spring tube | |
| CN204241044U (en) | A kind of high precision pressure-taking head of Pitot Pa flow sensor | |
| CN212159464U (en) | Quantitative visual experimental cavity for diffusion interface | |
| CN217980474U (en) | Salt manufacturing is with accurate measuring device of evaporating pot liquid level | |
| CN204270162U (en) | A kind of methanol storage drum supply and output-controlling device manufacturing medicine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |