DEVICE FOR COKE OVEN CHAMBER PUSHING LOW IN HEAT EXCHANGE

Abstract

A device for pushing the contents of a coke oven chamber includes a pusher ram head with pusher rams mounted there behind, wherein guiding plates or aprons are mounted to a pusher ram head which avoid a simultaneous pressing-in of air into the coke oven chamber, thus preventing a non-desired cooling-off of the coke oven chamber during pushing. The aprons also prevent the pusher ram and the rearward side of the pusher ram head from excessive heat burdens. The aprons can also serve for protecting measuring devices mounted in the enclosure. The aprons can be fabricated from a heat-resistant metallic or ceramic material. The aprons or the pusher ram head can also be provided with a heat-resistant or heat-reflecting coating or with heat-resistant or heat-reflecting tiles. Also shown is a method for pushing of coke oven chambers by applying the inventive device.

Description

The present invention relates to a device for pushing a coke cake through a coke oven chamber comprised of an opening on both sides. Pushing a coke cake from a coke oven chamber is carried out at the end of a coking process of a carbonization cycle. Depending on oven type and process technology configuration of a coke plant with varying charge bed height, charging coal blend and temperature in a coke oven, the coking process may take 16 to 192 hrs. Coke pushing is carried out from the opening of one coke oven side to the other coke oven side. As a rule, a coke car is positioned there to capture the coke cake and to carry it to a coke quenching tower. Coke pushing is usually performed with a so-called pusher ram which to this effect is carried on a car, transported to the battery to be pushed and moved by hydraulic facilities. Upon coke pushing, the oven is again charged with coal.

Preferably the coke oven chamber is a “Non-Recovery” or “Heat-Recovery” type coke oven which utilizes the coal by-products and coking gases derived from the carbonization process for combustion and for recovery of the heat needed for coal carbonization. But the coke oven chamber may also be a conventional so-called horizontal chamber type oven which captures and further processes coal by-products from the carbonization process. Coking processes are run at temperatures ranging from 800 to 1500° C. A substantial part of the heat is stored in the walls and oven top comprised of silica or fireclay bricks or any arbitrary refractory brickwork. Since combustion of coal by-products in most cases is just sufficient to generate the required coking energy, it is desired to keep the loss of heat during coke pushing as small as possible.

In coke pushing according to prior art in technology, the pusher ram head which a pusher ram is fastened to a slide by a suitable thrust device through the coke oven. At its rearward end, the pusher ram is equipped with a device that can exert a force of pressure on the pusher ram. On its front side, the pusher ram head, in turn, is equipped with a plate that affords protection from the enormous heat evolving from the coke cake. During coke pushing, the pusher ram and the pusher ram head are exposed to a substantial heat burden. As a result, component parts may get deformed or evidence a fracture in material already after a short service life. For this reason, there is a great deal of inventions which describe measures to counteract a substantial heating-up of the coke pushing device.

DE 4224491 A1 describes a device for pushing a coke oven which is comprised of a pusher ram head and a liquid-cooled pusher ram. The pusher ram itself is surrounded by a radiation screen which surrounds the pusher ram at a certain distance towards the outside and which is provided with cooling coils on its inside. A cooling medium preferably being water or liquid containing water flows trough the cooling coils. Supply and return of the cooling medium is realized through connected hoses. A back-cooling is realized through heat exchangers which are linked to the hose connections. The pusher ram can be formed by T-beams which for example are welded side by side. This device has a drawback in that passing a cooling medium through it is costly and susceptible to failures. For example, leakages in the cooling system may lead to unnoticed damage to the pushing device or coke oven chamber.

DE 840538 C describes a device comprised of a pusher ram for pushing of coke oven chambers which is of a box-type configuration and which is of a multiple component structure in its interior. The pusher ram is preferably configured in form of a T-beam. Air serving as cooling medium streams through the individual parts of the pusher ram, with the air being guided through the pusher ram in such a manner that the walls of the pusher ram are always flushed through in the same direction of flow. Thereby a distortion of the pusher ram is impossible. On the pusher ram proper, at the front end side, a pusher ram head is mounted which is not specified in greater detail in the relevant patent description. Though the device cools the pusher ram, it does not protect the material of the pusher ram from intensive heat radiation. Moreover, the configuration of the pusher ram admits substantial quantities of cold air from the environment into the coke oven chamber, depending on the shape of the pusher ram head.

DE 459600 C describes a device comprised of a pusher ram for pushing of coke oven cambers, wherein the pusher ram head is comprised of guide plates which are welded to the upper end of the pusher ram head towards the rearward side and which press the pusher ram head at the upper side against the coke oven top. Thereby, the coke oven pushing device can be so guided that it just leans to the upper coke oven wall. This upper wall is usually thicker than the coke oven sole which is relatively thin to allow for good heat transfer from the heating flues. In this manner, damage to the sensitive coke oven chamber floor is avoided. The improved heat retention in the coke oven chamber wall and protecting the pusher ram from heat do not play any role in this teaching. Moreover, the guide plate mounted on the upper side of the pusher ram head just covers a small part of the pusher ram. As a result, cold air from the environment can stream from all sides into the coke oven chamber.

Frequently, the pusher ram is fastened in the middle of the pusher ram head, thus leaving substantial space behind the pusher ram head through which cold air from the coke oven environment is pressed into the coke oven chamber at the same time as the oven is pushed. Moreover, through the free space pressed behind the pusher ram head next to the pusher ram into the oven, substantial part of the heat stored in the inner coke oven wall radiates towards the exterior. It constitutes a substantial loss of heat which must be offset again by the next coal carbonization process. As a result, coal burn-off is higher and coke produced is of an inferior quality. Owing to the increased heat radiation, the pusher ram is furthermore exposed to a severe temperature burden that may lead to its deformation and which may cause it to become brittle after a short service life. It represents a source of hazard because the pusher ram must take-up substantial mechanical forces and loads.

Therefore, a device is being searched for which on the one hand provides protection to the pusher ram head and to the pusher ram from high temperatures prevailing in a coal carbonization process. On the other hand, the desired device should also prevent cold air from entering into the interior of a coke oven chamber that might cool off the interior of the coke oven chamber during coke pushing which will entail increased coal consumption and inferior coke quality.

This task is solved by a guiding plate mounted on the pusher ram head and provided by the present invention. A guiding plate or an apron wrapping the pusher ram almost on its entire length is mounted on the pusher ram head. Thereby, a wrapping or enclosure is provided around the entire pushing device. The space created between the pusher ram and its enclosure can remain free. But it can also be filled-up to provide better insulation. Glass wool or ceramic fibres are suitable for this purpose. Owing to the enclosure, the pushing device assumes the shape of a quad if the pusher ram head is rectangular and wrapped on all sides by the inventive enclosure. In the interior, the pusher ram will then form a massive cylinder. The wrapping device is preferably made of a temperature-resistant material.

Owing to the guiding plates, the pusher ram is protected from high temperatures of the coke oven chamber and more particularly from the coke oven walls which are exposed after coke pushing. Since the thermal capacity and the heat-up rate of the enclosure is small, a cooling-off of the coke oven chamber and more particularly of the coke oven walls is largely prevented. Cold air from the environment cannot reach to the coke oven walls which cannot cool-off thereby either. If the interior of the enclosure contains an insulating filling, the coke oven walls stay nearly at the same temperatures, unless coke pushing takes excessive time.

Claimed in particular is a device for pushing the charge of a coke oven chamber, wherein

• • the device is shaped as a pusher ram in form of a ram bar comprised of an oven-side mounted pusher ram head in form of a plate,
    and which is characterized in that
  • the pusher ram head is surrounded by mounted-on rearwardly directed guiding plates or aprons thus forming the enclosure which has the same outer side lengths as a the pusher ram head and the outer shape of a quad with a uniform cross-section, if the pusher ram head is rectangular or quadratic, with the pusher ram positioned in the interior forming a massive cylinder if it is round in cross-section.

The pusher ram head preferably has the same cross-section as the opening of the coke oven chamber. The outer walls of the enclosure will then exactly lean to the coke oven chamber walls so that they are completely shielded from relatively cold temperatures of the coke oven environment when pushing-out the contents of the coke oven chamber. Thereby, the process of coke oven pushing can also be executed under adverse weather conditions. The aprons also protect the rearward side of the pusher ram head and the pusher ram from high temperatures during coke pushing.

For application on coke cake pushing, the pusher ram head can be rectangular or quadratic in shape. However, it is also feasible to configure it in a circular shape. This is particularly advantageous with a special shape of the coke oven. In principle, it is possible to configure the pusher ram head in any arbitrary shape if this is called for by an optimal process of coke pushing.

The pusher ram, too, may have any arbitrary shape and any arbitrary cross-section. In a simple configuration, the pusher ram is configured as a massive cylinder and has a round cross-section. As the pusher ram is advantageously mounted in the middle of the pusher ram head, it forms a massive cylinder in the quad or cylinder created by the enclosure, depending on the shape of the pusher ram head. However, for fabrication of the inventive device, the pusher ram may also have any arbitrary shape. For example, it may be configured as a quad. But it may also be fabricated of simple T-beams mounted on the head side. It is also feasible to weld T-beams together and to utilize these as pusher rams with improved stability. Finally, the pusher rams may be arbitrarily shaped, depending on the requirements of the coke pushing procedure.

Preference is given to a shape which the pusher ram head forms with the mounted-on wrapping or enclosure, being of a uniform cross-section in length. Thereby, the coke oven chamber walls are completely covered by the enclosure and do not get in contact with colder ambient air. Depending on requirements exacted from the pushing procedure, it may taper or thicken in length and vary in cross-section. For example, this may be useful with sensitive secondary air sole floors or chambers. The shape may also be irregularly formed if required by the coke oven chamber shape or for an optimal thermal protection. The entire device for pushing including the enclosure is advantageously so shaped that the process of pushing-out the contents of the coke oven chamber proceeds in manner that is as low in heat exchange as possible.

For fabrication of the inventive enclosure, the guiding plates can be mounted on all sides of the pusher ram head. Thereby, all ovens are protected from cooling-off or cooling-down due to a simultaneous penetration of cold ambient air when coke oven chambers are pushed. However, it is also possible to provide less than four sides of the pusher ram head with the rear-side apron, for example if the pusher ram head is rectangular in shape. For example, the lower side of the mould may remain free to protect the floor of the coke oven chamber which is usually thinner and thus less robust. It is also feasible to protect only one side of the pusher ram head with the inventive enclosure. The aprons may differ in length if this is called for to provide an optimal process for coke pushing.

The aprons or guiding plates utilized to set-up the inventive enclosure can be fabricated of a heat-resistant metallic material. But they can also be fabricated of a ceramic material. It is also feasible to fabricate the aprons of a metallic material and to provide them with a ceramic coating. Said coating may advantageously be so configured that it reflects or mirrors the heat from the environment. Likewise, it is possible to provide a coating comprised of a heat-reflecting layer, mentioning here a so-called “high-emission coating”, for example. For example, it can be integrated by way of a high-sintering temperature process into the outer layers of the material. Suitable heat-reflecting materials particularly are inorganic metal oxides in a blend with carbides, with chromium or iron oxides in a blend with silicon carbides being mentioned as an example. An exemplary description for a high-emission coating is given in EP 742276 A1. A design and structure of an apron fabricated from a heat-resistant material and comprised of a heat-resistant and insulating layer for improved insulation is considered optimal. The heat-resistant apron can be applied as a coating, but also in form of foils or tiles.

The pusher ram and the pusher ram head are made of a material which is resistant to high temperatures prevailing in the coke oven chamber. Preference is given to a pusher ram or a pusher ram head made of a material highly resistant to heat in order to withstand high temperatures prevailing in the interior of coke oven chambers. The pusher ram head, in particular, can also be provided with a heat-resistant coating for a better protection from high temperatures. For example, this may be a coating made of ceramic material, fireclay bricks, silica or a hydraulic guniting concrete. The pusher ram, too, can be provided with such an enclosure, if required to protect this structural part. As a rule, however, this is not required because low temperatures will prevail there owing to the aprons laid around the pusher ram.

The enclosure formed by mounting the aprons around the pusher ram head may also be comprised of additional devices which serve for controlling the pushing procedure. For example, these may be temperature measuring facilities or inspection sight glasses. However, the enclosure may also be comprised of devices which serve for improving the cokemaking process. Examples for such devices are insulating materials such as glass wool or ceramic fibres.

The device is also comprised of component parts which serve for fastening to a coke pusher machine or a driving device. These component parts are preferably fastened at the end of the pusher ram. But they can also be fastened to the end of the aprons or of the enclosure. It depends on the type of coke pusher machine or drive. To operate the inventive device, both mobile coke pusher machines and stationary coke pusher machines may be applied.

Finally claimed is a method that utilizes the inventive device for coke pushing. Usually the method is so configured that the coke pushing procedure is carried out after the procedure of door opening. As a rule this is done upon the end of a coal carbonization process which in a “Non-Recovery” or “Heat-Recovery” coke oven typically takes 16 to 192 hrs. The procedure of coke pushing is then followed by a renewed charging. As a matter of fact, the inventive device can also be utilized to execute a cleaning if apparatus facilities let it appear advantageous. Upon charging, the doors of the coke oven chamber are closed and a renewed coal carbonization cycle follows next. The inventive method is suitable for all types of coke ovens.

Moreover, the inventive device can serve for protection of measuring instruments that may be mounted on the pusher ram to monitor the oven status as well as the carbonization process and which can be protected by the described enclosure from radiation impacts originating from the oven interior.

The inventive device is elucidated by way of four drawings, with these drawings just representing examples of embodiments for the design of the inventive device.

FIG. 1 shows an opened coke oven chamber in a side view in which the coke cake is pushed by the inventive device.

FIG. 2 shows an inventive device for pushing in a vertical view from above.

FIG. 3 shows an inventive device with a pusher ram composed of two welded T-beams in a vertical view from above.

FIG. 4 shows a coke oven chamber during the procedure of coke pushing with an inventive device in a front view.

FIG. 1 shows an open coke oven chamber (1) in which the coke cake (2) is exposed upon opening of the coke oven chamber doors (3). The coke cake (2) is pushed with the pusher ram head (4) of the coke pushing device from the coke oven chamber. For this purpose, the pusher ram head (4) together with the pusher ram (5) is pushed through the coke oven. Rearwardly directed aprons (6a) are fastened to the pusher ram head (4). If the pusher ram head is rectangular, only the upper and lower apron can be seen in this view. The lateral aprons (6b) were omitted for better elucidation. Since cold air would be pressed into the coke oven chamber unless aprons are mounted behind the pusher ram head, these aprons prevent a cooling-off of the coke oven chamber. The pusher ram head is advantageously so shaped that it fits exactly between the door-encompassing coke oven chamber wall (7) and coke oven sole (8). Thereby an admission of further air from outside is prevented. Usually located under the coke oven sole are the secondary air soles (9) and the secondary air inlet devices (10) so that the floor can be a bit thinner. Also shown here are the primary air inlet devices (11) in the ceiling with control devices (11a) and rope tackles (12) to actuate the door with fastenings (12a).

FIG. 2 shows an inventive pushing device comprised of a pusher ram head (4) and a pusher ram (5). Fastened to it are the aprons (6b) which form an enclosure. If the pusher ram head is rectangular, only the lateral aprons can be seen in this view. A fastening for the coke pusher machine (13) still follows next to the pusher ram.

FIG. 3 shows an inventive pushing device with a pusher ram head and a pusher ram. The pusher ram head (4) and the pusher ram (5) are formed of two T-beams welded together. To be seen here are the lateral aprons. Applied on the pusher ram head is a layer (14) composed of a material which is highly resistant to heat.

FIG. 4 shows a coke oven chamber (1) in a front view, whose coke cake (2) is pushed-out with an inventive device. The coke oven chamber is opened through the pulled-up coke oven chamber doors (3) so that the coke cake (2) is exposed. The coke oven chamber wall (7) encompassing the door is concealed here by the pulled-up coke oven chamber door (3) and therefore it cannot be seen. The pusher ram head (4) advantageously has a cross-section which exactly fits into the opening so that the coke cake (2) lies behind the pusher ram head (4). The pusher ram head (4) is pushed out from the coke oven chamber by the aid of pusher rams (5). The pusher ram head (4) is equipped with aprons which are mounted in rearward direction (protruding from the plane of paper). Here the pusher ram head is rectangular so that both horizontal ((6a) and vertical (6b) aprons are fastened. The aprons prevent cold air from entering into the coke oven chamber behind the pusher ram head (4). To be seen here, too, are the secondary air soles (9), the openings for secondary air (10), the openings for primary air (11) in the oven top with control facilities (11a) and rope tackles (12) to pull-up the coke oven chambers doors including the fastening (12a).

LIST OF REFERENCE SYMBOLS

• 1 Coke oven chamber
• 2 Coke cake
• 3 Coke oven chamber door
• 4 Pusher ram head
• 4a Weld seam
• 5 Pusher ram
• 6a Horizontally mounted apron or enclosure
• 6b Vertically mounted apron or enclosure
• 7 Oven wall encompassing the door
• 8 Coke oven chamber sole
• 9 Secondary air sole
• 10 Access openings for secondary air
• 11 Access openings for primary air in the ceiling
• 11a Control facility for primary air
• 12 Chain or rope tackle to open coke oven chamber doors
• 12a Fastening of the door to the rope tackle
• 13 Fastening of the coke pusher machine to the pusher ram
• 14 Heat-resistant layer

Claims

1-23. (canceled)

24. A device for pushing the charge of a coke oven chamber, wherein

the device is shaped as a pusher ram in the form of a ram bar comprising an oven-side mounted pusher ram head in form of a plate, wherein

the pusher ram head is surrounded by mounted-on rearwardly directed guiding plates or aprons thus forming the enclosure which has the same outer side lengths as the pusher ram head and the outer shape of a quad with a uniform cross-section, if the pusher ram head is rectangular or quadratic, with the pusher ram positioned in the interior forming a massive cylinder if it is round in cross-section.

25. The device as defined in claim 24, wherein the pusher ram head has a round shape so that the device for pushing has the outer shape of a cylinder with a uniform cross-section.

26. The device as defined in claim 24, wherein the pusher ram head has any arbitrary shape so that the device for pushing has the extended outer shape of the cross-section of the pusher ram head.

27. The device as defined in claim 24, wherein the cross-section of the enclosure varies in the rearwardly directed course so that the enclosure has any arbitrary shape.

28. The device as defined in claim 24, wherein the aprons are shorter in length than the pusher ram.

29. The device as defined in claim 24, wherein the aprons on the sides of the pusher ram head differ in length.

30. The device as defined in claim 24, wherein the pusher ram has a round cross-section of any arbitrary shape and is cross-section-wise positioned in the center of the pushing device.

31. The device as defined in claim 24, wherein the pusher ram has any arbitrary cross-section of any arbitrary shape and is cross-section-wise positioned at any arbitrary position of the pushing device.

32. The device as defined in claim 24, wherein the device for pushing the contents of a coke oven chamber has exactly the cross-section of the opening of the coke oven chamber to be pushed or charged, respectively.

33. The device as defined in claim 24, wherein the aprons are mounted on all sides of the pusher ram head.

34. The device as defined in claim 24, wherein the aprons are mounted on less than all sides of the pusher ram head.

35. The device as defined in claim 24, wherein the pusher ram for pushing-out the coke cake is a T-beam.

36. The device as defined in claim 24, wherein the pusher ram for pushing-out the coke cake is a pusher ram comprising several T-beams welded together.

37. The device as defined in claim 24, wherein the enclosure is wholly or partly made of a heat-resistant metallic material.

38. The device as defined in claim 24, wherein the enclosure is wholly or partly made of a heat-resistant ceramic material.

39. The device as defined in claim 24, wherein the pusher ram at the pusher ram head or on the enclosure or at the pusher ram head and on the enclosure is provided with a coating made of a heat-protecting material.

40. The device as defined in claim 39, wherein the coating made of a heat-protecting material is applied in form of foils or tiles.

41. The device as defined in claim 39, wherein the coating is applied as a high-heat reflecting layer in form of a “high-emission” coating.

42. The device as defined in claim 41, wherein this coating comprises inorganic metal oxides blended with carbides.

43. The device as defined in claim 24, comprising facilities positioned in the interior of the shape formed by the enclosure to measure the temperature.

44. The device as defined in claim 24, comprising insulating materials positioned in the interior of the shape formed by the enclosure.

45. The device according to claim 44, wherein the insulating materials are glass wool or ceramic fibres.

46. A method for carbonization of coal comprising:

providing a pushing device as claimed in claim 24; and

applying the device to push the coke in a coke oven chamber.