CN1594959A - Heat supply direct-buried pipe hot air preheating method and hot air supply apparatus used thereby - Google Patents
Heat supply direct-buried pipe hot air preheating method and hot air supply apparatus used thereby Download PDFInfo
- Publication number
- CN1594959A CN1594959A CN 03144267 CN03144267A CN1594959A CN 1594959 A CN1594959 A CN 1594959A CN 03144267 CN03144267 CN 03144267 CN 03144267 A CN03144267 A CN 03144267A CN 1594959 A CN1594959 A CN 1594959A
- Authority
- CN
- China
- Prior art keywords
- pipeline
- temperature
- heating
- pipe
- stress
- 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.)
- Pending
Links
Landscapes
- Air Supply (AREA)
Abstract
This invention is a method of heat-supplying directed-embedding pipe of hot-wind preheating: (1) hot-wind preheat the prefabricating heat-preservation pipe, make it stretch freely and diminish the extra fixing stress of the pipe; (2) when the elongation of the pipe reaches the academic elongation, backfill the soil to press the pipe; (3) lower the temperature of the pipe, use one-off compensation to seal among each phase of preheating; (4) as the pipe working with heat, the pull and stress will gradually reduce along the rising of the temperature, when reaching the preheating temperature, the stress of the pipe is zero; continue to raise the temperature, the pressure of the pipe comes into being and gradually increase with the rising temperature; when the temperature reaches the working temperature, the stress of the pipe is still less than the permitting stress. The advantages of this invention are: 1. the wall temperature of the pipe rises equably, the pipe can elongate freely and equally, the experiment shows that the preheating achieves the perfect pipe preheating effect. 2. the construction cycle can be greatly reduced, the cost of preheating is low. 3. the environmental pollution is limited.
Description
Affiliated field:
The invention belongs to a kind of preheating laying method of heat supply pipeline, particularly a kind ofly in the urban heating engineering, provide a kind of method and used air heating device that carries out the hot-air pre-heating mounting process for laying of direct-burried prefabricated thermal insulation heat supply pipeline.
Background technique:
In China's urban heating industry, direct-burried prefabricated thermal insulation heat supply pipeline preheating mounting process method is to adopt in advance to the pipeline preheating, make pipe expansion arrive design load, the backfill sandy soil are pushed down pipeline, make it produce certain prestressing force in advance, when pipeline was normally carried thermal medium, the thermal stress that pipeline produces can be less than the stress of cold mounting process method generation, make pipeline stressed within the allowable stress scope of its material, to guarantee a kind of installation method of pipe safety operation.
For the pre-heating technique of direct-burried prefabricated thermal insulation heat supply pipeline, what tradition was used is the hot water pre-heating mean.This method adopts: will lay the prefabricated thermal insulation heat supply pipeline two ends welding blind plate closed conduct that finishes earlier, on blind plate, open an aperture welding water pipe, allow an end water pipe connect equipment such as circulating water pump, water supply tank, water-heating boiler and is connected the formation closed-circuit with the other end water pipe.Pour water in along water pipe toward pipeline, after water is full of pipeline, the ON cycle pump is constantly brought the hot water that boiler produces in the pipeline by water cycle, because pipeline is an insulation pipe, so water temperature constantly raises in the pipeline, when water temperature reaches preheating temperature, stop heat temperature raising, beginning backfill sandy soil, when sandy soil backfill reached requirement, the pipeline preheating finished.
Along with the development of society, utilize residual heat of electric power plant to carry out central heat supply, become the direction of urban heating development.The direct-burried prefabricated thermal insulation heat supply pipeline about 70% that lays from the power plant to user is big caliber (more than the DN500) pipeline, because these heavy-caliber pipelines are from great, big with contact area of ground, after adopting the water filling of hot water pre-heating mean, increased the pipeline positive pressure, strengthened the surface friction drag of pipeline, the thermal expansion of pipeline has been subjected to constraint, and pre-heat effect is affected.
Summary of the invention:
Purpose of the present invention just is to overcome above-mentioned the deficiencies in the prior art, and provide a kind of heating direct-burying pipeline hot-air pre-heating method and used air heating device, this method is pining for fully having discharged pipeline thermal stress in advance, has improved the uniformity of pipeline thermal elongation.
Technological scheme of the present invention is: a kind of heating direct-burying pipeline hot-air pre-heating method is characterized in that: 1. direct-burried prefabricated thermal insulation heat supply pipeline is carried out hot-air pre-heating, pipeline is freely extended, eliminate in the pipeline residual stress is installed; 2. reach or during near theoretical elongation, the backfill sandy soil are pushed down pipeline when the pipeline elongation; 3. pipeline is lowered the temperature, and between each preheating section, connect sealing with one-off compensator; 4. when the logical thermal technology of pipeline did, along with the rising of temperature, the pipeline tensile stress reduced gradually, and when reaching preheating temperature, integrated piping stress under this temperature is zero; Continue to heat up, the pressure stress of pipeline produces, and increases gradually along with the rising of temperature, and when temperature was raised to operating temperature, the pressure stress of pipeline was still less than the allowable stress of pipeline.
Above-mentionedly direct-burried prefabricated thermal insulation heat supply pipeline is carried out the used air heating device of hot-air pre-heating form, split two ends at heat supply pipeline by major and minor two groups of heating equipments; Two groups of heating equipments show and the control box composition by direct-combustion hot air machine, circulating fan, mixing box, connecting pipe, temperature; Circulating fan in the main heating equipment places the top, and connects in the direct-combustion hot air machine by mixing box; Circulating fan in the secondary heating equipment places the below, and connects in the direct-combustion hot air machine by mixing box; Two circulating fans will be for, water return pipeline series connection.Form open type closed-circuit heating mode; Into and out of air port and four the insulation mouth of pipe places temp probes are installed at major and minor heating plant; Temperature shows and control box is contained in the main heating equipment.
Above-mentioned preheating section length is 500-1500m.
Above-mentioned preheating temperature is between the minimum temperature of pipeline operating temperature and restriction.
Above-mentioned preheating wind speed is 6～20m/s.
Advantage of the present invention is: 1, owing to adopt the hot-air pre-heating method, pre-thermal medium is an air, the weight that unit length is attached on the pipeline is 1/1000 of water, and surface friction drag is little, so the pipeline wall temperature evenly raises, pipeline can evenly freely extend, and actual elongation and theoretical value basically identical, so when reaching theoretical value, as long as keep entering air temp, just backfill fast prevents resilience.Adopt hot-air pre-heating can fully discharge pipeline thermal stress in addition, be in complete free state after making the pipeline preheating, test shows that preheating reaches the ideal conduit pre-heat effect.2, construction period can shorten greatly, and preheating expense relatively hot water preheat is lower.3, little for the pollution of environment.Because adopting diesel oil is fuel, in the discharged flue gas flue dust, sulfur dioxide, nitrogen oxide, Lin Geman blackness of exhaustion all be lower than GB13271-2001 and/the DHJB1-1999 standard in the limit value of class two zone II period secondary standard.
Description of drawings:
Fig. 1 is for to carry out the used air heating device schematic representation of hot-air pre-heating to direct-burried prefabricated thermal insulation heat supply pipeline
Embodiment:
A kind of heating direct-burying pipeline hot-air pre-heating method, it is characterized in that: after the piping erection that is not less than two maximum length of installation sections finishes, pipeline is communicated with the air heating system, pipeline is carried out hot-air pre-heating, pipeline is freely extended, eliminate in the pipeline residual stress is installed.Be connected with the used air heating device of hot-air pre-heating then, this air heating device is made up of major and minor two groups of heating equipments 11,12, splits the two ends at heat supply pipeline, is respectively confession, water return pipeline hot wind supply; Two groups of heating equipments show by direct-combustion hot air machine 1, circulating fan 2, mixing box 3, connecting pipe 4, temperature and control box 5 compositions; Circulating fan in the main heating equipment places the top, and connects in the direct-combustion hot air machine by mixing box, temperature is housed in it shows and control box; Circulating fan in the secondary heating equipment places the below, and connects in the direct-combustion hot air machine by mixing box; The exhaust outlet of main heating equipment 11 is connected with direct-burried heating tube water supply line 6, the air blowing opening of secondary heating equipment 12 connects with direct-burried heating tube water return pipeline 7, make hot air enter water supply line from main heating equipment, deliver to secondary heating equipment, through heat temperature raising, send into water return pipeline, return main heating equipment, form open type closed-circuit mode of heating.By being installed in the temp probe 10 of major-minor heating equipment in the air port place 8,9 respectively, measure outlet and inlet temperature and tube wall temperature, reach and show and monitor and purpose that control system heats.When pipeline elongation reaches or during near theoretical elongation, pipeline is backfilled to the above 200mm in pipe top, compaction in layers with sand.Fill compaction is to minimum thickness of earth-fill cover again, manage compacting, anchor is dead.Remove thermal source, the pipeline cooling.This moment, the pipeline preheating finished.When pipeline returned to the installation temperature, pipeline had born certain tensile stress in advance.When the logical thermal technology of pipeline does, rising along with temperature, the pipeline tensile stress reduces gradually, when reaching preheating temperature, pipe stress can be considered zero, continues to heat up, the pressure stress of pipeline produces, and increase gradually along with the rising of temperature, when temperature was raised to operating temperature, the pressure stress of pipeline was still less than the allowable stress of pipeline.
Required numerical value is definite among the present invention: the Stress calculation during 1, uncompensated directly buried pipeline lays: can get axial stress according to Hooke's law; σ=E α Δ T----------(3)
The axial stress that is attached to by the circumference stress generation:
σ′＝V·σten --------------------------(4)
Under the acting in conjunction of axial stress and circumference stress, the axial stress of generation is:
σax＝E·α·ΔT+V·σten -------------------------(5)
Axial stress kgf/cm under two kinds of power effects of σ ax---
σ ten-circumference stress
The V-Poisson's coefficient
Circumference stress can be calculated as follows:
σten＝P·Dn/(2S)
P-manifold pressure kgf/cm
Dn-internal diameter of the pipeline mm
S-pipeline wall thickness mm
2, determining of uncompensated directly buried pipeline preheating temperature:
Preheating temperature is between the minimum temperature of pipeline operating temperature and restriction.If preheating temperature is Ty, pipeline heating medium Maximum operating temperature is Tmax, and when the pipeline internal medium temperature rose to Tmax by Ty, pipeline axial stress should be less than allowable stress (σ=1300kgf/cm), bring formula (5) into
-σ＝E·α·(Tmax-Ty)+V·σten ——(7)
The arrangement back:
Ty＝Tmax-{(σ)+V·σten}/(E·α) ——(8)
Suppose Tmax=120 ℃ of the interior medium Maximum operating temperature of pipe, Maximum operating pressure P=16kgf/cm, diameter of steel tube are DN500X10～DN1000X12.Obtain by formula (6) and formula (8)
During DN500, σ ten=400, Ty=63.7 ℃
During DN1000, σ ten=666.7, Ty=60.5 ℃
3, uncompensated directly buried pipeline allows determining of minimum temperature Tmin
When tube-cooled, will cause tensile stress, when reaching minimum operating temperature Tmin, pipeline axial stress can not surpass allowable stress (σ), promptly
(σ)=and E α (Ty-Tmin)+V σ ten---one (9)
The arrangement back:
Tmin=Ty-({ σ }-V σ ten)/(E α)---one (10)
Bringing formula (8) into formula (10) gets
Tmin＝Tmax-2(σ)/(E·α) ———————(11)
Bring heating parameter into following formula, then Tmin=16.8 ℃.That is to say diameter of steel tube in DN500 * 10～DN1000 * 12 scopes, after installing by preheating method, medium fluctuates in 16.8 ℃ of-120 ℃ of temperature ranges under 1.6MPa makes pressure in the pipe, also is safe even pipeline does not have any compensation.
When pipe network stops heat supply running, in the pipe during no pressure, σ ten=0 then:
Tmin＝Ty-(σ)/(E·α) ——(12)
Parameter substitution following formula, can get:
During DN500, Tmin=12.1 ℃
During DN1000, Tmin=8.9 ℃
Be pipe network when stopping heat supply running, the above pipe network of DN500 is remained on more than 15 ℃, uncompensated directly buried pipeline is only safe.
4, uncompensated directly buried pipeline elongation determines
Adopt spacious slot type pre-heating mean, insulation pipe preheating elongation calculates by following formula
ΔL＝α·(Ty--Th)·L----------------------------(13)
Δ L-pipeline elongation mm
α-pipe expansion coefficient: mm/m ℃
Ty-preheating temperature ℃
Th-ambient temperature ℃ (initial water temperature of preheating or steel pipe wall temperature)
L-preheating section duct length m
With preheating temperature, expansion coefficient, ambient temperature, economizer bank segment length (establishing L is 800 meters), it is 436.8mm that the substitution following formula obtains the pipeline elongation.
5, the choosing value of hot blast air quantity
Heat up with hot blast heating tube wall, belong to forced convection heat transfer.For the tube fluid fluid interchange, 1. the size of its heat exchange quantity depends on 4 performance parameters
q＝h·A·(Tw-Tb) ————(14)
The q-heat exchange quantity
The h-coefficient of heat transfer
The A-heat exchange area
The Tw-tube wall temperature
The Tb-air temperature
Here A heat exchange area, Tw tube wall temperature, Tb air temperature are the relative fixed parameters, and the h coefficient of heat transfer is the parameter that changes with changes in flow rate.Classical theoretical analysis is thought that fluid flows and is divided into laminar condition, transition state and turbulent condition, reflects the nondimensional quantity Nu-number Nu of coefficient of heat transfer feature in pipe
Nu＝f(h) ————(15)
Nu-number Nu is when laminar condition
Nu＝4.364 ————(16)
Nu-number Nu is when turbulent condition
Nu＝0.0395·Re
3/4·Pr
1/3 ————(17)
The nondimensional quantity of Re-reflection flowing state feature
The nondimensional quantity of Pr-reflection characteristic of fluid
In order to make the abundant heat exchange of fluid and tube wall, improve heat exchange quantity, should be set in turbulent condition flowing.The nondimensional quantity of reflection flowing state feature in pipeline
Re＝ud/r ————(18)
Speed m in the u-pipe
3/ s
D-pipe inner diameter m
R-kinematical viscosity m
2/ s
When Re 〉=5 * 10
5The time, laminar boundary layer becomes turbulent condition fully.With air movement viscosity r=18.7 * 10
-6m
2/ s, preheating caliber d=1m bring formula (18) into and try to achieve minimum flow velocity u=9.35m/s in the pipe.
From the heat exchange angle analysis, the minimum pre-hot blast rate of 1m pipe diameter hot-air pre-heating system is 26500m
3/ h.
6, preheating section length
The determining and will decide in conjunction with on-site actual situations of preheating section length generally is defined as 800m～1000m for well, too shortly understands increase preheating number of times.Long meeting strengthens the pipeline section head and the tail air temperature difference, influences pre-heat effect.If the problem of heating can suitably increase hot-air pre-heating length in the middle of can solving.
7, system resistance calculates
System resistance is made up of on-way resistance and local resistance, supposes that calculation of wind speed gets 12m/s, single line duct length 1000m, pipe diameter 1m, pipe roughness 0.15mm, allows the single line pipeline 1 1.5 times of 90 ° of elbow to be arranged and 4 45 ° of elbows are arranged
Try to achieve Re=6.42 * 10 by formula (18)
52. Lip river crust Prokofiev provides the on-way resistance coefficient formulas
λ＝1.42/(lg?Re·d/Δ)
2 ——————(19)
Δ-tube wall roughness m
Result of calculation, on-way resistance coefficient lambda=0.0153 on-way resistance H formula is
H＝λ·ρ·(L/d)*(u
2/2g) ——————(20)
ρ-air density kg/m
3
L-duct length m
G-gravity accleration m/s
2
On-way resistance H=132.25mm water column, i.e. 1323Pa.
The coefficient of partial resistance formula
ζ＝4τsin
2θ/2 ——————(21)
τ-correction factor gets 0.55
θ-angle of bend
Coefficient of partial resistance ζ=1.1 (90 ° of elbows), local resistance H '
H′＝ξ(u
2/2g) ——————(22)
Local resistance H '=8.082mm water column, i.e. 81Pa.Single lead is as 3 elbows, resistance 243Pa.
Above-mentioned resistance phase adduction be multiply by engineering nargin 1.5, and drag overall is 2349Pa.The static pressure head that is to say blower fan must be worth greater than this, could guarantee the mobile turbulent condition that is of inner air tube.
8, preheating quantity
Determining of preheating quantity is the foundation of selecting thermal source, also is the important parameter that carries out the air quantity coupling.The calculating of preheating quantity mainly contains three parts and forms:
A, prefabricated thermal insulation pipeline heat up needs the heat of absorption
Qa＝L·Gw·(Ty-Ta)·Rw ——————(23)
L-pipeline total length m
The weight kg/m (the pipeline 200kg/m that diameter is 1 meter) of the every mitron of Gw-road iron and steel
The initial wall temperature of Ta-steel pipe ℃
W/ ℃ of kg of Rw-steel pipe specific heat (0.14W/ ℃ of kg)
In the early spring and Qiu Mo season, ambient temperature is relatively cooler, and we suppose that the initial wall temperature of steel pipe this moment is 15 ℃.Require 62 ℃ of preheating temperatures.Then pipeline heats up needs the heat Qa=2632kW of absorption.
B, by prefabricated thermal insulation pipeline surface dispersed heat
Qb＝L·qw·(Ty-Ta) ——————(24)
Every meter heat preservation pipe prefabricated dispersed heat W/m ℃ h of qw-
According to reference test result 3., we calculate and select qw=0.8W/m ℃ of h.By prefabricated thermal insulation pipeline surface dispersed heat Qb=75.2kW/h.
Air temperature improves required heat in c, pipeline and the equipment
Qc＝(Vg+Vs)·(Ty-Ta)·Ra·ρ ——————(25)
Vg-thermal insulation pipe internal volume m
3
Vs-pre-heating device internal volume m
3
W/ ℃ of kg of Ra-air specific heat
The pre-heating device internal volume is about 30m
3, this heat Qc=25.2kW.
The heat of d, system's discharging waste gas
Qd＝〔2·Vzp+3·(Vp+Vf)〕·(Ty-Ta)·Ra·ρ?——(26))
Vzp-master burner discharge amount m
3/ h (20m
3/ h)
Vp-auxiliary burner discharge amount m
3/ h (12m
3/ h)
Vf-direct combustion fan delivery m
3/ h (3500m
3/ h)
The heat Qd=166.5kW/h of system's discharging waste gas.
Heat Qa, Qc, be disposable consumption of calorie, heat Qb, Qd, be consumption of calorie per hour.If design is 6 hours the temperature rise time, consumption of calorie 588.6kW per hour then.The thermal loss of considering pre-heating device needs 1.2 times of nargin, and gross heat input should be not less than 700kW.
