CA2510896A1 - Thermal-vacuum felt conditioning system - Google Patents
Thermal-vacuum felt conditioning system Download PDFInfo
- Publication number
- CA2510896A1 CA2510896A1 CA 2510896 CA2510896A CA2510896A1 CA 2510896 A1 CA2510896 A1 CA 2510896A1 CA 2510896 CA2510896 CA 2510896 CA 2510896 A CA2510896 A CA 2510896A CA 2510896 A1 CA2510896 A1 CA 2510896A1
- Authority
- CA
- Canada
- Prior art keywords
- felt
- steam
- vacuum
- jet ejector
- slot
- 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.)
- Abandoned
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F7/00—Other details of machines for making continuous webs of paper
- D21F7/008—Steam showers
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/32—Washing wire-cloths or felts
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F7/00—Other details of machines for making continuous webs of paper
- D21F7/08—Felts
- D21F7/12—Drying
Landscapes
- Paper (AREA)
Abstract
The invention comprises a method and an apparatus for felt conditioning in the process of paper manufacture. The design of the device is featured by a vacuum head equipped with two lenghtways suction slots installed under the felt, and from the side opposite to felt equipped with blow head fed by air-steam mixture. In the vacuum head vacuum is maintained by steam jet ejector.
Slot of blow box is situated axially towards the first slot of vacuum head on the opposite side of the felt.
The concept of the invention utilises both kinetic energy and enthalpy of steam for felt dewatering and conditioning being in a constant motion. Kinetic energy of steam allows to generate vacuum necessary for sucking away water contained in the felt. Enthalpy of decompressed steam is utilised for preheating the felt and its effective conditioning.
The characteristic feature of the solution is vacuum dewatering device connected with a separator, steam jet ejector powered by steam through control valve and lengthways blow nozzle mounted over the felt, fed by hot air- steam mixture from steam jet ejector.
Slot of blow box is situated axially towards the first slot of vacuum head on the opposite side of the felt.
The concept of the invention utilises both kinetic energy and enthalpy of steam for felt dewatering and conditioning being in a constant motion. Kinetic energy of steam allows to generate vacuum necessary for sucking away water contained in the felt. Enthalpy of decompressed steam is utilised for preheating the felt and its effective conditioning.
The characteristic feature of the solution is vacuum dewatering device connected with a separator, steam jet ejector powered by steam through control valve and lengthways blow nozzle mounted over the felt, fed by hot air- steam mixture from steam jet ejector.
Description
-1_ DESCRIPTION
The invention comprises apparatus and method for conditioning felt in the process of paper manufacture. In the paper manufacture process there is the need of dewatering and final drying end product_ The grade to which paper is dewatered is of great importance for achieving beneficial energy consumption indexes in the further production line, particularly in the drying process.
The invention concerns an apparatus for improving felt conditioning [Fig. lJ.
The essence of the invention is the device, equipped with two-slot vacuum head (3) that sucks away water & sir and a blow box that is fed by hot air- steam mixture. The vacuum head (3) is connected with steam jet ejector which in the head (3) generates absolute underpressure 25-75 kPa. Axially towards the first slot (4), on the opposite side of the felt is installed blow box (6) fed by decompressed air- steam mixture ('~ of the absolute pressure 100- 120 kPa generated by the steam jet ejector. A directed stream of hot air- steam discharged from the slot (10) of the blow box (6) is sucked in by felt (1) into slot (4) of de-watering head (3). Air from the surrounding is sucked in through second slot (5) of dewatering head (3). The Double Slot System featuring the dewatering head and deep underpressure contained inside contributes to highly effective felt de-watering. Simultaneous pre-heating felt and its water content together with reducing hydraulic pressure in the structure of felt causes effective partial suction of moisture to slot one (4). Sudden felt cooling (1) facilitates water evaporation to slot two (5). Felt conditioned in this way is more air permeable and improves paper dewatering.
The invention also concerns the method of felt conditioning [Fig. 2).
The essence of felt conditioning with the described system is the double utilization of steam energy due to employment of steam jet ejector generating vacuum (13), blow nozzle (12) for blowing hot air steam mixture after steam jet ejector, suction box (11) for sucking away water from preheated felt and a separator (14). Steam jet ejector (13) is fed by steam with an absolute pressure 200-3000 kPa that is regulated by valve (15), suction pipe of the steam jet ejector is connected with suction box ( 11 ) through separator ( 14) and the outlet pipe with a blow nozzle ( 12) is mounted axially over the suction box. Water from the separator ( 14) is returned to the process cycle( 16).
Steam, after decompressing in the steam jet ejector diffuser (13) imparts its kinetic energy to the sucked air with coincident generating deep underpressure in the suction box (11).
%Ow.~32 I~cr,~6y ~hv~~
The invention comprises apparatus and method for conditioning felt in the process of paper manufacture. In the paper manufacture process there is the need of dewatering and final drying end product_ The grade to which paper is dewatered is of great importance for achieving beneficial energy consumption indexes in the further production line, particularly in the drying process.
The invention concerns an apparatus for improving felt conditioning [Fig. lJ.
The essence of the invention is the device, equipped with two-slot vacuum head (3) that sucks away water & sir and a blow box that is fed by hot air- steam mixture. The vacuum head (3) is connected with steam jet ejector which in the head (3) generates absolute underpressure 25-75 kPa. Axially towards the first slot (4), on the opposite side of the felt is installed blow box (6) fed by decompressed air- steam mixture ('~ of the absolute pressure 100- 120 kPa generated by the steam jet ejector. A directed stream of hot air- steam discharged from the slot (10) of the blow box (6) is sucked in by felt (1) into slot (4) of de-watering head (3). Air from the surrounding is sucked in through second slot (5) of dewatering head (3). The Double Slot System featuring the dewatering head and deep underpressure contained inside contributes to highly effective felt de-watering. Simultaneous pre-heating felt and its water content together with reducing hydraulic pressure in the structure of felt causes effective partial suction of moisture to slot one (4). Sudden felt cooling (1) facilitates water evaporation to slot two (5). Felt conditioned in this way is more air permeable and improves paper dewatering.
The invention also concerns the method of felt conditioning [Fig. 2).
The essence of felt conditioning with the described system is the double utilization of steam energy due to employment of steam jet ejector generating vacuum (13), blow nozzle (12) for blowing hot air steam mixture after steam jet ejector, suction box (11) for sucking away water from preheated felt and a separator (14). Steam jet ejector (13) is fed by steam with an absolute pressure 200-3000 kPa that is regulated by valve (15), suction pipe of the steam jet ejector is connected with suction box ( 11 ) through separator ( 14) and the outlet pipe with a blow nozzle ( 12) is mounted axially over the suction box. Water from the separator ( 14) is returned to the process cycle( 16).
Steam, after decompressing in the steam jet ejector diffuser (13) imparts its kinetic energy to the sucked air with coincident generating deep underpressure in the suction box (11).
%Ow.~32 I~cr,~6y ~hv~~
Sucked air with diffused steam is a heating medium for feeding blowing nozzle (12). Hot air- steam mixture from blowing nozzles is sucked in to suction boxes ( 11 ) through the felt that is conditioned at the same time in the process. It leads to preheating material and water that it contains. A portion of moisture evaporates in the form of vapor and is sucked away. The rest of water in the liquid form is substantially easier sucked away in higher temperature due to decrease in its viscosity and density. As a consequence, simultaneous sucking and preheating felt by means of air-steam flow influences the intensification of conditionig and increases paper dewatering.
As a result, paper web subjected to thermal drying is characterized by higher dryness.
Steam jet ejector is designed to automatically adjust to the factual condition of felt. In case of poor felt permeability, steam jet ejector sucks little air: vacuum under the felt deepens and the temperature of air-steam mixture blown onto the felt increases. It causes opening the felt and changes operating parameters of the steam jet ejector. The amount of sucked air increases, pressure in suction box rises and the blow temperature drops.
The overall impact of the increase in felt permeability is improved vacuum and mechanical dewatering and advantageous energy balance of a paper machine.
r~~=t , R~.~ ~n~,~z ~a~,5
As a result, paper web subjected to thermal drying is characterized by higher dryness.
Steam jet ejector is designed to automatically adjust to the factual condition of felt. In case of poor felt permeability, steam jet ejector sucks little air: vacuum under the felt deepens and the temperature of air-steam mixture blown onto the felt increases. It causes opening the felt and changes operating parameters of the steam jet ejector. The amount of sucked air increases, pressure in suction box rises and the blow temperature drops.
The overall impact of the increase in felt permeability is improved vacuum and mechanical dewatering and advantageous energy balance of a paper machine.
r~~=t , R~.~ ~n~,~z ~a~,5
Claims (2)
1. The device designed for conditioning felt (Fig.1) which is in a constant motion, characterized by vacuum head (3) equipped with two lengthways suction slots (4 and 5) fitted under the felt (1) and from the opposite side equipped with blow box (6) featured by a slot (10) fed by pre-heated gas (advantageously by mixture of steam and air) with temperature above 100 ° C (advantageously 110-130 ° C) and absolute pressure 100 to 120 kPa [ advantageously 105 kPa]. In the vacuum head (3) vacuum is maintained at the level 25-75 kPa [advantageously 40 kPa]
generated by vacuum device [advantageously by steam jet ejector]. Slot (10) of head (6) is situated axially towards the first slot (4) of vacuum head (3) within 5- 15 mm of felt (1).
generated by vacuum device [advantageously by steam jet ejector]. Slot (10) of head (6) is situated axially towards the first slot (4) of vacuum head (3) within 5- 15 mm of felt (1).
2. The method of dewatering and conditioning felt (Fig.2) being in a constant motion characterised by vacuum dewatering device (11) mounted under the felt (10) connected with separator (14) and vacuum steam jet ejector (13) fed by steam with an absolute pressure 200 to 3000 kPa through control valve (15) and lengthways blowing nozzle (12) fitted over the felt, powered by hot mixture of steam and air from the steam jet ejector (13). Water from the separator (14) is returned to the process cycle(16).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2510896 CA2510896A1 (en) | 2005-05-30 | 2005-05-30 | Thermal-vacuum felt conditioning system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2510896 CA2510896A1 (en) | 2005-05-30 | 2005-05-30 | Thermal-vacuum felt conditioning system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2510896A1 true CA2510896A1 (en) | 2006-11-30 |
Family
ID=37480391
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2510896 Abandoned CA2510896A1 (en) | 2005-05-30 | 2005-05-30 | Thermal-vacuum felt conditioning system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2510896A1 (en) |
-
2005
- 2005-05-30 CA CA 2510896 patent/CA2510896A1/en not_active Abandoned
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |