Single Girder Crane for General Use & Special-Use up to 32 Ton

Single girder overhead cran is one economcial solution , compared with that of the double girder crane. And also to meet the vartious needs in different application conditions, there are types of single girder cranes developted. Generally, the single beam cranes are widely used for the geneal use and special purpose. General purpose: This single girder crane is widely used for many occasions such as mechanical processing, assembly, maintenance and warehouses, special-purpose crane is used for working in a particular condition and environment, such as explosion-proof single girder crane, metallurgical single girder crane.

Single Girder Crane for Geneal Use

1. LD-type electric single girder crane

LD electric single girder crane has such features as reasonable structure and fine rigidity. The whole crane is used with CD1, MD1 or other types electric hoist, it’s a light and small lifting machine. Its capacity is 1t～20t. Span is generally not morn than 31.5m, work duty is A3～A4, working environment temperature is -20℃～+40℃.

This crane is widely used to hoist goods at factories, warehouses, stock ground and other occasions, and prohibit from working in flammable, explosive and corrosive media environment. The crane has two modes : ground controlling and cab controlling. The cab has open type and closed type, is installed on the left or on the right according to the actual situation, the entry mode has side entry and end entry, to meet the user’s various needs. The basic pattern is shown in Figure1, Figure2 and Figure3.

1. end carriage 2. main girder 3. electrical device 4.electric hoist 5crane traveling

Figure1 LD type electric single girder crane (ground controlling)

1. crane traveling 2. closed-type cab 3. main girder , 4. electrical device 5. end carriage

Figure2 LD-type electric single girder crane (cab controlling)

1. crane traveling 2. main girder 3. electric hoist , 4. electrical device 5. end carriage

Figure 3 LDE -type electric single girder crane with double hoists.

2.LDP-type electric single girder crane

LDP-type electric single girder crane is a ultra-low-clearance, light and small crane. Electric hoist is located on the side of main girder, which increase the service space of the hook and can reduce the height of the plant to save the cost. This crane has such features as big wheelbase of trolley, smooth running, compact structure, good rigidity, sensitive operation, low noise, safe and reliable and attractive appearance.

Generally, the capacity of LDP-type electric single girder crane is not more than 10t, span is not more than 31.5m, working environment temperature is -20℃～+40℃, work duty is A3～A4, lifting height is not more than 12m, the basic pattern is shown in Figure 4.

1.end carriage 2.main girder 3. electrical device 4. angular trolley, 5. crane traveling

4 LDP-type electric single girder crane with low headroom design

3. LDZ-type crane with grab

LDZ-type electric single girder crane with grad is a handling equipment at workshop which is used together with grab hoist. The capacity is not more than 10t, span is not more than 31.5m, working ambient temperature is -20℃～+40℃.

This crane is widely used to grab the bulk materials on different occasions such as power plant, warehouse and stockyard, the basic pattern is shown in Figure 5.

1. end carriage 2.main girder 3.grab hoist 4.electrical device 5.crane traveling

Figure5 LDZ-type electric single girder crane with grab

4. LD-type electromagnetic single girder crane

LD-type electromagnetic single girder crane (electromagnetic) is a crane that ordinary single girder crane is used with electromagnetic chuck, work duty is A3～A4, working ambient temperature is -20℃～+40℃.

This crane is widely used to handle ferrous waste, bloom, structural steel, square billet, steel slab, wire rod in bundle, steel tape and other materials. The basic pattern is shown in Figure 6.

1. end carriage 2.main girder 3. electrical device 4.electric hoist(with electromagnetic chuck) 5. crane traveling

Figure6 LD-type single girder crane (electromagnetic)

5. LD-type low-clearance single girder crane

LD-type low-clearance single girder crane is a low-clearance, light and small crane, and is used with CD(GD), MD(GDS) low-clearance wire rope electric hoist, main girder is a box-type structure. This crane has attractive appearance, compact structure and reasonable, and is easy to operate.

The rated capacity of LD-type low-clearance single girder crane is rarely more than 16t, span is rarely more than 31.5m, work duty is A4, lifting height is not more than 12m, working ambient temperature is -20℃～+40℃. The basic pattern is shown in Figure 7.

1. end carriage 2.main girder 3. low clearance electric hoist , 4. electrical device 5. crane traveling

Figure7 LD-type low clearance single girder crane

6. HD-type electric single girder crane

HD-type electric single girder crane is a low clearance, light and small crane, and is used with European ND-type wire rope electric hoist. This crane has attractive appearance, compact structure and reasonable, easy to operate, safe and efficient operation, and confirms to the requirements of low noise, energy saving and environmental protection.

The rated capacity of HD-type electric single girder crane is not more than 10t, span is 7.5m～25.5m,work duty is A5, lifting height is not more than 12m, working ambient temperature is -20℃～+40℃. The basic pattern is shown in Figure 7.

1. end carriage 2. main girder 3.ND ND-type electric hoist , 4.electrical device 5. crane traveling device

Figure8 HD-type electric single girder crane with European style wire rope hoist

7. LX-type electric Under slung crane

LX-type electric Under slung crane is used with CD1, MD1 electric hoist and is a track traveling, light and small crane. Its bridge is composed of main girder, end carriage and traveling mechanism, main girder adopt I-steel with rolling U-type groove, end carriage is composed of channel steel, simple structure and easy to manufacture, main girder and end carriage are connected by hinge pin, which can ensure that wheels will uniform contact with track, and is easy to disassemble, transport and store. Single girder suspension crane applies to only ground operation, crane traveling speed is rarely more than 30m/min.

The capacity of LX-type electric suspension crane is rarely more than 20t, span is not more than 22.5m, the length of jib is not more than 1000mm, work duty is A3～A4, working ambient temperature is -20℃～+40℃, the basic pattern is shown in Figure 9 and Figure 10.

End carriages 2.electrical device 3.electric hoist 4.crane traveling

Figure9 LX-type multi-fulcrums single girder Under slung crane

1. end carriage 2. electrical device 3.crane traveling , 4. main girder 5.electric hoist (low clearance)

Figure10 LX-type multi-fulcrums electric Under slung crane

8. XG-type Under slung rail crane

XG-type Under slung rail crane is a professional lifting equipment used in power plant coal mill system for generating units, the main purpose is to maintain the coal mill, its bridge is composed of a set of main crane and several sets of auxiliary crane , main crane and auxiliary crane are respectively composed of main girder and end carriage.

XG-type Under slung rail crane, the capacity and span should be done according to customer’s specific requirements, work duty is A3～A4, working ambient temperature is -20℃～+40℃. The basic pattern is shown in Figure 11.

1. electrical device 2. electric hoist 3. main crane 4. rail device 5. auxiliary crane 6. crane traveling

Figure 11 XG-type electric Under slung rail crane

Special-purpose crane

According to the use of crane in different occasions, electric single girder crane is divided into explosion-proof electric single girder crane, metallurgical electric single girder crane and insulated electric single girder crane, which are collectively called special-purpose electric single girder crane.

1、LB-type explosion-proof electric single girder crane

LB-type explosion-proof electric single girder crane is a space transportation equipment adopted HB-type explosion-proof electric hoist as the lifting mechanism. Main role is to timely and quickly complete the displacement of objects through the hook or other handling device in the intermittent and cycle working way, and is the important tool and equipment for realizing production mechanization and automatization, relieving the heavy labor and improving labor productivity in the modernized industrial enterprise.

LB-type explosion-proof electric single girder crane is designed and manufactured to have the explosion-proof motor and explosion-proof electrics on the basis of ordinary electric single girder crane, then is provided with other auxiliary mechanical explosion-proof measures to ensure that electric spark, heat or combustible dust caused by the crane and working environment will not cause a fire, explosions or other hazards.

According to the provisions of GB3836.1 “Explosive Atmosphere Part 1: General Requirement for Equipments ” and GB3836.2 “Explosive Atmosphere Part 2: the Equipments Protected by Flameproof Enclosure “d”” , the motors and electrics of this crane is flameproof type. When explosion-proof degree is Exd II CT4, the running mechanism will be taken the spark-proof measures, the whole crane is in accordance with the provisions of JB/T 10219 “Specification for explosion-proof cranes with electric wire rope hoist”.

（1）Classifications

According to the provisions of Chapter 4 in GB3836.1, the crane is divided into class I and class II electrical equipments according to explosive gas atmosphere, In accordance with the provisions of GB 12476.1, the electrical equipments used in the combustible dust environment is only divided into a class, the corresponding crane classification is as follows.

Class I: Crane for coal mine

Class II: Crane used in other explosive gas environment except coal mine

Dust class: Crane used in the combustible dust atmosphere

Class II flameproof “d” explosion-proof crane and intrinsically-safe “i” explosion-proof crane can be divided into class IIA, class IIB and class IIC crane according to the characteristics of explosive gas. It should be indicated in the contract when there is acetylene in the IIC environment. The conditions of use for the class IIB explosion-proof hoist crane is applicable to class II A, the conditions of use for the class IIC explosion-proof hoist crane is applicable to class II A and class IIB.

Dust type crane is divided into A-type and B-type according to dust-proof capacity of electrical equipments, B type of them increases the requirements of heat cycle test on the basis of A-type, they are indicated by DIPA and DIPB. Dust-proof type of the enclosure of electrical equipments applied to explosion-proof electric single girder crane is recommended to choose A type.

（2）Temperature group

The surface temperature of electrical equipments or components of class I crane should not be more than:

—150℃, when the surface of electrical equipments or components may deposit the coal dust.

—450℃, when the surface of electrical equipment or components can not deposit the coal dust or have been taken measures to prevent the coal dust deposit (such as sealed against dust or ventilation).

The maximum surface temperature group of electrical equipment of class II and dust type explosion-proof crane are shown in Table 1.

Table 1 the maximum surface temperature group

（3）Division of explosion-proof hazardous area for explosive gas

0 zone: under normal circumstances, the location that explosive gas mixture appear continuously in a very short time or exist for a long time.

1 zone: under normal circumstances, the location that explosive gas mixture maybe appear.

2 zone: under normal circumstances, the location that explosive gas mixture can not appear, but under abnormal circumstances, it maybe appear in a short time when equipment is out of order or is operated by mistake.

At present, explosion-proof electric single girder crane applies only to 1 zone or 2 zone, and does not apply to 0 zone.

（4）Division of explosion-proof hazardous area for dust

20 zone: during normal operation, the location that combustible dust appear continuously or often appear, its quantity is enough to form the mixture of combustible dust and air and/or maybe form the uncontrollable and thick dust layer.

21 zone: During normal operation, the location that the quantity of dust is enough to form the mixture of combustible dust and air, but it is not divided into 20 zone. This zone includes the location that is directly adjacent to the places filled with or discharged dust , the location that appear the dust layer and maybe form the combustible mixture of combustible dust and air under normal operation.

22 zone: Under abnormal conditions, the location that combustible dust could occasionally appear and exist in a short time, or combustible dust may occasionally deposit or may exist in the dust layer and generate the mixture of combustible dust and air. It should be divided into 21 zone if not guarantee that combustible dust deposit or dust layer are avoided.

（5）Applicable environmental conditions for explosion-proof electric single girder crane

• Explosion-proof electric single girder crane is operated indoors, working ambient temperature is -20℃～+40℃, relative air humidity is not more than 85%(when ambient temperature is 25℃), altitude should not exceed 1000m. It should be determined after consultation with the user if there is any exceed above environment conditions .
• The working area of explosion-proof electric single girder crane is 1 zone or 2 zone divided in GB 3836.14 when operated in explosive gas atmosphere.
• The working area of explosion-proof electric single girder crane is 21 zone or 22 zone provisioned in GB 12476.3 when operated in combustible dust environment.
• The working environment should have good ventilation and the necessary facilities.

（6）Examples of motors and electrical equipments of explosion-proof hoist crane used in explosive gas atmosphere

Applicable explosive gas for each explosion-proof degree and corresponding temperature group of flameproof motor and electrical equipments are shown in table 2.

Table2 Explosive Gas

Applicable combustible dust for each dust-proof structure and corresponding temperature group of dust explosion-proof motor and electrical equipments are shown in table 3.

Table 3 Dust Name

Explosion-proof electric single girder crane is equipped with explosion-proof motor, explosion-proof switch box, explosion-proof flashlight doors, explosion-proof limit switch, explosion-proof over-load limiter, explosion-proof hoist limit device, explosion-proof junction boxes, gate switch and so on. Power wire adopt the flexible cable, the connection between electrical equipments use the rubber sheath multiple copper cores cable with ground core wire, wiring cable use the rubber sheath multiple copper cores cable, too. There should be not allowed to have the joints in the middle of cable. If necessary, explosion-proof junction boxes is provided. There is warning board “Do not open if there is electricity” on the obvious place of the enclosure of explosion-proof electrical equipment.

The work duty of the crane is A3. The operation mode of explosion-proof electric single girder crane for factory is usually ground controlling, traveling speed is 20m/min and should not be more than 25m/min. But the remote operation and cab operation are also selected according to specific conditions, the basic patterns are shown in Figure 12 and Figure 13. At present, the operation mode of this crane for mine can only be ground controlling, traveling speed is 20m/min, the basic patterns are shown in Figure14 and Figure15.

When explosion-proof degree is EXdIICT4, the wheel tread and flange parts should adopt copper alloy or other materials that cannot ignite the explosive gas because of the impact and friction. The pull wire of cable pulley should adopt the stainless steel wire rope. The hook should be taken measures to prevent dangerous sparts caused by the impact and friction. The traveling speed of crane and trolley is not more than 16m/min.

1. end carriage 2. main girder 3.electric hoist 4. electrical device 5. crane traveling

Figure 12 LB-type explosion-proof electric single girder crane

1. end carriage 2. electrical device 3. electric hoist 4. crane traveling

Figure13 LXB-type electric single girder Under slung crane

1. end carriage 2. main girder 3.electric hoist 4. electrical device 5. crane traveling

Figure 14 explosion-proof electric single girder crane for mine

1. end carriage 2. main girder 3.electrical device 4. electric hoist 5. crane traveling

Figure15 explosion-proof electric Under slung crane for mine

2、 Metallurgical electric single girder crane

Metallurgical electric single girder crane is designed according to GB 3811”Design Rules for Cranes” and JB/T 7688.1”Technical Conditions of Metallurgical Crane”, the design and manufacture of crane meet the [2007] No.375 document from the quality inspection office issued by the AQSIQ, it is a lifting equipment for workshop that uses YHII-type metallurgical electric hoist as the lifting mechanism, main purpose is to achieve timely and quickly the displacement of the lifting goods required in metallurgical production through hook or other lifting devices in the intermittent and cycle work way, it is very important tool and equipment that improve the labor productivity used in metallurgy and casting places in the modernized industrial enterprise.

Work duty of metallurgical electric single girder crane is A6, working ambient temperature is －20℃～+60℃, it is used under no flammable, explosive and corrosive medium environment conditions, the maximum capacity is 10t, span is usually 31.5m, the basic pattern is shown in Figure 16.

1. end carriage 2. main girder 3.metallurgical hoist 4.electrical device 5. crane traveling

Figure16 LDY-type metallurgical electric single-girder crane

The operation mode of crane has ground controlling, remote controlling and cab controlling which are selected according to specific conditions(Note: The crane is recommended to adopt the remote controlling in order to protect the safety of personnel.), cab operation uses closed-type cab, and should be in accordance with the requirements of GB/T 20303.5. Traveling speed for ground operation is 20m/min and 30m/min, traveling speed for cab operation is usually 30m/min and 45m/min, traveling speed for remote operation should be determined according to actual requirements.

The H class insulation motor should be used when ambient temperature is over 40℃. The bottom of main girder takes the special heat-insulating measures, the crane has thermal-protective coating and is coated with heat-resistant paint.

The lifting mechanism for metallurgical electric single girder crane is YHII-type metallurgical electric hoist, its work duty is M6, the main purpose is to hoist the molten metal in metallurgical environment. The main features are as follows.

The insulation class of traveling motor and lifting motor of electric hoist is H class, protection class is IP54.

The electric hoist uses the double brake structure: motor braking and mechanical braking (ratchet and pawl brake), the drum is braked directly by mechanical braking which the safety factor is greater than the ordinary electromagnetic braking.

The wire rope use steel-cored wire rope to increase the breaking force and safety factor.

3、 Insulation electric single girder crane

Insulation electric single girder crane is a electric single girder crane that can be operated safely and reliably in high voltage power supply environment through increasing the insulation measures and is a lifting equipment for workshop that uses the insulation electric hoist as a lifting mechanism. The main purpose is to achieve timely and quickly the displacement of the lifting goods in the process of production through hook or other lifting devices in the intermittent and cycle work way.

Insulation electric single girder crane must be able to work safely and reliably in smelting shop environment of non-ferrous metal electrolytic aluminum, copper, magnesium, lead and zinc. The altitude of the installation site does not exceed 2000m(The motor capacity should be checked if altitude exceeds 1000m.), the radiation heat temperature of the spreaders for lifting goods should not be more than 300℃. The range of ambient temperature is from -5℃ to +50℃, and the relative humidity should not be more than 50% when the ambient temperature is +50℃.

Insulation electric single girder crane should be provided with three-grade insulation, the first grade insulation is located between hook and pulley, the second grade insulation is located between track for trolley and main girder, the third grade insulation is located between track for crane and bearing-rail beam. Under normal temperature state (temperature is 20℃~25℃, relative humidity is not more than 85%), resistance value of each grade insulation measured by 1000V megger should not be less than 1MΩ. The insulation measures are shown in Figure 17, Figure18 and Figure19.

There should be taken steps to lower the temperature in the cab for insulation electric single girder crane with the cab operation, the cab should be equipped with the removable glass or organic glass in order to prevent the corrosive gas from damaging to glass and the affecting the driver’s line of sight.

The structure of insulation electric single girder crane is the same to the structure of ordinary electric single girder crane.

 

Figure17 Insulation Hook Figure18 connection between main girder and end carriage Figure19 Trolley with hoist