Claims (5)
1, a kind of heating direct-burying pipeline hot-air pre-heating method is characterized in that: 1. direct-burried prefabricated thermal insulation heat supply pipeline is carried out hot-air pre-heating, pipeline is freely extended, eliminate in the pipeline residual stress is installed; 2. reach or during near theoretical elongation, the backfill sandy soil are pushed down pipeline when the pipeline elongation; 3. pipeline is lowered the temperature, and between each preheating section, connect sealing with one-off compensator; 4. when the logical thermal technology of pipeline did, along with the rising of temperature, the pipeline tensile stress reduced gradually, and when reaching preheating temperature, integrated piping stress under this temperature is zero; Continue to heat up, the pressure stress of pipeline produces, and increases gradually along with the rising of temperature, and when temperature was raised to operating temperature, the pressure stress of pipeline was still less than the allowable stress of pipeline.
2, the used air heating device of a kind of heating direct-burying pipeline hot-air pre-heating method according to claim 1 is made up of major and minor two groups of heating equipments, splits the two ends at heat supply pipeline; Two groups of heating equipments show and the control box composition by direct-combustion hot air machine, circulating fan, mixing box, connecting pipe, temperature; Circulating fan in the main heating equipment places the top, and connects in the direct-combustion hot air machine by mixing box; Circulating fan in the secondary heating equipment places the below, and connects in the direct-combustion hot air machine by mixing box; Two circulating fans will be for, water return pipeline series connection.Form open type closed-circuit heating mode; Into and out of air port and four the insulation mouth of pipe places temp probes are installed at major and minor heating plant; Temperature shows and control box is contained in the main heating equipment.
3, heating direct-burying pipeline hot-air pre-heating method according to claim 1, it is characterized in that: above-mentioned preheating section length is 500-1500m.
4, heating direct-burying pipeline hot-air pre-heating method according to claim 1, it is characterized in that: above-mentioned preheating temperature is between the minimum temperature of pipeline operating temperature and restriction.
5, heating direct-burying pipeline hot-air pre-heating method according to claim 1, it is characterized in that: above-mentioned preheating wind speed is 6～20m/s.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03144267 CN1594959A (en) | 2003-09-12 | 2003-09-12 | Heat supply direct-buried pipe hot air preheating method and hot air supply apparatus used thereby |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03144267 CN1594959A (en) | 2003-09-12 | 2003-09-12 | Heat supply direct-buried pipe hot air preheating method and hot air supply apparatus used thereby |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1594959A true CN1594959A (en) | 2005-03-16 |
Family
ID=34659454
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 03144267 Pending CN1594959A (en) | 2003-09-12 | 2003-09-12 | Heat supply direct-buried pipe hot air preheating method and hot air supply apparatus used thereby |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1594959A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101975324B (en) * | 2009-12-30 | 2012-05-09 | 北京豪特耐管道设备有限公司 | Method for electric preheating construction of directly-buried pipeline |
| CN102563280A (en) * | 2012-02-29 | 2012-07-11 | 江苏太阳宝新能源有限公司 | Preheating and solidification prevention method for solar-thermal power generation molten salt energy-storage transmission pipeline |
| CN106439220A (en) * | 2016-10-31 | 2017-02-22 | 中国二十二冶集团有限公司 | Hot air heating prestretching device and method of heat distribution pipeline |
| CN108278423A (en) * | 2018-01-31 | 2018-07-13 | 长安大学 | A kind of cold area's pipeline heat-insulating system and test method |
| CN110440084A (en) * | 2018-05-05 | 2019-11-12 | 吴衍钊 | A kind of pipe support |
