Installation plan and acceptance standard of double girder bridge crane
Double girder bridge crane is a bridge crane with double girder, which is mainly composed of bridge, crane operation mechanism, trolley, electrical equipment, etc. The small edition introduces the installation scheme and acceptance standard of the next double girder bridge crane for your reference.
Installation scheme of double girder bridge crane
1.1 crane installation
1.1.1 bridge assembly
1.1.1.1 the crane bridge is delivered in two pieces. During assembly, two bridges are lifted to the installed track by 50 ton crane respectively, and then assembled. Besides, the bottom of four wheels of the crane traveling shall be on the same horizontal plane.
1.1.1.2 the bridge assembly takes the end beam bolt hole or the stop plate as the positioning benchmark, and the crane shall be assembled and tightened according to the mark drawing of the crane installation and connection part. The bolts for assembly are connected as per the requirements in the table below.
1.1.1.3 diagonal detection method of bridge:
Measure the distance between L1 and L2 by pulling the steel tape with spring scale, add the reading on the steel ruler and the revised value of the attached table as the measured data of the diagonal of the bridge.
1.1.1.4 measurement of horizontal side bending of main beam:
Fix the steel wire rope on the center line of the upper cover plate of the main beam to be measured, and as the measurement center line, measure the average value of the distance X1 and X2 (this value should be measured at the web 100mm away from the upper cover plate), namely, the horizontal side bending of the main beam, and the calculation formula is:
X=1/2(X1—X2)
1.1.1.5 measurement method of upper arch (lower deflection) of main beam:
A steel wire with diameter of 0.49-0.52mm is selected, one end is fixed on the fixed frame with pulley, the other end is tightened by pulley and a heavy hammer (15kg). The upper arch (lower deflection value) in the middle of the main beam span can be measured and calculated according to the following formula: upper arch: F = H – (H1 + H2) when f is negative, the lower deflection is indicated. H —— height of fixed support (including pulley diameter), generally 150-160mm;
H1 —– the distance between any point steel wire and upper cover plate mm H2: the sag of steel wire due to its own weight mm
On the basis of track, line a straight line at the center of wheel tread, hang a line along the line, and strike the straight line where the falling point is aligned to punch the holes a11, A22, A33, a44, and then drive the car away. Pull the spring scale to measure the span of L1 and L2 wheels, and the distance distance of diagonal L3 and L4, all of which add the correction value, which is the measured data.
1.1.1.6 detection method of wheel diagonal and span:
1.1.1.7 detection of wheel horizontal deflection:
Select a straight track as the foundation, pull a steel wire parallel to the outer side of the track on the beam at the same end (a from the center line of the wheel tread), and then measure the distance between the diameter of the wheel in the horizontal direction, the outermost B2, B3 and the innermost B1 and B4 respectively. The inclination value of the horizontal direction of the wheel is: Δ L1 = B1-B2 and Δ L2=b3—b4
The homolocation difference of the beam at the same end is: δ=( b1—b2)/2—(b3—b4)/2
1.1.1.8 the crane operation mechanism has been assembled with the bridge in the manufacturer, and it is not necessary to assemble on site. Before and after the bridge assembly, the overall inspection of the crane operation mechanism shall meet the relevant requirements.
1.1.2 installation and inspection of trolley running mechanism
1.1.2.1 the weight of the trolley operating mechanism is 6.227 tons. The trolley has been assembled and tested in the manufacturer, and the 50t crane is used for hoisting and positioning during installation.
1.1.2.2 the trolley shall be inspected according to the items specified in the table below before and after installation, and the detection method is the same as that of the crane.
1.1.2.3 quality standard of assembly trolley
1.1.3 inspection of lifting transmission machinery
1.1.3.1 all transmission machinery parts of crane have been installed in the manufacturer. After installation, the crane shall be inspected. All inspection items shall meet the requirements in the following table. If there is any problem, it shall be dealt with.
1.2 electrical installation
1.2.1 inspection before installation
1.2.1.1 on site unpacking inspection: all electrical equipment shall be transported and kept in accordance with the relevant provisions of the current national standards. Carry out unpacking inspection according to packing list and make records.
1.2.1.2 check whether the construction engineering quality related to the installation of crane electrical device on site conforms to the following regulations
(1) The quality of construction project shall conform to the relevant provisions in the current national construction and acceptance code for construction projects;
(2) The embedded parts and reserved holes of the installation holes of the sliding connection bracket reserved on the concrete beam and the suspension type soft cable terminal tension device shall be correct, and the holes shall be free of blockage and the embedded parts shall be firm;
(3) The painting shall be completed for the concrete beam with sliding connection.
1.2.1.3 the specifications of crane electrical device shall meet the requirements of the drawings, complete accessories and spare parts, and the technical documents of the manufacturer shall be complete.
1.2.1.4 all electrical devices shall be free of damage after appearance, and insulation resistance shall meet the requirements of relevant specifications.
1.2.2 installation procedure
1.2.2.1 installation of sliding line
(1) the sliding line support shall be supplied randomly, and the installation shall be carried out strictly according to the drawing requirements during installation.
(2) the installation of the support and insulator of the sliding line shall meet the following requirements:
a. The support shall not be installed at the joint of expansion joint and track beam of the building;
b. The support shall be installed in a flat and firm manner and shall be in the same horizontal or vertical plane;
c. Insulator and insulating sleeve shall not be damaged or defective; The surface shall be clean; The insulation performance shall be good;
d. Red steel paper gasket shall be added between insulator and bracket and steel fixing parts of sliding connection.
(3) the installation of sliding wiring shall meet the following requirements:
a. The slide line shall be installed straight and fixed on the support shall be able to be retracted;
b. The center line of the sliding line shall be parallel to the actual centerline of the crane track, and the deviation shall be less than 10 mm; c. The distance between sliding lines shall be consistent, horizontal deviation or vertical deviation shall be less than 10 mm;
d. When crossing the expansion joint of the building, the sliding connection shall be equipped with expansion compensation device;
e. The connection of sliding line and installation of expansion compensation device shall meet the requirements of relevant provisions in Section 2 of gb50256-1996.
1.2.2.2 safety signs shall be set for sliding line. The non-contact surface of sliding line shall be painted red, and safety signs shall be installed at appropriate positions or indicator lights with live phase line shall be installed.
1.2.2.3 electrical equipment shall be installed after the crane is assembled as a whole, and shall be installed according to the electrical schematic diagram, wiring diagram and general drawing of electrical equipment provided by the equipment manufacturer.
1.2.2.4 installation of trolley cable conductive device
(1) cable slide bracket installation: install trolley cable slide bracket outside the main girder of the crane according to the drawings, and then install steel slide;
(2) cable type steel slide is parallel to the center line of trolley track. After connection, sufficient mechanism strength shall be provided without obvious deformation. The contact surface of joint shall be smooth and the height difference shall not be greater than 0.5mm to ensure flexible movement of suspension cable trolley;
(3) before installation of soft cable, the cable shall be straightened out to eliminate resistance, and the cable clamps shall be arranged in the order required by the drawings. The cable length shall be adjusted to make sure that the suspension length of each section is basically the same. The cable shall be prepared and clamped with iron sheet every 500-700mm. It shall be ensured that each cable is clamped. Rubber shall be placed on the cable clamp plate, and then the traction steel rope shall be installed to ensure the force is exerted by the traction rope during operation, Finally, both ends of the cable are connected to the junction box of the bridge trolley.
1.2.2.5 the hoisting track shall be reliably grounded, and shall be conducted according to gb50169-92 code for construction and acceptance of grounding device in electrical installation engineering, and the grounding device shall be selected according to the design provisions. The grounding resistance of crane shall not be greater than 4 ohm.
1.2.3 electrical inspection and commissioning
Complete inspection and test shall be conducted after the electrical installation.
1.2.3.1 motor insulation, internal resistance inspection and brake insulation inspection.
1.2.3.2 resistance transmission test
1.2.3.3 the operation and simulation inspection of the limit switch of safety controller shall be carried out for the main circuit without power transmission control circuit to ensure the safety of lifting mechanism and meet the operation requirements.
1.2.3.4 under the condition that the crane and mechanical and electrical equipment are inspected as qualified, no-load trial operation can be carried out, and the limit switch for lifting of the large and small cars can be adjusted.
1.2.3.5 record installation and adjustment shall be made.
2 Crane test
2.1 preparation before commissioning
2.1.1 the installation of electrical system, safety interlock device, brake, controller, lighting and signal system shall meet the requirements, and its action shall be sensitive and accurate;
2.1.2 check whether there are obstacles on the track and the operation of crane, and clean up the surrounding environment;
2.1.3 the fixing of the end of the wire rope and its winding on the hook, the reclaiming device, the pulley block and the drum shall be correct and reliable;
2.1.4 the grease performance, specification and quantity added to each lubricating point and reducer shall conform to the provisions of design documents;
2.1.5 the disk operation mechanism shall not be blocked for one week;
2.1.6 static load and dynamic load test counterweight of crane shall be provided by the owner.
2.2 empty load test
2.2.1 the operation direction of the control mechanism shall be consistent with the operation direction of each mechanism of the crane;
2.2.2 start the motors of each mechanism respectively, and they operate normally, and the trolley shall not be stuck when they are running; Each brake can operate accurately and timely, and the action of limit switches and safety devices shall be accurate and reliable.
2.2.3 when the hook is placed at the lowest position, the number of coils of steel wire rope on the drum shall not be less than two cycles (except for fixing ring).
2.2.4 the speed of the winding and receiving shall be coordinated with the corresponding mechanism speed and can meet the requirements of the working limit position.
2.2.5 each test shall be conducted for no less than 5 times, and the action shall be accurate and correct.
2.3 static load test of bridge crane
Static load tests of 16 ton and 3.2 ton lifting mechanism are carried out respectively
2.3.1 first start the hoisting mechanism for the operation of empty load lifting, and make the trolley run back and forth on the full stroke. The no-load test shall be conducted for no less than three times without abnormal phenomenon;
2.3.2 stop the trolley at the middle of the span of the bridge crane, and gradually add load to start and lift the crane. After adding the rated load, the trolley will run back and forth several times on the full travel of the bridge. There shall be no abnormal phenomenon in each part. After unloading the load, the bridge structure shall be free of abnormal phenomenon;
2.3.3 stop the trolley at the middle of the span of the bridge crane, and lift the rated lifting load of 1.25 times without impact. At the height of 100-200mm from the ground, the suspension dwell time shall not be less than 10min, without instability, then unload the load, drive the trolley to the span end, check the metal structure of the bridge frame, and ensure there is no crack, weld crack Paint falling off and other defects affecting safety, such as damage and looseness.
2.3.4 the third test shall not exceed three times, and the third time shall be free of permanent deformation, and the actual camber value of main beam shall be measured.
2.3.5 check the static rigidity of the crane, drive the trolley into the span of the bridge, and measure the upper arch value after the crane and load are stationary. The difference between the results of the fourth item is the static stiffness of the crane, and the allowable value of the static stiffness is s/ 800mm. S is the span of the crane.
2.4 load test of crane
2.4.1 the purpose of dynamic load test is to verify the function of brake of each mechanism of crane. If each component can complete its function test, and no damage is found in the subsequent visual inspection of the mechanism or structure, and no looseness or damage occurs at the connection, the test results are considered to be qualified.
2.4.2 lift 1.1 times rated load, simultaneously start two mechanisms to operate in positive and negative direction. According to the corresponding power supply duration of the machine, there shall be interval time and control according to operation procedures. The test time shall be at least 1 hour in the order of working cycle. Each mechanism shall be sensitive in action, stable and reliable in operation, and the reliability of limit switches and protection interlock devices shall be checked. The temperature rise of motor and electrical components shall not exceed the specified standards, and abnormal noise and vibration shall not be observed.
2.2.3 after the test is qualified, fill in the test record.