CN1027592C - Dehydration and heat exchange equipment for treatment of petrol gas - Google Patents

Abstract

The present invention relates to a dewatering heat exchange device for the treatment of petroleum gas, which is used for the extraction of petroleum and petrochemical industry processes. The dewatering heat exchange device comprises a heat exchanger, a gas inlet and a gas outlet. The dewatering heat exchange device is characterized in that the dewatering heat exchange device also comprises a heat exchanger the same as a heat exchanger (1); the gas inlet is connected with a heat exchanger inlet by a valve bridge circuit; two heat exchanger outlets are connected with the gas outlet by a valve bridge circuit. A gas-water separating tower is positioned between the two valve bridge circuits, and each of the two heat exchangers is provided with a valve for the circulation of cooling working substances. The goal of dewatering is achieved by the relationship of the former and later exchange between the two heat exchangers.

Description

Dehydration and heat exchange equipment for treatment of petrol gas

A kind of dehydration and heat exchange equipment for treatment of petrol gas, it belongs to petroleum gas and handles and petrochemical equipment, be applicable to petroleum refining and petrochemical enterprise, the moisture that is used for changing the state of processed gas and removes processed gas guarantees normally carrying out of other treating processes.

In petroleum refining and the petrochemical complex, the gaseous phases (temperature and pressure) that change processed gas that use make it carry out the separation of gaseous fraction by transformation temperature more.So be used for fractionatedly being to use interchanger to change the state (temperature) of processed gas in petroleum refining and petrochemical complex, and then the separation column of gravity mode carries out fractionation then more.Owing to include the hydrocarbon component of multiple composition in the petroleum gas, but also contain certain moisture, isolating some light hydrocarbon component liquefying-point temperature lower, reach the below freezing of water, like this, moisture wherein can freeze in heat exchanger tube, reduce heat exchanger efficiency, stop up its passage.Present terms of settlement is to insert the molecular sieve adsorption device in the petroleum gas treatment loop, and the method for use molecular sieve adsorption is got rid of the moisture in the processed gas.This molecular sieve dehumidifying dehydration has following shortcoming: molecular sieve costs an arm and a leg, though can repeatedly regenerate, after each regeneration, performance all can decrease, and certain life problems is arranged.Under molecular sieve absorbs that moisture need be changed molecular sieve when saturated or whole absorption tower switched from workflow, regenerate.Each regeneration needs to consume many energy, increases a lot of workloads.Be to guarantee the continous-stable of Production Flow Chart, be equipped with two above absorption towers and take turns and change jobs.

The objective of the invention is to invent a kind of dehydration and heat exchange equipment for treatment of petrol gas.It is general gas converting heat device, can remove the moisture in the processed gas again, guarantees carrying out continuously of Production Flow Chart.Do not need special dehydration energy or regenerated energy, also need not consumptive molecular sieve expensive material, running cost is low.

The present invention as shown in Figure 1.It has interchanger (1), inlet mouth (3), air outlet (4), it is characterized in that: also have the interchanger (2) identical in the present invention with interchanger (1), inlet mouth (3) is by a cover valve (5), (6), (7) link to each other with the import of interchanger (1) and (2) with the valve bridge circuit (13) that (8) are formed, the outlet of interchanger (1) and (2) is by another set of valve (9), (10), (11) link to each other with air outlet (4) with the valve bridge circuit (14) that (12) are formed, between valve bridge circuit (13) and valve bridge circuit (14), a gas-liquid separator (15) is arranged, a controlled chilling operation round-robin by-pass valve control (16) and (17) are respectively arranged on interchanger (1) and (2).

Principle of work of the present invention is as follows.The processed gas that temperature is higher than zero degree enters apparatus of the present invention from inlet mouth (3).The present invention is when first kind of working order, and valve (5) is opened, and valve (6) is closed, and gas enters interchanger (1) by valve (5), simultaneously, valve (9) is opened, and (10) are closed, and valve (7) is closed, valve (8) is opened, and valve (11) is closed, and valve (12) is opened.After processed gas enters gas-liquid separator (15) by valve (9), enter interchanger (2) by the valve of opening (8) again, further carry out heat exchange, be transferred to air outlet (4) by valve (12) then.When second kind of working order, valve (5) is closed, and valve (6) is opened, and valve (7) is opened, and valve (8) is closed, and valve (9) is closed, and open (10), and valve (11) is opened, and valve (12) is closed.Processed gas at first enters interchanger (2) by the valve of opening, then by entering gas-liquid separator (15) behind the valve (10), processed gas by gas-liquid separator enters interchanger (1) by valve (7) again, is transferred to air outlet (4) by valve (11) then.In these two kinds of working ordeies, level position before and after interchanger (1) and interchanger (2) have been exchanged respectively, therefore heat exchange work of the present invention is that the branch front and back stages is carried out.Because adopt the front and back stages heat exchange, the cooling of processed gas can divide two stages, the temperature that can be controlled at the processed gas in prime heat exchanger exit place like this is not less than the freezing point of water.Therefore it is icing condensing of moisture can not occur in the prime interchanger, and it is temperature required to allow back level interchanger that processed gas temperature is dropped to.After the prime interchanger reduces processed gas temperature to a certain degree, it is liquid phase that existing portion water is divided aggegation, separated under action of gravity by gas-liquid separation (15) back, there is not separated moisture after entering back level interchanger, because temperature further reduces, cross condensation and form solid, be attached on the radiator element or pipe of back level interchanger.At this moment, the moisture of processed gas is removed substantially, has satisfied the moisture requirement to processed gas.Hydrogenesis at back level interchanger arrives to a certain degree (can control by time control or heat exchanger efficiency), allows two interchanger (1) and (2) switch.Knot originally the back level interchanger of ice switch to the prime interchanger, and enter into the de-icing work state, close heat-eliminating medium recycle valve (16) or (17) on prime (the being used for deicing) interchanger.Because the processed gas temperature that initially enters is higher, this has melted the ice of having tied on the one hand, and can also utilize the latent heat of phase change that is contained in the original ice to reduce the temperature of processed gas.Moisture after the gas-entrained liquefaction after the cooling enters gas-liquid separator (15), and liquid phase moisture is separated, and processed then gas enters new back level interchanger again, to reach the purpose of cooling and dehydration.After work for some time, after the freezing of prime removed that then level is icing and arrive to a certain degree, once switch again.The state graph of each valve of working cycle of the present invention as shown in Figure 2." 1 " expression conducting among the figure, " 0 " expression is turn-offed.

The present invention overlaps the valve that can switch interchanger front and back level at gas-liquid separator of two inter-stages increase and and has constituted a cover dehydration and heat exchange by interchanger is divided into two-stage.It has higher dewatering efficiency and the easily requirement of assurance dehydrating amount by the cooling dehydration condensation, and by switching, directly the energy with processed gas carries out deicing regeneration, need not increase the dehydration regenerated energy, has improved the energy utilization efficiency of system.Do not exist regeneration back usefulness to reduce problem yet.When the present invention is switched in work, move very fast, identical with the process of cut-in stand-by equipment in other method.Therefore can think that flow process is a successive, can just can guarantee continuous production without stand-by facilities.Simultaneously, the present invention does not re-use expensive molecular sieve, has reduced cost, particularly running cost yet.

In the work of the present invention, be to reduce switching times, after the deicing of prime interchanger finishes, might not switch at once, at this moment before level restoration feed heat-eliminating medium, carry out heat exchange, only freeze when reaching specified requirement at back level interchanger, just switch.All switchings can be controlled with computer, and this has improved operating speed and precision on the one hand, also can exempt workman's the duplication of labour on the other hand.The computer that uses can be prevailing microcomputer or single card microcomputer, also can be the part of whole production flow process control computer.Type can be TP801, T802, APPLE II or PC etc.The switching value switchboard of use standard or directly use their I/O mouth.

Claims (1)

1, a kind of petroleum gas is handled this device of dehydration heat-exchanger rig, it has interchanger (1), inlet mouth (3), air outlet (4), it is characterized in that: also have the interchanger (2) identical in this device with interchanger (1), inlet mouth (3) is by a cover valve (5), (6), (7) link to each other with the import of interchanger (1) and (2) with the valve bridge circuit (13) that (8) are formed, the outlet of interchanger (1) and (2) is by another set of valve (9), (10), (11) link to each other with air outlet (4) with the valve bridge circuit (14) that (12) are formed, between valve bridge circuit (13) and valve bridge circuit (14), a gas-liquid separator (15) is arranged, a controlled chilling working medium round-robin by-pass valve control (16) and (17) are respectively arranged on interchanger (1) and (2).

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