| CN114294569A (en) * | 2021-12-21 | 2022-04-08 | 锡林郭勒盟山金阿尔哈达矿业有限公司 | High-pressure warm air preheating device for long-distance pipeline in alpine region |
-
2003
- 2003-09-12 CN CN 03144267 patent/CN1594959A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101975324B (en) * | 2009-12-30 | 2012-05-09 | 北京豪特耐管道设备有限公司 | Method for electric preheating construction of directly-buried pipeline |
| CN102563280A (en) * | 2012-02-29 | 2012-07-11 | 江苏太阳宝新能源有限公司 | Preheating and solidification prevention method for solar-thermal power generation molten salt energy-storage transmission pipeline |
| CN106439220A (en) * | 2016-10-31 | 2017-02-22 | 中国二十二冶集团有限公司 | Hot air heating prestretching device and method of heat distribution pipeline |
| CN106439220B (en) * | 2016-10-31 | 2018-08-14 | 中国二十二冶集团有限公司 | Heat distribution pipeline Hot-blast Heating pre-stretching device and method |
| CN108278423A (en) * | 2018-01-31 | 2018-07-13 | 长安大学 | A kind of cold area's pipeline heat-insulating system and test method |
| CN110440084A (en) * | 2018-05-05 | 2019-11-12 | 吴衍钊 | A kind of pipe support |
| CN114294569A (en) * | 2021-12-21 | 2022-04-08 | 锡林郭勒盟山金阿尔哈达矿业有限公司 | High-pressure warm air preheating device for long-distance pipeline in alpine region |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1594959A (en) | Heat supply direct-buried pipe hot air preheating method and hot air supply apparatus used thereby | |
| CN205368958U (en) | Bituminous mixture heating mix device that regeneration of bituminous paving heat was cared car | |
| CN102947648A (en) | A flue having an adjustable flue gas flow unit having an optional integrated heat exchanger as a heat generator coupled in parallel | |
| CN110569553B (en) | Control method for water cooling age of lining concrete doped with fly ash with low heating value | |
| CN103758011B (en) | Plant-mixed cold recycling foamed bituminous mixture system | |
| CN206690296U (en) | A kind of circulating concrete curing device of hot-water bottle | |
| CN104896456B (en) | The steam generator system of Automated condtrol is carried out based on steam power consumption | |
| CN208733015U (en) | A kind of coke oven coke oven uprising tube raw coke oven gas waste-heat recovery device | |
| CN208218771U (en) | A kind of discarded plastic cement carbonization cracking system | |
| CN204963181U (en) | Heat exchange boiler | |
| CN209445393U (en) | A kind of device quickly heated for pitch | |
| CN208378791U (en) | A kind of worn-out agricultural film plastics pyrolysis oven | |
| CN206903784U (en) | Diesel equipment environmental protection and energy saving work system | |
| CN208059284U (en) | A kind of energy-saving type boiler | |
| CN206958585U (en) | A kind of blast furnace blower Lubricating oil heating device | |
| CN205537148U (en) | Water cooling plant of intermediate frequency electric stove | |
| CN205119455U (en) | Boiler based on internet of things | |
| CN1170858A (en) | Off-line control method for hot-blast stove operation | |
| CN209564943U (en) | Pill tank with conduction oil liquid level adjusting mechanism | |
| CN2874188Y (en) | Directly buried pipeline hot air preheating device for heat supply | |
| WO2022047861A1 (en) | Filling floating ball for cipp reversing-type hot water curing method | |
| CN204176229U (en) | A kind of detachable electrical tracing structure for expansion joint | |
| CN104236307A (en) | Small-sized multifunctional smelting furnace | |
| CN220472335U (en) | Heat exchange structure for recycling flue gas waste heat of coke oven | |
| CN219656616U (en) | Reverse control hot air pipeline |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C41 | Transfer of patent application or patent right or utility model | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20060310 Address after: Tianjin City, south of Hebei District branch No. 5 Applicant after: Tianjin Air Heater Factory Co-applicant after: North China Institute of Design & Research, China Municipal Engineering Address before: Tianjin City, south of Hebei District branch No. 5 Applicant before: Tianjin Air Heater Factory |
|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |